publications ICPEES depuis 2020 - extraction HAL

Design, synthesis and evaluation of an uncharged broad spectrum quinoline-oxime hybrid for the reactivation of nerve agent-inhibited human acetylcholinesterase

Julien de Sousa, André-Guilhem Calas, Eugenio de la Mora, Christophe Landry, Anne-Sophie Hanak, Alex Maryan-Instone, Anne-Julie Gastellier, Caroline Coisne, Charlotte Courageux, Johan Hachani, Fabien Gosselet, Marie-Pierre Dehouck, Catherine Rousseau, Christopher M Timperley, Martin Weik, Florian Nachon, Richard C D Brown, Rachid Baati, José Dias
European Journal of Medicinal Chemistry, 2026, 316, ⟨10.1016/j.ejmech.2026.119023⟩ | Publiée le 1 octobre 2026
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Abstract

<div><p>Organophosphorus nerve agents exert their acute toxicity by irreversibly inhibiting acetylcholinesterase (AChE), yet currently deployed oxime reactivators exhibit limited efficacy in the central nervous system due to poor blood-brain barrier (BBB) penetration. Addressing this limitation remains a critical challenge in the treatment of nerve agent exposure. We report the design, synthesis, and evaluation of JDS364, an uncharged hybrid oxime reactivator combining a quinoline-based peripheral site ligand with a 3-hydroxypyridinealdoxime nucleophile.</p><p>In vitro studies using human AChE inhibited by surrogates of G-and V-series nerve agents demonstrated that JDS364 possesses broad-spectrum reactivation activity, notably achieving a 300-fold increase in reactivation efficiency (k r2 ) over the clinical benchmark obidoxime against tabun-like inhibited hAChE. Evaluation in a human in vitro BBB co-culture model revealed that JDS364 exhibits high permeability, significantly outperforming clinically used quaternary oximes and exceeding the flux of earlier-generation uncharged hybrids. Ex vivo functional profiling studies in mice confirmed rapid systemic availability and significant protection against paraoxon challenge (Protective Index = 6.7 when combined with atropine), though a narrower therapeutic window was observed compared to clinical standards. X-ray crystallographic analysis of JDS364 bound to human AChE uncovered ligand-induced conformational plasticity, providing the first structural evidence of an opening of a "backdoor" via Tyr449 rearrangement in the 20 Å deep active site gorge. This confirms the hypothesis of enzyme "breathing" motions and validates alternative diffusion pathways for reactivation. These findings establish JDS364 as a mechanistically significant, CNS-accessible lead that defines a new structural paradigm for the development of next-generation countermeasures.</p></div>

Mechanism of the hydrazine hydrate electrooxidation reaction on Ni electrodes in alkaline media as revealed by isotopic (H/D) substitution, DFT, and kinetic modelling

Evgeniia Vorms, Evgenii Strugovshchikov, Mykola Isaiev, Yimin Zhang, Antoine Bonnefont, Marian Chatenet, Elena Savinova, Alexandr Oshchepkov
Electrochimica Acta, 2026, 571, pp.148995. ⟨10.1016/j.electacta.2026.148995⟩ | Publiée le 1 septembre 2026
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Abstract

<div xmlns="http://www.tei-c.org/ns/1.0"><p>OHad is an intermediate of the initial step of hydrazine oxidation on Ni • Co-adsorbed OHad lowers the activation barrier for N-H bond cleavage • The inability of Ni to catalyse the reaction in the absence of OHad accounts for the high 'onset' potential • Had is not an HHOR intermediate but its desorption kinetically limits the reaction Abstract The hydrazine hydrate oxidation reaction (HHOR) has attracted increasing attention owing to hydrazine's promise as a fuel, particularly for direct hydrazine hydrate fuel cells (DHHFCs); nevertheless, most studies have focused on noble metal catalysts, while the underlying reaction mechanism on Ni-based catalysts remains to be fully elucidated. In this work, the HHOR mechanism on Ni surfaces was studied by combining density functional theory (DFT) calculations, online differential electrochemical mass-spectrometry (DEMS), electrochemical measurements with isotopic</p></div>

Chemical recycling of post-consumer plastics: phosphine-free manganese-catalysed hydrogenative depolymerisation of polyesters, polycarbonates, and polyurethanes

Mariia Hruzd, Moifica Check Moïdine, Carine Duhayon, Stéphanie Bastin, Vincent Ritleng, Eric Pollet, Jean-Baptiste Sortais
Journal of Catalysis, 2026, 461, pp.116990. ⟨10.1016/j.jcat.2026.116990⟩ | Publiée le 1 septembre 2026
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Abstract

Hydrogenative depolymerisation of polyesters, polycarbonates, and polyurethanes was achieved on untreated post-consumer goods (bottles, packaging, textiles) using a phosphine-free manganese catalyst. Complete conversion to monomeric diols occurs under mild conditions (0.5 mol% catalyst, 60 bar H2, 150 °C), enabling sustainable chemical recycling with an earth-abundant metal.

Highly Transparent Layer-by-Layer Nanoassembled Multicomponent Films of TiO2 and Graphene for Increased Photocatalytic Performance

Pauline Barrois, Pierre Gibot, Christophe Colbeau-Justin, Loic Vidal, Thomas Cottineau, Hermenegildo Garcia, Gero Decher, Valérie Keller
Journal of the American Chemical Society, 2026, 148 (33), pp.36083-36094. ⟨10.1021/jacs.6c10666⟩ | Publiée le 15 août 2026
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Abstract

Abstract Here, we report novel highly transparent and photoactive multicomponent films for enhanced photocatalytic applications. Some films are based on intimately interfaced TiO2 nanoparticles and few-layer graphene (FLG) assembled through an environmentally friendly aqueous layer-by-layer (LbL) process. In contrast to reduced graphene oxide-based systems, directly exfoliated FLG was employed in order to preserve the intrinsic electronic conductivity of graphene and promote an efficient interfacial charge separation. The highly transparent and nanoporous LbL architecture minimizes photon scattering and enables precise control of film thickness, TiO2 loading, and photon absorption. The incorporation of FLG strongly improves charge separation, limits charge recombination, and reduces catalyst deactivation through enhanced storage of sulfur-containing byproducts. The photocatalytic activity was evaluated through the photo-oxidation of diethyl sulfide (DES), used as a model compound for mustard gas. TiO2/FLG multilayers exhibit photocatalytic activities up to 35-fold higher than conventional drop-cast TiO2 coatings and up to 6-fold higher than LbL films without FLG at comparable TiO2 loadings. Beyond the material composition itself, these results demonstrate that transparent and nanoporous LbL nanoarchitectures provide a powerful strategy for optimizing photon management and interfacial charge transfer in photocatalytic coatings.

Roadmap for neuromorphic organic devices

Michele Di Lauro, Fabien Alibart, Olivier Bardagot, Pietro Belleri, Mohammed Benwadih, Asma Benyahia, Lukas Bongartz, Alexander Boys, Ugo Bruno, Mario Caironi, Matías Ignacio Ceballos Hernández, Valeria Criscuolo, Séverine Danthon, Ghader Darbandy, Anna de Salvo, Michael Dickey, Sami Valentino El Nakouzi, Simone Fabiano, Marco Fattori, Elena Feltri, Didier Gallaire, Elodie Gerente, Paschalis Gkoupidenis, Amir Handelman, Marcello Ienca, Sahika Inal, Benjamin Iniguez, Esma Ismailova, Lina Kadura, Richard Kantelberg, Somayeh Kashani, Scott Tom Keene, Yerin Kim, Hans Kleemann, Emil List Kratochvil, Imke Krauhausen, Zonglong Li, Giovanni Ligorio, Nicolas Lobato-Dauzier, Alessandro Luzio, Christian David Matthus, Tommy Meier, Andreas Offenhaeusser, Shashi Paul, Nikita Prudnikov, Viviana Rincon Montes, Francesca Santoro, Wentao Shan, Ali Solgi, Ermias Telahun Teka, Laura Teuerle, Wei-Ting Ting, Fabrizio Torricelli, Laurent Tournon, Yoeri van de Burgt, Yazhou Wang, Yeohoon Yoon, Amer Zaibi, Daniele Zucchelli, Laurie Calvet
Neuromorphic Computing and Engineering, 2026, ⟨10.1088/2634-4386/ae9338⟩ | Publiée le 31 juillet 2026
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Abstract

Abstract Organic materials offer a transformative opportunity for smart edge applications due to their compatibility with large-area manufacturing, mechanical flexibility, scalability at low cost, and potentially reduced environmental impact. While their use in display technologies is now well-established, their integration into other applications domains is still in its early stages. Significant progress has been made in the development of materials for organic neuromorphic devices, enabling explorations of applications in neuroscience, soft robotics and healthcare. Additional promising directions include photonics, optoelectronics and memories. The goal of this roadmap is to consider how properties of these materials can be leveraged to implement alternative computing methodologies to enable a new generation of organic technologies

High‐Performance n‐Type Organic Thermoelectrics Enabled by Control Over Microstructure, Orientation and Contact Plane in Naphthalenediimide‐Bithiazole‐Copolymer Films

Suhao Wang, Said Oummouch, Huan Wei, Karl Thorley, Adam Marks, Arianna Magni, Xiuming Sun, Alessandra Pistillo, Bruno Schmaltz, Olivier Bardagot, Sabine Ludwigs, Alberto Salleo, Yuanyuan Hu, Martin Brinkmann
Advanced Functional Materials, 2026, 36 (69), pp.e77341. ⟨10.1002/adfm.77341⟩ | Publiée le 29 juillet 2026
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Abstract

ABSTRACT Conjugated polymers are promising thermoelectric materials offering solution processability, flexibility, and versatile synthesis. However, n‐type polymers lag behind their p‐type counterparts. Herein, we demonstrate that the combination of precise doping with control over crystalline contact plane, orientation, and microstructure helps design efficient n‐type films of a naphthalenediimide‐bithiazole‐based copolymer (PNDIOE7‐Tz2). Favorable fibrillar morphology and enhanced planarity lead to tight packing in films doped with N‐DMBI, resulting in a high electrical conductivity σ ≈ 10 S cm −1 . GIWAXS indicates a predominantly face‐on orientation in pristine films with a short π–π stacking distance of 3.47 Å. Incremental concentration doping enhances the σ to 45 S cm −1 with a power factor (PF≈17.5 µW m −1 K −2 ). Rubbing alignment causes a detrimental shift from face‐on to edge‐on, reducing σ below 5 S cm −1 and PF below 4 µW m −1 K −2 . Subsequent solvent vapor annealing converts aligned crystallites to mixed face‐on/edge‐on, promoting a strong enhancement of TE performance with a high PF up to 41µW m −1 K −2 , among the highest reported for n‐type polymers. This work underscores that controlling the contact plane effectively decouples σ and S for high‐performance n‐type polymer thermoelectrics.

Spent battery graphite in biochar waste composites for supercapacitive electrodes

Akshita Singh, Vimal Chandra Srivastava, Izabela Janowska
Materials Today Sustainability, 2026, 35, pp.101425. ⟨10.1016/j.mtsust.2026.101425⟩ | Publiée le 27 juillet 2026
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Abstract

According to the waste management concept, the biomass and spent Li-ion batteries have been valorized to synthesize sustainable supercapacitor electrodes. The peanut shell-derived biochar, along with recovered spent graphite (RSG) from battery waste, upon chemical activation with KOH, yielded a microporous, high-surfacearea composite (AC/RSG) with efficient charge transport. It reveals a specific capacitance of 376 F/g at 10 mV/s (and 197 F/g at 0.4 A/g) in a three-electrode cell set-up using 1 M KOH electrolyte. The reference samples are porous activated carbon (AC) and another composite containing few-layer graphene (FLG) from commercial expanded graphite. The addition of RSG and FLG to activated carbon increases capacitance by approximately 70% and 50%, with significant stability at extreme conditions (high current density and potential sweep rate), thus maintaining the energy density with power density increase. The capacitance retention increases from 48% (and 49%) for porous carbon to 89% (and 83%) and 81% (and 78%) for AC/RSG (and AC/FLG) composites, at 17.7 A/g (and 200 mV/s). The structural features of the three materials, particularly of the composites, impacting the storage behavior, are investigated with help of auxiliary samples (KOH-activated RSG and FLG). The cyclic stability test for the best-performing composite (AC/RSG) revealed 94% capacitance retention and 99.6% Coulombic efficiency over 5000 cycles at 4.4 A/g. Beside enhanced conductivity, the electrochemical analysis revealed a significant benefic impact of diffusion and charge transfer in the composites. Additionally, conductive carbon black (CB) additive is successfully replaced by RSG. This study paves the way for improving the electrochemical performance of traditional biomass-derived activated carbons by the incorporation of graphite waste.

Transformer-Based Prediction of Conversion Yield in Catalytic Methane Decomposition

Thi Huong Ly Nguyen, Nicolas Reiminger, Cuong Pham-Huu, Ahmed Essyed, Cédric Wemmert, Xavier Jurado
22nd IFIP WG 12.5 International Conference AIAI 2026, Jul 2026, Chania (Crète), Greece. pp.450-463, ⟨10.1007/978-3-032-30805-4_32⟩ | Publiée le 16 juillet 2026
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Abstract

Catalytic methane decomposition (CMD) is a promising process for the simultaneous production of high-purity turquoise hydrogen and valuable solid carbon without direct carbon dioxide emissions. In particular, the CMD process utilizing carbon-based catalysts under contactless induction heating has been extensively investigated due to its operational advantages, especially the strong reaction-catalyst synergy. Despite its significant potential, optimizing this reaction remains challenging because methane conversion is highly dependent on several nonlinear and interdependent factors, including catalyst characteristics, temperature, and gas flow rate. Consequently, this study proposes a timeseries forecasting model to predict methane conversion dynamically during the reaction. Given the complex interdependencies governing the CMD process, multidimensional inputs are required, comprising endogenous, exogenous, and static variables. Therefore, a Transformer-based architecture was employed and specifically tailored for conversion forecasting. The proposed model was trained and evaluated using empirical data obtained from laboratory-scale experiments. The results demonstrate the robust potential of machine learning to predict methane conversion accurately, which is essential for real-time reaction monitoring and performance optimization. Furthermore, the model exhibits a highly promising capability to generalize and predict conversion rates when a previously unseen catalyst is introduced to the system.

Ionic liquid crystals based on a triscatecholatotitanate( iv ) complex associated with imidazolium counter-ions

Laurent Barloy, Benoît Heinrich, Nicolas del Giudice, Matthieu Scarpi-Luttenauer, Laurent Douce, Pierre Mobian
Dalton Transactions, 2026, 55 (31), pp.11607 - 11617. ⟨10.1039/d6dt00695g⟩ | Publiée le 16 juillet 2026
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Abstract

<div><p>The triscatecholatotitanate(IV) anion (Ti(Cat) 3 2-) interacts with various imidazolium cations (2-7) to generate salts (A-F) where the titanium dianion complex is associated with two imidazolium monocations.</p><p>Two types of cation form these salts; species 2-4 bear methoxy groups, whereas one, two or three dodecyl linear alkyl chains are incorporated within 5, 6 and 7, respectively. These salts were characterized in solution by 1 H NMR and the crystal structure of salt C containing the complex Ti(Cat) 3 2-with two imidazolium cations substituted by two methoxy groups (3) was established. Differential scanning calorimetry (DSC) measurements and polarized optical microscopy (POM) observations attest to the thermotropic liquid crystal behavior of the salts, where long alkyl chains are present in salts containing imidazolium cations (5-7). The data extracted from the small-and wide-angle X-ray scattering (SWAXS) analysis of salts 5-7 enable the proposal of the supramolecular organisations of the three mesophases. This organisation is dependent on the number of alkyl chains that compose the imidazolium cations.</p></div>

Oxygen Reduction Reaction Performance in Phosphoric Acid of a Catalyst Library for High-Temperature Proton Exchange Membrane Fuel Cell

Axelle Baudy, Marion Scohy, Amaria Oudjdi, Tristan Asset, Camille Roiron, Marian Chatenet, Laetitia Dubau
ACS Catalysis, 2026, ⟨10.1021/acscatal.6c00952⟩ | Publiée le 26 mai 2026
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Abstract

High-temperature proton exchange membrane fuel cells (HT-PEMFCs) are advantageous for heavy-duty vehicles owing to their operating temperature (150-200°C), which facilitates the stacks heat management, hence decreases the system global weight. A HT-PEMFC membrane electrode assembly (MEA) commonly relies on phosphoric acid-doped polybenzimidazole membranes. While H3PO4 is optimal in terms electrolyte and membrane properties in HT-PEMFC, it strongly impacts the activity of Pt-based electrocatalysts. In this work, a wide catalyst library highlights most of the material characteristics that, according to the literature, influence phosphate poisoning mechanisms and possibly mitigate the penalty in oxygen reduction reaction (ORR): carbon support, Pt loading on carbon, Pt nanoparticles size, Pt-alloying effect (strain effect) and nano-particles morphology (octahedron (facets orientation), sponges, carbon cap). By electrochemically characterizing the catalyst library, this work aims to understand their ORR activity decline in 1 M H3PO4 vs 1 M HClO4 electrolytes at room temperature. The electrolyte used is relatively concentrated compared to model study in RDE in which the H3PO4 concentration does not exceed 0.1 M (often in a mix with HClO4). Whatever the electrocatalyst, the electrochemical surface area available in H3PO4 decreases by 20-40% compared to HClO4, while a ca. tenfold decline in ORR specific activity is observed. The results highlight the leading-order parameter influencing the absolute catalyst activity in H3PO4: the adsorbates coverage rate by various phosphates species (θ(HxPO4(3-x)-) and θ(HxPO3(3-x)-)), and a second order parameter: the Pt-O, with O from OH*, binding energy on each catalyst (catalyst material-dependent). Both parameters follow a Butler-Volmer model with Frumkin adsorption/desorption isotherm. The loss rate versus HClO4 suggest that the SA retention in H3PO4 also depends on a third order parameter: interactions between adsorbates at the surface of the catalyst, and in the electrochemical double-layer, described by the Frumkin correction, which is largely affected by operating conditions (electrolyte anions concentration and temperature).

Indoor PF2:ITIC organic solar cells with enhanced blue-light harvesting and high voltage

Ruoxue He, Nicolas Leclerc, Pierre Nickmilder, Philippe Leclère, Bernard Ratier, Johann Bouclé
Solar Energy, 2026, 314, pp.114733. ⟨10.1016/j.solener.2026.114733⟩ | Publiée le 25 mai 2026
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Abstract

<div>Organic solar cells Indoor energy harvesting Non-fullerene acceptors Internet of things (IoT</div>

Al-MOF CAU-10 for Sorption-Enhanced CO2 -to-Methanol Reaction: Role of the Hydrophilic/Hydrophobic Balance

Julia Duplessis-Kergomard, François Bihl, Dorian Rey, Michael Paris, Thomas Devic, Fabrice Salles, Anne-Cécile Roger, Philippe Trens
ACS Applied Materials & Interfaces, 2026, 18, pp.23827-23838. ⟨10.1021/acsami.6c02842⟩ | Publiée le 16 avril 2026
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Abstract

In this study, we conducted a comprehensive investigation relating to the efficiency of the Al-MOF CAU-10 as a sorbent in a Sorption Enhanced Reaction Process (SERP) based on its hydrophilic/hydrophobic balance. We confirmed both experimentally and through simulation that CAU-10 is a hydrophobic material at low pressure, whereas it shows a high affinity for methanol. The cosorption of water and methanol shows that both molecules are in competition, mostly for the oxygen atoms of the ligands. An important result is the influence of the relative pressure of the vapor mixture on the composition of the adsorbed phase. At low relative pressure, methanol is mostly adsorbed from the mixture, while water is only adsorbed from 0.16 p/p°. At higher relative pressures, water becomes predominant in the adsorbed phase. We therefore took advantage of this result to improve the catalytic reduction of CO2 into methanol by sorption of methanol or water. The catalytic test was performed at 270 °C under a total pressure of 50 bar. Under these conditions, the methanol yield increased by more than 6% compared to a catalytic reaction performed without sorbent, thus validating our fundamental approach.

KCa2Nb3O10 -Carbon Doped g-C3N42D-2D Heterostructure for Gas-Phase Solar-Light Driven CO2 Photoreduction Using Water Vapor as a Reducing Agent

Poonam Chaturvedi, Anil Kumar Bharwal, Valerie Keller, Thomas Fix, Tapas Kumar Mandal
ACS Applied Energy Materials, 2026, 9 (7), pp.3743-3764. ⟨10.1021/acsaem.5c03656⟩ | Publiée le 30 mars 2026
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Abstract

Dion-Jacobson layered perovskite KCa2Nb3O10 offers favorable redox potentials and structural robustness but remains limited in solar-driven CO2 conversion due to its wide band gap and inefficient charge utilization. Here, we report a carbon-doped g-C3N4/ KCa2Nb3O10 2D-2D heterojunction that enables controlled modulation of interfacial charge-transfer pathways. Carbon incorporation into g-C3N4 enhances visible-light absorption and tailors band alignment without altering the bulk crystal framework. In situ light-dark EPR reveals a transformation from type-II transfer in CN/KCNO-NS to a direct Z-scheme in CN-C/KCNO-NS, supported by complementary electrochemical and spectroscopic analyses demonstrating improved interfacial charge separation and reduced recombination. Under continuous gas-phase CO2/H2O vapor flow without sacrificial agents or noble metals, the optimized heterojunction exhibits enhanced activity, generating H2 as the dominant product together with CH4 and CO. The dominance of H2 formation is consistent with rapid interfacial electron delivery and the kinetic advantage of HER under gas-phase CO2/H2O conditions. This study demonstrates electronic-structure-driven 2D-2D heterojunction engineering as an effective approach for regulating charge flow in solar-driven gas-phase CO2 conversion systems.

Exploring the Synergistic Effects of Ultrafine Polyaniline Nanofibers and Oxygen-Modified Multi-Walled Carbon Nanotubes on Enhancing Pseudocapacitive Electrochemical Performance for Advanced Supercapacitors

Fahima Djefaflia, Ouanassa Guellati, Assia Nait Merzoug, Aicha Harat, Jamal El Haskouri, Izabela Janowska, Mihaela Baibarac
Materials, 2026, 19, ⟨10.3390/ma19071356⟩ | Publiée le 29 mars 2026
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Abstract

This work reports a systematic study concerning the synthesis of pure polyaniline ultrafine nanofibers (PANI-NFs) and their nanocomposites with oxygen-functionalized carbon nanotubes (PANI-NFs/O-MWCNTs) using diluted chemical polymerization and hydrothermal processes. We investigated the synergistic effects of various synthesis parameters, such as the concentration of the ammonium persulfate oxidant agent and growth temperature, on the physical, chemical, and electrochemical properties of the resulting products through structural, morphological, spectroscopic, and electrochemical characterization. Our study revealed the successful synthesis of thermally resistant polyaniline ultrafine nanofibers (PANI-NFs) in the form of emeraldine salt (ES), exhibiting a mean diameter in the range of 8-17 nm. The PANI-NFs and PANI-NFs/O-MWCNT nanocomposites demonstrated excellent electrochemical properties, with specific capacitances of up to 0.94-1.23 F cm -2 and 1410-2074 F/g, respectively, and with good rate capability. These characteristics are confirmed by the relaxation time constant τ 0 (41 and 8 ms, respectively) and lower internal R 0 /interfacial charge transfer R Φ resistances of around 0.2 Ω, as well as diffusion coefficients of around 10 -7 and 3.7 × 10 -7 cm 2 /s. This breakthrough in nanofiber synthesis paves the way for practical applications in diverse domains, from high-performance energy storage to biosensing and beyond, where the unique electroactive properties of the nanocomposites can be leveraged to achieve exceptional results.

Pt‐Decorated Bi ₄ Ti ₃ O ₁₂ /CeO ₂ Heterojunction for Highly Selective CO ₂ Photoreduction to Methane

Poonam Chaturvedi, Arreerat Jiamprasertboon, Valerie Keller, Tapas Kumar Mandal
ChemCatChem, 2026, 18 (6), ⟨10.1002/cctc.202600011⟩ | Publiée le 23 mars 2026
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Abstract

Solar-light-driven CO 2 photoreduction offers a promising route for mitigating carbon emissions while enabling sustainable fuel generation. Aurivillius-type bismuth titanate (Bi 4 Ti 3 O 12 ) is an attractive photocatalyst owing to its structural stability and ferro-/piezoelectric properties; however, its application in gas-phase CO 2 conversion is severely limited by low surface area, weak CO 2 adsorption, and poor visible-light absorption. To overcome these constraints, a visible-light-responsive heterojunction photocatalyst was constructed by coupling Bi 4 Ti 3 O 12 with high-surface-area CeO 2 via wet impregnation, followed by photodeposition of Pt nanoparticles (NPs). The optimized 1.0%-Pt/20%-Ce/BTO catalyst exhibits a pronounced enhancement in photocatalytic performance, delivering completely selective CH 4 formation with a yield of 6.64 µmol g -1 after 7 h of simulated solar irradiation, corresponding to activity enhancements of 7.7-and 9.5-fold compared to pristine Bi 4 Ti 3 O 12 and CeO 2 , respectively. Structural and spectroscopic analyses reveal that Pt nanoparticles ( ∼ 3.2 nm) act as efficient electron traps and enhance visiblelight absorption. The enhanced activity and selectivity arise from synergistic effects of improved CO 2 adsorption, efficient charge separation across the heterojunction, prolonged charge-carrier lifetime, and the reversible Ce 3 + /Ce 4 + redox couple in CeO 2 . This study demonstrates a straightforward and effective strategy for designing visible-light-driven heterostructures for highly selective gas-phase CO 2 photoreduction.

Hydrazine hydrate electrooxidation reaction mechanism on Ni electrode: Experiments

Evgeniia Vorms, Evgenii Strugovshchikov, Mykola Isaiev, Marian Chatenet, Elena Savinova, Alexandr Oshchepkov, Antoine Bonnefont
ACS Spring meeting 2026, American Chemical Society, Mar 2026, Atlanta (GA), United States | Publiée le 22 mars 2026
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Extended Fused Carbazole‐BODIPY, High Brightness NIR Organic Dyes

Fabien Ceugniet, Valentin Ott, Pascal Retailleau, Yann Bretonniere, Olivier Maury, Manon H E Bousquet, Lucie Sancey, Nicolas Leclerc, Denis Jacquemin, Gilles Ulrich
Angewandte Chemie International Edition, 2026, pp.e26011. ⟨10.1002/anie.202526011⟩ | Publiée le 13 mars 2026
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Abstract

Fluorescence‐based bioimaging enables noninvasive visualization of molecular and cellular processes with high sensitivity and without ionizing radiation. However, conventional fluorophores emitting in the visible or near‐red infrared I (NIR‐I) (650–800 nm) regions suffer from limited tissue penetration and scattering. Extending fluorescence emission into the deeper NIR region represents a promising strategy to overcome these drawbacks, yet achieving high brightness and stability in organic dyes remains a major challenge. We report an original family of hetero‐substituted‐fused boron‐dipyrromethene (BODIPY) dyes bearing carbazole and thienyl donors that exhibit record brightness and emission maxima up to 852 nm in toluene. The synthetic route combines successive Stille couplings from a 2,6‐dibromo‐3,5‐diiodo‐BODIPY precursor and an unprecedented silver(I)‐mediated oxidative cyclization, affording high yields and suppressing undesired chlorination. The resulting dyes display intense absorption ( ε = 1.8–2.5 × 10 5 M − 1 cm − 1 ) and exceptional fluorescence quantum yields ( Φ up to 0.73). Encapsulation in silica nanoparticles (NPs) preserves their photophysical properties and enables efficient NIR‐II in vivo imaging in mice, allowing tumor detection at doses as low as 0.2 nmol with tumor‐to‐muscle ratios &gt; 4. These fused BODIPY derivatives rank among the brightest NIR fluorophores reported to date and open new avenues for high‐contrast deep‐tissue imaging and image‐guided surgery.

Augmented Stainless Steel Porous Transport Layers through Co3O4 Spinel Deposition for the Oxygen Evolution Reaction in Alkaline Media

Garance Cossard, José Carlos Martinez Rosales, Gwénaëlle Kéranguéven, Eric Sibert, Vincent Martin, Frédéric Maillard, Thierry Dintzer, Antoine Bonnefont, Elena Savinova, Gaël Maranzana, Marian Chatenet
ACS Catalysis, 2026, 16 (7), pp.6563-6576. ⟨10.1021/acscatal.5c08886⟩ | Publiée le 13 mars 2026
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Abstract

Glycine-nitrate autocombustion was used to synthesize stainless steel Porous Transport Layers (PTL)supported Co 3 O 4 -spinel particles. This composite material was employed as platinum group metal (PGM)-free catalyst with high specific surface area and high activity for Anion-Exchange Membrane Water Electrolysis (AEMWE). Significant increase of the Oxygen Evolution Reaction (OER) activity of the PTLs was documented in a three-electrode setup, which was attributed to the combined effects of the increased specific surface area (vs the bare stainless steel PTL) and the enhanced intrinsic catalytic activity associated with the Co3O4 -spinel particles deposit. The diffusion of atoms (mostly iron and nickel) arising from the PTL stainless steel fibers into the Co3O4 -spinel structure enhances its mechanical stability and its OER activity. However, the formation of a thick oxide layer, especially rich in Cr, at the interface between the PTL fibers and the deposited Co3 O4 -spinel particles depreciates the electrode performance in a single cell AEMWE. The growth of this oxide layer, which is an intrinsic property of stainless steel, can be mitigated through the choice of refined post-synthetic heat-treatment. The beneficial effect of the spinel coating on the PTLs was also confirmed under AEMWE operating conditions, underscoring its potential for integration into AEM cells, although further optimization is still warranted.

Multidisciplinary science funding is more than ever a planetary priority: reflections from the Make Our Planet Great Again (MOPGA) program

Christina Richards, Barbara Ervens, Camille Parmesan, Pierre Amato, Christhel Andrade, Gayane Asatryan, Venkatramani Balaji, Ashley Ballantyne, Marc Barbier, Stéphane Blanc, Oliver Bossdorf, Frédéric Bouchard, Julien Boucharel, Christopher Cantrell, Emilie Capron, Chloe Carbonne, Marion Carrier, Davide Ceratti, Heechae Choi, Konstantinos Christoforodis, James Clark, Ludmila Cojocaru, Louis Derry, William Dewar, Titouan Dubo, Jhan-Carlo Espinoza, Alexey Fedorov, Alessandro Forte, Giuliano Giambastiani, Alessandra Giannini, Andreas Goldthau, Alberto González-García, Virginie Guemas, Lorie Hamelin, Eric Hill, Amir Hoveyda, Lara Hughes-Allan, Sanjay Jatav, Ugo Javourez, Jed Kaplan, Nilanka Keppetipola, Rainer Kiko, Thomas Lauvaux, David Lazarus, Carol Eunmi Lee, Redouane Lguensat, Philippe Lucas-Picher, Monalisa Mallick, Joenio Marques da Costa, Irina Melnikova, Guillaume Monnain, Volkan Özen, Ignacio Palomo, Madalin Parepa, Anna Possner, Delphine Renard, Valéry Ridde, Orestes Rivada-Wheelaghan, Gabrielle Rodrigues de Faria, Benjamin Sanderson, Clemens Scheer, Philip Schulz, Stavana Strutz, R Subramanian, Katsumasa Tanaka, Núria Teixidó, Matthias Tesche, Helmuth Thomas, Sara Todorović, Yutsung Tsai, Bruno Turnheim, Takaya Uchida, Vincent Vadez, Pierre Valla, Isolde van Riemsdijk, Lionel Villard, Emmanuel Vincent, Chien Wang, Henry Wu, Michael Zuerch
PLOS Climate, 2026, 5 (3), pp.e0000849. ⟨10.1371/journal.pclm.0000849⟩ | Publiée le 11 mars 2026
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Abstract

Global change poses “wicked problems” that have become ever more complex, pervasive, and damaging. Developing innovative solutions increasingly require diverse research approaches. The Franco-German Make Our Planet Great Again (MOPGA) program was designed to create a unique international network of top-level research, from fundamental to solution-oriented projects. MOPGA stands out from other large research initiatives by focusing not on a singular central research challenge but on facilitating multidisciplinary interactions between traditionally separated fields. MOPGA recognized that social, natural and engineering sciences share a unifying aim to address global change. In addition to addressing timely and innovative research questions within disciplines, MOPGA worked to improve communication across disciplines via annual meetings for all laureates and their research groups, scientific board exchanges, and public online seminars. Drawing on our MOPGA experiences, we discuss how such exchanges should be extended to meet the needs identified by the scientific community, international policy-makers, and regional stakeholders. In the current political landscape of scientific suppression and heightened mistrust in scientific expertise, the need for such bold, independent and collaborative scientific initiatives is greater than ever.

Study of a Novel Bi‐Layered Thermoplastic Polyurethane Patch for Congenital Diaphragmatic Hernia

Guillaume Leks, Julie Favre, Manon Zislin, Rodolphe Migneret, Jordana Hirtzel, Vincent Ball, Cendrine Seguin, Anne Hebraud, Emeline Lobry, Guy Schlatter, Nadia Bahlouli, Hamdi Jmal, Benoît Frisch, Sylvie Fournel, Isabelle Talon
Advanced Materials Interfaces, 2026, 13 (7), pp.e00850. ⟨10.1002/admi.202500850⟩ | Publiée le 4 mars 2026
Article dans une revue

Abstract

Congenital diaphragmatic hernia (CDH) is a rare disease that has been increasing in prevalence since the end of the 20th century. The recurrence rate of hernias is over 50%, increasing morbidity. Research is ongoing to identify a suitable solution to repair large defects because common prosthesis does not match the mechanical properties of the native tissue. This pilot study aims to evaluate a new non‐biodegradable thermoplastic polyurethane elastomer (TPU) bilayer patch. Its mechanical properties may be better suited to facilitate growth from childhood to adulthood. Its structure comprises a fibrous layer that promotes cell colonization and integration, and a smooth film layer that prevents cell adhesion. In vitro studies showed that both fibroblasts and myoblasts colonized the fibrous layers efficiently when they were optimized with an adhesive polydopamine (PDA) film and a collagen I (Coll I) coating. This facilitated early colonization, increased proliferation and cell spreading. New materials, whether functionalized or not, did not induce inflammation. Subsequent in vivo studies in rats showed significant cell integration in TPU patches without prosthetic debris. In contrast, phagocytosed prosthetic debris were detected in rats implanted with the reference material expanded polytetrafluoroethylene (e‐PTFE). These TPU patches appear as promising new implants for the treatment of diaphragmatic hernias.

Study of a Novel Bi‐Layered Thermoplastic Polyurethane Patch for Congenital Diaphragmatic Hernia

Guillaume Leks, Julie Favre, Manon Zislin, Rodolphe Migneret, Jordana Hirtzel, Vincent Ball, Cendrine Seguin, Anne Hebraud, Emeline Lobry, Guy Schlatter, Nadia Bahlouli, Hamdi Jmal, Benoît Frisch, Sylvie Fournel, Isabelle Talon
Advanced Materials Interfaces, 2026, 13 (7), pp.e00850. ⟨10.1002/admi.202500850⟩ | Publiée le 4 mars 2026
Article dans une revue

Abstract

Congenital diaphragmatic hernia (CDH) is a rare disease that has been increasing in prevalence since the end of the 20th century. The recurrence rate of hernias is over 50%, increasing morbidity. Research is ongoing to identify a suitable solution to repair large defects because common prosthesis does not match the mechanical properties of the native tissue. This pilot study aims to evaluate a new non‐biodegradable thermoplastic polyurethane elastomer (TPU) bilayer patch. Its mechanical properties may be better suited to facilitate growth from childhood to adulthood. Its structure comprises a fibrous layer that promotes cell colonization and integration, and a smooth film layer that prevents cell adhesion. In vitro studies showed that both fibroblasts and myoblasts colonized the fibrous layers efficiently when they were optimized with an adhesive polydopamine (PDA) film and a collagen I (Coll I) coating. This facilitated early colonization, increased proliferation and cell spreading. New materials, whether functionalized or not, did not induce inflammation. Subsequent in vivo studies in rats showed significant cell integration in TPU patches without prosthetic debris. In contrast, phagocytosed prosthetic debris were detected in rats implanted with the reference material expanded polytetrafluoroethylene (e‐PTFE). These TPU patches appear as promising new implants for the treatment of diaphragmatic hernias.

Tuning the specific surface area of pure monophasic hydroxyapatite nanoparticles synthesized by sol-gel method using a capillary-based microfluidic process

Leyla Aliyeva, Afsana Guliyeva, Christophe A Serra, Flora Lemaire, Marc Lenertz, Alain Carvalho, Fabrice Vigneron, Maxime Florent, Halima Kerdjoudj, Ulviyya Hasanova, Delphine Chan-Seng
Powder Technology, 2026, 476, pp.122359. ⟨10.1016/j.powtec.2026.122359⟩ | Publiée le 2 mars 2026
Article dans une revue

Abstract

The surfactant-free sol-gel synthesis of hydroxyapatite nanoparticles was adapted for in-flow production using a capillary-based microfluidic device. Different parameters have been investigated, including the capillary arrangements (core-shell and side-by-side), the capillary diameter, and the flow rate of the precursor solutions. The nanoparticles synthesized were characterized by X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and specific surface area measurement according to the Brunauer-Emmett-Teller (BET) theory. The results were compared with those of hydroxyapatite nanoparticles obtained by the conventional batch sol-gel synthesis method. The morphology of the nanoparticles changed due to the use of different capillary arrangements and thus exhibited a higher specific surface area than the batch process. The highest specific surface area was observed when using a side-by-side arrangement using a capillary with an internal diameter of 100 μm and a flow rate of 100 μL/min reaching an increase of the specific surface area by two-fold (61 m2/g) as compared to the conventional batch sol-gel method (29 m2/g) without affecting any of their other properties including cell viability.

Unveiling selectivity shift in CO2 methanation with TiO2 supported subnanometer Ru particles

Seema Shafiq, Clément Molinet-Chinaglia, Carole Le Berre, V. Collière, Katerina Soulantica, Alex-Cristian Tomut, Romuald Poteau, Frédéric Meunier, Guillaume Clet, Walid Baaziz, Ovidiu Ersen, Spyridon Zafeiratos, Davide Salusso, Philippe Serp
Journal of Catalysis, 2026, 456, pp.116768. ⟨10.1016/j.jcat.2026.116768⟩ | Publiée le 16 février 2026
Article dans une revue

Abstract

The regulation of selectivity in CO2 hydrogenation is critically important for energy conversion and storage, and has therefore been widely studied. Several hypotheses have been proposed to explain the shift in selectivity from methane to CO, most commonly invoking particle size effects, metal-support interactions, or anion adsorption. However, the catalytic behavior of supported subnanometric metal particles remains poorly understood, limiting the rational design of efficient catalysts for CO2-emission mitigation. Here, we show that for ultradispersed Ru/TiO2 catalysts (Ru &lt; 1 nm), product selectivity can be completely reversed simply by varying the temperature of the reductive pretreatment. A catalyst reduced at 140 °C yields CO at low reaction temperatures and methane above 160 °C, whereas a catalyst reduced at 260 °C produces methane exclusively over the entire 140–260 °C range. Combined ex situ and in situ characterization, supported by DFT calculations, reveals that the selectivity shift does not originate from strong metal-support interactions or particle size effects, but instead from changes in the oxidation state of ruthenium. When a sufficient fraction of metallic Ru is present, the catalyst becomes methane-selective, while a significant proportion of oxidized Ru favors CO formation. These findings provide a new strategy for tuning product selectivity in CO2 hydrogenation by controlling the oxidation state of Ru.

Unraveling the Blessing and Curse of the IrCu Aerogel Catalyst for the Oxygen Evolution Reaction

Amir Gasmi, Meryem Ennaji, Carlos A Campos-Roldán, Morgane Stodel, Tristan Asset, Vasiliki Papaefthymiou, Andrea Zitolo, Marc Dupont, Frédéric Lecoeur, Jakub Drnec, Deborah Jones, Raphaël Chattot
ACS Catalysis, 2026, 16 (5), pp.4528-4540. ⟨10.1021/acscatal.5c07713⟩ | Publiée le 12 février 2026
Article dans une revue

Abstract

<div><p>Improving the intrinsic activity and utilization of iridium (Ir)-based catalysts for the oxygen evolution reaction (OER) is essential to the market penetration of proton exchange membrane water electrolyzers (PEMWEs). However, conventional electronic structure modulation strategies relying on the introduction of transition metals through alloying and doping face serious stability issues. In this study, we examine the structure-activity-stability relationships toward the OER of an IrCu aerogel in comparison to dispersed IrCu nanoparticles and a commercial IrO x benchmark. Using a combination of ex situ, in situ, and post mortem techniques, we show that the high OER activity of the IrCu aerogel originates primarily from the presence of lattice distortions, i.e., through a structural effect rather than an alloying effect. Moreover, beyond decisively influencing the electrocatalytic activity, the structure is shown to inhibit the formation of stable Ir oxide species during operation unlike for isolated nanoparticles, which is detrimental to the aerogel stability during accelerated stress tests in PEMWE.</p></div>

Non-functionalized Iron Oxide Raspberry-shaped Nanostructures as Promising Tools for Viral and Bacterial Disinfection of Wastewaters

Joana Vaz-Ramos, Julie Challant, Isabelle Bertrand, Grégoire Herzog, Gregory Francius, Stéphane Le Calvé, Sylvie Begin
Journal of Cluster Science, 2026, 37 (1), pp.22. ⟨10.1007/s10876-026-02984-6⟩ | Publiée le 2 février 2026
Article dans une revue

Abstract

Pathogenic viruses are frequently detected in diverse aquatic environments, even in treated water, which poses dangers to human health. For water decontamination, there are conventional water treatments, which typically involve a combination of physical and chemical disinfection processes, but they are not always efficient and certain waterborne viruses exhibit resistance to these methods. Thus, there is a need for improved alternative approaches and the use of nanomaterials appears as interesting solution, given their potential ability to inactivate microbial pathogens. So, in this study, we proposed to investigate the antiviral capacity of non-functionalized superparamagnetic iron oxide raspberryshaped nanostructures (RSNs) in water. We synthesized iron oxide RSNs of ≈380 nm in mean diameter, consisting of oriented aggregates of nanograins, via a solvothermal polyol method and then assessed their antiviral activity with three different bacteriophage strains (T4, Phi6 and PhiX174). Plate assay results showed total virus inactivation for RSN concentrations higher than 106 µg/L. At lower RSNs concentrations (1-103 µg/L), we observed only a slight inactivation of T4 and PhiX174 phages and total inactivation of Phi6. We have shown that these RSNs are also able to release heat under near-infrared (NIR) irradiation. We have thus further evidenced that without RSNs, NIR irradiation alone had no effect on viral concentration when the combination of RSNs with photothermia led to &gt;91% inactivation for all phages. This demonstrated an effective synergetic effect of both RSNs and irradiation on virus inactivation. A possible antibacterial activity of RSNs has also been studied and evidenced only a slowing of the bacteria growth whatever the RSNs concentration. Thus, all these findings highlight the potential of such non-functionalized superparamagnetic iron oxide nanostructures combined with photothermia for water disinfection in wastewater treatment applications.

Tailoring selectivity of electrocatalytic glucose oxidation on (Ni)Au catalysts through the surface state control

Evgenii Strugovshchikov, Alejandra Medrano-Banda, Corinne Bouillet, Jing Sun, Vasilica Badets, Vasiliki Papaefthimiou, Mykola Isaiev, Philipp Röse, Elena Savinova, Alexandr Oshchepkov
Electrochimica Acta, 2026, 548, pp.147877. ⟨10.1016/j.electacta.2025.147877⟩ | Publiée le 1 février 2026
Article dans une revue

Addressing phosphate removal issues during peritoneal dialysis using colloidally stable iron oxide nanoclusters coated with tannic acid

Theo Lucante, Philippe Choquet, Joana Vaz-Ramos, Vincent Ball, Dominique Bégin, Cédric Leuvrey, Vasiliki Papaefthymiou, Spyridon Zafeiratos, Ariane Zaloszyc, Sylvie Bégin-Colin
Applied Surface Science, 2026, 717, pp.164782. ⟨10.1016/j.apsusc.2025.164782⟩ | Publiée le 1 février 2026
Article dans une revue

Abstract

Removal of chronic excess phosphates in blood is critical for patients suffering from end-stage renal disease (ESRD). ESRD patients can be treated with peritoneal dialysis (PD), during which phosphates are transported from the blood to a specific solution, named dialysate, introduced into their peritoneal cavity. However, phosphate removal in PD is currently insufficient but could be improved by introducing in dialysate phosphate adsorbents. Iron oxide nanoparticles are biocompatible and well-known effective phosphate adsorbents, but their colloidal stability at physiological pH and adsorption capacity in high ionic strength aqueous media such as dialysate are significant challenges. Here, we have evaluated the potential of tannic acid-coated iron oxide raspberry-shaped nanoclusters (RSNs@TA) for improving phosphate adsorption in dialysate. We have investigated the influence of the TA coating on phosphate adsorption by performing adsorption experiments with uncoated and TA-coated RSNs. In parallel, we have studied the influence of electrolytes and compounds in dialysate on phosphate adsorption by conducting experiments in pH 7 water and dialysate. The TA coating was shown to provide a high colloidal stability to the nanoclusters and mitigates the inhibitory effect of electrolytes in dialysate on phosphate adsorption. Indeed, electrolytes in dialysate decreased the phosphate adsorption on both nanoclusters but especially on uncoated ones by disturbing phosphate outer-sphere complexes. Thus, RSNs@TA demonstrated enhanced adsorption capacity compared to uncoated RSNs in dialysate (20.7 ± 6.4 mg P.g -1 ) and in pH 7 water (26.4 ± 8.1 mg P.g -1 ). These results established RSNs@TA as promising adsorbents for phosphate removal in dialysate during a PD process.

Stoichiometric engineering of aza-Michael chemistry for controlled foam generation

Vipin G Krishnan, Baptiste Clement, Antoine Duval, Leandro Jacomine, Léa Skorlic, Rémi Perrin, Alexandru Sarbu, Wiebke Drenckhan-Andreatta
Chemical Engineering Journal, 2026, 530, pp.173122. ⟨10.1016/j.cej.2026.173122⟩ | Publiée le 30 janvier 2026
Article dans une revue

Abstract

With rising concerns over the toxicity and environmental impact of isocyanates, it is high time to explore viable isocyanate-free alternatives for polymer foams. While polyurethane foams have long dominated the market due to decades of refinement, achieving comparable properties with alternative chemistries remains a challenge. The aza-Michael addition reaction, which proceeds under mild conditions, offers a promising route to synthesize crosslinked polymer foams without isocyanates. In this study, we demonstrate the preparation of rigid polymer foams via aza-Michael addition between multifunctional monomers using physical blowing agents. A key innovation lies in introducing an intermediate pre-reaction step, where varying the reactant stoichiometry allowed us to finely control the final polymerization kinetics and exothermicity. This tunability enabled modulation of foam rise, density and morphology, without altering the base formulation. The resulting foams were partially open-cell with densities as low as ∼71 kg·m−3, average cell radius of ∼500 μm, and thermal conductivity of ∼48 mW·m−1·K−1. The foams were mechanically robust, with excellent recovery after 80% compression. With further optimization of the foaming process and the use of tailored surfactants and blowing agents, aza-Michael-based foams could emerge as strong candidates to replace rigid polyurethane foams in commercial applications.

Field calibration of nitrogen-doped carbon-coated silicon carbide (NMC@SiC) passive air samplers to measure polar and non-polar semi-volatile organic compounds

Dani Khoury, Supansa Chimjarn, Olivier Delhomme, Maurice Millet
Environmental Technology and Innovation, 2026, 41, pp.104761. ⟨10.1016/j.eti.2026.104761⟩ | Publiée le 24 janvier 2026
Article dans une revue

Abstract

This study reports the first field calibration of nitrogen-doped carbon-coated silicon carbide (NMC@SiC) passive air samplers for measuring semi-volatile organic compounds (SVOCs) in the atmosphere of the Alsace region. The NMC@SiC samplers were deployed concurrently with conventional low-volume active samplers at a central urban site in Strasbourg, enabling direct comparison between passive and active sampling techniques. Sampling covered five two-week periods (2018–2019) plus extended three-to-four-week deployments (2019–2020). After exposure, target compounds adsorbed onto the sorbent were extracted using a two-step protocol involving accelerated solvent extraction followed by solid-phase extraction. Analytical quantification was performed via gas chromatography-mass spectrometry (GC-MS), gas chromatography-tandem mass spectrometry (GC-MS/MS), and liquid chromatography-tandem mass spectrometry (LC-MS/MS), ensuring robust compound-specific detection and quantification. NMC@SiC samplers effectively captured a broad spectrum of SVOCs, including PAHs, PCBs, organochlorine pesticides (OCPs), phenols, and organic acids. Mean sampling rates (Rs) ranged from 2.5 and 6.0 m³ day⁻¹, values comparable to or slightly exceeding those of established passive samplers. Importantly, NMC@SiC efficiently collected both highly semi-volatile and polar analytes (like phenols and carboxylic acids), underscoring its suitability for legacy and emerging pollutants. Its high surface area and polar coating facilitate uptake of both nonpolar and polar compounds, highlighting its promise as a robust tool for long-term SVOC air monitoring. This pioneering field deployment demonstrates NMC@SiC’s potential as a next-generation passive sampler for comprehensive air quality assessment.

Investigation of the Electrochemical Behaviour of Ag and Pd in Deep Eutectic Solvents: Insights from Modulation Excitation X-ray Absorption Spectroscopy

Benjamin Rotonnelli, S. Michel, Anthony Beauvois, Tristan Asset, Sophie Legeai
SUM2026, Jan 2026, Paris Saclay, France | Publiée le 15 janvier 2026
Poster de conférence

Spatial variability and atmospheric levels of phenolic compounds measured by passive samplers in the Strasbourg metropolitan area

Dani Khoury, Supansa Chimjarn, Olivier Delhomme, Maurice Millet
Environment International, 2026, 207, pp.110056. ⟨10.1016/j.envint.2026.110056⟩ | Publiée le 10 janvier 2026
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Abstract

Phenolic compounds are ubiquitous atmospheric pollutants mainly emitted by biomass burning, industrial activities and vehicular exhaust. In the current study, we quantified 54 phenols at six sites in the Strasbourg metropolitan area, classified into monophenols, chlorophenols, bromophenols, nitrophenols, aminophenols, and methoxyphenols. Passive samplers, consisting of nitrogen–doped carbon–coated silicon carbide foam, were deployed from 2018 to 2020 in urban, suburban and rural environments. After extraction, samples were analyzed by gas chromatography–mass spectrometry. Median concentrations ranged from &lt; 0.5 ng m−3 for most halogenated species to 1.6 ng m−3 for cresols, with phenol/cresols dominating. Spatial patterns revealed diffuse urban emissions for phenol/cresols and aminophenols, whereas methoxyphenols and halophenols displayed hotspots near industrial and residential combustion sources. Inter-annual comparisons within the sampling period indicated generally stable concentrations between 2018 and 2019, except at one suburban site where levels decreased markedly, suggesting reduced biomass-burning influence. Seasonal comparisons showed no major differences between heating and non–heating periods (except at one suburban site), implying that continuous traffic and industrial emissions override heating effects. These results highlighted the predominance of diffuse urban sources and specific hotspots for phenolic pollution in Strasbourg, and provided a baseline for evaluating mitigation strategies.

Waste-derived porous carbon/hematite composites as efficient supercapacitor electrode material

Akshita Singh, Ali Maged, Izabela Janowska, Vimal Chandra Srivastava
Journal of Energy Storage, 2026, 147, pp.120214. ⟨10.1016/j.est.2025.120214⟩ | Publiée le 6 janvier 2026
Article dans une revue

Abstract

According to the circular economy concept, including emerging materials, carbon/hematite composites are recovered entirely from wastes and investigated in view of sustainable energy storage. The pyrolysis and chemical activation of peanut shell waste yield a highly microporous carbon structure (PEAC) with a high specific surface area of 3041 m 2 /g, while acid-leaching, precipitation, and hydrothermal treatment of red mud waste allows to obtain hematite nanoflakes (IO). The materials and their composites with varying mass ratios were tested as supercapacitor electrodes in a three-electrode setup. Most of the composites demonstrated an improved performance compared to the individual components, exploiting the synergistic charge storage mechanism of electric double-layer capacitors and redox-active pseudocapacitors. The optimum composite containing 10 % hematite (PEAC/IO-10) exhibits a notable specific capacitance of 337 F/g at 10 mV/s and 269 F/g at 2 A/g on Ni foam. On a glassy carbon substrate, it demonstrates superior performance with capacitance up to 567.9 F/g at 10 mV/s and 284.3 F/g at 2 A/g in 1 M KOH electrolyte, outperforming 1 M Na 2 SO 4 and 1 M H 2 SO 4 . A significant contribution from both diffusive and capacitive charge storage was confirmed by Dunn's analysis. The symmetrical coin cell device test reveals a specific capacitance of 152 F/g at 1 A/g with an energy and power density of 7.6 Wh/kg and 720 W/kg, demonstrating 106 % retention of initial capacitance after 1000 cycles. The composite is competitive or superior to the best-known carbon/hematite systems obtained mostly from commercial precursors, while giving an advantage of waste management for a sustainable future.

Operando IR of Catalytic Reactions Under Microwaves at 5.8 GHz

Frederic Thibault-Starzyk, Ana Neto, Sébastien Thomas, Carlos Henriques, Gary Bond
Catalysis Today, 2026, 462, pp.115571. ⟨10.1016/j.cattod.2025.115571⟩ | Publiée le 1 janvier 2026
Article dans une revue

Abstract

A new spectroscopic cell was designed for operando IR observation of heterogeneous catalysis under microwave irradiation. Oxidation of CO on Pt-H-BEA zeolite was performed under conventional and microwave heating at the same space velocity to assess the efficiency of microwave heating, which was confirmed by an infrared in-situ temperature scale. A temperature of 230-240°C was obtained after 2 min microwave irradiation. Infrared monitoring evidences a moderate sintering of the platinum particles after microwave irradiation, probably due to hotspots on the metal. Infrared observation indicates a strong perturbation of electron density in the Pt particles by microwave during catalysis.

First evidence of deleterious effect of pesticide mixture on health status in semi-captive grey partridges

Sophie M Dupont, Agathe Gaffard, Anaïs Rodrigues, Maurice Millet, Coraline Bichet, Maria Teixeira, Vincent Bretagnolle, Karine Monceau, Olivier Pays, Jérôme Moreau
Environmental Research, 2026, 289, pp.123332. ⟨10.1016/j.envres.2025.123332⟩ | Publiée le 1 janvier 2026
Article dans une revue

Abstract

<div><p>Pesticides are mainly used in agroecosystems to control pests. Due to their limited specificity, the resulting widespread contamination may cause unintended effects on non-target organisms that use these habitats. While increasing attention is paid to the relationship between single substances and phenotype on non-target species, their combined impacts are still largely unknown. Since interactions between pesticides may also impact organisms' health, studying them as complex mixtures is the more realistic approach. Here, we present the first experimental study testing the relationship between an environmentally relevant pesticide mixture and health biomarkers on a farmland avian non-target model. To do so, we used 40 semi-captive grey partridges (Perdix perdix) fed for five months with conventional grains. Their plant protection product (PPP) load (i.e., the number of PPPs, the total sum of scaled pesticide concentrations and the total toxicity index) in blood and proxies of health status (evaluated using behavioral and physiological features) were monitored at the end of the exposure period. We demonstrated, for the first time, concerning correlations between PPP load indexes and bird healthrelated features (physical activity, flight initiation distance, eye ring redness and acetylcholinesterase activity). Overall, we highlighted the urgent need to consider environmentally-relevant PPP mixture when biomonitoring non-target vertebrates in ecotoxicological studies.</p></div>

Ru/TiO2 catalysts for selective formation of ring hydrogenation or ring-opening products from biomass-derived 5-hydroxymethylfurfural

Preeti Kashyap, Marcin Jędrzejczyk, Mingjun Gu, Stephan Steinmann, David Kubička, Nicolas Keller, Carine Michel, Agnieszka Ruppert
Green Chemistry, 2026, ⟨10.1039/D5GC06439B⟩ | Publiée le 1 janvier 2026
Article dans une revue

Abstract

A novel catalytic strategy using Ru/TiO2 enables selective ring hydrogenation or ring-opening of biomass-derived 5-hydroxymethylfurfural. Combined experimental and theoretical studies elucidate structure–activity relationships and reaction pathways.

Tannin-coated polyurethane foams as a non-innocent structured support for Pd-catalysed alkyne semi-hydrogenation, nitroarene reduction and Suzuki coupling under air

Sara Viggiano, Han Peng, Thierry Romero, Vasiliki Papaefthimiou, Maria Laura Alfieri, Lucia Panzella, Alessandra Napolitano, Vincent Ritleng
Molecular Catalysis, 2026, 588, pp.115540. ⟨10.1016/j.mcat.2025.115540⟩ | Publiée le 1 janvier 2026
Article dans une revue

Abstract

Polyurethane foams (PUF) were coated with hydrolyzable (HT) or condensed (CT) tannins, derived from chesnut and quebracho woods, and Pd was anchored onto the HT or CT layer via simple immersion of HT@PUF and CT@PUF in a water-ethanol (1:5) solution of Pd(NH3)4Cl2H2O at room temperature under air to afford Pd@HT@PUF and Pd@CT@PUF composites. XPS showed a partial reduction of the Pd(II) salt to Pd(0) in agreement with the reducing properties of the HT and CT coatings, and SEM and SEM-EDX suggested a coordination of evenly dispersed Pd(II) ions by the phenol moieties of the HT or CT layer together with the formation of Pd (nano)particles. The palladium loading, as determined by ICP-AES measurements, varied with the concentration of the aqueous tannin solution (0.1 or 0.5g/L) used for the HT or CT coating procedure; the higher the concentration, the higher the Pd loading. A high loading of Pd, hence of Pd(0), on the as-synthesized macroscopic catalyst guaranteed a stable catalytic activity and selectivity from the beginning without prior activation procedure in alkyne-to-alkene hydrogenation. A lower Pd loading resulted in a gradual improvement of the catalytic activity overtime that conincidated with a reduction of the chelated Pd(II) ions to Pd(0) under the reaction conditions. Notably, both Pd@HT@PUF and Pd@CT@PUF proved reusable for up to 6 cycles without catalyst activity and selectivity decrease, in a convenient “dip-and-play” mode, in selective alkyne semi-hydrogenation and/or nitroarene reduction, as well as in fast Suzuki coupling under air.

Reversible Strong Metal‐Support Interactions in Co/TiO 2 Catalysts Driven by CO 2

Aurélien Durupt, Canio Scarfiello, Léon Schmidt, Doan Pham Minh, Katerina Soulantica, Frédéric Meunier, Ovidiu Ersen, Spyridon Zafeiratos, Guillaume Clet, Philippe Serp
ChemCatChem, 2026, 18 (1), pp.e01392. ⟨10.1002/cctc.202501392⟩ | Publiée le 1 janvier 2026
Article dans une revue

Abstract

Strong metal–support interactions can significantly influence catalytic performance. On titania supports, these interactions often involve the formation of a substoichiometric TiO X overlayer during high‐temperature reduction, which can be reversed by treatments under dioxygen. Under CO 2 hydrogenation conditions, where water is produced, complete removal of the TiO X overlayer has been reported, raising questions about its stability in the presence of a mild oxidant such as CO 2 . In this study, in situ and operando techniques were employed to examine the effect of varying conditions on both the titania overlayer and cobalt species in a Co/TiO 2 catalyst. After reduction at 350 °C, the overlayer consisted of stoichiometric anatase TiO 2 , while cobalt remained partially reduced. Exposure to CO 2 /H 2 at 220 °C enabled complete cobalt reduction without affecting the TiO 2 overlayer. In contrast, pure CO 2 at 220 °C caused overlayer removal and full cobalt oxidation. The impact of this CO 2 ‐mediated reversibility on CO 2 hydrogenation was also evaluated. Although steady‐state activity was largely unaffected, the transient regime showed substantial changes in selectivity and behavior. These results demonstrate that different treatments can strongly influence both the stability and reactivity of Co/TiO 2 catalysts, highlighting the importance of dynamic SMSI effects in CO 2 hydrogenation.

Premature aging and neuropathic behaviours induced by an acute low-dose exposure to a sarin surrogate

Alexandre Champault, Sarah Leterrier, Rosalie Bel, Julie Knoertzer, Amélie Soyer, Sébastien Goutal, Rachid Baati, Sabine Francois, Nicolas Tournier, Gregory Dal Bo, Karine Thibault
Toxicology, 2026, 519, pp.154327. ⟨10.1016/j.tox.2025.154327⟩ | Publiée le 1 janvier 2026
Article dans une revue

Abstract

Acute poisoning from organophosphorus (OP) compounds induced a cholinergic toxidrome. Neurological complications may manifest weeks after the initial exposure, including muscle weakness and progressive loss of sensitivity. These symptoms may be analogous to those observed in elderly individuals. However, the delayed neurological impact of OP exposure has received limited attention and remains an under-explored area of research. The present study investigated the long-term effects of OP exposure on the sensorimotor system using a mouse model exposed to a sublethal dose of a sarin surrogate. The mice received a 0.5 LD50 dose of 4-nitrophenyl isopropylmethylphosphonate (NIMP), and were observed for a period of six months. Our results demonstrate that NIMP exposure induced a mild intoxication severity in mice, without affecting weight evolution. Behavioral evaluation, using locomotor and sensory tests, revealed that mice exhibited persistent muscle weakness and an increase in mechanical sensitivity. Six months after NIMP exposure, acetylcholinesterase activity remained inhibited in specific regions of the cerebral cortex, while the spinal cord exhibited a return to normal values. Positron emission tomography scans and microcomputed tomography imaging revealed alterations in cerebral glucose metabolism and bone density. Luminex multiplex immunoassay analyses revealed an increase in specific biomarkers of aging. The present study demonstrates that a sublethal dose of NIMP triggered premature aging phenotype, resulting in long-term sensorimotor impairments, neurometabolic and cellular disturbances. These findings underscore the importance of identifying intoxication hallmarks, even in cases of asymptomatic OP exposure.

Breaking Methane without Metals: Induction‐Heated Carbon Catalyst at Low‐Temperature Process

Van‐hieu Ngo, Ahmed Essyed, Thierry Romero, Jean Mario Nhut, Michael Dumont, Andre Grishin, Isabelle Bétrémieux, Arnaud Brazier, Spyridon Zafeiratos, Cuong Pham‐huu
Advanced Energy and Sustainability Research, 2026, 7 (3), pp.e202500503. ⟨10.1002/aesr.202500503⟩ | Publiée le 1 janvier 2026
Article dans une revue

Abstract

The large-scale production of hydrogen and the direct sequestration ofcarbon in solid form, through the decomposition of natural gas, could constitute an attractive economic alternative for hydrogen production if catalyst deactivation by coke formation or sintering could be mitigated. Here, we report on the use of a carbon-based catalyst to achieve the catalytic methane decomposition at medium temperature of 800°C, under contactless inductive heating. Analyses of the catalytic performance and the characterization of the spent catalyst show that the carbon deposited during the reaction acts as the active phase and can thus be recycled indefinitely. This autocatalytic effect is observed only when the carbon-based catalyst is operated under inductive heating. The carbon formed is in the form of a graphene-like layer with a high degree of graphitization and is distinctly different from the carbon black powder typically obtained in other processes. These promising results could set the ground for developing an industrially and economically viable method to convert natural gas into hydrogen, using renewable energy and low-cost catalysts, with improved resistance to poisoning by impurities present in the feedstock.

Methodological insights into the dip-and-pull X-ray photoelectron spectroscopy technique: analysing electrochemical interfaces under in situ/operando conditions

Benjamin Rotonnelli, Amandine Brige, Alexandr Oshchepkov, Jean-Jacques Gallet, Fabrice Bournel, Antoine Bonnefont, Alexander Yaroslavtsev, Andrey Shavorskiy, Robert Temperton, Elena Savinova, Tristan Asset
Journal of Synchrotron Radiation, 2026, 33 (1), ⟨10.1107/S1600577525008811⟩ | Publiée le 1 janvier 2026
Article dans une revue

Abstract

Gaining insight into structural and compositional transformations occurring at the electrode/electrolyte interface during the operation of electrochemical systems is fundamental to understanding and, thus, optimizing their performance. Such an analysis must be performed in operando conditions, owing to the potential, electrolyte and time dependence of these transformations. Here, the use of X-ray photoelectron spectroscopy (XPS) is particularly attractive due to its surface sensitivity and ability to provide quantitative information on the oxidation state and chemical environment of an element. In specific instrumental configurations [ e.g. in `dip-and-pull' (D&amp;P) or `meniscus' setup], it can be used to analyse not only the electrode but also the electrolyte side of the interface, under in situ / operando conditions. In this article, we discuss how D&amp;P XPS can provide unique information on both sides of the electrode/electrolyte interface, briefly review publications demonstrating its capabilities, highlight the challenges the method faces, and share our views on its future developments. This article aims to provide a practical guide to new D&amp;P synchrotron users and help them to understand the technique, and physical phenomena that may impede the acquisition of reliable data.

(NHC-olefin)-nickel(0) nanoparticles: an efficient and selective catalyst for hydrogenation reactions at low temperature and pressure

Marta G Avello, Geetika Singh, Lai Truong-Phuoc, Loïc Vidal, Vasiliki Papaefthimiou, Matthieu Chessé, Nathalie Gruber, Michael J Chetcuti, Kumar Vanka, Vincent Ritleng, Cuong Pham-Huu, Christophe Michon
Journal of Catalysis, 2026, 453, pp.116487. ⟨10.1016/j.jcat.2025.116487⟩ | Publiée le 1 janvier 2026
Article dans une revue

Abstract

The reduction of a NHC-cinnamyl nickel(II) organometallic complex through the use of different MeMgBr or MeMgCl reagents led to two types of NHC-olefin-coordinated nickel nanoparticles. Both of these unsupported nickel-NHC based nanomaterials behaved under hydrogen pressure as effective and selective catalysts operating at low temperature (≤ 80 °C), pressure (≤ 20 bar) and loading (≤ 6 mol%) for the reductions of broad scopes of alkenes, alkynes, imines and heterocycles, including a challenging tetra-substituted alkene. Among these two nickel-NHC nanocatalysts, the one generated with MeMgCl showed a significant high catalytic activity with high yields and could stand the comparison with Raney nickel and state-of-the-art nickel nanocatalysts. For example, by studying the hydrogenation of 1-phenylcyclohexene in ethanol at 60°C under 10 bar of H₂, 3 mol% of this catalyst achieved the reaction within a single hour on a 5 mmol / 0.8 g substrate scale with a yield of 96%, a turnover number (TON) of 32 and a turnover frequency (TOF) of 32. Characterizations confirmed the coordination of the NHC-olefin ligands to the nickel nanoparticles, the reduced state of the nickel and the (poly-)crystallinity of the nanoparticles.

A comprehensive review of organic pollutants removal techniques: adsorption, degradation, and advanced treatment processes

Narinj Taghiyeva, Elshan Abdullayev, Firas Baroudi, Ulviyya Hasanova, Maurice Millet
Total Environment Engineering, 2026, 7, pp.100082. ⟨10.1016/j.teengi.2026.100082⟩ | Publiée le 1 janvier 2026
Article dans une revue

Abstract

Pesticides, along with polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and phenols, are among the most common organic pollutants globally due to their persistent nature and widespread distribution in various ecosystems. Despite undergoing biological, chemical, physical, and physicochemical degradation processes, these contaminants exhibit high stability and, in some cases, water solubility, enabling their prolonged persistence in various environmental matrices such as water, air, and soil, where they pose significant environmental and health risks, necessitating remediation through diverse strategies within these classifications. This review provides an in-depth analysis of both well-established and emerging methods for the removal of pesticides, PCBs, PAHs, and phenols, focusing on specific remediation strategies within these classifications. Techniques include bioremediation using microorganisms, adsorption via clays, graphene-based composites, and polymeric materials, as well as chemical treatments such as advanced oxidation processes. The key characteristics, advantages, and limitations of each technique and material are discussed to provide a comprehensive understanding of current strategies for organic pollutant remediation.

Bilan et Analyse du mandat 2023-2026 du Comité Scientifique d’Orientation Recherche & Innovation (CSO R&I) de la Stratégie Ecophyto 2030

Sonia Lequin, Véronique Gouy-Boussada, André Miralles, Elise Pelzer, Laurent Parrot, Julie Subervie, Jeanne Garric, Laurent Deliere, Jérome Moreau, Ingrid Arnault, Marc Audibert, Jean Guyot, Pierre Lebailly, Vincent Martinet, Marc Gallien, Gérard Bernadac, Sébastien Lemiere, Caroline Gibert, Maurice Millet, Dimi Théodore Doudou, Agnès Langlois, Aurélie Bravin, Eric Chantelot, Philippe Le Gall, Stéphane Mortaud, Fabienne Goutille, Julien Parinet
INRAE - UMR 1347 Agroécologie, Dijon, France. 2026 | Publiée le 1 janvier 2026
Rapport

Abstract

Les objectifs de réduction des produits phytopharmaceutiques portés par la Stratégie Ecophyto 2030 apportent de nouveaux défis à l’Agriculture. L’enjeu de l’Axe 4 Recherche Innovation Formation est de mobiliser l’ensemble du système de recherche-innovation afin d’apporter les connaissances nécessaires pour les relever et d’appuyer les politiques publiques dans la transition vers un modèle agroécologique des cultures. Cet axe est piloté et orienté par un Comité Scientifique d’Orientation (CSO R&amp;I). Ce document « Héritage CSO R&amp;I » dresse un bilan et une analyse synthétiques des actions conduites par les membres du CSO R&amp;I lors du mandat 2023-2026. Il met en perspective les réflexions scientifiques stratégiques, leurs concrétisations en actions (appels à projets, animation scientifique, valorisation…), les freins rencontrés et les perspectives pour le prochain mandat 2027-2030

Less Is More: Practical Insights into Multivariate Regression Models for Raman Spectroscopy in Bioprocess Monitoring

Antoine Borg, Mourad Elhabiri, Stéphane Le Calvé, Vincent Portaluri
Biotechnology and Bioengineering, 2025, ⟨10.1002/bit.70118⟩ | Publiée le 19 décembre 2025
Article dans une revue

Abstract

<div><p>Process Analytical Technology (PAT) has been encouraged in bioprocess industries as a transformative approach for real-time process monitoring. However, two decades after its introduction, PAT implementation remains limited, particularly in quantitative online monitoring, partly due to the perceived complexity of chemometrics and contradictory communication from PAT suppliers. This review aims to demystify chemometrics in the context of multivariate regression models based on Raman spectroscopy, a versatile tool for bioprocess monitoring. By providing a critically evaluated workflow for model developmenti.e., pre-treatment, pre-processing, modelling, and evaluation -this review advocates for practical, simplified methodologies emphasizing robustness, transparency, and maintainability over convoluted processes. Two applications of Raman-based models, glucose monitoring in fermentation and lactate monitoring in cell culture, are herein examined to highlight common pitfalls, best practices, and opportunities for improvement. Ultimately, this report seeks to challenge the idea that chemometrics is inaccessible and provide practical insights to enable researchers to develop accurate and reliable models for real-world bioprocess applications.</p></div>

Development of multifunctional hydrogels based on zeolite/biopolymer composites for the treatment of chronic wounds

Baylar Zarbaliyev
Material chemistry. Université de Strasbourg; French-Azerbaijani University (Bakou), 2025. English. ⟨NNT : 2025STRAF073⟩ | Publiée le 18 décembre 2025
Thèse

Abstract

In this thesis, it was aimed to prepare the composites based on biopolymers and zeolites. In the first stage, FAU zeolites with varying sizes and cation-exchanged FAU zeolite have been assessed in wound healing by using adsorption, cation release, and the Fenton reaction as model reactions. As a result, room-temperature synthesized nanozeolite and Ag-Y were selected as promising multifunctional materials for the given application. In the next step, the incorporation of cation-exchanged FAU-Y nanozeolites into chitosan hydrogel demonstrated controlled cation release. The mathematical modelling revealed the release was governed by diffusion. In the final stage, gelatin hydrogels with high thermal stability were developed with a novel strategy. The material exhibited self-healing and adhesion properties, making it attractive for wound-healing applications.

Organic semiconducting nanoparticles for photocatalytic hydrogen production : influence of the internal morphology

Corentin Rieb
Polymers. Université de Strasbourg, 2025. English. ⟨NNT : 2025STRAE048⟩ | Publiée le 16 décembre 2025
Thèse

Abstract

Organic semiconductor (OSC) nanoparticles (NPs) were developed for applications in photovoltaics and photocatalysis. Two different preparation processes, miniemulsion and nanoprecipitation, were implemented that result in NPs with different internal morphology : core/shell or intermixed. A microfluidic system was also used to explore the preparation of intermixed NPs without surfactant. The internal morphology of the NPs were characterized in Synchrotron SOLEIL by Scanning Transmission X-ray Microscopy (STXM) and Soft X-ray Ptychography (SXP). Using soft X-ray, chemical composition maps can be obtained by STXM. SXP was explored to increase spatial resolution. We compared the spatial resolution and radiation damage of SXP and STXM with Fourier Ring Correlation. At Nitrogen K-edge (~400 eV), STXM is limited by zone plate used, in our case this theoretical limit resolution is 30.5 nm. SXP can give better spatial resolution (20-25 nm) and decrease the radiation damage by a factor 6. Finally, the influence of the morphology of the OSC NPs on photocatalytic hydrogen (H2) production, was studied in the presence of platinum as co-catalyst and ascorbic acid as hole scavengers. We demonstrated, with triplicates, the influence of the internal morphology of PTQ10/ITIC-4F NPs in H2 production, from 1.5 ± 0.4 mmol/h/gcat (core/shell) to 93 ± 14 mmol/h/gcat (intermixed). Due to the delay between the beginning of illumination and the production of H2, core/shell produced, after 6 hours, 4.87 ± 0.97 mmol/gcat versus 559 ± 88 mmol/gcat for intermixed, who produced directly H2.

Versatile synthesis of nanosized Ni-CeO₂ catalysts with tunable composition for power-to-gas applications

Mathias Barreau, Fengchen Zhou, Anastasia Pappa, Bachchar Hadrane, Ulrike Küst, Javier Ivanez, Salusso Davide, Franck Morfin, Laurent Piccolo, Jan Knudsen, Spyridon Zafeiratos
Journal of Materials Chemistry A, 2025, 14 (11), pp.6250-6266. ⟨10.1039/d5ta08097e⟩ | Publiée le 16 décembre 2025
Article dans une revue

Abstract

liste mot clefs

Electrification of catalytic processes with induction heating: The possible hidden role of non-thermal magnetic fields

Spyridon Zafeiratos, Gilles Ulrich, Jean-Mario Nhut, Christophe Michon, Cuong Pham-Huu
Materials Today Catalysis, 2025, 12, pp.100134. ⟨10.1016/j.mtcata.2025.100134⟩ | Publiée le 10 décembre 2025
Article dans une revue

Abstract

The electrification of the chemical industry is a crucial step toward moving away from fossil fuels and achieving a more sustainable energy future. In this context, induction heating has emerged as a promising strategy to enhance catalytic performance in both metal-free carbon catalysts and metal-supported systems. This perspective emphasizes its strong potential, showing that induction heating improves performance not only through localized thermal effects but also through possible non-thermal contributions from alternating current magnetic fields. These fields can influence radical lifetimes, spin states, adsorption-desorption equilibria, and defect reactivity, thereby enabling reaction pathways and selectivities that remain inaccessible under conventional heating. Coupling carbon and supported metal catalysts with induction heating also offers an effective way to mitigate deactivation, as defect sites can act as adsorption centers that, under magnetic field stimulation, promote targeted transformations. Direct evidence for non-thermal contributions to catalytic performance remains scarce, mainly due to the limited availability of operando investigations. Nevertheless, the substantial gains in activity and selectivity observed under induction heating cannot be explained solely by localized thermal effects, suggesting an additional non-thermal influence. These findings point toward new opportunities for designing nextgeneration catalysts with improved operability and stability. In addition, the combined evidence of localized thermal effects, non-thermal field interactions, and the advantages of carbon-based catalysts shows that the synergy between advanced material design and induction heating provides a powerful pathway for electricitydriven catalysis, with significant implications for decarbonizing the chemical industry and advancing the energy transition.

Design of Heavy-Atom Free Dipyridomethene Boron Complexes for Singlet Oxygen Emission with Induced Chirality

Carlotta Figliola, Camille Chériaux, Nicolas Oppé, Lilian Estaque, Pascal Retailleau, Nicolas Vanthuyne, Grégory Pieters, Denis Jacquemin, Gilles Ulrich
Chemical Communications, In press, 62 (6), pp.1919-1922. ⟨10.1039/D5CC06879G⟩ | Publiée le 9 décembre 2025
Article dans une revue

Abstract

The straightforward synthesis of the first difluoro dipyridomethene boron complexes as heavy-atom-free photosensitizers is described. These molecules show good singlet oxygen generation (phi Delta = 10 to 47%) and significant nonplanar arrangement, inducing axial and boron-centered chirality.

Efficient and selective glucose conversion in a low temperature photocatalysis-assisted hydrothermal process over TiO2-few layer graphene and Ta-doped TiO2 (photo)catalysts

Hamza El Marouazi, Insaf Abdouli, Nadine Essayem, Chantal Guillard, Valérie Keller, Izabela Janowska
Cleaner Chemical Engineering, 2025, 11, ⟨10.1016/j.clce.2025.100205⟩ | Publiée le 1 décembre 2025
Article dans une revue

Abstract

The study reports significantly enhanced glucose conversion under coupled low temperature hydrothermal-photocatalytic conditions with TiO2 nanoparticles (NPs) catalysts and the formation of various high-value-added chemicals such as gluconic acid, arabinose, erythrose and presumably levulinic acid (LevA) isomer, referred to single activation mode. TiO2 NPs, TiO2 combined with few layer graphene (FLG/TiO2) and TiO2 doped with tantalum catalysts with different physicochemical features, including surface acidity properties are investigated (Lewis acid sites in the catalysts are assessed by dihydroxyacetone (DHA) transformation and pyridine adsorption by FTIR). The doping with Ta is beneficial in the photocatalytic conversion, while the FLG integration has a positive impact in photo-, and especially in thermal- and coupled process. On the other hand, the coupled process reveals the synergetic effect of the photo and thermal mode with doubled/tripled conversion of glucose, particularly for FLG/TiO2 (1 wt% of FLG). The improved properties of this original catalyst are related to high density of jaggy FLG edges as significant acid sites, sites for glucose adsorption and TiO2 efficient surface and interface formation, along with high charge transport and heat transfer via the conjugated C = C lattice. The results pave the way for ongoing engineering of catalysts and processes for efficient and selective biomass valorization at low thermal energy.

Editorial overview: Solar photocatalytic and photoelectrochemical hydrogen evolution using novel and effective materials

Laura Clarizia, Tejraj Aminabhavi, Gunda Mohanakrishna, Nicolas Keller, Cui Toe
Current Opinion in Chemical Engineering, 2025, 50, pp.101194. ⟨10.1016/j.coche.2025.101194⟩ | Publiée le 1 décembre 2025
Article dans une revue

Unveiling selectivity shift in CO2 methanation with TiO2 supported subnanometer Ru particles

Seema Shafiq, C. Molinet-Chinaglia, Carole Le Berre, V. Collière, Katerina Soulantica, Alex-Cristian Tomut, Romuald Poteau, F.C. Meunier, Guillaume Clet, Walid Baaziz, Ovidiu Ersen, Spiros Zafeiratos, Davide Salusso, Philippe Serp
GDR NINO, Nov 2025, Paris (Université Paris Cité), France | Publiée le 26 novembre 2025
Poster de conférence

Resonance-Enhanced Excited-State Intramolecular Proton Transfer Emission by Base-Mediated Formation of α-Cyano-γ-lactone

Théo Andris, Timothée Stoerkler, Gilles Ulrich, Pascal Retailleau, Adèle Laurent, Denis Jacquemin, Julien Massue
Organic Letters, 2025, 27 (48), pp.13240-13245. ⟨10.1021/acs.orglett.5c04134⟩ | Publiée le 24 novembre 2025
Article dans une revue

Abstract

This article describes the synthesis, structural, photophysical and theoretical properties of novel fluorescent dyes derived from 2-(2’-hydroxyphenyl)benzoxazole, functionalized by tricyanofurane or α-cyano-γ-lactone groups, prone to undergo an excit-ed-state intramolecular proton yransfer (ESIPT) process. We serendipi-tously found out that tricyanofurane can induce the formation of the corresponding lactone in basic media, leading to a highly fluorescent derivative, owing to the formation of a merocyanine in the excited-state.

Thioether-NHC Bidentate Manganese Complexes as Efficient Phosphine-Free Catalysts for Hydrogenation at Room Temperature

Jean-Baptiste Sortais, M. Hurzd, Stéphanie Bastin, Vincent Ritleng, Eric Pollet
4th Trans Pyrenean Meeting in Catalysis (TraPCat4), Nov 2025, Barcelone, Spain | Publiée le 20 novembre 2025
Poster de conférence

Unveiling selectivity shift in CO2 methanation with TiO2 supported subnanometer Ru particles

Seema Shafiq, C. Molinet-Chinaglia, Carole Le Berre, V. Collière, Katerina Soulantica, Alex-Cristian Tomut, Romuald Poteau, F.C. Meunier, Guillaume Clet, Walid Baaziz, Ovidiu Ersen, Spiros Zafeiratos, Davide Salusso, Philippe Serp
4th Trans Pyrenean Meeting in Catalysis (TrapCat), Nov 2025, Barcelona, Spain | Publiée le 20 novembre 2025
Communication dans un congrès

Optimisation of ZSM-5 zeolite properties by low valence metal ions for application in MTO catalytic reaction

Senlin Dong
Other. Université de Strasbourg, 2025. English. ⟨NNT : 2025STRAF046⟩ | Publiée le 7 novembre 2025
Thèse

Abstract

This thesis investigates the modification of ZSM-5 zeolites with low-valence metal cations to tune their structure and acidity in the MTO reaction, with the aim of improving light olefin selectivity and catalytic stability. The effects of Li+, Na+, K+, Mg2+, Ca2+ and Cu2+ were evaluated as a function of aluminum content. Li+ enhances structural stability, reduces hydrogen-transfer reactions and improves selectivity, while Na+ increases crystallinity. Among alkaline-earth metals, Mg2+ converts strong acid sites into weaker ones, significantly extending catalyst lifetime. The effect of Ca2+ depends on the Al content, whereas Cu2+ excessively reduces acidity. The study shows that the choice of cation allows fine control of ZSM-5 properties and effective optimization of its MTO performance.

Efficiently doped P3HT and polystyrene blend with porous 3D structure for thermoelectric applications

Souhail Essadiki, Alain Carvalho, Fabrice Vigneron, Guillaume Fleith, Jérôme Combet, Doru Constantin, Nicolas Stein, Laure Biniek
Journal of Materials Chemistry C, 2025, ⟨10.1039/D5TC03145A⟩ | Publiée le 3 novembre 2025
Article dans une revue

Abstract

This study describes a reproducible process for forming highly mesoporous, mechanically robust, and handleable aerogels based on entangled poly(3-hexylthiophene) (P3HT) and syndiotactic polystyrene (sPS) nanofibers for thermoelectric applications. The highly porous structure results in low thermal conductivity, allowing the temperature difference (between the hot and the cold side) to be maintained across the aerogel sample. Porosity also enables dopants to diffuse efficiently within the sample. When using 2,3,5,6-tetrafluoro-7,7,8,8-tetracyano-quinodimethane (F4TCNQ), the highest dopant uptake leads to a maximum apparent electrical conductivity of 2 × 10−2 S cm−1 and a Seebeck coefficient (58 µV K−1) close to the values obtained in thin films. The Seebeck coefficient is not affected by the high porosity of the material. To improve the doping level of the P3HT:sPS aerogels, FeCl3 or a mixture of F4TCNQ:FeCl3 is also used as a dopant. This enhances the power factor (0.2 µW m−1 K−2) without significantly increasing the thermal conductivity (30–40 mW m−1 K−1). Finally, the use of the doped aerogel as a vertical thermoelectric generator with one leg is demonstrated by generating a few tens of nW at a thermal difference of 11 K. This result highlights the potential for integrating these polymer aerogels into wearable thermoelectric generators for powering microelectronics.

Impact of Aryl Extension on the Proton-Triggered Transition Switch in Azaheterocycle-Functionalized ESIPT Fluorophores

Timothée Stoerkler, Théo Andris, Gilles Ulrich, Adèle Laurent, Denis Jacquemin, Julien Massue
Dyes and Pigments, 2025, 242, pp.112975. ⟨10.1016/j.dyepig.2025.112975⟩ | Publiée le 1 novembre 2025
Article dans une revue

Abstract

This article describes the synthesis along with full photophysical characterization in both solution and solid-state of a series of 2-(2'-hydroxyphenyl)benzazole linked to an aza-heterocycle (pyridine or isoquinoline) by one or two aryl rings. The impact of the length of the spacer is investigated in the light of emission wavelength, quantum yield, sensitivity to protons and possibility of transition switch upon protonation. Correlation of first-principle calculations and experimental results help decipher the excited-state dynamics, allowing to draw and discuss hypotheses concerning the nature of the excited species.

Reusable oil-coated hierarchical structures for passive urban particulate matter mitigation: A high-traffic road case study in Strasbourg, France

Tuan-Hoang Trinh, Jean-Mario Nhut, Nicolas Reiminger, Xavier Jurado, Thi-Huong-Ly Nguyen, Fabrice Vigneron, Loïc Vidal, Thierry Romero, Charlotte Pham, Cuong Pham-Huu
Sustainable Cities and Society, 2025, 134, pp.106931. ⟨10.1016/j.scs.2025.106931⟩ | Publiée le 1 novembre 2025
Article dans une revue

Abstract

Traffic-related particulate matter (PM) is a significant public health concern in urban areas. This study evaluates a novel, passive air filtration prototype installed along a high-traffic ring road in Strasbourg, France. The filtration process focuses on a porous polyester fiber matrix coated with a thin layer of vegetable oil. Over a 14-week period, the prototype achieved a total PM capture rate of up to 84 ± 6 g. m−2. Chemical analysis revealed that the majority of trapped particles originated from tire and pavement abrasion, with a minor contribution from metallic particles from the brake system. The filtration performance can be varied with meteorological conditions, which was explained by the use of weather monitoring and interpolation models. Regression models further demonstrated an influence of the oil viscosity on the captured PM quantity. Compared to existing passive air filtration systems, this concept offers a material with a very low-pressure drop, a critical factor for passive performance, enhanced by the coating liquid layer. Furthermore, the system addresses practical deployment challenges through its washability and reusability, significantly reducing waste associated with PM collection after filtration. These findings underscore the potential of this low-maintenance, scalable passive filtration concept for targeted PM exposure reduction near roadways and in sensitive urban settings.

Herbicide Residues in Soil of Former Phosphate Sludge Basins Converted to Agricultural Land in Mboro, Niayes Area, Senegal

Mame Mor Dione, Sitor Diouf, Birame Ndiaye, Ibrahima Diagne, Cheikh Tidiane Dione, Dame Cisse, Maoudo Hane, Seydou Ba, Ousmane Ka, Mamadou Sarr, Maurice Millet, Momar Ndiaye
Journal of Applied Chemical Science International, 2025, 16 (2), pp.241-253. ⟨10.56557/jacsi/2025/v16i29860⟩ | Publiée le 22 octobre 2025
Article dans une revue

Abstract

Herbicides have been widely used in agriculture for many years to control weeds. Triazines are one group of herbicides. Their degradation products are mobile and soluble in water, and can be strongly adsorbed to soil. They are highly toxic and a source of concern in terms of environmental safety. Open-pit mining of the Taïba phosphate mines by Chemical Industries of Senegal (ICS) leaves deep basins on the mined sites. Downstream, these basins serve as storage areas for phosphate washing sludge. This highly fertile farmland is used by over 2,000 local farmers of all kinds. In such a context, it is essential to study the evolution of the behavior and fate of herbicides in the soil of the ponds. In this study, residue levels of three herbicides (atrazine, Terbutryne and Cybutryne) were determined in the soil of four of these ponds (B9, B10, B11 and B17). Extraction was performed using the QuEChERS method. Analyses were carried out by gas chromatography coupled with tandem mass spectrophotometry (GC-MS/MS). Statistical analysis of the results shows an abundance of active substances in the following descending order: Terbutryne ˃ Atrazine ˃ Cybutryne. It also shows that: Terbutryne residue levels range from 2.351 to 83.457 µg.kg-1, with a mean of 32.172±5.777 µg.kg-1 and a median value of 31.681±1.810 µg.kg-1. Atrazine residue levels range from 0.059 to 0.444 µg. kg-1, with a mean value of 0.312±0.082 µg.kg-1 and a median value of 0.318±0.004 µg.kg-1. Cybutryne residue levels range from 0.300 to 0.402 µg.kg-1, with mean and median values of 0.309±0.006 and 0.304±0.002 µg.kg-1 respectively. The presence of these three pesticides in sometimes significant quantities is partly due to the clayey nature of the soil studied. Their behavior depends on agricultural practices in the basins: the timing of herbicide application, soil turning, crop rotation and soil dilution by watering and rain. This study shows soil contamination by unregistered pesticides. The search for these and other more toxic and banned phytosanitary substances in the soils of the entire Niayes area and the market garden produce grown there is therefore essential to protect the environment and ensure the health and food safety of the population.

In Situ Fourier-Transform Infrared Spectroscopy Study of Carbon Monoxide Adsorption on Silver Nanoparticles Contained in BETA Zeolite Nanocrystals

Farah Kawtharani, Sébastien Thomas, Olivier Marie
Langmuir, 2025, 41 (42), pp.28825-28835. ⟨10.1021/acs.langmuir.5c04287⟩ | Publiée le 18 octobre 2025
Article dans une revue

Targeting of amyloid peptide fibers, a biomarker of Alzheimer's disease, by designing specifically functionalized Iron Oxide Nanoparticles

Gabriel Guerrero Porras, Adèle Brison, Anaïs Becker, Stéphane Le Calvé, Marie David, Gilles Ulrich, Valérie Mazan, Marc Schmutz, Alexis Bigo-Simon, Damien Mertz, Céline Kiefer, Alberto Bencomo Martínez, Chryslaine Rodríguez Tanty, Alicia Díaz García, Christelle Hureau, Marquiza Sablón Carrazana, Sylvie Bégin-Colin
ACS Applied Nano Materials, 2025, 8 (43), pp.20822-20834. ⟨10.1021/acsanm.5c03459⟩ | Publiée le 16 octobre 2025
Article dans une revue

Abstract

Alzheimer's disease (AD) is the leading cause of dementia and a major global health issue, affecting over 50 million people worldwide and projected to rise to 139 million by 2050. The disease is marked by senile plaques (SPs) formed from β-amyloid (Aβ) peptides assembling and neurofibrillary tangles made of tau protein. Brain changes in AD begin decades before symptoms, making early diagnosis critical for potential intervention. Currently, definitive diagnosis is postmortem, but imaging methods like PET and MRI are being explored for early detection. MRI, due to its wide accessibility and high resolution, is promising but lacks sensitivity for SPs unless contrast agents (CAs) are used. In that context, we propose to vectorize CAs in order that they allow imaging specifically SPs. Iron oxide nanoparticles (IONPs) are suitable T2 MRI contrast agents due to their biocompatibility and MRI properties and easy functionalization. Indeed, functionalizing these IONPs with targeting ligands specific of senile plaques is very promising to ensure an early diagnosis of Alzheimer disease. Thus, this study focuses on developing a new class of MRI CAs by attaching Amylovis-a compound developed to bind specifically to Aβ peptides-to dendron-coated IONPs. The targeting ligand, Amylovis, was first demonstrated to have high affinity for Aβ in silico even if coupled to dendronized IONPs. Then, dendronized IONPs were synthesized and amylovis was successfully coupled to them: the amount of coupled amylovis was determined as well as the effect of this coupling on colloidal stability and relaxivity measurements of dendronized IONPs. Finally, dendronized IONPs were demonstrated to interact with Aβ-1-40/42 fibers only when they bore the amylovis targeting ligand. The results showed the strong potential for these targeted nanoparticles as novel MRI CAs for early and specific diagnosis of Alzheimer's disease Graphical

Development of AEM Electrolysis as Part of the DAEMONHYC Project: Some Points of Understanding

Garance Cossard, Julie Guehl, José Carlos Martinez Rosales, Xin Shen, Ying Sun, Tristan Asset, Gwénaëlle Kerangueven, Alexandr Oshchepkov, Elena Savinova, Vasilica Badets, Laurent Ruhlmann, Antoine Bonnefont, Eric Sibert, Marian Chatenet, Frédéric Maillard, Linda Chikh, Thi Khanh Ly Nguyen, Nadège Dib, Mohamed Mallouki, Odile Fichet, Jérôme Dillet, Giuseppe Sdanghi, Sophie Didierjean, Feina Xu, Tien Dung Le, Léa Droguet, Rémi Bligny, Nicolas Richet, Arthur Mofakhami, Gaël Maranzana
248th ECS Meeting, The Electrochemical Society, Oct 2025, Chicago (Illinois), United States | Publiée le 12 octobre 2025
Communication dans un congrès

Abstract

As part of the DAEMOHYC project funded by the French government, we are developing alkaline anion exchange membrane electrolysis without platinum group materials, down to the 25cm2 single cell scale. Our consortium comprises five university laboratories and two industrial partners. Our strategy is to explore different ways of shaping materials, from the simplest, cheapest and most robust to the most performing, expensive and complex. For example, for the anode, we began by considering the use of simple activated stainless steel felts, without the use of ionomer [1]. We then textured these felts and decorated them with cobalt spinels. The advantage of this shaping method is the robustness of the resulting electrodes and their good electronic conductivity, compared with electrodes obtained by ink deposition. The disadvantage is their low ionic conductivity, which essentially depends on the KOH concentration within the electrode. We have demonstrated that it is possible to increase the KOH concentration within the electrode thanks to the system architecture (dry cathode operation) and the good management of mass transport (PTL permeability), so as to maintain a pH gradient between the electrode and the feeding channels. Experimental studies combined with modeling work have enabled us to define stability domains for the various materials used, and to deduce optimal system control parameters (temperature, electrolyte pH, pressures, flow rates, clamping stress). In this presentation, we propose to take stock of the various advances made in the DAEMONHYC project in terms of materials, shaping, modeling and testing on the scale of the 25cm2 single cell. The idea is to share some insights that will help those involved in anion exchange membrane electrolysis to define their R&amp;D strategy.

Etude de matériaux pour le développement d’une production de méthanol améliorée par sorption : sorption enhanced reaction process (SERP) CH3OH

François Bihl
Catalyse. Université de Strasbourg, 2025. Français. ⟨NNT : 2025STRAF019⟩ | Publiée le 6 octobre 2025
Thèse

Abstract

Le changement de paradigme lié à l’épuisement des ressources fossiles carbonés et à la nécessité de la transition écologique et énergétique incitent les milieux académiques et industriels à repenser les modes de production de l’industrie chimique. Dans ce cadre, le projet SIMPA a pour objectif de démontrer la faisabilité d’un Sorption-Enhanced Reaction Process (SERP) appliqué à la synthèse de méthanol à partir de syngas. Les travaux présentés dans ce manuscrit portent sur plusieurs volets de cette technologie : d’une part, la synthèse et la caractérisation de catalyseurs à base de Cuivre-Zinc-Alumine (CZA) dopés au Palladium ; d’autre part, une étude cinétique basée sur un catalyseur CZA commercial dans des conditions semblables à celles d’un SERP. En parallèle, différentes zéolithes (13X, 3A et 4A) ainsi que plusieurs MOFs (MIL-118a, MIL-120, MIL-121, CAU-10) sont étudiés en tant que sorbants. L’aboutissement de ces recherches consiste en des expériences de réaction-sorption menées dans des conditions standards, mettant en évidence les gains significatifs apportés par l’intégration de certains sorbants au sein du lit catalytique.

Hydrodesulfurization of thiophene over Ni‐doped MoS 2 ‐supported mesoporous silica

Joël Aguesse, Abdallah Amedlous, Chunzheng Wang, Xavier Portier, Francesco Dalena, Mathias Barreau, Davide Salusso, Spyridon Zafeiratos, Valérie Ruaux, Nicolas Barrier, Svetlana Mintova
ChemCatChem, 2025, 2025, pp.e01253. ⟨10.1002/cctc.202501253⟩ | Publiée le 27 septembre 2025
Article dans une revue

Abstract

The growing demand for ultra‐low sulfur fuels requires the development of advanced hydrodesulfurization catalysts with enhanced activity and selectivity. In this work, we present a one‐pot synthesis of mesoporous SBA‐15‐supported MoS 2 (SBA‐15@MoS 2 ) and Ni‐doped MoS 2 (SBA‐15@Ni‐MoS 2 ) catalysts for the hydrodesulfurization (HDS) of thiophene. Structural and spectroscopic characterization confirmed the formation of few‐layered MoS 2 nanosheets and the successful incorporation of Ni, which modifies the electronic environment and surface acidity of the active sites. CO‐IR spectroscopy revealed a higher density and diversity of catalytically relevant edge sites, particularly S‐edge sites, upon Ni doping. Catalytic performance results demonstrated that the Ni‐doped catalyst (SBA‐15@Ni‐MoS 2 ) significantly outperforms the undoped catalyst (SBA‐15@MoS 2 ), doubling the reaction rate and exhibiting greater selectivity toward paraffinic products via the hydrogenation pathway. These findings highlight the synergistic effect of Ni in enhancing hydrogen activation and promoting the formation of Ni–Mo–S phases, offering a rational approach to the design of HDS catalysts.

Development of new biobased non-isocyanate polyurethanes from lignins : from synthesis towards application

Nathan Wybo
Polymers. Université de Strasbourg, 2025. English. ⟨NNT : 2025STRAE010⟩ | Publiée le 25 septembre 2025
Thèse

Abstract

Polyurethanes (PUs) are a family of versatile and high-performance polymers used in a wide range of applications. Their impact on the environment and human health is significant, with the use of fossil-based synthons and toxic isocyanates in their synthesis. In this context, lignin, one of the main components of wood, has emerged as an attractive source of aromatic structures to provide renewable synthons for PUs. Within a circular bioeconomy approach, and in order to propose a sustainable alternative to conventional PUs, aromatic isocyanate-free polyurethanes (NIPUs) were developed from lignins. Novel chemical modifications of lignins were designed following the principles of green chemistry. Different synthetic routes were explored to obtain NIPUs, leading to innovative crosslinked materials with tunable properties. The end-of-life of these materials was addressed, and both their physical and chemical recyclability were demonstrated. These new approaches show great potential to provide more environmentally friendly materials suitable for a wide range of applications.

Devices for passive trapping of fine particulate matters in outdoor air

Tuan Hoang Trinh
Material chemistry. Université de Strasbourg, 2025. English. ⟨NNT : 2025STRAF022⟩ | Publiée le 22 septembre 2025
Thèse

Abstract

Particulate matter (PM) pollution has become one of the major atmospheric pollution, especially in big cities, where anthropogenic activities are, in most cases, the main PM emission source. As PM is one of the main causes of several respiratory diseases and chronic illnesses, PM reduction might be the priority in air pollution mitigation for both indoor and outdoor air. In this work, a new concept of passive outdoor air filtration was developed and tested. A layer of vegetable oil was coated on a washable and reusable filter structure, which has low pressure drop for favouring air circulation and the contact of air with the fibre. Experimental prototypes in proximity of high traffic city ring roads were successfully deployed and used for testing the long-term effects of PM trapping. The coating layer is certified to have a crucial role in PM captage and retention, and the optimised exposure duration can extend up to 12-14 weeks. With its simple mechanism, the filter device can also be installed on the bicycle for trapping PM while moving. The emphasis of the air filtration device with the natural aerodynamics of the air highlights the benefit of passive filtration with no electricity needed for the filter to function. Influences of weather aleatory and variation on PM captage are also discussed, while analysing weather data for extrapolating and optimising PM filtration. Computational fluid dynamics (CFD) can be used to simulate the procedure, and predict different scenarios of passive outdoor air filter deployment and scale-up.

Enhancing stainless steel activity for the Oxygen Evolution Reaction in Alkaline Electrolyte using Co3O4 spinel deposition

Garance Cossard, José Carlos Martinez Rosales, Gaël Maranzana, Elena Savinova, Antoine Bonnefont, Eric Sibert, Gwénaëlle Kéranguéven, Marian Chatenet
76 th Annual Meeting of the International Society of Electrochemistry (ISE), International Society of Electrochemistry, Sep 2025, Mainz (Mayence), Germany | Publiée le 7 septembre 2025
Communication dans un congrès

Exciton dynamics in planar dumbbell-shaped electron-donor molecules for organic optoelectronics

Jiang Jing, Emilie Steveler, Amira Mounya Gharbi, Sébastien Marbach, Pascal Didier, Gilles Ulrich, Ibrahim Bulut, Nicolas Leclerc, Wilfried Uhring, Jérémie Léonard, Benoît Heinrich, Patrick Lévêque, Thomas Heiser
Journal of Materials Chemistry A, 2025, ⟨10.1039/d5ta06394a⟩ | Publiée le 4 septembre 2025
Article dans une revue

Abstract

Exciton dynamics play a crucial role in determining the efficiency of organic photovoltaic devices and photo-detectors. However, establishing clear correlations between molecular structure and exciton diffusion length remains a significant challenge, limiting the rational design of more efficient materials. In this study, we investigate exciton transport in thin films of a planar dumbbell-shaped electron donor composed of discotic triazatruxene end-groups and an electron-deficient central unit. These molecules self-assemble into unique bridged-columnar structures, which are known to support efficient charge transport, although their impact on exciton dynamics had not yet been explored. Using a combination of time-resolved photoluminescence (TRPL), spatially resolved TRPL, and exciton–exciton annihilation measurements, we examine how structural order influences exciton diffusion in both the columnar-nematic and crystalline phases. We show that crystallization leads to a twofold increase in exciton diffusion length, reaching values comparable to those observed in state-of-the-art non-fullerene acceptors. Although the molecules exhibit a typical Stokes shift that is not particularly favorable for Förster energy transfer (FRET), efficient exciton transport is nonetheless achieved—enabled by long exciton lifetimes and anisotropic energy transfer within its distinctive bridged-columnar architecture. These results, supported by FRET analysis, highlight the effectiveness of the molecule's tailored dumbbell-shaped design and its ability to self-assemble into ordered structures that support both long-range exciton diffusion and efficient charge mobility.

Éliminer les hydrocarbures aromatiques polycycliques (HAP) de l’environnement :

Joana Vaz-Ramos, Stéphane Le Calvé, Sylvie Bégin
L'Actualité Chimique, 2025, 506, pp.39-45. ⟨10.63133/scf.act-chim.2025.506.04⟩ | Publiée le 1 septembre 2025
Article dans une revue

Abstract

Les hydrocarbures aromatiques polycycliques (HAP) sont des polluants persistants très répandus qui présentent des risques importants pour la santé. Il est essentiel de surveiller leur présence et de les éliminer de l'environnement. La présence de HAP a été confirmée dans l'air à Strasbourg par une campagne de mesures et des nanomatériaux composites à base de graphène/acide tannique/oxyde de fer ont été développés pour adsorber ces hydrocarbures. Le potentiel de dépollution des nanomatériaux développés a été évalué lors d'expériences d'adsorption et des efficacités d'élimination supérieures à 99 % ont été obtenues pour l'adsorption du benzo(a)pyrène (BaP), l'un des HAP les plus cancérigènes. En outre, une sélectivité d'adsorption pour les composés polyaromatiques a été mise en évidence alors que les espèces monoaromatiques étaient peu piégées. Ces expériences d'adsorption ont ainsi confirmé le potentiel de ces nanomatériaux pour des applications environnementales. De plus, leur caractère magnétique permet une récupération facile de l'adsorbant, qui peut ensuite être régénéré par extraction par solvant ou désorption thermique.

Investigation of potential biases in the comparison of membrane and conventional reactors in CO2 to methanol processes using process optimization

Vincent Gautier, Luc Bertier, Vincent Lacroix, Albin Chaise, Audrey Hertz, Anne-Cécile Roger
Journal of Cleaner Production, 2025, 523, pp.146394. ⟨10.1016/j.jclepro.2025.146394⟩ | Publiée le 1 septembre 2025
Article dans une revue

Abstract

Membrane reactors applied to methanol synthesis from CO2 aim to alleviate low reaction conversions by shifting the thermodynamic equilibrium through in-situ water removal. The comparison between membrane reactors and conventional fixed-bed reactors has been previously studied in the literature at the process level. In fact, in the literature, membrane and conventional fixed-bed reactors have been so far compared under identical operating conditions at the process scale. However, studies at the reactor scale have identified that these types of reactors might have different optimal operating conditions. Therefore, potential biases in previous process simulation studies are investigated in the present article through process optimization using an energy cost criterion. This study uses design-free pseudo-homogeneous isothermal and isobaric plugflow reactor models allowing the use of simplified and broad optimization variables. As a result, the optimal operating conditions for the membrane reactor process were found to depend significantly on the reactor’s GHSV and the membrane’s selectivity, and these conditions can differ greatly from those of a conventional fixed-bed reactor process. As such, comparing the two reactor types under the same operating conditions at the process level can lead to a bias favoring one reactor type depending on the chosen conditions. This study also explores the advantages of using compressed sweep gas and compares the performance of the two reactor types when varying levels of energy penalties are applied to high recycle ratios through the purge rate.

Densification-Related Optical and Photodetection Properties of Green-Synthesized MAPbI₃ and MAPbI₃@Graphite Powders

Yihui Cai, Azhar Ali Ayaz Pirzado, Dominique Begin, Cedric Leuvrey, Saraf Khan, Thomas Fix, Richard D Schaller, Clément Sanchez, Sylvie Begin-Colin
ACS Omega, 2025, 10, pp.38540 - 38554. ⟨10.1021/acsomega.5c02836⟩ | Publiée le 19 août 2025
Article dans une revue

Abstract

For photodetection applications using 3D hybrid perovskites (HPs), dense and thick films or compacted powders in wafer form are needed and generally require large amounts of HPs. HPs are also often combined with a graphene/carbon layer to improve their conductivity. Among HP synthesis methods, mechanosynthesis, a green synthesis method, provides a large amount of powders, which are furthermore easily densified in compact wafers due to their mechanical activation. Thus, methylammonium lead iodide (MAPI) and MAPI with 3 and 5 wt % graphite powders were synthesized, densified by uniaxial compaction, and their photoluminescent (PL) and photodetection properties were studied. MAPI wafers compacted under 100 and 500 MPa showed a PL blue shift compared to the MAPI powder, and photodetection measurements indicated that composite wafers exhibited an enhanced photoresponse with improved photocurrent generation due to the addition of graphite. However, they exhibited weaker photoswitching (on/off) sensitivity with high detected currents in comparison to the MAPI wafer. Such unexpected photodetection behavior with composite wafers were explained by characterizing their microstructural and optical properties. Microstructural characterizations showed no grain coalescence in all MAPI and composite wafers compacted at 100 MPa, but a preferential crystallographic orientation along the {002} plane was detected. Additionally, an unusual graphite segregation near the wafer surface was noticed in composite wafers, questioning the effect of graphite in photodetection performance. Furthermore, all optical measurements evidenced lattice distortions and a decrease of the PL reabsorption phenomenon as a function of the densification pressure, in agreement with the observation of a higher population of photoexcited charge carriers in MAPI compacted at 500 MPa, as observed in transient absorption spectroscopy. These findings demonstrate that green-synthesized MAPI and graphite composites can be easily shaped into dense wafers through simple low-pressure compaction and emphasize the importance of microstructural and optical characterizations to fully understand the resulting properties.

Filtration systems for particulate matter reduction in outdoor air: a review

Tuan-Hoang Trinh, Charlotte Pham, Nicolas Reiminger, Jean-Mario Nhut, Cuong Pham-Huu
Journal of Environmental Management, 2025, 390, pp.126263. ⟨10.1016/j.jenvman.2025.126263⟩ | Publiée le 1 août 2025
Article dans une revue

Abstract

Outdoor particulate matter (PM) pollution poses a critical socio-economic and public health challenge worldwide. This review systematically evaluates over 250 studies on PM sources, health impacts, and outdoor filtration strategies, with a focus on both active and passive approaches. Our objectives were to (i) categorize major PM emission sources: transport, industry/construction, agriculture, and natural sources; (ii) assess the performance and operating costs also possibility of recycling, regeneration of leading active outdoor filtration systems (e.g., SMOG Free Tower, Mann + Hummel filter cube, electrostatic filters, etc.); (iii) examine passive methods such as urban green walls, passive outdoor filters, passive house air regulation. In the current trending, numerical modeling (CFD) emerges as indispensable for optimizing large-scale deployment, with the possibility of integration with artificial intelligent to predict the outcome results. We conclude that integrating targeted active units with passive methods offers a great cost-effective benefice for PM mitigation plan, potentially applicable in the same time for short- and long-term strategies in urban management.

Complex interactions between the gut microbiota, pesticide contamination and physiological traits in grey partridges

Léa Bariod, Joël White, Maurice Millet, Jérôme Moreau, Karine Monceau
2025 | Publiée le 18 juillet 2025
Pré-publication, Document de travail

Abstract

The intensification of agriculture in recent years, particularly through the massive use of pesticides and fertilizers, has caused a decline in biodiversity, specifically among farmland birds. Emerging research highlights the adverse effects of chronic and low-dose pesticide exposure, particularly on the gut microbiota, which is essential for host metabolism and immune health. Understanding how pesticides disrupt microbial diversity and physiological traits is thus critical to inform management and conservation strategies. This study examines the impact of pesticide contamination on the gut microbiota composition and physiological responses of captive-bred male grey partridges, a threatened species frequently exposed to pesticide cocktail residues through their habitat and diet. We detected residues of 27 pesticide molecules in the birds' blood, including fungicides, herbicides, and insecticides. Among the different microbial diversity metrics analysed, only bacterial richness was significantly affected by the interaction between pesticide load and body condition, with contrasting effects observed across different body condition groups. Furthermore, higher microbial diversity was positively associated with hematocrit levels, suggesting that microbial diversity may be related to the physiological health of birds. These findings highlight the complex relationship between pesticide exposure, gut microbiota, and host physiology, emphasizing the need for further research to understand these interactions in wildlife health.

Characterization and modeling of the performance and durability of praseodymium oxide infiltrated oxygen electrodes

Gaurav Tambade, Maxime Hubert, Vincent Guigoz, Katherine Develos-Bagarinao, Spiros Zafeiratos, Laura Guesnet, Davide Cademartori, Cintia Hartmann, Marie Petitjean, Jean-Marc. Bassat, Julien Vulliet, Jérôme Laurencin
19th International Symposium on Solid Oxide Fuel Cells - SOFC-XIX, The Electrochemical Society, Jul 2025, Stockholm, Sweden. pp.213, ⟨10.1149/MA2025-031213mtgabs⟩ | Publiée le 13 juillet 2025
Communication dans un congrès

Self-Decontaminating Photocatalytic Textiles: Layer-by-Layer Deposition of Commercial TiO 2 References for DMMP Degradation

Maël Morguen, Alain Rach, Christophe Colbeau-Justin, Didier Robert, Valérie Keller
ACS Applied Engineering Materials, 2025, 3 (7), pp.1995-2006. ⟨10.1021/acsaenm.5c00200⟩ | Publiée le 3 juillet 2025
Article dans une revue

Abstract

<div><p>Protection against chemical warfare agents (CWA) needs to be improved, and the addition of self-decontaminating properties to passive protective clothes is a promising tool to avoid (cross-)contamination issues. The purpose of this work was to investigate the layer-by-layer (LbL) deposition of photocatalytically active TiO 2 nanoparticles over textiles for providing additional organophosphorus degradation properties. Here, it is shown how to control the homogeneous and efficient coverage of textile fibers by finding the optimal conditions of the LbL deposition parameters. Then, various commercial TiO 2 references (P25, P90, UV100, PC500, Anatase nanopowder, and Rutile nanopowder from Sigma) differing in their structural, surface, and morphological properties were examined. The resulting functionalized textiles were assessed and compared toward dimethyl methylphosphonate droplets (DMMP, used as an analogue for neurotoxic CWA) photocatalytic degradation under artificial UV irradiation. Preparation/structure/activity correlation of the resulting functionalized textiles highlighted the crucial impact of (i) the surface charges and particle size of TiO 2 in the precursor suspension during LbL deposition and (ii) the charge carrier generation and dynamics under UV-A activation (studied by time-resolved microwave conductivity measurements). Finally, we investigated the mechanisms of DMMP degradation over TiO 2functionalized textiles through DMMP elimination kinetics monitoring and X-ray photoelectron spectroscopy and FTIR studies.</p></div>

N‐Aryl or N‐Alkyl Pyridinium‐Substituted Excited‐State Intramolecular Proton Transfer Fluorophores

Timothée Stoerkler, Gilles Ulrich, Adèle Laurent, Denis Jacquemin, Julien Massue
ChemPlusChem, 2025, 90 (7), ⟨10.1002/cplu.202500138⟩ | Publiée le 1 juillet 2025
Article dans une revue

Abstract

In this article, we describe the synthesis of a series of fluorophores consisting of N-alkyl or N-aryl pyridinium groups connected at different positions of a 2-(2'-hydroxyphenyl)benzoxazole (HBO) scaffold and the exploration of the photophysical properties in solution (dichloromethane) and in the solid-state, as amorphous powders. All dyes display a bathochromically shifted fluorescent transition from an excited keto state, formed after ESIPT process. A full chemical engineering study was performed by changing the nature of the substitution at the pyridinium site (alkyl or aryl), the position of the pyridinium substitution and the nature of the counterion (6 examples). The nature of the radiative transitions observed in these fluorescent dyes was confirmed by TD-DFT calculations.

Alternative Supports for Electrocatalysis of the Oxygen Evolution Reaction in Alkaline Media

Gwénaëlle Kéranguéven, Ivan Filimonenkov, Thierry Dintzer, Matthieu Picher
Electrochem, 2025, 6 (3), pp.23. ⟨10.3390/electrochem6030023⟩ | Publiée le 25 juin 2025
Article dans une revue

Abstract

The anodic stability of tungsten carbide (WC) and iron oxide with a spinel structure (Fe3O4) were compared against similar data for nanostructured, boron-doped diamond (BDD), and the benchmark Vulcan XC72 carbon, in view of their eventual application as alternative supports for the anion exchange membrane electrolyzer anode. To this end, metal oxide composites were prepared by the in situ autocombustion (ISAC) method, and the anodic behavior of materials (composites as well as supports alone) was investigated in 1 M NaOH electrolyte by the rotating ring–disc electrode method, which enables the separation oxygen evolution reaction and materials’ degradation currents. Among all supports, BDD has proven to be the most stable, while Vulcan XC72 is the least stable under the anodic polarization, with Fe3O4 and WC demonstrating intermediate behavior. The Co3O4-BDD, -Fe3O4, -WC, and -Vulcan composites prepared by the ISAC method were then tested as catalysts of the oxygen evolution reaction. The Co3O4-BDD and Co3O4-Fe3O4 composites appear to be competitive electrocatalysts for the OER in alkaline medium, showing activity comparable to the literature and higher support stability towards oxidation, either in cyclic voltammetry or chronoamperometry stability tests. On the contrary, WC- and Vulcan-based composites are prone to degradation.

Over Tenfold Increase in Current Amplification Due to Anisotropic Polymer Chain Alignment in Organic Electrochemical Transistors

Olivier Bardagot, Pablo Durand, Shubhradip Guchait, Han‐yan Wu, Isabelle Heinzen, Wissal Errafi, Victor Bouylout, Alessandra Pistillo, Chi‐yuan Yang, Gonzague Rebetez, Priscila Cavassin, Badr Jismy, Julien Réhault, Simone Fabiano, Martin Brinkmann, Nicolas Leclerc, Natalie Banerji
Advanced Materials, 2025, 37 (32), pp.2420323. ⟨10.1002/adma.202420323⟩ | Publiée le 2 juin 2025
Article dans une revue

Abstract

Organic electrochemical transistors (OECTs) are central to the development of highly sensitive (bio)sensors, energy‐efficient neuromorphic devices, and high‐precision electrophysiological monitoring systems. With growing interest in these strategic electronic devices, a novel PBTTT polymer bearing single‐ether side chains ( PBTTT‐⁸O) in OECTs is investigated. Pristine isotropic non‐aligned OECT performance matches state‐of‐the‐art transconductance, highlighting the potential of single ethers for designing high‐performance organic mixed ionic‐electronic conductors (OMIECs). Moreover, a 13× enhancement of current output is achieved by anisotropic polymer chain alignment of PBTTT‐⁸O , opening doors to unprecedented device sensitivity. Compared to pristine ones, aligned OECTs afford a 6× increase in the normalized transconductance (g m L/Wd), reaching an unprecedented 2 580 S cm^-1. Such improvement is mainly due to a gain in carrier mobility µ, as evidenced by four distinct methods. In addition, aligned OECTs exhibit faster doping front propagation, ON switching, and OFF switching compared to pristine ones. This study hence reports a versatile and easily transferable approach to concomitantly boost signal amplification and accelerate the response time of bioelectronic devices.

Ti-LaFeO₃ perovskite for enhanced tetracycline degradation and disinfection via photo-Fenton reactions: Performance and mechanistic insights

Niloofar Arabbaseri, Jorge Rodríguez-Chueca, Mahsa Moradi, Fernando Fresno, Pilar García-Armada, Nicolas Keller, Patricia García-Muñoz
Journal of Water Process Engineering, 2025, 75, pp.108026. ⟨10.1016/j.jwpe.2025.108026⟩ | Publiée le 1 juin 2025
Article dans une revue

Enhanced Electromagnetic Wave Absorption in Mapbi₃ Hybrid Perovskite Through a Defect‐Tunable Green Synthesis

Yihui Cai, Dominique Bégin, Christophe Lefevre, Charles Sidhoum, Erik Elkaïm, Pascal Boulet, Pierre Desgardin, Marie-France Barthe, Ricardo Helm, Werner Egger, Maik Butterling, Andreas Wagner, Vasiliki Papaefthimiou, Spiros Zafeiratos, Damien Cianferani, Loic Mager, Ovidiu Ersen, Catherine Corbel, Clément Sanchez, Sylvie Bégin-Colin
Small Structures, 2025, 6 (9), pp.2500066. ⟨10.1002/sstr.202500066⟩ | Publiée le 21 mai 2025
Article dans une revue

Abstract

Defect engineering and structure‐property relationship understanding in methylammonium lead iodide (MAPI) hybrid perovskites (HPs) attract significant scientific interest, as synthesis‐related defects may strongly influence intrinsic properties. We have explored a green solvent‐free synthesis—mechanosynthesis—leading to large quantities of MAPI powder with tuneable defect density suitable to study MAPI as an electromagnetic wave absorbing (EMWA) material. A dielectric loss enhancement was revealed at 11.4 GHz (X‐band) for 4 h‐ground MAPI powders (MAPI4h), compared to 30 min‐ground powders (MAPI30) when the particle size was &lt;20 μm. MAPI powders display a fractal microstructure with agglomerates of clusters of (nano)grains (≈80 nm for MAPI4h), consisting further of oriented smaller nanograin (5–10 nm) clusters. A strong reabsorption in smaller particles was evidenced due to a surface‐defective layer. MAPI4h was shown to display a more surface‐defective layer with a higher defect density gradient from surface to (nano)grains core and unique open defects different from those in solution‐processed MAPI. These vacancy‐type surface defects would enhance dipole polarization by stabilizing methylammonium dipoles, thereby increasing permittivity. The improved dispersion of MAPI particles (&lt;20 μm) in polymeric matrixes enhanced the surface effects and effective interactions with electromagnetic waves. This study demonstrated the potential of this green synthesis for producing large amount of HPs and tuning defects, opening new avenues for HPs EMWA application.

Metaproteomics as a Powerful Tool for an Extensive Characterization of Ambient Bioaerosols

Mathieu Galmiche, Lauriane Kuhn, Maurice Millet, Yannis-Nicolas François
Journal of Proteome Research, 2025, ⟨10.1021/acs.jproteome.4c00936⟩ | Publiée le 21 mai 2025
Article dans une revue

Stabilization of Fe-N4 sites by platinum during oxygen reduction reaction in acid medium

Nicolas Ishiki, Keyla Teixeira Santos, Nicolas Bibent, Kavita Kumar, Ina Reichmann, Yu-Ping Ku, Tristan Asset, Laetitia Dubau, Michel Mermoux, Hongxin Ge, Sandrine Berthon-Fabry, Tzonka Mineva, Hazar Guesmi, Viktoriia Saveleva, Vinod Paidi, Pieter Glatzel, Andrea Zitolo, Serhiy Cherevko, Edson Antonio Ticianelli, Frédéric Maillard, Frederic Jaouen
247th ECS Meeting, The Electrochemical Society, May 2025, Montréal (Québec), Canada. pp.2653-2653, ⟨10.1149/MA2025-01552653mtgabs⟩ | Publiée le 18 mai 2025
Communication dans un congrès

Abstract

The deployment of proton-exchange-membrane fuel cells is hindered by the large amount of Pt required for anode and cathode electrocatalysis. While Fe–N–C materials have shown promising initial oxygen reduction reaction (ORR) activity, they lack durability. Key degradation mechanisms include direct demetallation of Fe-N 4 sites and indirect deactivation caused by reactive oxygen species. Enhanced durability of Fe–N–C materials can be achieved by interfacing them with a low amount of Pt nanoparticles (NPs) or even Pt single atoms. 1-2 The original idea was to lean on the known activity of bulk Pt and Pt NPs towards H 2 O 2 electroreduction. However, different Pt and Fe active sites can emerge in the current process for preparing Pt/Fe-N-C hybrid materials due to a relatively high-temperature step needed to reduce the Pt salt, leading to the transformation of some Fe-N 4 sites into Pt@FeO x core-shell structures, etc. The presentation will show that it is possible to add controlled amounts of Pt NPs (0.25-2.0 wt. %) via a soft polyol method, resulting in unmodified Fe coordination, well-defined Pt structures and stable Pt/Fe–N–C hybrids. The approach is first validated for various mainstream Fe–N–Cs, including ZIF-8-derived Fe-N-C, aerogel derived Fe-N-C and silica-templated Fe-N-C. With operando techniques, we demonstrate that the Pt addition nearly suppresses H 2 O 2 production during ORR and strongly reduces the Fe leaching rate during ORR, while post mortem Mössbauer spectroscopy reveals that the highly active but unstable Fe(III)N 4 site is partially stabilized. The similar H 2 O 2 electroreduction activity of Pt/Fe–N–C and Fe–N–C and other analyses point toward a long-distance electronic effect of Pt NPs in stabilizing FeN 4 sites. This key stability property of Fe-N 4 sites during ORR brought by a low amount of Pt is experimentally elusive to understand. Possible synergistic effects between Pt and Fe-N 4 sites were further studied with density functional theory and a proposed mechanism will be presented that could explain the experimental observations. Fig. 1 . Characterization of catalysts in PEMFC or in gas diffusion electrode (GDE) setup. a) Chronoamperometry at U = 0.5 V, b) Online ICP-MS results conducted in a GDE setup in O 2 -saturated 0.1 M HClO 4 electrolyte, the Fe dissolution rates of Fe–N–C Aero and Pt/Fe–N–C Aero were normalized to catalyst loading during an accelerated stress test (AST) consisting of 200 square cycles of 3.2 s at -49.7 mA·cm -2 and 2.1 s at -0.1 mA·cm -2 . The aerogel-derived Fe-N-C catalyst (Fe-N-C Aero ) has an Fe content of 1.25 wt. %, and 1 wt. % Pt NPs was deposited onto it to form the Pt/Fe-N-C Aero hybrid. References: Mechler, A. K.; Sahraie, N. R.; Armel, V.; Zitolo, A.; Sougrati, M. T.; Schwämmlein, J. N.; Jones, D. J. ; Jaouen, F.; Electrochem. Soc. 2018 , 165, F1084. Bae, G.; Kim, M. M.; Han, M. H.; Cho, J.; Sougrati, M-T.; Kim, J.; Lee, K-S.; Joo, S. H.; Goddard, W. A.; Oh, H-S.; Kim, H.; Jaouen, F.; Choi, C. H.; Nature Catal. 2023 , 6, 1140-1150. Figure 1

Improved Activity and Durability of Carbon-Capped Pd and PdNi Catalysts─From Model Active Layers to Anion-Exchange Membrane Fuel Cell Electrodes

Ricardo Sgarbi, Huong Doan, Simon Amigues, Nicolas Bibent, Vincent Martin, Viktoriia Zemtsova, Frédéric Jaouen, Julien Thuilliez, Marian Chatenet
ACS Catalysis, 2025, 15 (11), pp.9379-9392. ⟨10.1021/acscatal.5c00704⟩ | Publiée le 16 mai 2025
Article dans une revue

Versatile Direct (Hetero)Arylation Polymerization of Electro‐Deficient Unsubstituted Thiazolo[5,4‐d]Thiazole: A Tool to Lower the LUMO Level

Badr Jismy, Pablo Durand, Jasmine P Jacob, Fanny Richard, Olivier Boyron, Benoit Heinrich, Bruno Schmaltz, Patrick Lévêque, Olivier Bardagot, Nicolas Leclerc
Macromolecular Rapid Communications, 2025, 46 (16), pp.2500243. ⟨10.1002/marc.202500243⟩ | Publiée le 13 mai 2025
Article dans une revue

Abstract

A series of novel conjugated semiconducting polymers based on the unsubstituted thiazolo[5,4-d]thiazole (TzTz) unit is synthesized using atom-economic and environmentally friendly direct (hetero)arylation polymerization (DHAP). The versatility of the proposed polymerization conditions, employing a non-chlorinated and moderately toxic solvent and cooperative palladium/copper bimetallic catalytic system, is demonstrated through the use of seven comonomers with varying electron-withdrawing strength: 2,2′-bithiophene (BT), 6,7-difluoroquinoxaline (Qx), thieno[3,4-c]pyrrole-4,6(5H)-dione (TPD), 5,6-difluorobenzo[c][1,2,5]thiadiazole (BTD), isoindigo (IID), para-azaquinodimethane (AQM) and 2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione (DPP). The resulting TzTz-based copolymers exhibit optical bandgaps between 1.5 and 2.0 eV with HOMO/LUMO energy levels spanning from -5.2/-3.3 eV to -5.4/-3.9 eV. They all show satisfactory thermal stability for electronic applications (Td = 300-360 °C). Notably, TzTz-based copolymers are observed they generally exhibit improved backbone planarity and deeper LUMO levels than their thiophene derivatives. A synthesis tool to finely lower the LUMO levels of next-generation A-A' copolymers in view of increasing the performance and air-stability of doped organic electronics is believed to be provided by this work.

Hydrogenation of esters and alkenes promoted by bidentate NHC-based manganese catalysts

Romane Pointis, Mariia Hruzd, Stéphanie Bastin, Vincent Ritleng, Eric Pollet, Jean-Baptiste Sortais
International Symposium on Green Chemistry (ISGC), May 2025, La Rochelle, France | Publiée le 12 mai 2025
Communication dans un congrès

Bilayer Electrospun Polyurethane Membrane With Tunable Elastomeric Properties for the Treatment of Congenital Diaphragmatic Hernia

Rodolphe Migneret, Guillaume Leks, Julie Favre, Emeline Lobry, Hamdi Jmal, Guy Schlatter, Isabelle Talon, Isabelle Talon, Nadia Bahlouli, Anne Hébraud
Journal of Biomedical Materials Research Part A, 2025, 113 (5), ⟨10.1002/jbm.a.37926⟩ | Publiée le 11 mai 2025
Article dans une revue

Abstract

Congenital diaphragmatic hernia is a rare condition characterized by the development of a defect in the diaphragm during early embryogenesis. For the most severe cases, when the diaphragmatic defect is large, the gap is currently closed by a prosthetic patch made of e‐PTFE (Gore‐Tex) materials, which lack sufficient elasticity, causing early rupture of stitches and subsequent hernia recurrence. In this study, we introduce a novel thermoplastic polyurethane membrane designed to accommodate the child's growth. This film/fiber bilayer membrane, produced in a single continuous electrospinning process by varying the flow rate, exhibits a smooth surface to prevent adhesion of the tissues on the abdominal side and a rough surface to promote adhesion of the diaphragm muscle on the thoracic side. Mechanical properties of the membrane were evaluated under various deformation modes, including uniaxial tensile tests and equibiaxial tensile tests by the bubble inflation technique. We demonstrated the ability to tune the elastic modulus by adjusting the thickness of the film and fibers, achieving greater stretchability than specified for supporting child growth and respiration both in uniaxial and inflation tests. Moreover, in vitro biological tests showed that the membrane promotes cellular colonization without pro‐inflammatory effect, making it a promising candidate to replace the currently used prosthesis.

Effect of Au nanoparticle size on the Au/TiO₂-catalyzed plasmon-induced reduction of CO₂ with water

Leila Hammoud, Justine Quinet, Katia Fajerwerg, Vincent Bley, Valérie Caps, Christian Lorber, Pierre Fau
Gold 2025, May 2025, San Sabastian, Spain | Publiée le 11 mai 2025
Poster de conférence

Sustainable energy cycles based on liquid oxygenates as carbon-neutral hydrogen carriers: A holistic vision

James Highfield, Agnieszka Ruppert, Nicolas Keller
Catalysis Today, 2025, 451, pp.115207. ⟨10.1016/j.cattod.2025.115207⟩ | Publiée le 1 mai 2025
Article dans une revue

Abstract

Simple energy-dense liquid oxygenates obtained directly from biomass e.g., fermentation ethanol, or “solar methanol”, synthesised from renewable hydrogen (via PV-driven water electrolysis) and recycled carbon dioxide, could provide the basis of an energy cycle that is climate-neutral and promotes long-term sustainability in industrial chemical processing. The development of new earth-abundant heterogeneous (photo-)catalysts and associated reaction engineering promoting hydrogen release (by steam-reforming) and insertion (by CO2 hydro-deoxygenation) under mild conditions will be pivotal to its success. This review anticipates the key methodologies involved in future bio-refineries and forecasts the increasing role therein of modular and portable low-power solar concentrators as renewable (photonic and thermal) resources. The techno-economic prospects for oxygenates like acetaldehyde, ethylene glycol, and glycerol, are also considered based on their reactivity (C2) and/or a pre-existent supply glut in need of valorisation (C3). Many examples highlighting the growing importance of computational (DFT and microkinetic) modelling in catalyst development are presented.

Development of a transportable High-Performance Liquid Chromatograph with Ultraviolet detection and a method for the rapid analysis of 13 carbonyl compounds hydrazones

Audrey Grandjean, Anaïs Becker, Mathilde Mascles, Franck Amiet, Jean-Philippe Amiet, Damien Bazin, Stéphane Le Calvé
Journal of Chromatography Open, 2025, 7, pp.100201. ⟨10.1016/j.jcoa.2024.100201⟩ | Publiée le 1 mai 2025
Article dans une revue

Abstract

In environments with elevated air pollution, highly reactive aldehydes pose significant health concerns. This study proposes a simultaneous analysis of 13 carbonyl compounds, according to the ISO 16,000–3 reference method, adapted for a novel transportable High-Performance Liquid Chromatograph (HPLC) system. The transportable HPLC system consists of a reinforced analytical suitcase and a computer suitcase, each equipped with spring systems to fortify them against impact. The system features a straightforward isocratic pump, ensuring reliability and ease of operation, while sample delivery is managed by a piston pump coupled to a multiplexing valve. Derived carbonyl compounds with 2,4-dinitrophenylhydrazine were separated in isocratic mode using water and acetonitrile with a reverse-phase column in less than 20 min. Out of the 13 hydrazones, only 2-butanone-2,4-DNPH (BO-DNPH) and butanal-2,4-DNPH (BA-DNPH) were fully coeluted, and separation of the other critical pairs containing 3 and 4 carbons was achieved. The method was applied to the transportable HPLC equipped with a UV or light-emitting diode (LED) detector. These results were compared with the ones obtained on two benchtop laboratory HPLCs equipped with a diode array detector (DAD). The limit of detection (LOD) for the hydrazones of the carbonyl compounds ranged from 0.12 to 0.38 mg L–1 with the UV detector and 0.45 to 1.04 mg L–1 with the LED detector. Precision was determined from consecutive injections of the analytes to yield RSD&lt;11.5% (UV) and RSD&lt;14.1% (LED). Performances were close to that of the laboratory HPLCs, either in sensitivity, resolution, or repeatability with overall more accurate and robust results with the UV than with the LED detector. Despite the LED system not fully meeting the standard method requirements with linearities correlation coefficients lower than 0.999, both systems and methods were validated for the isocratic analysis of hydrazones for aldehydes and ketones quantification. An additional comparison was made with the literature regarding both the isocratic method developed and the transportable system.

Synthesis and Characterization of Ni-Doped Iron Oxide/GO Nanoparticles by Co-Precipitation Method for Electrocatalytic Oxygen Reduction Reaction in Microbial Fuel Cells

Sandra Benito-Santiago, Brigitte Vigolo, Jaafar Ghanbaja, Dominique Bégin, Sathish-Kumar Kamaraj, Felipe Caballero-Briones
Ceramics, 2025, 8 (2), pp.40. ⟨10.3390/ceramics8020040⟩ | Publiée le 21 avril 2025
Article dans une revue

Abstract

Nickel-doped iron oxide/graphene oxide powders were synthesized by the co-precipitation method varying the Ni/Fe ratio, and the activity of the materials towards the oxygen reduction reaction in a microbial fuel cell (MFC) was studied. The samples presented X-ray diffraction peaks associated with magnetite, maghemite and Ni ferrite, as well as evidence of hematite. Raman spectra confirmed the presence of maghemite (γ-Fe2O3) and NiFe2O4. Scanning electron micrographs showed exfoliated sheets decorated with nanoparticles, and transmission electron micrographs showed spherical nanoparticles about 10 nm in diameter well distributed on the individual graphene sheet. The electrocatalytic activity for the oxygen reduction reaction (ORR) was studied by cyclic voltammetry in an air-saturated electrolyte, finding that the best catalyst was the sample with a 1:2 Ni/Fe ratio, using a catalyst concentration of 15 mg·cm−2 on graphite felt. The 1:2 Ni/Fe catalyst provided an oxygen reduction potential of 397 mV and a maximum oxygen reduction current of −0.13 mA; for comparison, an electrode prepared with GO/γ-Fe2O3 showed a maximum ORR of 369 mV and a maximum current of −0.03 mA. Microbial fuel cells with a vertical proton membrane were prepared with Ni-doped Fe3O4 and Fe3O4/graphene oxide and tested for 24 h; they reached a stable OCV of +400 mV and +300 mV OCV, and an efficiency of 508 mW·m−2 and 139 mW·m−2, respectively. The better performance of Ni-doped material was attributed to the combined presence of catalytic activity between γ-Fe2O3 and NiFe2O4, coupled with lower wettability, which led to better dispersion onto the electrode.

Cyclodextrin-based formulations for delivering broad-spectrum nerve agent antidote to the central nervous system: stability, physicochemical characterization and application in a human blood–brain barrier model

Léa Thiberville, Vincent Faivre, Christina Sizun, Marie-Pierre Dehouck, Christophe Landry, Rachid Baati, Nicolas Tsapis
International Journal of Pharmaceutics, 2025, 674, pp.125505. ⟨10.1016/j.ijpharm.2025.125505⟩ | Publiée le 15 avril 2025
Article dans une revue

Abstract

<div><p>Nerve agents, such as VX and sarin, represent a significant threat to global security due to their devastating neurotoxic effects and potential for misuse. The therapeutic inefficacy of current countermeasures underscores the urgent need for more effective alternatives. In this context, recent advances have identified JDS364.HCl, an uncharged hybrid antidote, as a promising candidate. However, its instability in aqueous solution remains a significant challenge. To address this, cyclodextrin-based formulations were developed using two EMA-approved cyclodextrins: HP-β-CD and SBE-β-CD. These formulations significantly improved JDS364.HCl stability for over two months at room temperature. Interaction studies revealed a 1:1 stoichiometry for both cyclodextrin complexes, with JDS364.HCl: SBE-β-CD exhibiting a 100-fold higher affinity constant, attributed to additional electrostatic interactions with SBE-β-CD sidechains. While SBE-β-CD provided superior plasma stability compared to HP-β-CD, the high binding affinity of JDS364.HCl: SBE-β-CD complexes hindered the molecule's release and reduced its ability to cross the BBB, as observed in a human BBB model. Nonetheless, the results for both cyclodextrins are encouraging, as they enhance JDS364.HCl's stability in plasma while allowing its passage across the BBB. Notably, JDS364.HCl demonstrated superior BBB permeability compared to marketed antidotes such as 2-PAM. These findings highlight the potential of cyclodextrins to improve the efficacy of JDS364.HCl as a nerve agent antidote.</p></div>

Improvement of semiconducting and thermomechanical properties of polymer materials based on polypyrrole and polyvinylpyrrolidone

Khaled Zeggagh, Sad Atia, Mohamed Trari, Thierry Dintzer, Christophe Mélart, Patrick Lévêque, Olivier Bardagot, Zitouni Benabdelghani
Journal of Materials Science, 2025, 60 (15), pp.6565-6580. ⟨10.1007/s10853-025-10819-4⟩ | Publiée le 13 avril 2025
Article dans une revue

Abstract

In this study, we investigate how the addition of polyvinylpyrrolidone (PVP), a thermoplastic polymer, contributes to enhance the processability, thermomechanical and semiconducting properties of a semiconducting polymer without side chains. Here, polypyrrole (PPy) is chosen as reference semiconducting polymer. Different blend ratio of polyvinylpyrrolidone/ polypyrrole (PPy/PVP) is prepared by in situ polymerization in acidic solution. The pre-requisite for an effective gain in mechanical properties is to ensure an intimate mixing of both polymers. The miscibility of PPy with PVP is assessed preliminarily using thermodynamic approaches derived from the appropriate group contribution theory which is confirmed experimentally by thermal measurements using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), respectively. All PPy/PVP blend ratios exhibit a single glass transition temperature (T g) characteristic of their appropriate miscibility in the solid state. The morphology and thermal behavior of PPy/PVP mixtures are investigated by DSC and TGA. The potential specific interactions between PPy and PVP moieties are investigated both qualitatively and quantitatively using Fourier transform infrared spectroscopy (FTIR). The FTIR study reveals specific interactions mainly hydrogen bonding between antagonist groups of PPy and PVP. The TGA showed an improved thermal stability. The optical gap of PPy in the mixture PPy/PVP (0.8–0.5 eV) determined by UVVisible spectrophotometry is attributed to π → π* transition, while the electric conductivity measured by the four-point method revealed their semiconducting behavior (57–3960 μS cm−1). Electrochemical impedance spectroscopy (EIS) exhibits semicircles attributed to bulk material, whose diameter decreases with increasing temperature, thus confirming the semiconducting behavior of PPy; the data obey to an Arrhenius law with an activation energy of 0.1 eV and the conduction occurs by electrons delocalization through alternating double bonds.

Bridging the gap between precatalysts and electrocatalysts

Tristan Asset
Nature Materials, 2025, 24 (5), pp.662-663. ⟨10.1038/s41563-025-02210-0⟩ | Publiée le 10 avril 2025
Article dans une revue

High-entropy Tungsten-Based Oxide as Electrocatalyst and Potential Photo-electro-catalyst for H 2 Evolution

Magan Himanshu, Mohammad Slim, Adrien Moll, David Bérardan, Nita Dragoe, Dodzi Zigah, Claudia Gomes de Morais, Junsoo Han, Emilie Gaudry, Thomas Cottineau, Emmanuel Maisonhaute
4th MOMENTOM International Congress, Apr 2025, Orsay, France | Publiée le 2 avril 2025
Poster de conférence

Abstract

<div>High-entropy oxides (HEOx) have emerged as a promising class of materials for photocatalysis due to their unique properties and exceptional stability. This study investigates ( Co 0.2 Ni 0.2 Fe 0.2 Cu 0.2 Zn 0.2 )WO <p>4 HEOx material synthesized using a top-down approach. The material exhibits a single phase, a suitable band gap for visible light absorption, and a promising electrocatalyst for oxygen evolution reaction (OER) compared to their corresponding individual tungstates. Additionally, the initial tests for Photo-current and MB degradation show the potential for hydrogen (H 2 ) production, making HEOx potential catalysts for solar-driven H 2 generation. ΔS mix = RΣ x n lnx n</p></div>

Effect of Cationic Dopant on the Physicochemical Properties and Visible Light Photocatalytic Degradation Activity of (M,N) Codoped TiO 2 Nanoparticles (M = Nb, Ta, W)

Qingyang Xi, Marc Lenertz, Nolwenn Le Breton, Clément Maheu, Valérie Keller, Bertrand Vileno, Thomas Cottineau
ACS Applied Nano Materials, 2025, 8 (14), pp.7073-7084. ⟨10.1021/acsanm.5c00206⟩ | Publiée le 31 mars 2025
Article dans une revue

Abstract

(M,N) codoped TiO2 nanoparticles (with M = Nb, Ta, or W) were synthesized via a sol-gel process, followed by a thermal nitridation in ammonia. The doping cation role in determining the codoped materials' physicochemical properties and their photocatalytic activity was studied. In situ temperature-dependent XRD analysis indicated an inhibition of rutile formation due to cation doping for all codoped TiO2 nanomaterials. Depending on the thermal nitridation conditions, two types of absorption behaviors have been identified for each (M,N) codoped sample family: mild nitridation induced an absorption increase between 400 and 550 nm, while harsh nitridation induced additional absorption at a longer wavelength (>550 nm). Furthermore, the presence of W in the TiO2 lattice has been revealed to be more favorable than Nb and Ta to promote nitrogen insertion. A similar charge compensation mechanism, involving defects such as oxygen vacancies, was revealed for (Nb,N) and (Ta,N) codoped materials: low defect concentrations were achieved by the mild nitridation, while the harsh nitridation created a large amount of Ti3+ acting as charge recombination centers. On the opposite end, the defect concentration for (W,N) codoped TiO2 nanoparticles remains low under both mild and harsh nitridation conditions. Additionally, for (W,N) codoped TiO2 samples, W5+ was created by the harsh nitridation condition instead of Ti3+, resulting in an improved visible light photocatalytic activity.

Catalytic Approaches for CO 2 Conversion to Value‐Added Products: An Overview of Life Cycle Assessment Studies

Anastasia Pappa, Cuong Pham-Huu, Spiros Papaefthimiou, Spyridon Zafeiratos
Advanced Energy and Sustainability Research, 2025, 6 (8), ⟨10.1002/aesr.202400399⟩ | Publiée le 23 mars 2025
Article dans une revue

Abstract

The urgent need to address climate change has driven efforts to develop sustainable strategies for environmental mitigation. Among these, the catalytic and electrocatalytic conversion of CO 2 into value‐added products using renewable energy holds significant promise. E‐fuels, produced through heterogeneous catalytic processes involving CO 2 and renewable hydrogen, exemplify this potential, offering sustainable alternatives. Life cycle assessment (LCA) is a critical tool to evaluate the environmental impacts of CO 2 utilization technologies, providing a comprehensive analysis of a broader sustainability metrics. This review synthesizes findings from selected LCA studies, focusing on the environmental impacts of CO 2 conversion processes, particularly those utilizing heterogeneous catalysis and electrochemical reduction. The goal is to provide practical insights and recommendations to help technology developers identify pathways with the lowest environmental impact and optimize sustainable CO 2 utilization technologies. It is highlighted that despite the widely recognized advantages of CO 2 ‐based processes, the environmental benefits cannot be guaranteed, while the carbon intensity of the electricity source used significantly affects the outcomes. The review identifies possible improvement strategies associated with electricity sources, CO 2 capture methods, catalytic processes, and H 2 production pathways, as the electrification of the chemical sector shows great potential for enormous greenhouse gas (GHG) emission mitigation despite the emerging challenges.

Size-controlled Au and Pt nanoparticles for enhanced CO₂ photoreduction with water under visible light

Leila Hammoud, Justine Quinet, Katia Fajerwerg, Clément Roux, Guillaume Baffou, Thomas Cottineau, Valérie Keller, Valérie Caps, Christian Lorber, Pierre Fau
C'Nano 2025, Mar 2025, Paris, France | Publiée le 18 mars 2025
Communication dans un congrès

Insights into the structure‐property relationship of difluoro boron dipyridomethene derivatives

Camille Chériaux, Thomas Papineau, Pascal Retailleau, Carlotta Figliola, Denis Jacquemin, Gilles Ulrich
ChemPhotoChem, In press, ⟨10.1002/cptc.202400395⟩ | Publiée le 17 mars 2025
Article dans une revue

Abstract

To elucidate the molecular structure of the difluoro dipyridomethene system and to establish structure‐property relationships an extensive synthetic work is reported. Four classes of novel fluorescent BF2‐DIPYR complexes are prepared via Suzuki‐Miyaura cross coupling reaction from the corresponding mono‐ and bis‐brominated dyes in moderate to good yields. Our strategy allowed the introduction of a large panel of electron‐donating and ‐withdrawing groups on the meso, 3 and/or 7 position of the aromatic BF2‐DIPYR core. The new symmetric and asymmetric mono‐, bis‐and tris‐substituted dyes were thoroughly characterized by X‐ray diffraction analysis and spectroscopic measurements. Furthermore, the latter were rationalized by TD‐DFT calculations.

Kinetics of hydrazine hydrate oxidation on nickel electrode

Evgeniia Vorms, Evgenii Strugovshchikov, Aleksandr S Oshchepkov, Mykola Isaiev, Elena Savinova, Antoine Bonnefont, Marian Chatenet
Telluride workshop “Platinum Group Metal and Platinum Group Metal-free Electrocatalysts: Diagnostics, Modeling and Characterization, Plamen Atanassov, Mar 2025, Telluride (CO), United States | Publiée le 17 mars 2025
Communication dans un congrès

Versatile selective-absorber-based photothermocatalytic reactor for solar fuel synthesis

Fernando Fresno, Nicolas Keller
Chem, 2025, 11 (3), pp.102490. ⟨10.1016/j.chempr.2025.102490⟩ | Publiée le 13 mars 2025
Article dans une revue

Abstract

In this preview, we showcase Peters, Agapie, Atwater, and co-workers' recent findings published in Device. The team developed a versatile and scalable selective-absorber-based photothermocatalytic reactor for sunlight-driven sustainable fuel synthesis. Ethylene oligomerization reactions using homogeneous and heterogeneous Ni catalysts were efficiently carried out in both batch and flow configurations.</p><p>The global rise in energy demand coupled to the environmental consequences of the consumption of fossil fuels, have led to a surge in interest in sustainable methods for the synthesis of fuels, energy and chemicals. Solar energy, though intermittent, is the most relevant renewable source, with the potential to meet future demands in a span of applications. Effectively harnessing and integrating its photonic and thermal components into catalytic processes will be crucial in developing a sustainable, CO₂-neutral industry for renewable-based chemicals. 1,2 Recent studies have reported the use of direct solar-to-thermal

Zinc (II) Imidoyl Azide Coordination Polymer, an Unexpected Compound with Insensitive Explosive Properties

Lucas Blanck, Thibaud Alaime, Geneviève Eck, Julie Perouel, Rachid Baati
European Journal of Organic Chemistry, 2025, 28 (20), ⟨10.1002/ejoc.202500079⟩ | Publiée le 12 mars 2025
Article dans une revue

Abstract

A wide interest has recently been shown for the use of the tetrazole ring structures in the preparation of insensitive high‐energy materials. Tetrazoles provide a perfect balance between insensitivity and explosive performances and several synthetic routes are available to generate such compounds in high yields. When studying the two‐step synthesis of N,N’‐bis((1H‐tetrazol‐5‐yl)methyl)nitramide (BTMNA), suggested by Shreeve et al ., an unexpected intermediate structure was observed. This stable intermediate in aqueous conditions, reacted with hydrochloric acid to generate the desired tetrazole heterocycle suggesting the existence of a scarce organozinc imidoyl azide compound, also coined “open tetrazole” . This unusually stable structure is exceptionally isolated as a solid. Furthermore, the possibility of zinc ions coordinating several organic imidoyl azide molecules at the same time, creates a sparse and unprecedented coordination polymer. This new polymeric intermediate is revealed in the synthesis of BTMNA when the starting material, the iminodiacetonitrile (IDA), reacts with sodium azide in water with the assistance of zinc chloride. The intermediate was characterized by Infrared spectroscopy (IR), Differential Scanning Calorimetry (DSC), Thermogravimetric analysis (TGA), and Inductively Coupled Plasma Optical Emission Spectroscopy (ICP‐OES). The observation of such unprecedented intermediates shows the mechanism complexity of the Demko‐Sharpless [3+2] cycloaddition and broadens the understanding of the formation and potential use of organic zinc imidoyl azide coordination polymers as insensitive explosives.

Unlocking sustainable, aromatic, and versatile materials through transurethanization: development of non-isocyanate polyurethanes from lignins

Nathan Wybo, Elise Cherasse, Antoine Duval, Luc Avérous
Journal of Materials Chemistry A, 2025, 13 (16), pp.11557 - 11572. ⟨10.1039/d4ta08582e⟩ | Publiée le 7 mars 2025
Article dans une revue

Abstract

Polyurethanes (PUs) are nowadays essential for a wide range of key applications, thanks to their exceptional and adaptable properties, which arise from their wide variety of macromolecular architectures. However, conventional PUs are predominantly fossil-based, synthesized from highly toxic isocyanates, and are difficult to recycle since most of them are thermosets. This study presents a novel approach to address these issues by developing bio-based, aromatic, and crosslinked non-isocyanate polyurethanes (NIPUs) derived from lignin, which are synthesized for the first time via transurethanization. This reaction was used as a simple, powerful and safe polymerization process. This method eliminates the need for lignin purification and requires only widely available compounds. A comprehensive analysis of the polymerization process and the resulting NIPU materials was conducted. It was observed that lignin could be introduced in the crosslinked architectures up to 32 wt%, and these aromatic NIPUs showed elastomeric behaviors with tunable properties. Additionally, two end-of-life management strategies based on mechanical and chemical recycling were also evaluated. These bio-based and aromatic materials offer a promising pathway toward sustainable and easy production of NIPU from lignin while adhering to multiple green chemistry principles, including the use of renewable feedstocks, safe reagents, limited synthesis steps, and waste prevention.

Insight into charge carrier dynamics and interface design of {0 0 1} TiO2 coupled with TiOF2 for photocatalytic degradation of contaminants of emerging concern

Marta Kowalkińska, Nicolas Keller, Fernando Fresno, Christophe Colbeau-Justin, Anna Zielińska-Jurek
Applied Surface Science, 2025, 695, pp.162893. ⟨10.1016/j.apsusc.2025.162893⟩ | Publiée le 1 mars 2025
Article dans une revue

Abstract

<div><p>Herein, the role of titanium oxyfluoride (TiOF2) on the charge carriers generation and electron transport in the {0 0 1} TiO2/TiOF2 heterojunction photocatalysts was examined. Time-resolved microwave conductivity (TRMC), fluorescence lifetime spectroscopy, and DFT calculations were applied to investigate the charge carriers dynamics. These binary photocatalysts in a broad TiOF2 content were further studied in photocatalytic generation of hydroxyl radicals (•OH) and degradation of several organic contaminants of emerging concern (CECs), namely 4-chlorophenol (4CP), myclobutanil (MCL) and carbamazepine (CBZ).</p><p>Regardless of the CEC tested, it was found that the combination of highly-energetic {0 0 1} TiO2 with TiOF2 phase improved the photocatalytic activity compared to the pristine anatase.</p><p>The presence of the TiOF2 phase in the heterojunction increased the interfacial charge carriers separation and enhanced the generation of •OH radicals. Maximised photocatalytic activity and TOC reduction were observed for composites with a TiOF2 content of 1.5%-6%, which exhibited the highest number of photogenerated charge carriers and a longer lifetime compared to those with higher TiOF2 content. DFT calculations revealed high potential barriers within the TiOF2 structure, which explains the optimum at a low level of TiOF2 amount. Finally, high photocatalytic activity was maintained in five consecutive degradation cycles.</p></div>

Direct and indirect effects of pesticide exposure on the gut microbiota of a farmland raptor

Léa Bariod, Elva Fuentes, Maurice Millet, Samuel Jacquiod, Joël White, Jérôme Moreau, Karine Monceau
Journal of Hazardous Materials, 2025, 485, pp.136857. ⟨10.1016/j.jhazmat.2024.136857⟩ | Publiée le 1 mars 2025
Article dans une revue

Abstract

Recent studies in humans have shown that certain pesticides could affect the composition and functions of the gut microbiota, an essential modulator of vertebrate physiology, leading to potential dysbiosis. However, this relationship remains largely unknown in wild birds despite the implications of pesticides in the current decline of farmland species. The present study sought to fill this gap by providing data on the association between pesticide concentrations in blood and gut microbiota characteristics in relation to individual traits in a farmland raptor, the Montagu’s harrier (Circus pygargus). Results showed that females with higher body condition and higher pesticide load exhibited greater gut bacterial richness and diversity, while the relationship was opposite in males with higher body condition. In terms of taxonomic composition, Proteobacteria emerged as the dominant phylum across all nestlings. Differences in the abundance of specific phyla and genera were observed according to pesticide load, with higher levels of Bacteroidota and Leifsonia, but lower levels of Bulkholderia, in nestlings with higher pesticide concentrations in their blood. This study highlights differences in microbiota and contamination by several pesticides according to the phenotypic characteristics of a wild raptor, and shows that farmland birds can represent relevant biosentinels for assessing the health/proper functioning of ecosystems (One Health approach).

Modulation of NH 2 ‐UiO‐66 Based MOFs for Gas Phase CO 2 Photocatalytic Reduction

Marie Duflot, Clément Marchal, Vincent Artero, Konstantinos Christoforidis, Valérie Keller
Advanced Energy Materials, 2025, 15 (24), pp.2500104. ⟨10.1002/aenm.202500104⟩ | Publiée le 26 février 2025
Article dans une revue

Abstract

<div><p>To solve both the greenhouse effect and energy crisis issues, direct capture and conversion of CO 2 appears as a promising contribution. Artificial photosynthesis is an encouraging and very attractive complementary way to convert CO 2 into high‐value‐added chemicals. Nevertheless, efficient CO 2 conversion remains challenging, mainly due to the poor CO 2 adsorption , the high activation energy required to break C═O bonds, and the slow dynamics of charge carriers in light‐harvesting materials. In recent years, some Metal‐organic frameworks (MOFs) have emerged in the photocatalysis field, especially due to their huge CO 2 adsorption capability and light‐harvesting properties behavior. In this study, a series of defective NH 2 ‐UiO‐66 MOF materials, using formic acid (FA) is synthesized as a modulating agent. Then, a series of binary (MOF/TiO 2 ) catalysts is obtained by varying the defective MOFs content, followed by further deposition of gold (Au) nanoparticles (NPs) to result in three‐component MOF/TiO 2 /Au composites. These composites are assessed for gas‐phase CO 2 photoreduction in the presence of water vapor as the only reducing agent. This hybrid ternary photocatalyst not only increases CO 2 adsorption but also promotes CH 4 formation. Among these resulting MOF/TiO 2 /Au samples, the optimized photocatalytic activity results in a mean production rate of 17.2 µmol.h −1 .g −1 catalyst of CH 4 , which is 6‐fold higher than the one observed for the reference TiO 2 /Au photocatalyst..</p></div>

Polycyclic aromatic hydrocarbons in water environments: Impact, legislation, depollution processes and challenges, and magnetic iron oxide/graphene-based nanocomposites as promising adsorbent solutions

Joana Vaz-Ramos, Stéphane Le Calvé, Sylvie Begin
Journal of Hazardous Materials, 2025, 490, pp.137726. ⟨10.1016/j.jhazmat.2025.137726⟩ | Publiée le 24 février 2025
Article dans une revue

Abstract

Environmental pollution is a big challenge of today’s world, as population continues to grow, and industrialisation and urbanisation increase. Out of the different micropollutants in the atmosphere and aquatic environments, polycyclic aromatic hydrocarbons are of particular importance because they have known severe associated health risks to human life and they have high stability, leading to their persistence in the environment. They are generally present in the environment in low concentrations, but, even at these levels, they pose threats. This review thus focuses on this family of pollutants, on their occurrence and consequences, as well as the current methodologies employed to remove them from water environments and the challenges that remain. This work then focuses on the potential of magnetic iron oxide/graphene nanocomposites for the adsorption of PAHs, extensively discussing past and undergoing works, as well as the interactions between these adsorbents and PAHs.

Mesoporous Semi‐Permeable Flexible Polyurethane Membranes: Advancing Bioartificial Pancreas Design for Type 1 Diabetes Treatment

Bryan Gross, Emeline Lobry, Séverine Sigrist, Elisa Maillard, Jordan Magisson, Charles‐thibault Burcez, Manuel Pires, Anne Hébraud, Guy Schlatter
Macromolecular Rapid Communications, 2025, ⟨10.1002/marc.202500049⟩ | Publiée le 14 février 2025
Article dans une revue

Abstract

This study reports the development of elastomeric mesoporous polyurethane (PU) membranes for bioartificial pancreas applications in type 1 diabetes treatment. The membranes are designed to exhibit semi-permeable properties, enabling insulin diffusion while restricting larger immune molecules, such as immunoglobulin G (IgG). Although electrospinning is a widely used technique for fabricating porous membranes for controlled drug release, it typically results in an average pore size on the order of few micrometers, which is two orders of magnitude larger than the mesoporous scale required. In this work, a green-electrospinning process using waterborne PU suspension and poly(ethylene oxide) (PEO) is employed, followed by thermal annealing and washing steps. The resulting membranes exhibit a controlled pore size in the mesoporous range (≈20 nm measured by capillary flow porometry). Diffusion tests confirmed selective permeability, with a recovery rate of 25% for insulin and a recovery rate below 5% for IgG, meeting therapeutic needs. In vivo characterizations show no degradation and good biocompatibility of the membranes without chronic inflammation. Moreover, mechanical characterization demonstrates the membranes' flexibility and strength, making them suitable for minimally invasive surgical implantation. These findings underscore the potential of PU membranes for long-term biomedical applications, addressing critical challenges in permeability and mechanical stability.

Generation of electronically unsaturated carbon sites on carbon materials and study of their magnetic and chemical properties

Mathieu Vidal, Maryam Dehaghani, Javier Navarro-Ruiz, Takeharu Yoshii, Keigo Wakabayashi, Hirotomo Nishihara, Mathias Barreau, Fabrice Bournel, Jérôme Volkman, Guillaume Clet, Spirydon Zafeiratos, Nolwenn Le Breton, Pascal Puech, Iann Gerber, Athanassios Boudalis, Thomas Blon, Philippe Serp
Journal of Physical Chemistry C, 2025, 129 (7), pp.3539-3560. ⟨10.1021/acs.jpcc.4c07975⟩ | Publiée le 10 février 2025
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Abstract

The presence of defects in carbon materials, such as electronically unsaturated carbon sites, can profoundly affect their magnetic ordering and chemical reactivity. The detailed analysis of these species (edge states, σ free radicals, or carbene), which are pivotal for many applications, remains a significant challenge for carbon bulk materials. Today, the engineering of defective carbon materials often relies on the use of hardly up-scalable physical methods not accessible to synthetic chemists. It is therefore important to develop simple and scalable methods to generate well-defined electronically unsaturated sites in carbon materials. Herein, we followed the transformation and evolution of surface oxygen functional groups of various oxidized carbon materials during thermal treatment under an inert atmosphere using various analytical techniques and ab initio molecular dynamics, with the aim of producing stabilized localized electronic states from condensation reactions. Synchrotron-based in situ XPS analyses show a decrease in the number of carboxylic surface groups with a concomitant increase in the number of defect sites upon defunctionalization, which is expected from condensation reactions. Echo-detected field-swept EPR spectra show the apparition of a signal only upon defunctionalization, particularly for samples showing a high proportion of prismatic surface. The contribution of these electronically unsaturated carbon sites to the catalytic activity for the catalytic oxidative dehydrogenation of indoline is moderate, and the surface oxygen functional groups are the main active sites.

Fluorination Strategies for Mn₃O₄ Nanoparticles: Enhancing Reversibility and Capacity in Li-Ion Batteries

Régis Porhiel, Batiste Clavier, Taylan Karakoç, Sergey Pronkin, Dominique Foix, Elodie Petit, Malika El-Ghozzi, Katia Guérin
Batteries, 2025, 11 (2), pp.53. ⟨10.3390/batteries11020053⟩ | Publiée le 28 janvier 2025
Article dans une revue

Abstract

Transition metal oxides (TMOs) occupy an increasing share in the search for new electrode materials for Li-Ion batteries. Despite promising electrochemical performances (up to 1000 mAh g−1 in the case of conversion), these materials have poor cyclability linked primarily to hysteresis phenomena. To improve their electrochemical performance, one strategy consists of reducing the particle size. A second strategy relies on the incorporation of fluorine directly into electrode materials to limit the solid–electrolyte interface (SEI). Our study focuses on the impact of fluorination on the electrochemical performance of manganese oxide obtained by solid combustion synthesis (SCS). Two fluorinating agents were used: pure gaseous molecular fluorine F2 and radical fluorine F• through xenon difluoride XeF2 decomposition. The use of F2 results in strong fluorination localized primarily at the particle surface while XeF2 diffuses deeper into the particle, resulting in the removal of residual carbon from the synthesis by combustion. The electrochemical performance of the oxide fluorinated with XeF2 reaches more than 750 mAh g−1 after 160 cycles, whereas that of the oxide fluorinated by F2 barely exceeds that of the non-fluorinated oxide, less than 200 mAh g−1 after 200 cycles.

Kinetics of hydrazine hydrate and other carbon-free fuels oxidation on nickel electrode

Evgeniia Vorms
Theoretical and/or physical chemistry. Université de Strasbourg, 2025. English. ⟨NNT : 2025STRAF003⟩ | Publiée le 28 janvier 2025
Thèse

Abstract

Electrochemical energy production from carbon-free fuels has recently attracted much attention. This manuscript focuses on studying the mechanism of the hydrazine oxidation reaction (HHOR) on Ni electrodes and comparing it with the ones of the borohydride and ammonia-borane oxidation reactions (BOR, ABOR). Metallic Ni sites were identified as the catalytic sites for the HHOR, BOR, and ABOR, while the presence of Ni (hydr)oxide sites was found to negatively affect activity without a clear influence on the reaction mechanism. Based on the results of DFT calculations, microkinetic modelling, and online DEMS measurements, a mechanism for HHOR on Ni was proposed. It involves the direct reaction of dissolved hydrazine with adsorbed Ni-OH species forming N2Hx,ad (x<4) intermediate, which is subsequently electrochemically oxidized, leading to the formation of N2 and water.

Effect of the shell thickness on the oxygen evolution activity of core@shell Fe 3 O 4 @CoFe 2 O 4 nanoparticles

Iryna Makarchuk, Benjamin Rotonnelli, Lisa Royer, Simon Hettler, Jean-Jacques Gallet, Fabrice Bournel, Julie Guehl, Amandine Brige, Andrea Zitolo, Gwénaëlle Kéranguéven, Antoine Bonnefont, Raul Arenal, Elena Savinova, Tristan Asset, Benoit Pichon
Chemistry of Materials, 2025, 37 (3), pp.833-844. ⟨10.1021/acs.chemmater.4c01784⟩ | Publiée le 22 janvier 2025
Article dans une revue

Abstract

<div><p>Hydrogen production via water splitting requires efficient electrocatalysts to reduce overpotentials of the anodic oxygen evolution reaction (OER) and cathodic hydrogen evolution reaction (HER). In this study, we investigate the influence of the apparent shell thickness on the electrocatalytic activity of Fe3O4@CoFe2O4 core@shell nanoparticles, an efficient noble-metal-free OER catalyst in alkaline media. Three different types of core@shell nanoparticles were synthesized by seed-mediated crystal growth of cobalt ferrite on pristine magnetite nanoparticles. The synthesis conditions were adapted to modulate the shell structure. Importantly, all proposed core@shell structures showed excellent stability during electrochemical testing, an important quality for eventual industrial application. We show that the electrocatalytic performance of Fe3O4@CoFe2O4 core@shell nanoparticles is significantly influenced by the shell structure. The cooperative redox mechanism proposed to be at the origin of the activity enhancement in core@shell nanoparticles was investigated using in-situ soft Xray absorption spectroscopy (XAS). XAS revealed that cooperative redox interactions occur between Co(II) and Fe(II) residing in close proximity at the core@shell interface, hence requiring a thin and continuous CoFe2O4 shell. Overall, this study provides insights into the design of efficient core@shell nanocatalysts for the OER, offering a path toward performance improvement of earth-abundant transition metal oxide (TMO) catalysts for sustainable H2 production.</p></div>

Optimisation des cellules solaires organiques à couche active PF2:ITIC pour des applications en éclairage intérieur

Ruoxue He, Nicolas Leclerc, Pierre Nickmilder, Philippe Leclère, Johann Bouclé, Bernard Ratier
Cinquième Congrès National Sciences et Technologies des Systèmes pi-Conjugués (SPIC2025), Jan 2025, Paris, France | Publiée le 20 janvier 2025
Communication dans un congrès

A Label‐Like Monolithic Organic Thermoelectric Generator Enabled by Local Inkjet Doping of Aligned Polymer Films

Nathan James Pataki, Shubhradip Guchait, Badr Jismy, Nicolas Leclerc, Adrica Kyndiah, Martin Brinkmann, Mario Caironi
Advanced Energy Materials, 2025, ⟨10.1002/aenm.202404656⟩ | Publiée le 16 janvier 2025
Article dans une revue

Abstract

The proliferation of distributed microelectronics and sensors necessitates adaptable, scalable, and cost‐effective power supplies. Organic thermoelectric generators (TEGs) that promise to harness heat sustainably and cost‐effectively are seen as pivotal elements in shaping future sensor infrastructures. Recent strides in morphological control through the alignment of conjugated polymer backbones have enhanced the thermoelectric performance of doped organic semiconductors to record values, matching expectations for real applications. However, the hurdles in crafting and deploying organic TEGs effectively exploiting aligned polymer films remain unexplored. This work presents a design and fabrication method to incorporate aligned films into a thin label‐like TEG. Thin films of regioregular poly(3‐hexylthiophene) (P3HT) and poly(2,5‐bis((7‐butoxyheptyl)thiophen‐2‐yl)thieno[3,2‐ b ]thiophene) (PBTTT‐ 8 O) are aligned via high‐temperature rubbing technique inducing a high degree of anisotropy in their charge transport properties. The crystal structure and anisotropy of the films are exploited to realize monolithic TEGs by patterning conductive thermoelements via local inkjet doping of films transferred on ultrathin parylene substrates. The TEGs based on aligned P3HT and PBTTT‐ 8 O exhibit exceptional TEG power factors of 0.33 and 1.04 nW cm −2 K −2 , respectively. Lastly, as a proof‐of‐concept use case for the TEGs, a thermoelectrically‐powered volume‐indicating label is presented as a potential application in the healthcare and food industries.

Germanium atoms exceed the tetrahedral coordination in MFI zeolite

Eddy Dib, Qiudi Yue, Giorgia Confalonieri, Davide Salusso, Georgi Vayssilov, Mathias Barreau, Stoyan Gramatikov, Rossella Arletti, Francesco Dalena, Kirill Lomachenko, Diogenes Honorato Piva, Valentin Valtchev, Zhengxing Qin, Zi-Feng Yan, Xionghou Gao, Franck Fayon, Spyridon Zafeiratos, Oleg Lebedev, Svetlana Mintova
Journal of the American Chemical Society, 2025, 147 (4), pp.3274-3282. ⟨10.1021/jacs.4c13278⟩ | Publiée le 14 janvier 2025
Article dans une revue

Abstract

Germanium is known to occupy tetrahedral sites by substituting silicon in germanosilicate zeolites. In this study, we present pioneering findings regarding the synthesis of zeolites with an MFI structure (GeMFI) incorporating a high germanium amount (16% Ge). Remarkably, the germanium atoms feature a slight electron deficiency with respect to GeO2, and the typical coordination number of 4, as usually reported for the germanosilicate zeolites, is exceeded, giving rise to Ge dimers in a double-bridge configuration. Notably, the compensation of the ammonium template is achieved not through fluorine ions in the [4$^1$5$^2$6$^2$] cages of the framework, as conventionally considered, but rather through oxygen. The GeMFI zeolite with the high Ge content reported in this work demonstrated exceptional thermal and hydrothermal stability, surpassing up to 1050 °C, thanks to both the double-bridge configuration and the defect-free structure. The unexpected role of germanium in MFI zeolite challenges previous assumptions, representing a paradigm shift in the understanding of porous germanosilicate structures, paving the way for a reevaluation of their synthesis, hydrolysis, and potential applications.

Introducing phenol-yne chemistry for the design of lignin-based vitrimers: towards sustainable and recyclable materials

Lisa Sougrati, Antoine Duval, Luc Avérous
Journal of Materials Chemistry A, 2025, 13 (7), pp.4921 - 4939. ⟨10.1039/d4ta07880b⟩ | Publiée le 7 janvier 2025
Article dans une revue

Abstract

Lignins are the main source of renewable aromatic compounds on the Earth. These polyphenols of high functionality are biobased building blocks of great interest for the development of aromatic polymer materials. However, one shortcoming of these thermosets is their inefficient recyclability, which increases their environmental impact in a situation where the need for high-performance materials with controlled end-of-life is paramount. Conceptualization of lignin-based vitrimers is an attractive solution to address this global challenge. In this work, we report the synthesis, evaluation and recycling of lignin-based phenol-yne vitrimers adhering to the principles of circular bioeconomy. Herein, the potential of phenols substituted in ortho position with one or two methoxy groups (G and S units) to undergo vinyl ether bond exchanges was examined with model compounds. Then, the addition kinetics of aliphatic hydroxyls and di-substituted phenols was investigated on model molecules representatives of lignin heterogeneous reactive groups. Subsequently, a series of materials from different lignin sources was prepared via a one-step click-addition under solvent-free conditions and achieved full atom-economy in accordance with different green chemistry principles. These high lignin-content (39 to 49 wt%) vitrimers were duly characterized. The thermal, morphological, rheological, and mechanical properties were comprehensively assessed. It was observed that the vitrimers underwent rearrangement through vinyl ether bond exchanges. Relaxation times in the range of 74 to 476 s were obtained at 200 °C. The determined activation energies were in the range of 72 to 89 kJ mol−1. Network structures and properties were analyzed through successive physical recycling steps, and the chemical recycling potential was surveyed via acid-catalyzed hydrolysis. Results clearly showed a proof-of-concept for the closed-loop recycling of lignin-based phenol-yne vitrimers, offering further upcycling opportunities for the development of sustainable aromatic materials for a greener future and towards a cradle-to-cradle approach.

Synthesis, crystal growth, structure and photophysical properties of decafluoroanthracene and its co-crystals with polycyclic arenes

Alexandra Friedrich, Lisa Schraut-May, Florian Rauch, Pablo Durand, Johannes Krebs, Paul N Ruth, Sebastian Hammer, Rüdiger Bertermann, Maik Finze, Stewart J Clark, Jens Pflaum, Nicolas Leclerc, Todd B Marder
Organic Chemistry Frontiers, 2025, 12 (3), pp.736-753. ⟨10.1039/d4qo01825g⟩ | Publiée le 1 janvier 2025
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Abstract

A series of 1 : 1 co-crystals of decafluoroanthracene with naphthalene, anthracene, tetracene, pyrene, perylene, and triphenylene were grown and characterised using single-crystal X-ray diffraction at low and ambient temperature, (polarisation-dependent) fluorescence spectroscopy, and quantum mechanical computations. All of the molecular co-crystal structures are built from infinite stacks of alternating arene and decafluoroanthracene molecules representing the arene–perfluoroarene supramolecular synthon. Intermolecular interactions and packing features are discussed in detail. As a by-product, the heterodimer of tetracene and decafluoroanthracene was obtained after exposure to room light or under UV-irradiation of a solution of the monomers, and was structurally characterised. The fluorescence properties of the co-crystals of decafluoroanthracene with naphthalene, tetracene, pyrene, perylene, and triphenylene are similar to those of one of their components with only a small bathochromic or hypsochromic shift. This shows that the interaction between the components is weak and fits well into the picture of an arene–perfluoroarene interaction. An exception is 1 : 1 anthracene : decafluoroanthracene, which shows a bathochromic shift of both excitation and especially emission spectra of the co-crystal compared to those of its components, which indicates weak charge transfer coupling in the ground state followed by an exciplex-like emission.

Synthesis, Photophysical properties and Ab Initio Calculations of Dual Solution-Solid-State Emitting Ethynyl-Extended Boranil Complexes

Timothée Stoerkler, Denis Frath, Gilles Ulrich, Pascal Retailleau, Denis Jacquemin, Julien Massue
Journal of Organic Chemistry, 2025, 90 (21), pp.6980-6991. ⟨10.1021/acs.joc.5c00403⟩ | Publiée le 1 janvier 2025
Article dans une revue

Abstract

We describe herein the synthesis along with full photophysical and computational studies of three series of boranil complexes (Series I-III), incorporating extended ethynyl-substitution, either on the imino side (Series I), on the phenolic side (Series II), or on both sides (Series III), in order to assess the impact of the insertion of electron donors or acceptors on the fluorescence properties. A full photophysical study in solution (various solvents) demonstrated the presence of a strong intramolecular charge transfer process within these boron complexes, with fluorescence colors spanning the whole visible range. Additionally, these compounds are also emissive in the solid-state, on a similar wide fluorescence range thus providing more examples of dual solution-and solid-emissive fluorophores, based on boron complexes. Theoretical calculations on both anil ligands and boranil complexes rationalize the charge transfer nature of the excited-states involved in the emissive transitions.

The ESIPT-suppressed 2-(2'-hydroxyphenyl)benzoxazole derivative as a new photoinitiator for multiphoton polymerization

João V P Valverde, André L Do S Romero, Renan Cunha, Rafael de Q Garcia, Timothée Stoerkler, Julien Massue, Leonardo de Boni, Cleber R Mendonça
Journal of Materials Chemistry C, 2025, 13 (14), pp.7130 - 7139. ⟨10.1039/d4tc05477f⟩ | Publiée le 1 janvier 2025
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Abstract

The quest for new photoinitiators (PIs) capable of efficiently absorbing multiple photons, particularly three photons, has intensified due to the multiphoton polymerization (MPP) technique. MPP enables the fabrication of next-generation photonic micro-and nanodevices with resolution beyond the diffraction limit and without shape limitation, offering considerable advantages over other methods. However, designing organic compounds acting as effective multiphoton PIs while enabling smart functionalization of manufactured structures remains challenging. In this contribution, we report using a 2-(2'-hydroxyphenyl)benzoxazole (HBO) derivative, named HBO-NBu$_2$ , as a PI for two-and three-photon polymerization. HBO fluorophores are well-known to undergo an excited-state intramolecular proton transfer (ESIPT) process, but in this structure, the combination of a planar and linear push-pull dipolar structure, with an extensive π-conjugation, led to a complete suppression of ESIPT, subsequently exhibiting an excellent nonlinear response. Herein, we investigate the linear photophysical properties, excited-state dynamics, and multiphoton absorption of HBO-NBu 2 , supported by quantum chemical calculations. Our results demonstrate that HBO-NBu 2 exhibits structural rigidity, resulting in a fluorescence quantum yield of 62% in dichloromethane solution, owing to the absence of ESIPT and substantial intramolecular charge transfer (ICT) due to its push-pull nature. Moreover, this molecule shows significant two-and threephoton absorption cross-sections of 80 GM (at 800 nm) and 4 ± 1 10$^{-81}$ cm$^6$ (s per photon)$^2$ (at 1030 nm), respectively. Finally, we demonstrate a proof of concept of MPP using HBO-NBu2 as a PI, showing that even at low concentrations, it outperforms widely used PIs

Pesticide contamination patterns in Montagu's harrier (Circus pygargus) chicks

Elva Fuentes, Jérôme Moreau, Anaïs Rodrigues, Maurice Millet, Vincent Bretagnolle, Karine Monceau
Environmental Science and Pollution Research, 2025, 32, pp.21816-21827. ⟨10.1007/s11356-024-34937-9⟩ | Publiée le 1 janvier 2025
Article dans une revue

Abstract

Biomonitoring of persistent pesticides in birds of prey has been carried out for decades, but few studies have investigated their relevance for the monitoring of non-persistent pesticides. Herein, we determined the contamination patterns of multiple pesticides in Montagu's harrier (Circus pygargus) chicks in an intensive farming area of southwestern France. Blood samples from 55 chicks belonging to 22 nests in 2021 were assessed for 104 compounds (herbicides, fungicides, insecticides, safeners and synergists). All chicks had at least one herbicide in their blood, and half had at least two compounds. The 28 compounds detected comprised 10 herbicides, 12 fungicides, 5 insecticides and 1 synergist. Mixtures in blood were predominantly composed of herbicides, and six chicks presented a mixture of the three pesticide classes. The most prevalent compounds were sulcotrione (96% of chicks), tebutam (44%) and chloridazon (31%), of which the latter two had been banned in France for 19 and 3 years, respectively, at the time of sampling. Most compounds are considered non-acutely toxic, but sulcotrione is potentially carcinogenic, mutagenic and reprotoxic, raising questions about the effects on the health of nestlings. Biomonitoring of multiple pesticides through Montagu's harrier chicks in agroecosystems is clearly relevant because it reflects the general pattern of agricultural pesticide use in the study area. It also raises questions about exposure pathways in chicks, and further investigations are needed to disentangle the roles of dietary routes and maternal transfer for the established pesticide contamination patterns.

pH and Cation Concentration Effect on the Interfacial Recharging of Mn Oxides: Experiment and Modeling

Kirill Dosaev, Pierre-Antoine Bonnefont, Sergey Ya. Istomin, Evgeny Antipov, Galina Tsirlina, Elena Savinova
Journal of Physical Chemistry C, 2025, 129 (40), pp.18222-18233. ⟨10.1021/acs.jpcc.5c03746⟩ | Publiée le 1 janvier 2025
Article dans une revue

Abstract

The influence of electrolyte composition on the kinetics of electrocatalytic reactions was discussed in the seminal works of Frumkin. However, recent findings have reignited interest in the role of cations and pH in electrocatalysis, particularly in alkaline environments. Manganese oxides have attracted much attention as catalysts for both the oxygen reduction (ORR) and oxygen evolution reactions (OER). In addition, some Mn oxides are promising materials for supercapacitors due to their high pseudocapacitance. In this work we combine electrochemical measurements with microkinetic modeling to unveil influence of pH and cation concentration on the interfacial recharging behavior of α-MnOOH, α-Mn₂ O₃ and LaMnO₃ . Titration experiments revealed that the isoelectric point of the manganese oxides is around 5, indicating that they are negatively charged in alkaline environments. Cyclic voltammetry showed that both OH⁻ and Na⁺ concentrations influence the Mn(III)/Mn(IV) redox transition at the oxide-electrolyte interface, with distinct behaviors for α-MnOOH, α-Mn₂O₃ , and LaMnO₃ . It is noteworthy that α-MnOOH exhibits two types of interfacial redox centers, protonated and cationic, which emphasises that the redox behavior is determined by ion-exchange equilibria.

8th International Conference on Semiconductor Photochemistry: Selected contributions

Nicolas Keller, Peter K.J. Robertson, Patricia García-Muñoz, Fernando Fresno
Journal of Photochemistry and Photobiology A: Chemistry, 2025, 458, pp.115913. ⟨10.1016/j.jphotochem.2024.115913⟩ | Publiée le 1 janvier 2025
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Tuning Selectivity in Direct 5‐Hydroxymethylfurfural Hydrodeoxygenation to 5‐Methylfurfural or 2,5‐bis(hydroxymethyl)furan over Ni/TiO₂ Catalysts

Martyna Przydacz, Preeti Kashyap, Nathalie Tanchoux, Dris Ihiawakrim, David Kubička, Nicolas Keller, Agnieszka Malgorzata Ruppert
ChemCatChem, In press, ⟨10.1002/cctc.202401818⟩ | Publiée le 1 janvier 2025
Article dans une revue

Abstract

The platform molecule 5‐Hydroxymethylfurfural (HMF) can be derived from biomass feedstocks and catalytically hydrogenated into various high‐value molecules. Its conversion to 5‐methylfurfural (5‐MF), a versatile synthetic intermediate and perfuming agent, is particularly challenging, as the selective hydrodeoxygenation of the C–OH group in HMF is far less favorable ‐ kinetically and thermodynamically ‐ than the hydrogenation of the C=O group, which leads to 2,5‐bis(hydroxymethyl)furan (BHMF). Herein, for the first time, we demonstrate that Ni/TiO₂ catalysts can be tuned to promote the selective removal of a hydroxyl group in the presence of an aldehyde moiety, achieving a high 5‐MF yield. Among various synthesis approaches, the direct ion‐exchange incorporation of Ni into a TiO₂ network prepared via an alginate synthesis route enabled identifying key factors directing the reaction selectivity toward 5‐MF. The highest 5‐MF selectivity (86%) at nearly full conversion was favored by high acidity and ultra‐high dispersion of Ni atoms on the surface, while the crucial role of titania was discussed. By contrast, increasing the reduction temperature to 700°C significantly lowered acidity and led to the formation of larger Ni particles, which favored C=O activation, and in turn, promoted a selectivity shift toward BHMF, achieving 86% selectivity at nearly full conversion.

Estimating Spatial Resolution and X-ray Radiation Dose in a Comparative Study of Composite Organic Nanoparticles Using Soft X-ray Scanning Transmission X-ray Microscopy and Soft X-ray Ptychography

Corentin Rieb, Nicolas Leclerc, Stéphane Méry, Anne Hébraud, Sufal Swaraj
Journal of Physical Chemistry C, 2025, 129 (41), pp.18537-18547. ⟨10.1021/acs.jpcc.5c04620⟩ | Publiée le 1 janvier 2025
Article dans une revue

Abstract

Scanning transmission X-ray microscopy (STXM) and soft X-ray ptychography (SXP) are powerful techniques for nanoscale imaging, offering high spatial resolution with chemical sensitivity. However, the interplay between spatial resolution and X-ray radiation damage remains a critical consideration for sensitive samples, such as organic materials. In this study, we quantitatively compared spatial resolution and radiation damage between the two techniques. Spatial resolution is assessed using Fourier ring correlation (FRC), applying both the 1/2-bit threshold and a signal-to-noise ratio (SNR) threshold mathematically computed for each spatial frequency. SXP achieves superior spatial resolution due to its phase-retrieval capabilities and enhanced coherent imaging properties. In this paper, a resolution of 20-25 nm with SXP at the nitrogen K-edge (∼400 eV) was achieved for the first time, while STXM is limited by zone plate used, outermost zone width as 25 nm giving a theoretical resolution of 30.5 nm (1.22 × outermost zone width). Moreover, in our measurements, we find that the X-ray radiation dose required for SXP is approximately 6 times lower than for STXM, leading to a remarkably low damage level, highlighting its potential for damage-sensitive studies. These findings establish SXP as a highly efficient and minimally invasive imaging technique for the nanoscale characterization of organic material.

Synthesis and photophysical properties of 6-aryl-2,4-bis(2′-hydroxyphenyl) pyrimidines ligands and their boron fluoride complexes

Clément Diguet, Amparo Navarro, M. Paz Fernández-Liencres, Sonia B. Jiménez-Pulido, Nuria A. Illán-Cabeza, Julien Massue, Sebastien Gauthier, Françoise Robin-Le Guen, Sylvain Achelle, Julián Rodríguez-López
Dyes and Pigments, 2025, 236, pp.112660. ⟨10.1016/j.dyepig.2025.112660⟩ | Publiée le 1 janvier 2025
Article dans une revue

Abstract

A new family of 6-aryl-2,4-bis(2 &#039;-hydroxyphenyl)pyrimidines has been efficiently synthesized and characterized using Suzuki-Miyaura reactions, demonstrating their ability to function as rigid tridentate O&quot;N&quot;O chelating ligands for the preparation of four-coordinate organoboron compounds. Similar to related structures, the uncoordinated compounds do not exhibit fluorescence in either solution or the solid state. The intramolecular hydrogen bonds in their molecular structure promote an excited-state intramolecular proton transfer (ESIPT) process, leading to an excited keto tautomer that deactivates through non-radiative decay. Protonation and boron complexation can successfully inhibit the ESIPT process, resulting in fluorescence recovery, which can be finely tuned by modifying the substituents on the aryl group. Advanced techniques, including X-ray diffraction, density functional theory (DFT), and time-dependent DFT (TD-DFT), provide critical insights into the electronic structure and emission properties. This work offers a deeper understanding of the role of boron chelation in modulating emission properties, opening new avenues for the design of functional fluorescent materials.

Evidence for the stabilization of FeN$_4$ sites by Pt particles during acidic oxygen reduction

Nicolas A Ishiki, Keyla Teixeira Santos, Nicolas Bibent, Kavita Kumar, Ina Reichmann, Yu-Ping Ku, Tristan Asset, Laetitia Dubau, Michel Mermoux, Hongxin Ge, Sandrine Berthon-Fabry, Viktoriia A Saveleva, Vinod K Paidi, Pieter Glatzel, Andrea Zitolo, Tzonka Mineva, Hazar Guesmi, Serhiy Cherevko, Edson A Ticianelli, Frédéric Maillard, Frédéric Jaouen
Nature Communications, 2025, 16 (1), pp.6404. ⟨10.1038/s41467-025-61806-x⟩ | Publiée le 1 janvier 2025
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Abstract

While Fe–N–C materials have shown promising initial oxygen reduction reaction (ORR) activity, they lack durability in acidic medium. Key degradation mechanisms include FeN$_4$ site demetallation and deactivation by reactive oxygen species. Here we show for mainstream Fe–N–Cs that adding 1 wt.% Pt nanoparticles via a soft polyol method results in well-defined and stable Pt/Fe–N–C hybrids. The Pt addition strongly reduces the H2O2 production and Fe leaching rate during ORR, while post mortem Mössbauer spectroscopy reveals that the highly active but unstable Fe(III)N4 site is partially stabilized. The similar H$_2$O$_2$ electroreduction activity of Pt/Fe–N–C and Fe–N–C and other analyses point toward a long-distance electronic effect of Pt nanoparticles in stabilizing FeN$_4$ sites. Computational chemistry reveals that spin polarization of distant Pt atoms mitigates the structural changes of FeN$_4$ sites upon adsorption of oxygenated species atop Fe, especially in high-spin state.

Quinoline-Substituted Excited-State Intramolecular Proton Transfer Fluorophores as Stimuli-Sensitive Dual-State Fluorophores

Timothée Stoerkler, Gilles Ulrich, Adèle Laurent, Denis Jacquemin, Julien Massue
Organic Chemistry Frontiers, 2025, ⟨10.1039/D5QO00639B⟩ | Publiée le 1 janvier 2025
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Abstract

This article describes the synthesis along with full photophysical and ab initio properties of a series of 2-(2’-hydroxyphenyl)benzoxazole (HBO) fluorophores, a family of compounds prone to undergo Excited-State Intramolecular Proton...

Pesticide mixture effects on physiological stress and morphology of growing wild nestlings

Elva Fuentes, Jérôme Moreau, Maurice Millet, Vincent Bretagnolle, Karine Monceau
Journal of Hazardous Materials, 2025, 496, pp.139346. ⟨10.1016/j.jhazmat.2025.139346⟩ | Publiée le 1 janvier 2025
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Abstract

Synthetic pesticides may pose a risk to non-target organisms, notably farmland birds, through their hazardous effects on life-history traits, but their impacts on growth and physiological stress have never been assessed in natura. We investigated these effects on skeletal growth, mass gain, body condition and physiological stress (basal and stress-induced corticosterone secretions) of 35 nestlings of Circus pygargus, a farmland apex predator, blood-sampled twice during their development. We found contamination levels ranging from 0 to 9 pesticides detected out of the 116 searched. We observed an age and sex-dependent pattern of pesticide mixture effects on nestlings’ growth and baseline corticosterone. Males (≤17 days old) having shorter tarsus when their pesticide load was high while this was found in older females (≥18 days old). Higher pesticide loads were linked to poorer body condition of young nestlings irrespective of their sex. Similarly, depressed corticosterone secretion was found in more contaminated young nestlings, and in females irrespective of their age. These alterations observed in young nestlings are caught up later during their development. No relationship between contamination levels and stress-induced corticosterone was found. Including other life-history traits would provide more information on other stress endpoints and potential energetic trade-offs between an active defence against pesticides and important functions of the organism.

Pesticide exposure in farmland wild passerines: bio-indicators of a widespread contamination despite organic farming

Audrey Bailly, Karine Monceau, Vincent Bretagnolle, Anaïs Rodrigues, Maurice Millet, Jérôme Moreau
Environmental Research, 2025, 285 (2), pp.122389. ⟨10.1016/j.envres.2025.122389⟩ | Publiée le 1 janvier 2025
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Abstract

Agricultural intensification has led to widespread pesticide contamination, contributing to the decline of farmland bird populations. Organic farming (OF) presents an alternative approach, relying on nature-based methods and prohibiting synthetic pesticides. This study aimed to investigate contamination patterns in wild farmland passerines and compare pesticide exposure levels between OF and conventional farming (CF) environments. During the breeding season, five passerine species were captured across 9 hedgerows surrounded by OF and 10 hedgerows adjacent to CF. Blood samples were analysed for 104 pesticide residues, providing insights into recent and local exposure. Contamination levels were assessed using two metrics: (1) the number of compounds detected and (2) the total concentration of pesticides. Overall, 84.5 % of the birds were contaminated with at least one compound, with 57 compounds detected, including 14 pesticides banned for over a year. Contamination patterns varied across species: Eurasian blackcaps (Sylvia atricapilla) exhibited the lowest pesticide load, whereas cirl buntings (Emberiza cirlus) had the highest number of detected compounds, and common blackbirds (Turdus merula) displayed the highest total pesticide concentration. While the number of compounds did not significantly differ between agricultural systems, common blackbirds and Eurasian blackcaps had lower pesticide concentrations in OF than in CF, suggesting that organic farming may offer some reduction in exposure. However, pesticide contamination remains persistent across environments, indicating potential exposure risks for other species, including humans, with possible health implications under the One Health framework.

A blessing and a curse: impact of urea derivatives on the secondary building unit of Ca-MOFs prepared in deep eutectic solvents

Michaël Teixeira, Benoît Louis, Stéphane A Baudron
Dalton Transactions, 2025, 54 (12), pp.5006-5016. ⟨10.1039/D4DT03254C⟩ | Publiée le 1 janvier 2025
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Abstract

Deep eutectic solvents (DESs) based on a 1 : 2 combination of choline chloride with either urea or e-urea (2-imidazolidinone) have been studied as media for the preparation of Ca(II) metal–organic frameworks (Ca-MOFs). In particular, the impact of the urea derivative on the secondary building unit (SBU) has been investigated by exploring the formation of Ca-MOFs with a series of ten di- and tetra-carboxylic acids, varying in length, steric hindrance and the number and relative orientation of coordinating units. While several of these ligands have, to the best of our knowledge, not been previously reported to form Ca-MOFs, eleven new materials could be prepared and characterized by single-crystal and powder diffraction, elemental and thermogravimetric analyses as well as absorption and emission spectroscopy. The DES incorporating e-urea was found to be especially prone to the formation of crystalline materials. However, a recurrent one-dimensional SBU based on bridging carboxylate moieties and the carbonyl unit of e-urea was observed. Coordination of the solvent molecule is assisted by hydrogen bonding of the NH groups, leading to a strongly stabilizing motif preventing these materials from thermal activation without loss of crystallinity.

Zeolite composite prepared by quasi in-situ interzeolite conversion approach

Ruizhe Zhang, Bo Wang, Jiani Xu, Honghai Liu, Hongjuan Zhao, Jiujiang Wang, Shutao Xu, Shunsuke Asahina, Francesco Dalena, Camille Longue, Benoît Louis, Ludovic Pinard, Simona Moldovan, Zhengxing Qin, Xionghou Gao, Svetlana Mintova
Chem Catalysis, 2025, 5 (5), pp.101298. ⟨10.1016/j.checat.2025.101298⟩ | Publiée le 1 janvier 2025
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Abstract

The design of zeolites with optimized textural properties is a continuous goal. Here we report a composite comprising mesoporous ultra stable zeolite Y (USY) and nanosized ZSM-5 with enhanced acid site accessibility and pore connectivity through quasi in-situ interzeolite conversion in a solvent-free medium. It begins with a spatial and elemental-biased dissolution of USY with impregnated TPAOH. This results in a hierarchical zeolite with increased mesopore volume and improved pore connectivity. Simultaneously, the solute provides all the necessary nutrients for the growth of ZSM-5 zeolite. Due to the constrained mass transfer during the quasi-solid-state dissolution, the resulting ZSM-5 crystals are as small as 10 nm and intimately connected with the USY zeolite. The advantageous synergy between zeolites Y and ZSM-5 in the composite was demonstrated through the methanol-to-olefin reaction and the cracking of n-hexane.

Hydrogen production by photocatalytic dehydrogenation of formic acid

Laura Valenzuela, Zahraa Abou Khalil, Agnieszka Ruppert, Marco Daturi, Mohammad El-Roz, Nicolas Keller
Current Opinion in Chemical Engineering, 2025, 49, pp.101175. ⟨10.1016/j.coche.2025.101175⟩ | Publiée le 1 janvier 2025
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Abstract

This mini-review updates the most significant recent advances in the promising field of hydrogen production via photocatalytic dehydrogenation of formic acid. The focus is on utilizing formic acid both as a Liquid Organic Hydrogen Carrier and as an effective internal hydrogen source for driving hydrogenation reactions. We present a subjective overview of key-developments from the past three years in both aqueous and gasphase reactions, as well as in the rapidly evolving field of dual-mode photonic/thermal catalysis. Particular attention is given to insights into reaction mechanisms through operando FTIR studies, which allow for the direct observation of surface intermediates and the elucidation of possible reaction pathways.

Tuning intrinsic electronic properties via size-controlled hydrothermal crystalline transformation from tetragonal BiVO4 spheroids to monoclinic plates

Miquel Torras, Marie Anne Dourges, Justine Quinet, Anaëlle Demange, Thomas Cottineau, Jean-Pierre Delville, Marie-Hélène Delville, Thierry Toupance
ACS Applied Energy Materials, 2025, 8 (6), pp.3929-3941. ⟨10.1021/acsaem.5c00215⟩ | Publiée le 1 janvier 2025
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Abstract

This study reports the synthesis of monoclinic clinobisvanite BiVO4 crystals with well-defined {010} and {110} facets and nanometer sizes through controlled reactant addition and hydrothermal treatment. By adjustment of the Bi3+ precursor addition rate, nanoplates with significantly reduced edge length and thickness were obtained compared to conventional microplates. The formation process involves the nucleation of surfactant-coated tetragonal zircon BiVO4 nanocrystals, which aggregate into spheroids before being transformed into monoclinic clinobisvanite plates. A proposed model explains this size-tuning mechanism through partial dissolution, phase transformation, and facet-selective growth. Reducing the size of tetragonal zircon BiVO4 spheroids enhanced photocatalytic water oxidation, while for monoclinic clinobisvanite BiVO4 plates, size reduction had the opposite effect. Photoelectrochemical analysis revealed a shift from n-type behavior in microplates to p-type behavior in nanoplates under negative bias. These findings highlight the need to integrate size control with surface chemistry, bulk doping, and defect engineering to optimize BiVO4 for catalytic and electronic applications.

Pyrimidine‐Based Four‐Coordinate O^N^O Boron Complexes: Synthesis, Photophysical and Theoretical Studies, and TADF‐Based OLED Devices

Clément Diguet, Amparo Navarro, M. Paz Fernández-Liencres, Sonia B. Jiménez-Pulido, Nuria A. Illán-Cabeza, Abdullah Almutairi, Denis Tondelier, Sébastien Gauthier, Françoise Robin-Le Guen, Julián Rodríguez-López, Julien Massue, Sylvain Achelle
Chemistry - A European Journal, 2025, ⟨10.1002/chem.202501089⟩ | Publiée le 1 janvier 2025
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Abstract

This article describes the synthesis, along with the full photophysical and computational characterization, of a series of push‐pull boron complexes comprising a sterically hindered donor connected to a pyrimidine‐based O^N^O boron chelate. The dimethylacridan‐functionalized fluorophore appears to be the most emissive in the series, both in toluene solution and in the solid state (as a powder), displaying thermally activated delayed fluorescence (TADF) emission in degassed media due to a small singlet‐triplet energy gap. This result is in line with a previously reported pyridine analogue, which also exhibits delayed emission. Incorporation of this TADF compound into an organic light‐emitting diode led to the observation of intense electroluminescence, with EQEmax values reaching 9.7% at a 5 wt% doping concentration.

Thioether–NHC bidentate manganese complexes as efficient phosphine-free catalysts for hydrogenation at room temperature

Mariia Hruzd, Sabrina L Kleynemeyer, Christophe Michon, Stéphanie Bastin, Eric Pollet, Vincent Ritleng, Jean-Baptiste Sortais
Chemical Communications, 2025, 61 (14), pp.2969-2972. ⟨10.1039/D4CC06627H⟩ | Publiée le 1 janvier 2025
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Abstract

A series of four original phosphine-free thioether–NHC manganese complexes have been synthesised and fully characterized. These complexes have been applied as efficient catalysts for the hydrogenation of alkenes and ketones at room temperature, with low catalyst loadings (TON up to 900).

Impact of Side Chain Chemical Structure on Doping and Thermoelectric Properties of Oriented PBTTT Thin Films

Shubhradip Guchait, Saïd Oummouch, Pablo Durand, Narayanaswamy Kamatham, Badr Jismy, Laurent Herrmann, Stéphane Mery, Nicolas Leclerc, Martin Brinkmann
Small, 2024, 21 (6), pp.2410073. ⟨10.1002/smll.202410073⟩ | Publiée le 24 décembre 2024
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Abstract

In this contribution, doping of oriented thin films is investigated for three PBTTT polymers bearing different side chains including linear alkyl ─(CH2)12─H, single ether ─(CH2)7─O─(CH2)4─H and alkyl-siloxane ─(CH2)5─(Si(CH3)2O)2─Si(CH3)3 A combination of transmission electron microscopy, polarized UV–vis–NIR spectroscopy and transport measurements helps uncover the essential role of the chemical nature of side chains on the efficacy of the doping and on the resulting thermoelectric performances in oriented PBTTT films. Siloxane side chains help to reach record alignment level of PBTTT with dichroic ratio beyond 50 for an optimized rubbing temperature but they impede effective doping of PBTTT crystals with F6TCNNQ, resulting in very poor TE properties. By contrast, doping the amorphous phase of all three PBTTTs with magic blue (MB) results in excellent TE performances. Both, chemical nature of side chains and semi-crystalline structure of the polymer determine the efficacy of doping. The use of siloxane side chains further impacts the scaling laws S ∝ σ−1/s between the Seebeck coefficient S and the charge conductivity σ. An unexpected s = 2 exponent is observed and tentatively attributed to the dimensionality of charge transport in the highly oriented mesophase of PBTTT.

Two-step conversion of waste plastic into light olefins and aromatics on metal-free carbon felt catalyst under radiofrequency heating

Cuong Duong-Viet, Lai Truong-Phuoc, Jean-Mario Nhut, Lam Nguyen-Dinh, Christophe Michon, Charlotte Pham, Cuong Pham-Huu
Chemical Engineering Journal, 2024, 502, pp.158158. ⟨10.1016/j.cej.2024.158158⟩ | Publiée le 15 décembre 2024
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Abstract

Plastic waste represents the most serious global problem for ecosystem and environmental balance, which urges the development of new recycling process for the improvement of circular economy. Chemical recycling of waste plastic to produce back light olefins, ethylene and propylene, is of high interest to reduce the use of fossil sources and allows the direct reuse of waste plastic with a concomitant reduction of associated carbon footprint. In this present work, we report on the development of metal-free carbon catalyst, with high deactivation resistance, coupled with contactless induction heating with high heat efficiency and low energy for the direct conversion of waste plastics back to light olefins and aromatics.</p><p>Such process is critical yet challenging in industrial applications. Relevant characterizations proved that exclusive surface heating, significantly improves the selective cracking of waste plastics, either model or industrial ones, to produce light olefins and aromatics during longterm operating process. The commercial carbon felt displays remarkable performance for the chemical recycling of waste plastics, surpassing the conventional metal and zeolite catalysts for such relevant environmental problem. The influence of an alternating magnetic field on the catalytic mechanism is advanced to explain such high performance.

Depletion-Induced Tunable Assembly of Complementary Platonic Solids

Rahul Nag, Nina Rouvière, Jaime Gabriel Trazo, Jules Marcone, Nika Kutalia, Claire Goldmann, Marianne Impéror-Clerc, Damien Alloyeau, Doru Constantin, Cyrille Hamon
Nano Letters, 2024, 24 (51), pp.16368-16373. ⟨10.1021/acs.nanolett.4c04923⟩ | Publiée le 12 décembre 2024
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Abstract

Multicomponent self-assembly has been explored to create novel metamaterials from nanoparticles of different sizes and compositions, but the assembly of nanoparticles with complementary shapes remains rare. Recent binary assemblies were mediated by DNA base pairing or induced by solvent evaporation. Here, we introduce depletion-induced self-assembly (DISA) as a novel approach for constructing tunable binary lattices. In situ structural analysis in the real and the reciprocal spaces demonstrates DISA of a binary mixture of octahedra and tetrahedra into extended supercrystals with Fm3 m symmetry. The inter-particle distance, adjustable by depletant concentration, offers a versatile method for assembling nanoparticles into ordered structures while they remain dispersed in a liquid phase. We show that DISA can control the packing fraction of such binary supercrystals between φ=0.37 and φ=0.66, much lower than dense packing in the dry state. These findings highlight DISA's potential for creating complex and highly ordered metamaterials with tailored properties.

Surface chemistry study on the SOEC electrodes during high-temperature H2O electrolysis

Jinming Zhang
Theoretical and/or physical chemistry. Université de Strasbourg, 2024. English. ⟨NNT : 2024STRAF049⟩ | Publiée le 12 décembre 2024
Thèse

Abstract

This thesis focuses on the electrochemical performance and surface chemistry of advanced Solid Oxide Electrolysis Cells (SOECs), with particular emphasis on the behavior of Ni/YSZ electrodes in water electrolysis. SOECs hold significant potential for hydrogen production through water electrolysis and energy storage, while Solid Oxide Fuel Cells (SOFCs) use hydrogen for power generation. Given the cost-effectiveness, thermal compatibility, and high conductivity of nickel-based composites, widely used in industrial applications, this research concentrates on improving these materials through surface modification. Using Near Ambient Pressure X-ray Photoelectron Spectroscopy (NAP-XPS), the interaction between Ni/YSZ electrodes and water vapor under both open-circuit and polarization conditions was investigated. Modifications to traditional porous Ni/YSZ cathodes were made to directly observe the functional electrode areas near the YSZ electrolyte. Results revealed dynamic changes in the oxidation states and composition of Ni/YSZ in H2 and H2O atmospheres. Additionally, the study emphasizes the impact of electrode oxidation on degradation during electrolysis and highlights the relationship between the nickel surface oxidation state and the cell’s electrochemical performance. Cerium-based nanoparticles (NPs) were introduced to modify the surface of Ni/YSZ electrodes. Two types of NPs—Ni-doped ceria (NiCeOx) and undoped ceria (CeOy)—were synthesized and used to impregnate pre-fabricated Ni/YSZ cermet electrodes. The comparative study demonstrated that NiCeOx exhibited superior performance due to enhanced dispersion and reduced particle size. Synchrotron results further showed that Ni doping altered the redox properties of ceria, leading to stronger reduction of Ni/YSZ compared to CeOy, which increased the number of active sites and improved electrolysis efficiency. Additionally, the thesis presents experimental trials involving vanadium and cobalt-doped ceria nanoparticles, although their performance enhancements were limited. Finaly the surface state of La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) electrodes were explored, focusing on Sr segregation. The study also examined Pr6O11 as a potential alternative electrocatalyst for SOEC applications. Overall, the research highlights the significant impact of nanoparticle surface modifications on the electrochemical performance of electrodes in water electrolysis, revealing substantial improvements in both efficiency and stability. The combination of innovative material design and advanced characterization techniques offers valuable insights for the future of sustainable energy solutions.

Membrane reactors for methanol synthesis : from material science to process simulations

Vincent Gautier
Other. Université de Strasbourg, 2024. English. ⟨NNT : 2024STRAF073⟩ | Publiée le 10 décembre 2024
Thèse

Abstract

Catalytic hydrogenation of CO2 to methanol, using hydrogen derived from low-carbon energy sources, offers a sustainable alternative to fossil hydrocarbons. However, in traditional fixed-bed reactors, large quantities of water are produced, limiting yields. To address this, catalytic reactors incorporating membranes that can selectively separate water have demonstrated their effectiveness. To compare membrane reactors with conventional reactors for methanol synthesis, an approach combining membrane material development, catalyst design, and process simulations is proposed. By testing advanced membrane materials and suitable catalysts, this study aims to generate key data to evaluate the viability of membrane reactors and identify areas for improvement in their design.

One-Stage Aqueous Colloid Process: From the Synthesis of Few-Layer Graphene–PVA Colloids to Efficient Electrospun Nanofibers

Kamel Shoueir, Emeline Lobry, Guy Schlatter, Izabela Janowska
ChemEngineering, 2024, 8 (6), ⟨10.3390/chemengineering8060126⟩ | Publiée le 9 décembre 2024
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Abstract

Sustainability requirements must be met by the appropriate selection of efficient and environmentally friendly materials and processes. We present materials obtained via all-in-water methods: first, few-layer graphene (FLG)-polyvinyl alcohol (PVA) colloids and then electrospun PVA-FLG fibers. The effects of the FLG concentration, and indirectly of ultrasound, are reflected via the modification of the structural and physical properties, including the microstructure, viscosity, thermal degradation and mechanical properties, of colloids and fiber mats. The primary results are highly encouraging for further optimization and the development of conductive, and mechanically resistant, materials.

Biomimetic three-dimensional scaffolds with aligned electrospun nanofibers and enlarged pores for enhanced cardiac cell colonization

Florence Flaig, Anne Hébraud, Emeline Lobry, Damien Favier, Antoine Egele, Patrick Kékicheff, Pierre Joanne, Onnik Agbulut, Guy Schlatter
Materials & Design, 2024, 248, pp.113481. ⟨10.1016/j.matdes.2024.113481⟩ | Publiée le 3 décembre 2024
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Abstract

Among the wide range of biomimetic scaffolds, those made of aligned nanofibers represent an important class for tissue engineering applications, and particularly for cardiac repair. Electrospinning is a powerful technique allowing the fabrication of scaffolds with aligned nanofibers. However, the resulting morphology is characterized by low porosity and small pore size due to the formation of a compact structure of aligned fibers preventing cell colonization inside the scaffold. In the present work, supported by numerical simulation, it is demonstrated that when optimal electrostatic interactions occur during the simultaneous deposition of electrospun nanofibers and electrosprayed microparticles on a collector rotating at high speed, a 3D structured scaffold is obtained. Thanks to a self-organization mechanism, islands of microparticles intercalate inside a network of loosely packed and highly aligned nanofibers. In the case of poly(lactic acid) electrospinning and poly(glycerol sebacate)/cyclodextrin electrospraying, the resulting 3D biomimetic scaffold, deeply investigated by X-ray microtomography and mechanical characterization, shows an open porosity with enlarged interconnected pores with a mechanical behavior mimicking that of cardiac tissue. Finally, after functionalizing the fiber surface using laminin, it is shown an efficient 3D colonization of cardiac cells through a network of aligned nanofibers.

From macro to mesoporous semi-permeable membranes via green-electrospinning : towards a bioartificial pancreas

Bryan Gross
Material chemistry. Université de Strasbourg, 2024. English. ⟨NNT : 2024STRAE029⟩ | Publiée le 3 décembre 2024
Thèse

Abstract

Semipermeable membranes play a crucial role in fields ranging from filtration to biomedical applications, such as encapsulation devices for the treatment of type 1 diabetes. These membranes are designed to allow the selective passage of small molecules while blocking others of higher molar mass. The efficiency of membranes depends on several factors, including their structure, morphology and chemical composition, which must be optimized for dedicated applications. The development of semipermeable membranes suitable for medical devices is of paramount importance in improving the quality of current treatments. This thesis project focuses on the design of semipermeable membranes dedicated to the fabrication of a bioartificial pancreas for the treatment of type 1 diabetes. The main goal of this work is to elaborate a membrane that enables an efficient insulin exchange by diffusion, while protecting insulin-secreting cells from attack by the immune system. To achieve this, strategies of electrospinning, a process for elaborating nanofibrous materials, coupled with thermomechanical post-processing were studied in relation to the morphological properties of the resulting membranes. Using environmentally friendly processes, we demonstrated that mesoporous membranes with an average pore size of around 20 nm can be obtained, enabling selective permeability according to molecule size and which could ultimately be used to produce a bioartificial pancreas.

First evidence of age-dependent decreases in non-persistent pesticide mixtures in nestlings of a farmland raptor

Elva Fuentes, Jérôme Moreau, Maurice Millet, Vincent Bretagnolle, Karine Monceau
Environmental Research, 2024, 263 (2), pp.120179. ⟨10.1016/j.envres.2024.120179⟩ | Publiée le 1 décembre 2024
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Abstract

<div><p>Intensive use of synthetic pesticides in conventional agriculture may harm non-target organisms through sublethal effects on life-history traits. Farmland birds are exposed throughout their life cycle, but the fate of nonpersistent pesticide mixtures in wild birds remains unknown. In this study, we investigated changes in pesticide contamination levels in Montagu's harrier (Circus pygargus) nestlings during their growth. In total, 35 chicks were sampled twice during the rearing period, and blood was tested for 116 pesticides to assess pesticide load through two proxies; the number of pesticides detected and the sum of pesticide concentrations. Body mass and tarsus length were also measured to estimate body condition. Across the two sampling times, nine herbicides, five insecticides and four fungicides were detected. Contamination levels decreased significantly with nestling age irrespective of sampling date, and there was no relationship between pesticide load and body condition. Moreover, concentrations of chlorpyrifos-methyl, fenpropidin, metamitron, picloram and S-metolachlor, all detected throughout the rearing period, were unrelated to any of the explanatory variables. However, ethofumesate concentrations decreased significantly with chick age. This study provides the first evidence that nonpersistent pesticide mixtures can decrease with age in wild nestlings. This has implications for understanding how chicks are contaminated and provides new insights on pesticide fate within organisms.</p></div>

Mechanism of the Hydrazine Hydrate Electrooxidation Reaction on Metallic Ni Electrodes in Alkaline Media as Revealed by Electrochemical Methods, Online DEMS and Ex situ XPS

Evgeniia Vorms, Vasiliki Papaefthymiou, Théo Faverge, Antoine Bonnefont, Marian Chatenet, Elena Savinova, Alexandr Oshchepkov
Electrochimica Acta, 2024, 507, pp.145056. ⟨10.1016/j.electacta.2024.145056⟩ | Publiée le 1 décembre 2024
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Abstract

<div><p>Metallic Ni surface was examined as a catalyst for the hydrazine hydrate oxidation reaction (HHOR) by cyclic voltammetry, chronoamperometry, and on-line differential electrochemical massspectrometry (DEMS). It was found that N2 is a sole gaseous product formed during the HHOR on Ni and 4 electrons are transferred in the process, which corresponds to a complete oxidation of the hydrazine molecule. The mechanism of the HHOR on the Ni surface involves OH -and adsorbed OHads intermediate, the latter improving the rate of the HHOR. Ni catalysts were found to be poisoned during the HHOR, the extent of poisoning depending on the number of surface sites, hydrazine concentration, and the α-Ni(OH)2 coverage. Ex situ X-ray photoelectron spectroscopy (XPS) measurements were performed to characterize the species poisoning Ni surface.</p></div>

Selected contributions from the 8th International conference on semiconductor photochemistry – Introduction by guest editors

Nicolas Keller, Fernando Fresno, Sixto Malato, Frank Osterloh
Catalysis Today, 2024, 442, pp.114921. ⟨10.1016/j.cattod.2024.114921⟩ | Publiée le 1 décembre 2024
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H2 production by formic acid decomposition on ceria-modified Ru/TiO2 catalysts under dual photonic/thermal excitation

José Montes-Monroy, Ramón Manzorro, Laura Valenzuela, Javier Ivanez, José Pérez-Omil, Nicolas Keller
Catalysis Today, 2024, 441, pp.114852. ⟨10.1016/j.cattod.2024.114852⟩ | Publiée le 1 novembre 2024
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Abstract

Formic acid is a high-prospect energy carrier of sustainable H2 and can also favorably supply sustainable H2 to hydrogenation catalysts in replacement of external pressurized H2. A solar photon-assisted synthesis method was successfully implemented for decorating a ceriamodified TiO2 support with ultra-dispersed Ru nanoclusters with a large fraction of low atomicity species and Ru single atoms. Adding ceria to the TiO2 support at a quarter of the theoretical monolayer is a suited surface modification for partially reducing the detrimental intrinsic activity of the bare TiO2 surface for the dehydration of formic acid, what allows the undesired formation of CO to be mitigated and higher selectivities to H2 to be achieved when using the Ru/CeO2/TiO2 catalyst. The dual (combined) photonic/thermal excitation of the Ru/CeO2/TiO2 catalyst boosted the H2 production rate and allowed the dehydrogenation reaction to be conducted at a lower temperature compared to the dark conditions, for instance with a 80°C downshift at 190°C, what corresponded to a 42% relative gain compared to the dark conditions. Advanced electron microscopy characterization has been crucial to unveil the atomic-level nature of the Ru/CeO2/TiO2 photo-thermo catalyst, bringing to light the presence of ultra-dispersed metallic Ru nanoclusters, both (i) decorating nanometric size flat CeO2 nanoparticles interfaced in epitaxy with high-index TiO2 facets, and (ii) being homogeneously distributed over the TiO2 surface in close vicinity with low atomicity CeO2 species.

Ru–modified graphitic carbon nitride for the solar light–driven photocatalytic H2O2 synthesis

Laura Valenzuela, Frael-Benjamin Yimbou, Antoine Ewin, Christophe Lefèvre, Ramón Manzorro, Nicolas Keller
Catalysis Today, 2024, 441, pp.114881. ⟨10.1016/j.cattod.2024.114881⟩ | Publiée le 1 novembre 2024
Article dans une revue

Abstract

Hydrogen peroxide (H2O2) is an efficient and environmentally friendly oxidant as well as a promising energy-carrier alternative to hydrogen. Its solar light-driven photocatalytic synthesis from H2O and O2 is a high-prospect sustainable alternative to the industrial anthraquinone process. Hybrid Ru-modified graphitic carbon nitride (g-C3N4) catalysts were prepared by thermal polymerisation of melamine/Ru(III) acetylacetonate mixtures, and subsequent thermal exfoliation. Simultaneous Ru incorporation and thermal exfoliation impacted the morphology and the structure of the g-C3N4 sheets, and low-atomicity Ru species with small nanoclusters and single atoms were observed only in the Ru-modified exfoliated g-C3N4 photocatalysts. We demonstrated the potential of a joint thermal exfoliation and modification with Ru to enhance the H2O2 synthesis efficiency of the g-C3N4 photocatalyst under simulated sunlight. A volcano-type behavior was observed with increasing the Ru content, and the best performance was obtained for exfoliated g-C3N4 with an ultra-low Ru content of 0.019 wt.%, that outperformed both its bulk counterpart and the pristine exfoliated reference in terms of initial H2O2 synthesis rate and H2O2 formation rate constant. The enhanced performance was attributed to the presence of highly dispersed low atomicity Ru as well as to more accessible active sites and carrier migration channels. Quenching experiments revealed a mixed reactional pathway involving both two-step one-electron and one-step two-electron O2 reduction in the photocatalytic H2O2 production.

Portable temperature-controlled permeation device for the generation of formaldehyde gas standard

Audrey Grandjean, Anaïs Becker, Coralie Kustner, Michel Wolf, Christophe Sutter, Romain Severac, Jean-Philippe Amiet, Damien Bazin, Stéphane Le Calvé
Microchemical Journal, 2024, 206, pp.111544. ⟨10.1016/j.microc.2024.111544⟩ | Publiée le 1 novembre 2024
Article dans une revue

Abstract

Formaldehyde is a major indoor air pollutant. Accurate analysis of airborne formaldehyde is essential for effective monitoring and risk assessment. For many formaldehyde analysis techniques, the accuracy of the results depends on the calibration system. Existing formaldehyde calibration methods often face limitations, such as instability over time or limited concentration range. They also lack practicality for on-field calibration either because of bulkiness or because of high gas consumption. To address these challenges, a device using a paraformaldehyde permeation tube within a custom-built, temperature-controlled system was designed and evaluated.</p><p>The device weighs less than 3 kg and operates using a nitrogen source. Its low gas consumption (30-100 mL min -1 ) enables the use of a portable gas cylinder of pure nitrogen (&lt;2 kg) as gas supply. Formaldehyde concentrations ranging from 8.3 to 464 µg/m -3 were successfully generated, demonstrating the device's versatility. A custom-built high-emission permeation tube could generate concentrations from 5 940 to 49 471 µg/m -3 using the same system. Additionally, the emission rate is independent of the flow rate and follows Antoine's law with respect to temperature, enabling accurate prediction of concentration in various conditions over the evaluated range and beyond. Furthermore, the study confirms the long-term stability (1 year) of the low-emission paraformaldehyde permeation tube, with emission rates remaining mostly within ± 5 % of the average value for each temperature.</p><p>The temperature-controlled permeation system approach enabled rapid stabilisation of formaldehyde generation at various concentrations and low flow rates, eliminating the need for additional dilution equipment and facilitating on-site instrument calibration at various gas concentrations. This reliable and efficient portable formaldehyde generator offers a valuable solution for field calibration, providing accurate and stable reference gas for diverse analytical needs.

Probing Prismatic/Basal Surfaces of Carbon Materials upon Graphitization by Gas Adsorption, TPD, and XPS

Mathieu Vidal, Maryam Dehaghani, Takeharu Yoshii, Keigo Wakabayashi, Ignacio Cameán, Mathias Barreau, Nolwenn Le Breton, Iann Gerber, Pascal Puech, Athanassios Boudalis, Thomas Blon, Tobias Placke, Hirotomo Nishihara, Spyridon Zafeiratos, Philippe Serp
Journal of Physical Chemistry C, 2024, 128 (44), pp.18993-19012. ⟨10.1021/acs.jpcc.4c06100⟩ | Publiée le 25 octobre 2024
Article dans une revue

Abstract

The prismatic and basal plane surfaces of carbon materials dictate most of their anisotropic physicochemical properties. For many applications where interfacial interactions are key, high-temperature treatments are performed to achieve their graphitization. Such treatment changes edge and basal plane configuration, impacting the energetical behavior of the carbon surfaces, particularly for carbon nanomaterials, with consequences for their properties. Therefore, efforts should be devoted to probing the prismatic and basal plane surfaces of such materials to understand their surface properties for the development of high-performance carbon materials. Herein, we investigate the effect of high-temperature graphitization (3073 K) on the structural, textural, chemical, and magnetic properties of graphitic carbon nanomaterials presenting different prismatic/basal surfaces. The evolution of the prismatic/basal surfaces has been probed by nitrogen adsorption, temperature-programmed desorption, and X-ray photoelectron spectroscopy (XPS). Although these three techniques are in agreement for the starting materials, they diverge in the case of materials that have undergone thermal annealing. This is linked in particular to the formation of loops following the heat treatment, which are identified as belonging to the prismatic surface by XPS and modified the N2 adsorptive potentials. Formed small vacancies on closed loops and nonperfect closure of certain loops can contribute to the accumulation of very reactive defects at the loop level. The thermal annealing also has a pronounced influence on the magnetic properties of these materials. Interestingly, we show that a positive correlation exists between the spin density of the annealed graphitic carbons and their prismatic and basal surfaces.

Influence of perovskite catalysts synthesis methods: Application to dry methane reforming

Faicel Belgacem, Raphaël Schneider, Jean-François Portha, Ghouti Medjahdi, Lavinia Balan, Ksenia Parkhomenko, Anne-Cécile Roger, Laurent Falk
International Journal of Hydrogen Energy, 2024, 91, pp.977-988. ⟨10.1016/j.ijhydene.2024.10.119⟩ | Publiée le 20 octobre 2024
Article dans une revue

Abstract

Perovskites refer to ceramic materials with an ABO3 structure. The optimization of synthesis parameters and material composition can enhance the catalytic efficiency in various chemical reactions, such as dry methane reforming. In order to highlight the differences in the catalytic properties, this study aims to compare three synthesis methods (citrate, auto-combustion and Pechini) for a same perovskite formulation namely SrZr0·5Ni0·4Fe0·1O3. The crystal structure and reducibility profile are determined by XRD and TPR experiences respectively. Surface properties and composition are identified by chemisorption tests (allowing the study of basicity and nickel dispersion) and XPS analyses, respectively. Isothermal catalytic experiences from 600 to 750 °C, under atmospheric pressure and for a WHSV of 40L/(h.g) together with stability tests for 25 h at 750 °C were conducted. The outcomes show the importance of properly choosing the perovskite preparation methods in order to achieve the desired surface, structural and reactivity properties.

Washable oil-coated structured support for passive outdoor particulate matters trapping

Tuan-Hoang Trinh, Charlotte Pham, Jean-Mario Nhut, Fabrice Vigneron, Christophe Vieville, Nicolas Reiminger, Xavier Jurado, Housseinou Ba, Thierry Romero, Lai Truong-Phuoc, Nicolas Hertel, Christophe Legorgeu, Loïc Vidal, Cuong Pham-Huu
Sustainable Cities and Society, 2024, 116, pp.105884. ⟨10.1016/j.scs.2024.105884⟩ | Publiée le 18 octobre 2024
Article dans une revue

Glucose oxidation reaction on ni-based electrodes studied using electrochemical methods, modeling and operando spectroscopies

Alejandra Medrano-Banda
Other. Université de Strasbourg, 2024. English. ⟨NNT : 2024STRAF075⟩ | Publiée le 16 octobre 2024
Thèse

Abstract

This study explores the glucose oxidation reaction (GOR) on Ni-based electrodes via electrochemical measurements, microkinetic modeling, and in situ/operando techniques. The GOR on Ni(OH)2/NiOOH follows an EC' mechanism, where Ni(OH)2 is required for glucose adsorption and NiOOH for its chemical oxidation. X-ray absorption spectroscopy (XAS) confirms the electrochemical transformation of Ni(OH)2 into NiOOH and its reduction by glucose. XAS also attributes early glucose electrooxidation to the initial steps of this transformation. Infrared spectroscopy and liquid chromatography reveal C-C bond cleavage, producing formate and arabinose. The study of other molecules shows that only vicinal diols with a third oxygen-containing group undergo EC' oxidation at low potential. This work highlights GOR’s potential to lower electrolyzer cell voltage, promoting sustainable hydrogen production.

Ru/TiO2 catalyzed high‐yield synthesis of furanic diols by 5‐hydroxymethylfurfural hydrogenation with switchable selectivity

Preeti Kashyap, Marcin Jędrzejczyk, Maryam Akhgar, Jaroslav Aubrecht, David Kubička, Nicolas Keller, Agnieszka Malgorzata Ruppert
ChemCatChem, 2024, ⟨10.1002/cctc.202401433⟩ | Publiée le 16 octobre 2024
Article dans une revue

Abstract

5‐Hydroxymethylfurfural (HMF) is a versatile platform molecule that can be derived from biomass feedstocks and catalytically converted into various value‐added chemicals. In this work, selective hydrogenation of HMF is investigated to produce valuable furan‐based diols, namely 2,5‐bis‐hydroxymethylfuran (BHMF) and 2,5‐bis‐hydroxymethyltetrahydrofuran (BHMTHF), using TiO2 supported Ru catalysts. The catalyst performance was fine‐tuned to achieve over 98% yield to BHMF and BHMTHF under optimized reaction conditions with very good recyclability. We pointed out several key factors allowing to maximize the yield towards the respective diols. Features such as the Ru nanoparticle size, the strength of metal‐support interactions and the presence of residual chlorine were found to significantly influence the reaction. A characteristic volcano‐shaped relationship was obtained between the particle size and the catalytic activity giving the highest diol yield for an optimum Ru nanoparticle size of 1.6 nm. Further, metal‐support interactions were found to be responsible for providing optimum Ru‐TiOx interfacial surface sites and chlorine was affecting the electronic properties of Ru nanoparticles, potentially benefiting to the selective formation of BHMF. The reaction time was shown to control the hydrogenation of the furan ring and the selectivity of the reaction, that can be directed optimally towards BHMF or BHMTHF.

A New Life for Tionite Industrial Waste: Regeneration Strategy towards Photocatalytic Applications

Lorenzo Viganò, Barbara Di Credico, Francesco Parrino, Nicolas Keller, Maurizio Bellotto, Massimiliano D’arienzo, Silvia Mostoni, Saverio Latorrata, Anna Dotti, Roberto Nisticò, Roberto Scotti
ChemSusChem, 2024, ⟨10.1002/cssc.202401698⟩ | Publiée le 15 octobre 2024
Article dans une revue

Abstract

Industrial waste management is an urgent problem to solve possibly by recycling, reuse and recovery of resources. In this framework, the sludge of the TiO2 manufacturing, called tionite, is of certain interest because it contains metallic oxide‐bearing impurities, dangerous to the environment. Hence, we propose a strategy to recover TiO2 from tionite, towards its effective re‐use as a photocatalyst. In detail, tionite was treated under acidic or alkaline conditions to remove impurities and improve the TiO2 accessibility, and each single purification step was monitored by a thorough multi‐technique characterization. The photocatalytic activity of the modified tionite materials was tested for the partial oxidation of ferulic acid to vanillin, a relevant sustainable green reaction, being vanillin an industrially relevant high added value compound and ferulic acid an abundant component of lignin present in industrial waste. All the tionite catalysts have shown significant efficiency in terms of vanillin selectivity respect to the benchmark TiO2 P25. In particular, the sample treated under acidic conditions showed the best performances, due to specific interaction between the organic substrates and the catalyst. Results demonstrated that an industrial waste such as tionite can be valorized by proposing a tailored regeneration strategy.

Structural design of inorganic transition metal oxide / carbon composite materials for optimizing their electrochemical performance in energy storage devices

Taylan Karakoç
Theoretical and/or physical chemistry. Université de Strasbourg, 2024. English. ⟨NNT : 2024STRAF053⟩ | Publiée le 11 octobre 2024
Thèse

Abstract

Nitrogen doping of microporous activated carbon showed impressive electrochemical performances as electrodes for supercapacitors, reaching over 320 F/g in acidic media. This study highlighted the advantage of doping with nitrogen-containing functional groups (e.g. pyrrole), which can generate additional charge storage through pseudocapacitance. The use of a simplified geometric model to fit impedance data demonstrated its usefulness for in-depth analysis of the properties of porous carbon electrodes and their measured capacitances. Various observations obtained by in situ characterization using temperature-controlled diffuse reflectance Fourier transform infrared spectroscopy (TD-DRIFTS) describe the importance of manganese(II) ion complexation in the starting preparation. The addition of ammonium citrate, a strong complexing agent, provides greater uniformity and stability throughout solvent evaporation, preventing the formation of hydroxide and/or other metal salts/complexes. Pure phases can be produced, notably mesoporous Mn3O4 spinel, which showed capacitances in excess of 100 F/g and 370 μF/cm2 in an aqueous basic medium. The engineering of Fe3O4 iron spinel structures was enabled by the polyol synthesis method in hollow "raspberry"-shaped nanostructures, as well as few-layer graphene composites (FLG). For supercapacitors, a composite with a moderate but low Fe3O4 content showed capacitances similar to Mn3O4 oxide, with over 350 μF/cm2 achievable. As conversion reaction electrode materials, very high capacities of up to 923 mAh/g were achieved, with cycle retention enhanced by the addition of FLG, serving as an electronically conductive support and preventing the isolation of iron metal particles, improving the reversibility of the conversion reaction.

Dégagement d'oxygène en milieu alcalin à partir de spinelles Co3O4 supportés sur acier inoxydable

Garance Cossard, Elena Savinova, Éric Sibert, Marian Chatenet, Gwénaëlle Kéranguéven
4ème Réunion Plénières de la Fédération de l'Hydrogène, Fédération de l'Hydrogène (FRH2) du CNRS, Oct 2024, La Grande Motte (34280), France | Publiée le 7 octobre 2024
Communication dans un congrès

Abstract

L’électrolyse à membrane échangeuse d’anions permet de considérer l’utilisation d’une vaste gamme de catalyseurs dérivés des métaux de transition, disponibles et abondants, pour la production décarbonée d’hydrogène. Parmi ceux-ci, les aciers inoxydables et les spinelles Co3O4 sont deux catégories de matériaux très compétitifs pour la réaction du dégagement d’oxygène, à l’anode de l’électrolyseur. D’abord, l’acier inoxydable, a la propriété remarquable de former à sa surface des oxo-hydroxydes de nickel et de fer, en cours de fonctionnement [1]. Néanmoins, il est difficile de texturer ces aciers sous forme de nanoparticules, avec une importante surface développée, ce qui n’est pas idéale pour une utilisation en électrolyse. D’autre part, les spinelles de cobalt Co3O4 sont des catalyseurs efficaces et stables pour le dégagement d’oxygène, qui peuvent être synthétisés sous formes de nanoparticules par des procédés simples et maîtrisés. En revanche, la faible conductivité de ces spinelles exigent qu’ils soient déposés sur un support conducteur [2]. Il a alors été considéré de combiner les avantages de ces deux matériaux en opérant la synthèse et le dépôt des spinelles Co3O4 sur des fibres d’acier inoxydable par le procédé d’autocombustion [3]. Les catalyseurs obtenus à l’issue de cette synthèse présentent à leur surface un dépôt de spinelles fin et poreux (Fig. 1A). Cette porosité permet notablement d’augmenter la surface spécifique active, ce qui s’accompagne d’une augmentation des performances des catalyseurs pour le dégagement d’oxygène (Fig. 1B). Par ailleurs, les matériaux ainsi synthétisés peuvent également subir une activation suite à un cyclage en potentiel, induite par une reconstruction structurale à la surface de l’électrode (Fig. 1B). Tous ces points seront développés dans l’exposé.

Determination of PAHs in Surface Sediments along Dakar Coast Using QuECHERS and Gas Chromatography Coupled to Tandem Mass Spectrometry

Dame Cisse, Birame Ndiaye, Cheikh Tidiane Dione, Ibrahima Diagne, Maoudo Hane, Mame Mor Dione, Sitor Diouf, Mamadou Sarr, Ousmane Ka, Maurice Millet, Momar Ndiaye, Seydou Ba
Chemical Science International Journal, 2024, 33 (6), pp.1-15. ⟨10.9734/CSJI/2024/v33i6919⟩ | Publiée le 5 octobre 2024
Article dans une revue

Abstract

Untreated sewage, which is a source of many pollutants, can also deposit a mass of sediment on beaches. These sediments can trap many pollutants, including PAHs, which are toxic and mutagenic to DNA and RNA in organisms. In this study, we investigated the contamination of sediments from the beaches of Hann, Soumbédioune and Ngor on the coast of Dakar by the 16 priority PAHs identified by the US Environmental Protection Agency (EPA). The sediment samples were taken between June and September 2018. Analyses were carried out using the GC-MS technique in tandem mode. For extraction and purification, QuECHERS and dSPE RESTEK salts were used, respectively, with recoveries ranging from 83.87 to 98.10%. For PAH repeatability, the %RSD values ranged from 0.02 to 3.08%, while those obtained for reproducibility varied from 0.01 to 1.29%. The results show that the highest levels were recorded in September: pyrene with 35.763 µg.Kg-1, benzo(a)anthracene (22.396 µg.Kg-1) and benzo(k)fluoranthene (18.678 µg.Kg-1) in Hann. At Soumbédioune, dibenzo(a,h)anthracene is at 15.782 µg.Kg-1 and at Ngor coronene has the highest content (9.030 µg.Kg-1). Analysis of the Shapiro-Wilk normality test reveals that most of the p-values for the variances of the various PAHs are above the 5% threshold. For the Levene test, apart from pyrene, the rest of the hydrocarbons satisfied the heteroscedacity hypothesis (inequality of at least two variances) with p-values below the 5% threshold.

Development of new biobased and aromatic covalent adaptable networks from lignins

Lisa Sougrati
Polymers. Université de Strasbourg, 2024. English. ⟨NNT : 2024STRAE020⟩ | Publiée le 3 octobre 2024
Thèse

Abstract

Lignocellulosic biomass represents the largest source of renewable aromatic compounds on Earth. Among the various compounds derived from this feedstock, lignin emerged as an attractive source of phenols for the synthesis of sustainable polymers. Because of its high functionality, lignin is widely used for the preparation of thermosets, whose crosslinked structure considerably limits their recyclability potential. Covalent adaptable networks (CANs) have revealed to be an elegant strategy to address the recyclability issues of traditional thermosets without compromising on properties. In this context, new macromolecular architectures with controlled end-of-life were designed from lignin, embracing a circular bioeconomy philosophy. New lignin chemical modifications were developed and characterized. Innovative dynamic chemistries were used to synthesize new polymers. Thermal and mechanical properties of theses architectures were characterized. Rheological behaviors of the different dynamic chemistries employed was investigated to determinate the polymers optimal thermo-mechanical recycling conditions. Their recyclability potential was highlighted through physical and chemical recycling studies. The designed systems present tunable properties making them suitable for a wide range of applications, revealing their potential as innovative materials for a more sustainable future.

Prompt and Thermally Activated Delayed Fluorescence of Quinazoline‐Based Derivatives: a Joint Experimental and Theoretical Study

Maxime Hodée, Tatiana Moshkina, Julien Massue, Arnaud Fihey, Thierry Roisnel, Claudine Katan, Emiliya Nosova, Sylvain Achelle
ChemPhotoChem, 2024, 9, pp.e202400259. ⟨10.1002/cptc.202400259⟩ | Publiée le 1 octobre 2024
Article dans une revue

Abstract

During the last decade, thermally activated delayed fluorescence has been the topic of intense research due to its great potential for highly efficient all organic light emitting devices. While the quinazoline heterocycle has been used for its electron withdrawing ability in various push‐pull dyes, quinazoline derivatives have been rarely considered for TADF emitters. Here we design and synthesize a new series of dyes with phenyl‐ or methoxy‐substituted quinazoline rings combined with 9,9‐dimethylacridan, phenoxazine or phenothiazine and either 1,4‐phenylene or 2,5‐thienylene as linker. Combining optical spectroscopy and theoretical investigations, we demonstrate that delayed fluorescence is observed in the solid state for the phenyl‐substituted quinazoline derivatives for which both quasi‐equatorial and quasi‐axial conformations are predicted to coexist. Calculations further suggest that the reversed intersystem crossing is likely to involve the second triplet state that shows small energy splitting with the first singlet state. These results prompt further investigations of phenyl‐substituted quinazoline based dyes for TADF.

Synthèse et caractérisation de solutions solides ZnO/CeO2 et CeO2/La2O3/ZnO pour la minéralisation photocatalytique du diclofénac de sodium en solution aqueuse

Meryem Abbadi
Matériaux. Université de Strasbourg; Université Mohammed V (Rabat ; 1957-..), 2024. Français. ⟨NNT : 2024STRAF019⟩ | Publiée le 23 septembre 2024
Thèse

Abstract

La présence de résidus pharmaceutiques dans les milieux aquatiques est une préoccupation majeure. Parmi ceux-ci, le diclofénac de sodium est un anti-inflammatoire non stéroïdien détecté dans les eaux usées. Parmi les méthodes de traitement de ces eaux, la photocatalyse hétérogène constitue une méthode efficace et prometteuse. Comparé au TiO2, largement utilisé en photocatalyse, le ZnO est une alternative présentant une activité photocatalytique intéressante sous irradiation UV. Cependant, son activité photocatalytique est atténuée par une recombinaison de charge plus rapide et une mauvaise séparation des paires électron-trou sous irradiation visible, et sa sensibilité à la photo-corrosion limite sa capacité à minéraliser les polluants récalcitrants sous rayonnement UV-visible. Afin d'améliorer l’activité photocatalytique du ZnO dans la région visible, son association avec des espèces métalliques est très attractive. Pour cela, nous avons opté pour l’oxyde de cérium CeO2 considéré comme un bon accepteur d’électrons et un excellent support de stockage d’oxygène en dehors de sa grande stabilité thermique et sa non-toxicité. Des matériaux de la solution solide Ce1-xZnxO2-x lacunaires en oxygène ont été préparés par voie de chimie douce en présence d’acide citrique et caractérisés par diverses techniques. L'insertion du cérium génère des lacunes en oxygène et des sites actifs responsables d'une meilleure minéralisation photocatalytique du diclofénac sous la lumière visible. Ensuite, nous avons synthétisé des composés ternaires CeO2/La2O3/ZnO et leur activité photocatalytique a été évaluée sous irradiation solaire pour la dégradation du diclofénac. Les résultats ont montré que l’addition de lanthane au sein de la solution solide Ce1-xZnxO2-x permet d’améliorer d’avantage la minéralisation photocatalytique du diclofénac dans l’eau.

Comparison of pesticide contamination between captive-reared and wild grey partridges: insights into environmental exposure disparities

Léa Bariod, Agathe Gaffard, Anaïs Rodrigues, Maurice Millet, Vincent Bretagnolle, Olivier Pays, Karine Monceau, Jérôme Moreau
Environmental Science and Pollution Research, 2024, 32 (37), ⟨10.1007/s11356-024-34925-z⟩ | Publiée le 16 septembre 2024
Article dans une revue

Abstract

<div><p>Pesticide contamination is often cited as a key factor in the global decline of farmland birds. However, the majority of studies on pesticide exposure in non-target fauna are not representative of what happens in nature because they are limited to artificial conditions. The aim of this study was to define and compare, for the first time, pesticide contamination in grey partridges (Perdix perdix) from two different contexts, i.e., captivity vs. the wild. Blood samples taken from 35 captive and 54 wild partridges in 2021-2022 were analysed for 94 pesticides most commonly used in French agriculture. Captive partridges had 29 molecules detected in their blood (12 herbicides, 14 fungicides, and three insecticides) compared to wild partridges, which had 50 molecules (13 herbicides, 23 fungicides, and 14 insecticides). Of these pesticide compounds found in individuals, 26 were banned. Captive partridges had significantly fewer pesticide molecules than wild partridges, with one to 14 pesticides per captive individual and 8 to 20 pesticides per wild individual. Nineteen molecules were common to both groups, with concentrations up to three times higher in wild partridges than in captive partridges. Our results thus show multiple exposures for most of our individuals, especially in wild partridges, which can lead to cocktail effects, which are never considered. Furthermore, the difference in contamination between the wild and captive partridges reflects the multiple routes of contamination in nature, in particular, due to the use of a wide range of habitats by wild partridges.</p></div>

Développement de matériaux pour le couplage de la valorisation de CO2 avec l'électrolyse haute température (HTE) pour la production d'éthylène

Morvan Guillon
Catalyse. Université de Strasbourg, 2024. Français. ⟨NNT : 2024STRAF026⟩ | Publiée le 4 septembre 2024
Thèse

Abstract

La production de l’éthylène est un enjeu énergétique majeur du XXIème siècle. La réaction du couplage oxydant du méthane permet la production d’éthylène à partir de méthane et d’oxygène. Cette réaction présente ainsi un intérêt particulier puisqu’elle permet la production d’éthylène en s’affranchissant d’une dépendance aux matières premières pétrolières, principalement utilisées pour la production de l’éthylène. Dans cette étude l’objectif est de développer un matériau en vue d’une insertion à l’anode d’un électrolyseur haute température pour produire de l’éthylène décarboné à partir de CO2. Après une étape de réduction à la cathode de ce même électrolyseur, du méthane peut être produit avec la technologie et power-to-methane. Le méthane est ainsi injecté à l’anode de l’électrolyseur pour effectuer la réaction du couplage oxydant du méthane. Les matériaux développés dans ce travail doivent donc répondre aux caractéristiques associées à une bonne anode et doivent agir comme catalyseur de la réaction du couplage oxydant du méthane. Ainsi la synthèse et la caractérisation d’oxydes mixtes ont été réalisées. L’activité des catalyseurs a été évaluée à l’échelle du laboratoire en variant les paramètres opératoires pour déterminer les conditions optimales pour obtenir le meilleur rendement en éthylène. Des optimisations de synthèses, avec des ajustements des compositions et des dopages, ont été réalisées pour obtenir la meilleure performance catalytique dans le cadre du couplage oxydant du méthane.

Evidence of different positron annihilation quantum states in Methylammonium Lead Iodide depending on Preparation

P. Aversa, R. Helm, H. Jun, Y. Cai, H. Nahdi, P. Desgardin, D. Tondelier, J.E Bourée, S. Bégin, F. Oswald, Y. Bonnassieux, T. Fischer, J. Mitteneder, M.O. Liedke, K. Madaan, G. Roma, P. Pochet, J. L. Liszkay, Maik Butterling, M. Dickmann, A. Wagner, M.F. Barthe, W. Egger, B. Geffroy, C. Corbel
International Workshop on Positron Studies of Defects 2024 (PSD-24), Prof. Rafael Ferragut (Chairman), Sep 2024, Como, Italy. pp.13-14, ⟨10.4028/b-JwTbe6⟩ | Publiée le 1 septembre 2024
Communication dans un congrès

Thermophysical Profile of Industrial Graphene Water-Based Nanofluids

Soulayma Gal, David Cabaleiro, Walid Hassen, Anaghim Nasri, Yannick Lafue, Cuong Pham-Huu, Housseinou Ba, Patrice Estellé
Nanomaterials, 2024, 14 (17), pp.1401. ⟨10.3390/nano14171401⟩ | Publiée le 28 août 2024
Article dans une revue

Abstract

The exceptional properties of high-grade graphene make it an ideal candidate for thermal dissipation and heat exchange in energy applications and nanofluid development. Here, we present a comprehensive study of few-layer graphene (FLG) nanofluids prepared in an industrial context. FLG nanofluids were synthesized through an ultrasound-assisted mechanical exfoliation process of graphite in water with a green solvent. This method produces FLG of high structural quality and stable nanofluids, as demonstrated by electron microscope, dynamic light scattering and ζeta potential analyses. Thermal conductivity measurements of FLG-based nanofluids were conducted in the temperature range of 283.15 K to 313.15 K, with FLG concentrations ranging from 0.005 to 0.200% in wt. The thermal conductivity of FLG nanofluids is up to 20% higher than water. The modeling of nanofluid thermal conductivity reveals that this enhancement is supported by the influence of the thermal resistance at the FLG interface, and the content, average dimensions and flatness of FLG sheets; this latter varying with the FLG concentration in the nanofluid. Additionally, the density and heat capacity of FLG suspensions were measured and compared with theoretical models, and the rheological behavior of FLG nanofluids was evaluated. This behavior is mainly Newtonian, with a weak 5% viscosity increase.

Comparison of hydroxyapatite and honeycomb micro-structure in bone tissue engineering using electrospun beads-on-string fibers

Nicolas Rivoallan, Marc Mueller, Timothée Baudequin, Pascale Vigneron, Anne Hébraud, Rachid Jellali, Quentin Dermigny, Anne Le Goff, Guy Schlatter, Birgit Glasmacher, C. Legallais
The International Journal of Artificial Organs, 2024, The International Journal of Artificial Organs, Volume 47, Issue 8 Pages: 642 - 649, 47 (8), pp.642-649. ⟨10.1177/03913988241268033⟩ | Publiée le 21 août 2024
Article dans une revue

Abstract

Thick honeycomb-like electrospun scaffold with nanoparticles of hydroxyapatite (nHA) recently demonstrated its potential to promote proliferation and differentiation of a murine embryonic cell line (C3H10T1/2) to osteoblasts. In order to distinguish the respective effects of the structure and the composition on cell differentiation, beads-on-string fibers were used to manufacture thick honeycomb-like scaffolds without nHA. Mechanical and biological impacts of those beads-on string fibers were evaluated. Uniaxial tensile test showed that beads-on-string fibers decreased the Young Modulus and maximal stress but kept them appropriate for tissue engineering. C3H10T1/2 were seeded and cultured for 6 days on the scaffolds without any growth factors. Viability assays revealed the biocompatibility of the beads-on-string scaffolds, with adequate cells-materials interactions observed by confocal microscopy. Alkaline phosphatase staining was performed at day 6 in order to compare the early differentiation of cells to bone fate. The measure of stained area and intensity confirmed the beneficial effect of both honeycomb structure and nHA, independently. Finally, we showed that honeycomb-like electrospun scaffolds could be relevant candidates for promoting bone fate to cells in the absence of nHA. It offers an easier and faster manufacture process, in particular in bone-interface tissue engineering, permitting to avoid the dispersion of nHA and their interaction with the other cells.

Fifty Years of Research in Environmental Photocatalysis: Scientific Advances, Discoveries, and New Perspectives

C. Guillard, D. Robert
Catalysts, 2024, 14 (8), pp.547. ⟨10.3390/catal14080547⟩ | Publiée le 21 août 2024
Article dans une revue

Synthesis and Characterization of Novel Adsorbents Based on Functionalization of Graphene Oxide with Schiff Base and Reduced Schiff Base for Pesticide Removal

Narinj Taghiyeva, Ulviyya Hasanova, Maurice Millet, Carole Gardiennet, Zarema Gakhramanova, Mushfig Mirzayev, Lala Gahramanli, Cuong Pham-Huu, Solmaz Aliyeva, Gunel Aliyeva, Fuad Rzayev, Eldar Gasimov, Corentin Boulogne, Haji Vahid Akhundzada
Materials, 2024, 17 (16), pp.4096. ⟨10.3390/ma17164096⟩ | Publiée le 18 août 2024
Article dans une revue

Abstract

Graphene oxide (GO) nanosheets were functionalized with Schiff base and reduced Schiff base. Covalent and non-covalent functionalized GO nanostructures have been tested for the removal of pesticides with different chemical structures and properties (e.g., Epoxiconazole, Dimethomorph, Cyprodinil, Chlorothalonil, Acetochlor, Trifluralin) from aqueous solutions. The structure and morphology characteristics of the prepared structures were analyzed using techniques such as solid-state nuclear magnetic resonance (SSNMR), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Results of the experiments showed that, although the non-covalent functionalization did not affect the adsorption properties of GO much, the covalent functionalization increased the adsorption capacity of GO against the mentioned pesticides.

Conductive and Cytocompatible Poly(3,4)ethylene-dioxythiophene:poly(styrenesulfonate) Hierarchical Porous Materials: From Liquid to Solid Foams

Quentin Bailleul, Laurie Grall, Leandro Jacomine, Christine Affolter-Zbaraszczuk, Eric Mathieu, Sergey Pronkin, Antoine Egélé, Pierre Schaaf, Florent Meyer, Wiebke Drenckhan-Andreatta, Fouzia Boulmedais
ACS Applied Polymer Materials, 2024, 6 (16), pp.9892-9904. ⟨10.1021/acsapm.4c01755⟩ | Publiée le 14 août 2024
Article dans une revue

Abstract

Poly(3,4)ethylene-dioxythiophene (PEDOT), mainly associated with poly(styrenesulfonate) (PSS), is widely used to create thin conductive films or, more recently, conductive 3D porous materials as scaffolds for tissue engineering. Such conductive materials allow the direct delivery of electrical, electrochemical, and electromechanical stimuli to cells. Typically, surfactants are combined with the PEDOT:PSS dispersion to design conductive films by gelation. To the best of our knowledge, no foams have been reported using PEDOT:PSS/surfactant mixtures and a simple drying process. In this article, to develop a cytocompatible and conductive 3D porous material by a simple process, a PEDOT:PSS/cationic surfactant mixture was used to design solid foams by simple foaming followed by a drying step. We exploit the electrostatic interactions between negatively charged commercial PEDOT:PSS and positively charged N-octyltrimethylammonium bromide (C8TAB) surfactant to develop conductive solid foams via the solidification of liquid foams. The stable and homogeneous liquid PEDOT:PSS/C8TAB foams were dried to obtain solid and conductive foams with a high conductivity of 2.05 ± 0.80 S/cm. The high conductivity of the bulk PEDOT:PSS/C8TAB thin film, at 17 ± 4 S/cm, confirmed a doping effect of C8TAB. This increased conductivity in the presence of the surfactants is probably due to an increased interpenetration of the PEDOT:PSS particles during film formation. The resulting foams are highly conductive and noncytotoxic, allowing the proliferation of murine fibroblasts. These foams have great potential for biomedical applications.

Selective electroreduction of CO 2 to C 2+ products on cobalt decorated copper catalysts

Sanaz Soodi, Jun-Jun Zhang, Jie Zhang, Yuefeng Liu, Mohsen Lashgari, Spyridon Zafeiratos, Andreas Züttel, Kun Zhao, Wen Luo
Chemical Synthesis, 2024, 4 (3), ⟨10.20517/cs.2024.11⟩ | Publiée le 6 août 2024
Article dans une revue

Abstract

Cu-catalyzed electrochemical CO2 reduction reaction (CO2RR) to multi-carbon (C2+) products is often plagued by low selectivity because the adsorption energies of different reaction intermediates are in a linear scaling relationship. Development of Cu-based bimetallic catalysts has been considered as an attractive strategy to address this issue; however, conventional bimetallic catalysts often avoid metals with strong CO adsorption energies to prevent surface poisoning. Herein, we demonstrated that limiting the amount of Co in CuCo bimetallic catalysts can enhance C2+ product selectivity. Specifically, we synthesized a series of CuCox catalysts with trace amounts of Co (0.07-1.8 at%) decorated on the surface of Cu nanowires using a simple dip coating method. Our results revealed a volcano-shaped correlation between Co loading and C2+ selectivity, with the CuCo0.4% catalyst exhibiting a 2-fold increase in C2+ selectivity compared to the Cu nanowire sample. In situ Raman and Infrared spectroscopies suggested that an optimal amount of Co could stabilize the Cu oxide/hydroxide species under the CO2RR condition and promote the adsorption of CO, thus enhancing the C2+ selectivity. This work expands the potential for developing Cu-based bimetallic catalysts for CO2RR.

Green Electrospinning of Highly Concentrated Polyurethane Suspensions in Water: From the Rheology to the Fiber Morphology

Bryan Gross, Guy Schlatter, Pascal Hébraud, Flavien Mouillard, Lotfi Chehma, Anne Hébraud, Emeline Lobry
Macromolecular Materials and Engineering, 2024, 309 (12), pp.2400157. ⟨10.1002/mame.202400157⟩ | Publiée le 5 août 2024
Article dans une revue

Abstract

Suspension electrospinning allows the environmental-friendly fabrication of nano-micro-fibrous membranes since it is based on the processing of an aqueous particle suspension in which a hydrosoluble template polymer is added to insure the formation of a continuous fiber. Here, the case of polyurethane (PU) aqueous suspensions formulated with poly(ethylene oxide) (PEO) as the template polymer is studied. The effect of several parameters (particle size, PU/PEO ratio, PEO molar mass, and PEO concentration in the continuous phase) on particle-particle and particle-template polymer interactions that influence the rheological properties of the formulation and finally the electrospinning and the fiber morphology, is studied. The goal is to process a formulation with the highest particle content as possible. Thanks to a deep rheological investigation and the study of interactions and suspension morphology by zeta potential and diffusing wave spectroscopy, it is shown that regular fibers are efficiently produced when small particles are electrospun under favorable particle-template polymer interactions and without screening the electrostatic repulsion between particles. Finally, a fibrous membrane is obtained from a formulation with a PU/PEO weight ratio equal to 50 under very stable and efficient production conditions.

Carbon nitride coupled with carbon nanohorns for improved photocatalytic hydrogen production and dyes degradation

Eirini-Olga Alexandridou, Maria Anagnostopoulou, Elton Dias, Zois Syrgiannis, Valerie Keller, Camille Petit, Konstantinos Christoforidis
Journal of Photochemistry and Photobiology A: Chemistry, 2024, 453, pp.115620. ⟨10.1016/j.jphotochem.2024.115620⟩ | Publiée le 1 août 2024
Article dans une revue

Membrane reactors for methanol synthesis: from material science to process simulation

Vincent Gautier, Audrey Hertz, Albin Chaise, Anne-Cécile Roger
ICC 2024 - International Congress on Catalysis, IACS, Jul 2024, Lyon, France | Publiée le 14 juillet 2024
Communication dans un congrès

Abstract

The catalytic hydrogenation of CO$_2$ to methanol and DME with hydrogen (synthesized from low-carbon energy) aims to provide a sustainable alternative to fossil hydrocarbons. However, large quantities of water, generated during the reaction, limit production yields and prematurely deactivate the catalyst. To address this problem, the use of membranes able to selectively separate water within the catalytic reactor has shown to be effective in the literature.

Unveiling Key Interface Characteristics of Ni/Yttria-Stabilized Zirconia Solid Oxide Cell Electrodes in H 2 O Electroreduction Using Operando X-ray Photoelectron Spectroscopy

Jinming Zhang, Mathias Barreau, Thierry Dintzer, Michael Haevecker, Detre Teschner, Anna Efimenko, Wen Luo, Spyridon Zafeiratos
ACS Applied Materials & Interfaces, 2024, 16 (29), pp.37915-37926. ⟨10.1021/acsami.4c05046⟩ | Publiée le 11 juillet 2024
Article dans une revue

Controlling conjugated polymer morphology by precise oxygen position in single-ether side chains

Pablo Durand, Huiyan Zeng, Badr Jismy, Olivier Boyron, Benoît Heinrich, Laurent Herrmann, Olivier Bardagot, Ioannis Moutsios, Alina Mariasevskaia, Alexey Melnikov, Dimitri Ivanov, Martin Brinkmann, Nicolas Leclerc
Materials Horizons, 2024, 11 (19), pp.4737-4746. ⟨10.1039/D4MH00492B⟩ | Publiée le 10 juillet 2024
Article dans une revue

Abstract

Recently, polar side chains have emerged as a functional tool to enhance conjugated polymer doping properties by improving the polymer miscibility with polar chemical dopants and facilitate solvated ion uptake. In this work, we design and investigate a novel family of side chains containing a single ether function, enabling the modulation of the oxygen atom position along the side chain. A meticulous investigation of this new polymer series by differential scanning calorimetry, fast scanning chip calorimetry and X-ray scattering shows that polymers bearing single-ether side chains can show high degree of crystallinity under proper conditions. Importantly, due to a gauche effect allowing the side chain to bend at the oxygen atom, the degree of crystallinity of polymers can be controlled by the position of the oxygen atom along the side chain. The further the oxygen atom is from the conjugated backbone, the more crystalline the polymer becomes. In addition, for all new polymers, high thermomechanical properties are demonstrated, leading to remarkable electrical conductivities and thermoelectric power factors in rub-aligned and sequentially doped thin films. This work confirms the potential of single-ether side chains to be used as polar solubilizing side chains for the design of a next generation of p- and n-type semiconducting polymers with increased affinity to polar dopants while maintaining high molecular order.

Tailoring the pore structure of iron oxide core@stellate mesoporous silica shell nanocomposites: effects on MRI and magnetic hyperthermia properties and applicability to anti-cancer therapies

Joëlle Bizeau, Justine Journaux-Duclos, Céline Kiefer, Barbara Freis, Dris Ihiawakrim, Maria de los Angeles Ramirez, Theo Lucante, Ksenia Parkhomenko, Charlotte Vichery, Julian Carrey, Olivier Sandre, Caroline Bertagnolli, Ovidiu Ersen, Sylvie Bégin-Colin, Véronique Gigoux, Damien Mertz
Nanoscale, 2024, 16 (33), pp.15585-15614. ⟨10.1039/d4nr01388c⟩ | Publiée le 9 juillet 2024
Article dans une revue

Abstract

Core–shell nanocomposites made of iron oxide core (IO NPs) coated with mesoporous silica (MS) shells are promising theranostic agents. While the core is being used as an efficient heating nanoagent under alternating magnetic field (AMF) and near infra-red (NIR) light and as a suitable contrast agent for magnetic resonance imaging (MRI), the MS shell is particularly relevant to ensure colloidal stability in a biological buffer and to transport a variety of therapeutics. However, a major challenge with such inorganic nanostructures is the design of adjustable silica structures, especially with tunable large pores which would be useful, for instance, for the delivery of large therapeutic biomolecule loading and further sustained release. Furthermore, the effect of tailoring a porous silica structure on the magneto- or photothermal dissipation still remains poorly investigated. In this work, we undertake an in-depth investigation of the growth of stellate mesoporous silica (STMS) shells around IO NPs cores and of their micro/mesoporous features respectively through time-lapse and in situ liquid phase transmission electron microscopy (LPTEM) and detailed nitrogen isotherm adsorption studies. We found here that the STMS shell features (thickness, pore size, surface area) can be finely tuned by simply controlling the sol–gel reaction time, affording a novel range of IO@STMS core@shell NPs. Finally, regarding the responses under alternating magnetic fields and NIR light which are evaluated as a function of the silica structure, IO@STMS NPs having a tunable silica shell structure are shown to be efficient as T2-weighted MRI agents and as heating agents for magneto- and photoinduced hyperthermia. Furthermore, such IO@STMS are found to display anti-cancer effects in pancreatic cancer cells under magnetic fields (both alternating and rotating).

A toolbox for enzymatic modification of nucleic acids with photosensitizers for photodynamic therapy

Germain Niogret, Camille Chériaux, Frédéric Bonhomme, Fabienne Levi-Acobas, Carlotta Figliola, Gilles Ulrich, Gilles Gasser, Marcel Hollenstein
RSC Chemical Biology, 2024, 5, pp.841-852. ⟨10.1039/d4cb00103f⟩ | Publiée le 8 juillet 2024
Article dans une revue

Abstract

Photodynamic therapy (PDT) is an approved cancer treatment modality. Despite its high efficiency, PDT is limited in terms of specificity and by the poor solubility of the rather lipophilic photosensitizers (PSs). In order to alleviate these limitations, PSs can be conjugated to oligonucleotides. However, most conjugation methods often involve complex organic synthesis and result in the appendage of single modifications at the 3′/5′ termini of oligonucleotides. Here, we have investigated the possibility of bioconjugating a range of known PSs by polymerase-mediated synthesis. We have prepared a range of modified nucleoside triphosphates by different conjugation methods and investigated the substrate tolerance of these nucleotides for template-dependent and -independent DNA polymerases. This method represents a mild and versatile approach for the conjugation of single or multiple PSs onto oligonucleotides and can be useful to further improve the efficiency of the PDT treatment.

Optimization of PF2 Organic Solar Cells for Indoor Application

Ruoxue He, Nicolas Leclerc, Pierre Nickmilder, Philippe Leclère, Johann Bouclé, Bernard Ratier
First Indoor Photovoltaic Conference (IPVC-1), Jul 2024, Tampere, Finland | Publiée le 4 juillet 2024
Communication dans un congrès

Utilization of carbon‐black industry waste to synthesize electrode material for supercapacitors

Akshita Singh, Vimal Chandra Srivastava, Izabela Janowska
Energy Storage Materials, 2024, 6 (5), ⟨10.1002/est2.677⟩ | Publiée le 4 juillet 2024
Article dans une revue

Abstract

Solid waste utilization in synthesizing porous carbon materials for supercapacitor electrodes has been a fast‐progressing research domain in past decades. Different types of agricultural and industrial waste have the potential to act as a precursor supply for carbon with porous structures. In this study, the waste generated from a furnace‐grade conductive carbon black manufacturing industry was utilized to synthesize porous carbon through pyrolysis at 400°C for 2 hours, followed by chemical activation at 800°C for 1 hour. Different activating agents, precisely, potassium hydroxide, orthophosphoric acid, and zinc chloride, were used. Similar activation conditions as well as the mass ratio of activating agent to sample (4:1), were maintained to make a comparative study. All three samples were then tested in a three‐electrode set‐up through cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy for their performance as electrode material for supercapacitors with a mass loading of 4.0 mg/cm 2 in 1 M Na 2 SO 4 electrolyte. The largest specific capacitance was obtained for the KOH‐activated sample, that is, 21.3 F/g, followed by 17.9 F/g for H 3 PO 4 activated sample and 13.7 F/g for the ZnCl 2 ‐activated sample, at a scan rate of 50 mV/s. Though the obtained capacitance is much smaller for its practical application, the study acts as a base for further modifications and upgrades to utilize this high carbon‐containing waste in energy storage.

Design and analysis of biodegradable and potentially biobased multiphase systems from starch and co-polyesters

Alexis Morinval, Nadège Follain, Luc Avérous
European Polymer Journal, 2024, 215, pp.113231. ⟨10.1016/j.eurpolymj.2024.113231⟩ | Publiée le 1 juillet 2024
Article dans une revue

Structured carbon felt with chemical functionalization as Pd catalyst support for selective hydrogenation of cinnamaldehyde

Zhenxin Xu, Bing Li, Jiaying Bi, Vasiliki Papaefthimiou, Yuefeng Liu, Spyridon Zafeiratos, Thierry Romero, Cuong Pham-Huu
Applied Surface Science, 2024, 661, pp.160055. ⟨10.1016/j.apsusc.2024.160055⟩ | Publiée le 1 juillet 2024
Article dans une revue

Faceting effect on magnetism in manganese ferrites nanoparticles

Ahmed Essyed, Mohamed Alae Ait Kerroum, Sylvain Bertaina, Wafaa Azouzi, Ahmed Al Shami, Ismail Benabdallah, Hicham Labrim, Dris Ihiawakrim, Rachid Baati, Mohammed Benaissa
Materials Today Chemistry, 2024, 39, pp.102168. ⟨10.1016/j.mtchem.2024.102168⟩ | Publiée le 1 juillet 2024
Article dans une revue

Development of Ni@NiOx/C cathodes for the hydrogen evolution reaction by electrodeposition

Julie Guehl, Alexandr Oshchepkov, Antoine Bonnefont, Eric Sibert, Elena Savinova, Tristan Asset
37th Topical Meeting of the International Society of Electrochemistry, Jun 2024, Stresa, Italy, Italy | Publiée le 9 juin 2024
Poster de conférence

Abstract

Ni/NiOx heterostructured materials are considered one the most promising non-noble metal catalysts for the hydrogen evolution reaction (HER) in alkaline media.1 Indeed, while metallic Ni has rather poor intrinsic HER activity (as Ni strongly adsorbs Hads), it can be significantly increased by combining Ni metal sites with NiOx (β-Ni(OH)2 or NiO) sites, reaching an optimum at roughly 30% or 50% surface coverage by NiOx on polycrystalline nickel2 and Ni nanoparticles3, respectively. Nanoparticulated materials with a high specific surface area (i.e. a high density of HER active sites) present a special interest for practical application. However, it is currently unknown how the nanoparticle size will affect the optimum Ni/NiOx ratio for the HER, along with the stability of this active state of the Ni surface under operating conditions. Unveiling the correlations between the nickel nanoparticle size, the optimal Ni/NiOx ratio for the HER and its stability in operating conditions is the objective of this work. For this purpose, we prepared Ni nanoparticles supported on various carbon black templates of different morphology by electrodeposition. This is the only technique that allows to easily explore the full range of NiOx coverages starting from fully metallic surfaces (Figure 1a). First, we show that the size of Ni nanoparticles depends on several factors, including carbon black surface area, deposition charge (Figure 1b), electrodeposition solution concentration, and applied potential. The Ni nanoparticles diameter was assessed by both electrochemical methods and transmission electron microscopy. Then, we investigated the electrochemical behavior of the prepared samples in alkaline media using a rotating disk electrode to ultimately correlate their HER activity, and stability with the size of Ni nanoparticles and oxide surface coverage.

Oxygen evolution reaction in alkaline media using Co-spinels and stainless steel based electrodes

Garance Cossard, Gwénaëlle Kerangueven, Elena Savinova, Marian Chatenet, Eric Sibert
37th Topical Meeting of the International Society of Electrochemistry, International Society of Electrochemistry, Jun 2024, Stresa, Lago Maggiore, Italy | Publiée le 9 juin 2024
Communication dans un congrès

Abstract

As the need for low-carbon hydrogen increases, developing low-cost and high-availability of transition metal -based electrodes for their use in alkaline electrolysis becomes an intense area of research. This study aims to associate two competitive materials for the oxygen evolution reaction (OER) in order to combine their benefits: stainless steel (containing Fe, Cr and Ni) and Co-oxides with spinels structure. On the one hand, stainless steel has been proven to be an efficient OER catalyst due to the formation on its surface of highly active NiFe oxy-hydroxide during potential cycling. This behavior provides stainless steel with an excellent resistance towards on/off operation mode [1]. On the other hand, Co- spinels (e.g. Co3O4) are very active and stable OER catalysts that can be synthesized into nanoparticles, which is essential for the development of high active surface area. However the poor electrical conductivity of Co3O4 requires the use of another conductive material to support these particles. The addition of carbon, for example, allows one to increase the electronic conductivity, to enhance the surface utilization of oxides nanoparticles and thus their apparent electrocatalytic activity [2], but of course, carbon would not be durable in OER conditions. Herein, it is proposed to use stainless steel as the conductive substrate for Co3O4 nanoparticles. Such nanoparticles were deposited on stainless steel fiber felts through the autocombustion of Co precursors. This deposition is homogenous throughout the felt (Fig. 1A) and its thickness can be controlled by adjusting synthesis conditions. Such materials are significantly more active for the OER than pure stainless steel (Fig. 1B). Quite interestingly, after potential cycling, an improvement of the OER performance of these stainless steel supported spinels is observed (Fig. 1B). This improvement is due to a modification of the surface structure and/or composition during potential cycling.

Sustainable ammonia synthesis on TiO2-based photo-thermo catalysts

Laura Valenzuela, Javier Ivanez, Nicolas Keller
Catalysis Today, 2024, 435, pp.114723. ⟨10.1016/j.cattod.2024.114723⟩ | Publiée le 1 juin 2024
Article dans une revue

Organic farming reduces pesticide load in a bird of prey

Elva Fuentes, Jérôme Moreau, Maurice Millet, Vincent Bretagnolle, Karine Monceau
Science of the Total Environment, 2024, 930, pp.172778. ⟨10.1016/j.scitotenv.2024.172778⟩ | Publiée le 1 juin 2024
Article dans une revue

Abstract

Human activities have led to the contamination of all environmental compartments worldwide, including bird species. In birds, both the environment and maternal transfer lead to high inter-brood variability in contamination levels of pollutants, whereas intra-brood variability is generally low. However, most existing studies focused on heavy metals or persistent compounds and none, to our knowledge, addressed the variability in contamination levels of multiple pesticides and the factors influencing it. In this study, the number of pesticides detected (of 104 compounds searched) and the sum of their concentrations in the blood of 55 Montagu's harrier (Circus pygargus) nestlings from 22 nests sampled in 2021 were used as metrics of contamination levels. We investigated the effect of organic farming at the size of male's home range (i.e., 14 km2) and chicks' sex and hatching order on contamination levels. We did not find a difference between inter-brood and intra-brood variability in pesticide contamination levels, suggesting a different exposure of siblings through food items. While chicks' sex or rank did not affect their contamination level, we found that the percentage of organic farming around the nests significantly decreased the number of pesticides detected, although it did not decrease the total concentrations. This finding highlights the potential role of organic farming in reducing the exposure of birds to a pesticide cocktail.

Improving Indoor Energy Efficiency with PF2:ITIC Organic Solar Cells for IoT Applications

Ruoxue He, Nicolas Leclerc, Pierre Nickmilder, Philippe Leclère, Johann Bouclé, Bernard Ratier
International Workshop on Emerging Solar Energy Materials and Applications (ESEMA 2024), May 2024, Hyères, France | Publiée le 27 mai 2024
Communication dans un congrès

Instability of Cobalt-Substituted Polyoxometalates during the Oxygen Evolution Reaction: An Operando X-ray Absorption Spectroscopy Study

Benjamin Rotonnelli, Benedikt Lassalle-Kaiser, Antoine Bonnefont, Séverine Renaudineau, Delphine Garnier, Anna Proust, Fabrice Bournel, Jean-Jacques Gallet, Tristan Asset, Elena Savinova
Journal of Physical Chemistry C, 2024, 128 (19), pp.7968-7976. ⟨10.1021/acs.jpcc.4c01265⟩ | Publiée le 6 mai 2024
Article dans une revue

Abstract

Complexes of cobalt(II) stabilized by lacunary polyoxometalates (CoPOMs) are highly discussed water oxidation catalysts (WOC). While their activity and stability in the oxygen evolution reaction (OER) have been widely explored, there is still no consensus between those claiming that CoPOMs are active and stable OER catalysts and those suggesting that they rather act as precatalysts, which degrade into OER-active heterogeneous CoOx catalysts. In this work, we use operando X-ray absorption spectroscopy along with electrochemical methods (cyclic voltammetry, chronoamperometry) to assess the activity and stability of [Co9(H2O)6(OH)3(HPO4)2(PW9O34)3]16– (Co9POM) under chemical and electrochemical operating conditions. First, we demonstrate that Co9POM dissolved in a phosphate buffer quickly degrades during an electrochemical OER, leaving a Co(III)/Co(II)-containing layer on the electrode surface that acts as a heterogeneous OER catalyst. This degradation is detected using both the post mortem and operando X-ray absorption near-edge structure and extended X-ray absorption fine structure. Then, the electrochemical OER is studied in the presence of 2,2′-bipyridine, which is used to eliminate Co2+ aqua-complexes resulting from Co9POM dissociation equilibrium. Yet, this does not avoid the formation of a Co-containing precipitate, albeit of a different composition. Finally, to differentiate between degradation associated with the catalytic cycle itself and the one provoked by local pH changes in the vicinity of the electrode during the OER, the Co9POM is studied as a homogeneous WOC with NaClO as a chemical oxidant. An irreversible loss of Co from the Co9POM is detected after the addition of two NaClO equivalents per Co ion. These combined insights provide clear operando evidence of Co9POM instability under either electrochemical OER or chemical WOC operating conditions.

Carbon-free fuels for direct liquid-feed fuel cells: Anodic electrocatalysts and influence of the experimental conditions on the reaction kinetics and mechanisms

Evgeniia Vorms, Alexandr Oshchepkov, Antoine Bonnefont, Elena Savinova, Marian Chatenet
Applied Catalysis B: Environmental, 2024, 345 (2), pp.123676. ⟨10.1016/j.apcatb.2023.123676⟩ | Publiée le 1 mai 2024
Article dans une revue

Abstract

An optimized potential window for efficient platinum electrodissolution, the first step of a Pt recycling process, is proposed.

Experimental and theoretical comprehension of ESIPT fluorophores based on a 2-(2′-hydroxyphenyl)-3,3′-dimethylindole (HDMI) scaffold

Timothee Stoerkler, Gilles Ulrich, Adele D. Laurent, Denis Jacquemin, Julien Massue, Pascal Retailleau
Chemical Science, 2024, 15 (19), pp.7206-7218. ⟨10.1039/D4SC01937G⟩ | Publiée le 16 avril 2024
Article dans une revue

Abstract

Excited-State Intramolecular Proton Transfer (ESIPT) emission is associated with intense single or multiple fluorescence in the solid-state, along with enhanced photostability and sensitivity to the close environment. As a result, ESIPT probes are attractive candidates for ratiometric sensing of a variety of substrates. A new family of ESIPT fluorophores is described herein, inspired by the well-known 2-(2'hydroxyphenyl)benzazole (HBX) organic scaffold. The connection of 3,30-dimethylindole (or 3H-indole) derivatives with phenol rings triggers the formation of novel 2-(20-hydroxyphenyl)-3,30-dimethylindole (HDMI) fluorophores, capable of stimuli-responsive ESIPT emission. This brand new family of dyes displays redshifted emission, as compared to HBX, along with an unprecedented acid/base-mediated stabilization of different rotamers, owing to supramolecular interactions with methyl groups. These compounds are therefore highly sensitive to external stimuli, such as the presence of acid or base, where protonated and deprotonated species have specific optical signatures. Moreover, a new pyridine-functionalized HDMI dye displays acid-sensitive AIE properties. The photophysical properties of all compounds have also been studied using ab initio calculations to support experiments in deciphering the nature of the various radiative transitions observed and the related excited rotameric species.

Photovoltaic spatial light modulators: material selection and processing to enhance device performance

Thomas Heiser, Yuhan Zhong, Sadiara Fall, Yaochen Lin, Martin Brinkmann, Nicolas Brouckaert, Malgosia Kaczmarek, Nicolas Leclerc, Elise Jouaiti, Thomas Ducatel
SPIE Photonics Europe, 2024, 7-11 April 2024, Strasbourg, France, Apr 2024, Strasbourg, France. ⟨10.1117/12.3021862⟩ | Publiée le 7 avril 2024
Communication dans un congrès

Abstract

Photovoltaic spatial light modulators (PSLM) are self-activated optical devices that can be used as dynamic glazing or as optically addressable spatial light modulator. The range of potential applications of this new kind of optical device is highly dependent on its clear-state transmittance, spectral distribution of transmittance modulation, as well as on its response time, stability, and spatial resolution. These features are in turn mainly determined by the materials used for the various parts making up a PSLM, namely the photovoltaic unit, the liquid crystal layer, the liquid crystal alignment layers, and the polarizers. This contribution will focus on the multiple links between material properties and device performance and present our recent results on the design and processing of organic semiconductor materials designed to broaden the field of applications of PSLMs.

Influence of Nitridation Conditions on the Doping Sites and Photocatalytic Visible Light Activity of Nb,N-Codoped TiO₂

Qingyang Xi, Vasiliki Papaefthimiou, Nolwenn Le Breton, Marc Lenertz, Mai Takashima, Valérie Keller, Bertrand Vileno, Thomas Cottineau
Chemistry of Materials, 2024, 36 (8), pp.3705 - 3716. ⟨10.1021/acs.chemmater.3c03280⟩ | Publiée le 6 avril 2024
Article dans une revue

Abstract

The photocatalytic performance of Nb,N-codoped TiO 2 nanoparticles obtained via the sol-gel method was compared to that of N-doped TiO 2 . The study focused on investigating the effects of nitridation conditions on nitrogen insertion with a highlight on the nature of the doping sites in the photocatalyst depending on the initial presence of niobium in the TiO 2 . The photodegradation of methylene blue in solution under UV, visible, and simulated solar light was used to evaluate the photocatalytic activity of TiO 2 , Nb-or N-doped TiO 2 , and Nb,N-codoped TiO 2 nanoparticles. Codoped TiO 2 produced by mild thermal nitridation exhibits the best photocatalytic activity, with a strong contribution from visible light. On the contrary, the codoped TiO 2 produced by more intense thermal nitridation presents lower photocatalytic performances than TiO 2 despite a small improvement of activity in the visible range. In addition to material characterization (X-ray diffraction, UV-vis spectroscopy, and X-ray photoelectron spectroscopy), electron paramagnetic resonance and reversed double-beam photoacoustic spectroscopy measurements were used to identify the respective doping sites and ultimately propose the electronic band structure for each sample of Nb:TiO 2 , N:TiO 2 , and Nb,N:TiO 2 . Proper thermal nitridation conditions improve the charge compensation between Nb 5+ and N 3-, thereby enhancing the photocatalytic activity. However, too intense nitridation conditions led to the generation of oxygen vacancies and a large amount of Ti 3+ acting as charge recombination centers, resulting in significant deterioration of the photocatalytic performances. This study highlights the importance of understanding the intricate charge compensation process in codoped (M,N) TiO 2 materials, as the photocatalytic performance cannot be elucidated solely by the cation/anion ratio but also by considering the nature of the doping sites generated during synthesis.

High levels of polycyclic aromatic compounds in outdoor and indoor PM10 of an urban residential environment during a winter pollution event in Strasbourg, France

Mathieu Galmiche, Olivier Delhomme, Stéphane Le Calvé, Yannis-Nicolas François, Maurice Millet
Air Quality, Atmosphere & Health, 2024, 17 (4), pp.737-755. ⟨10.1007/s11869-023-01476-0⟩ | Publiée le 1 avril 2024
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Influence of the chemical structure of polyester polyols on the properties and fire resistance of polyisocyanurate foams

Antoine Duval, Johan Sarazin, Cecile de Haas, Alexandru Sarbu, Serge Bourbigot, Luc Avérous
European Polymer Journal, 2024, 210, pp.112938. ⟨10.1016/j.eurpolymj.2024.112938⟩ | Publiée le 1 avril 2024
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Concomitant determination of PAH, PCBs, and phthalates in indoor air and dust from residential houses in the Strasbourg region of France

Josephine Al-Alam, Alexandre Sonnette, Olivier Delhomme, Laurent Alleman, Patrice Coddeville, Maurice Millet
Journal of Environmental Exposure Assessment, 2024, 3 (1), ⟨10.20517/jeea.2023.47⟩ | Publiée le 29 mars 2024
Article dans une revue

Abstract

Global attention is drawn to the significant issue of indoor pollution, given its direct negative impact on human health and wellness. Typically, individuals can nowadays spend 80% or more of their time in enclosed built locations where they can be prone to a multitude of harmful toxic chemicals distributed in particulate and gas phases. Therefore, a systematic efficient monitoring of such chemicals in indoor environments is urgently required to devise and implement various measures that allow their control. The objective of this study is to evaluate the concomitance occurrence of phthalates, polycyclic aromatic hydrocarbons (PAHs), and polychlorinated biphenyls (PCBs) within the indoor settings of residential homes in Strasbourg. It focused on both the indoor air and dust samples collected in nine residential homes in Strasbourg for a one-year sampling period, February 2016 - February 2017. For this, Radiello®, SiC© foams, and Tenax-TA® were successfully introduced and used as reliable passive samplers for the aforementioned matrices. Extractions were carried out using pressurized solvent extraction (PSE) followed by ATD-GC/MSMS analysis. The findings of the presented study revealed that 12 PAHs, 18 PCBs, and 7 phthalates were regularly perceived in the indoor environments of the houses under assessment. In gaseous samples, the average concentrations of the detected pollutant were approximately 3,919, 4.3, and 601.6 ng/sampler for PAHs, PCBs, and phthalates, respectively. As for dust samples, the average concentrations of the detected pollutant were approximately 3,438, 6.2, and 1,816.2 ng/g, respectively. The obtained results showed that PCBs exhibited the lowest concentration in both matrices. However, air samples were mostly contaminated by PAHs, while dust samples showed higher levels of phthalates. These results are correlated to the physico-chemical properties of these compounds and to their origin and source of emission. The findings of this study stress the importance of indoor pollution assessment so that the risks associated with it could be controlled.

Aqueous inks for ecofriendly processing of organic solar cells: investigation of morphological changes

Mohammad Rammal, Paul Nizet, Géraldine Layrac, Sufal Swaraj, Benoit Heinrich, Jiang Jing, Émilie Steveler, Thomas Heiser, Nicolas Leclerc, Patrick Lévêque, Anne Hébraud
Synthetic Metals, 2024, 305, pp.117599. ⟨10.1016/j.synthmet.2024.117599⟩ | Publiée le 28 mars 2024
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Abstract

Aqueous dispersions of organic semiconducting nanoparticles (NPs) are particularly attractive as inks for the environmentally friendly preparation of organic solar cells. The internal morphology of the NPs, which depends on their elaboration process, is a key parameter, which has a significant influence on the final morphology of the active layer and therefore its effectiveness. In the present study, core-shell (PF2:PC71BM) NPs were prepared by miniemulsion. Their internal morphology including the composition of the two phases was characterized by scanning transmission X-ray microscopy (STXM) showing a core composed of 77% PC71BM and a shell composed of 75% PF2. It was found that thermal annealing promotes PC71BM diffusion from the core to the shell, increasing its proportion in the shell from 25% to 42%. This annealing, when applied after NPs deposition by spincoating, allows partial coalescence of the NPs, reducing the roughness of the active layer, and increases electron mobility, thus demonstrating the formation of PC71BM percolation paths for electron transport. A PCE of 1.6% could thus be obtained after 10 min of thermal annealing at 100°C. At higher temperature, Grazing-Incidence Wide-Angle X-Ray Scattering (GIWAXS) analyses demonstrate the modification of the PF2 structuration from randomly oriented lamella after deposition to edge-on orientation after annealing, leading to an unfavorable decrease of the hole mobility in the direction perpendicular to the substrate, while increasing the hole mobility in the substrate plane. This study demonstrates the need to systematically characterize the internal morphology of NPs in order to rationalize the morphology of the active layer and optimize its properties.

Cu-Metalated Porphyrin-Based MOFs Coupled with Anatase as Photocatalysts for CO2 Reduction: The Effect of Metalation Proportion

Maria Anagnostopoulou, Valérie Keller, Konstantinos Christoforidis
Energies, 2024, 17 (6), pp.1483. ⟨10.3390/en17061483⟩ | Publiée le 20 mars 2024
Article dans une revue

Abstract

Converting carbon dioxide (CO2) into valuable chemicals such as fossil resources via photocatalysis requires the development of advanced materials. Herein, we coupled zirconium-based metal–organic frameworks (MOFs) containing porphyrin and Cu-porphyrin with anatase TiO2. The effect of the porphyrin metalation proportion was also investigated. Notably, while the use of free-base porphyrin as the organic linker resulted in the development of PCN-224, the presence of Cu-porphyrin provided mixed-phase MOF structures containing both PCN-224 and PCN-222. MOF/TiO2 composites bearing partial (50%) metalated porphyrin were proven more active and selective towards the production of CH4, at ambient conditions, in the gas phase and using water vapors without the use of hole scavengers. The optimized composite bearing 15 wt.% of the partial metalated MOF was three times more active than pure TiO2 towards CH4 production. This study provides insights on the effect of precise materials engineering at a molecular level on the development of advanced MOF-based photocatalysts for CO2 reduction.

Dispositifs pour le piégeage passif des particules fines en environnement extérieur

Tuan-Hoang Trinh, Charlotte Pham, Jean-Mario Nhut, Fabrice Vigneron, Christophe Vieville, Nicolas Reiminger, Xavier Jurado, Housseinou Ba, Thierry Romero, Lai Truong-Phuoc, Nicolas Hertel, Christophe Legorgeu, Loïc Vidal, Cuong Pham-Huu
37ème Congrès Français sur les Aérosols, Association française d'études et de recherches sur les aérosols, Mar 2024, Paris, France | Publiée le 19 mars 2024
Communication dans un congrès

Abstract

La réduction de la concentration des aérosols (fines et ultrafines) en suspension est indispensable afin d’améliorer la qualité de l’air extérieur dans les milieux urbains. Notre projet vise à capturer des particules fines dans l’air avec une solution simple, mais efficace et éco-responsable. Deux prototypes ont été installés à proximité des deux axes routiers bien fréquentés de l’agglomération de Strasbourg (France), pour l’étude du captage des particules fines et ultrafines avec des pièges passifs, lavables, régénérables, avec une faible consommation d’énergie, tout en respectant la nature et le bien-être de la communauté environnante. Les pièges ont permis de capturer jusqu’à 90 g PMtotal/m² sur une période d’exposition de 14 semaines. Les modèles empiriques ainsi que des simulations théoriques sont en cours de développement, et basées sur différentes données collectées in situ, en temps réel tout au long de l’expérience. La solution proposée pourrait être un moyen efficace dans la réduction des fortes pollutions par des particules d’une agglomération urbaine.

Nickel Nanoparticles Confined in Core–Shell Derived from Covalent Organic Framework for the Efficient Electrocatalytic NO Reduction to NH3

Yuyeon Song, Renata Maia, Vincent Ritleng, Benoît Louis, Sangaraju Shanmugam
ACS Applied Energy Materials, 2024, 7 (6), pp.2514-2523. ⟨10.1021/acsaem.4c00048⟩ | Publiée le 4 mars 2024
Article dans une revue

Abstract

The electrocatalytic nitric oxide reduction reaction (NORR) has attracted significant attention as an eco-friendly alternative to conventional Haber-Bosch process for producing ammonia (NH3). However, the poor selectivity to NH3 and low catalyst stability under harsh conditions are great challenges in NORR. Herein, core-shell structure of nickel nanoparticles enclosed with nitrogen-doped carbon layer (Ni@NC) electrocatalyst derived from covalent organic frameworks is employed for high performance in NORR. The Ni@NC-700 achieved the highest FENH3 of 82.94% with an NH3 yield rate of 19.00 µmol cm-2 h-1 at 0.16 V (vs. RHE) in a 0.1 M HClO4 electrolyte. Control experiments revealed that the nickel nanoparticles (Ni NPs) acted as active centers in Ni@NC for efficient production of NH3. The ideal carbon shell protecting of Ni NPs and high inherent catalytic TOF of Ni@NC-700 revealed a promising candidate for efficient NORR electrocatalyst. The stability test demonstrated the remarkable stability of Ni@NC. The Ni NPs were protected by carbon nanostructures resembling core-shell catalysts, preventing metal dissolution during rough electrolysis.

Oxidized detonation nanodiamonds act as an efficient metal‐free photocatalyst to produce hydrogen under solar irradiation

Clément Marchal, Lorris Saoudi, Hugues A Girard, Valérie Keller, Jean‐charles Arnault
Advanced Energy and Sustainability Research, 2024, 5 (3), pp.2300260. ⟨10.1002/aesr.202300260⟩ | Publiée le 1 mars 2024
Article dans une revue

Abstract

Herein, it is revealed for the first time that oxidized detonation nanodiamonds (Ox‐DND) can produce hydrogen under solar irradiation without addition of cocatalyst or formation of heterojunction with another semiconductor. This hydrogen production is investigated using two sacrificial reagents and compared to the one of hydrogenated detonation nanodiamonds (H‐DND). The effect of the Ox‐DND and sacrificial reagent concentrations on the hydrogen production is also studied. At its maximum, a H$_2$ production yield of 32 μmol h$^{−1}$ is obtained for a Ox‐DND concentration of 12.5 μg mL$^{−1}$ (using only 1 vol% of triethanolamine as sacrificial reagent), similar to the one of TiO$_2$ nanoparticles tested at the same concentration in the same illumination conditions.

Influence of Impurities in the Chemical Processing Chain of Biomass on the Catalytic Valorisation of Cellulose towards γ-Valerolactone

Preeti Kashyap, Magdalena Brzezińska, Nicolas Keller, Agnieszka Ruppert
Catalysts, 2024, 14 (2), pp.141. ⟨10.3390/catal14020141⟩ | Publiée le 12 février 2024
Article dans une revue

Abstract

The conversion of lignocellulosic biomass to valuable chemicals such as levulinic acid and γ-valerolactone is a promising approach for achieving a sustainable circular economy. However, the presence of impurities during the stepwise chemical processing chain of the biomass feedstock can significantly impact both the hydrolysis and hydrogenation steps implemented to convert the cellulosic feedstock to levulinic acid and further to γ-valerolactone, respectively. This review article explores the effects of those impurities by classifying them into two groups, namely endogenous and exogenous types, based on whether they originate directly from the raw lignocellulosic biomass or arise during its multi-step chemical processing. Endogenous impurities include heavy metals, alkali metals, alkaline earth metals, proteins, and side products from the downstream treatment of cellulose, while exogenous impurities are introduced during physical pre-treatments such as ball milling or during the hydrolysis step, or they might originate from the reactor setup. The specific catalyst deactivation by carbonaceous species such as humins and coke is considered. The mechanisms of impurity-induced catalyst deactivation and by-product formation are thoroughly discussed. Additionally, strategies for minimizing the detrimental effects of impurities on biomass conversion and enhancing catalytic efficiency and stability are also proposed.

Synthèse de matériaux catalytiques de type oxydes mixtes pour la production de méthanol par la précipitation en flux continu en système microfluidique

Diego Rua Gonzalez
Catalyse. Université de Strasbourg, 2024. Français. ⟨NNT : 2024STRAF001⟩ | Publiée le 9 février 2024
Thèse

Abstract

Le réchauffement climatique est une préoccupation pour les générations actuelles et futures en raison de l'augmentation des émissions de gaz à effet de serre (GES) dans l'atmosphère, principalement dues à la dépendance aux combustibles fossiles. L'utilisation de carburants alternatifs tels que le méthanol durable produit à partir de H2 renouvelable et de CO2 contribuerait à réduire les émissions de GES et les effets du changement climatique. La synthèse du méthanol à partir de matières premières riches en CO2 se fait préférentiellement en utilisant un catalyseur solide composé de CuO, ZnO et ZrO2. Ce type de catalyseur peut être produit par coprécipitation des espèces métalliques à l'aide d'un dispositif microfluidique, avec des avantages qui ont été démontrés par rapport aux catalyseurs synthétisés par coprécipitation discontinue. Dans ce travail, différents catalyseurs pour l'hydrogénation du CO2 en méthanol ont été synthétisés en utilisant la technique microfluidique dans différentes conditions, afin d'explorer différents paramètres de synthèse pouvant conduire au développement de catalyseurs plus actifs. Les différences de propriétés et d'activité entre un catalyseur synthétisé par la méthode microfluidique et un autre synthétisé par la méthode batch ont été étudiées, suivies d'une exploration des effets du temps de vieillissement et de la température de coprécipitation sur les catalyseurs. Enfin, l'effet de différentes compositions de catalyseurs sur les propriétés et l'activité a été déterminé, en étudiant différentes teneurs en CuO, l'utilisation de CeO2 comme promoteur et l'utilisation de In2O3 comme promoteur et comme métal actif.

Dual-path glucose electrooxidation reaction on Ni(OH)2/NiOOH catalysts in alkaline media

Alejandra Medrano-Banda, Julie Guehl, Gwénaëlle Kéranguéven, Alexandr Oshchepkov, Elena Savinova, Pierre-Antoine Bonnefont
Electrochimica Acta, 2024, 476, pp.143692. ⟨10.1016/j.electacta.2023.143692⟩ | Publiée le 1 février 2024
Article dans une revue

Abstract

Glucose electrooxidation has been widely studied for its application in biosensors, fuel cells and electrosynthesis of value-added products. Nickel is known to catalyze the glucose oxidation reaction (GOR) in alkaline media, but the mechanism, the nature of the active sites, and reaction products are still being debated. This study focuses on elucidating the reaction pathways of the GOR on a Ni(OH)2/NiOOH electrode through electrochemical measurements, in-situ Fourier transform infrared spectroscopy (FTIRS) and microkinetic modeling. The electrode was prepared by Ni electrodeposition on glassy carbon (NiED/GC) followed by electrochemical oxidation into Ni(OH)2/NiOOH. The shape of the cyclic voltammograms obtained during the GOR was found to be significantly influenced by the presence of Fe impurities in the NaOH electrolyte. With the help of microkinetic modeling, a dual-path mechanism was proposed for the glucose electrooxidation on the Ni(OH)2/NiOOH surface, comprised of Eley-Rideal and Langmuir-Hinshelwood pathways, with NiOOH reacting either with glucose from solution or adsorbed on Ni(OH)2 sites. In-situ FTIR measurements reveal the formation of formate at potentials as low as 1.17 V vs. RHE.

Mixed phase anatase nanosheets/brookite nanorods TiO2 photocatalysts for enhanced gas phase CO2 photoreduction and H2 production

Thaleia Ioannidou, Maria Anagnostopoulou, Ioanna Vasiliadou, Clément Marchal, Eirini-Olga Alexandridou, Valérie Keller, Konstantinos Christoforidis
Journal of Environmental Chemical Engineering, 2024, 12 (1), pp.111644. ⟨10.1016/j.jece.2023.111644⟩ | Publiée le 1 février 2024
Article dans une revue

Abstract

CO2 photoreduction and H2 photocatalytic production reactions have been studied on different TiO2 polymorphs (anatase and brookite) engineered with specific nanocrystal shape. Anatase TiO2 materials of nanosheet morphology and brookite TiO2 of nanorod morphology were developed via a hydrothermal synthesis process. Mixed-phase anatase/brookite TiO2 materials of the above extreme cases were also developed, controlling the phase composition. The materials were fully characterized by a variety of techniques including structural, morphological, textural and electronic properties characterization. N2 physisorption analysis and CO2 adsorption isotherms have shown that minimum amount of brookite phase (i.e. ca. 7 wt%) in the final material improved the textural properties and the CO2 uptake ability. Electron paramagnetic spectroscopy (EPR) provided evidences for improvements in the formation and availability of photogenerated electrons in the mixed-phase materials. CO2 photoreduction was increased by ca. 220% in the optimized mixed-phase anatase/brookite TiO2. Photocatalytic H2 production rates were also improved by ca. 140%. The results in the present study have shown that the TiO2 phase as well as the amount of each TiO2 polymorph plays vital role in photocatalytic efficiency and that the photocatalytic improvement depends greatly on the specific reactions. The new insights provided herein would be of interest for studied focusing on materials shape engineering and phase composition and their effect on activity.

Formation pathways of MII/MIII layered double hydroxides: A review

Didier Tichit, Géraldine Layrac, Mayra Alvarez, Ioan-Cezar Marcu
Applied Clay Science, 2024, 248, pp.107234. ⟨10.1016/j.clay.2023.107234⟩ | Publiée le 1 février 2024
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Evaluation of the Hydrophilic/Hydrophobic Balance of 13X Zeolite by Adsorption of Water, Methanol, and Cyclohexane as Pure Vapors or as Mixtures

Meryem Saidi, François Bihl, Olinda Gimello, Benoit Louis, Anne-Cécile Roger, Philippe Trens, Fabrice Salles
Nanomaterials, 2024, 14 (2), pp.213. ⟨10.3390/nano14020213⟩ | Publiée le 18 janvier 2024
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Abstract

Adsorption isotherms of pure vapors and vapor mixtures of water, methanol, and cyclohexane were studied using a synthesized 13X zeolite (FAU topology), by means of a DVS gravimetric vapor analyzer. These results were validated by GCMC calculations. The surface chemistry of the adsorbent was characterized by the thermodesorption of ammonia, and its textural properties were studied using nitrogen physisorption. The 13X zeolite was found to be strongly acidic (BrØnsted acid sites, Si/Al = 1.3) and its specific surface area around 1100 m2·g−1. Water was found to be able to diffuse within both the supercages and the sodalite cavities of the FAU structure, whereas methanol and cyclohexane were confined in the supercages only. The water/methanol sorption selectivity of the 13X zeolite was demonstrated by co-adsorption measurements. The composition of the water/methanol adsorbed phase could be calculated by assuming IAST hypotheses. This model failed in the case of the water/cyclohexane co-adsorption system, which is in line with the non-miscibility of the components in the adsorbed state. The sorption isotherms could be successfully simulated, confirming the robustness of the forcefields used. The 13X zeolite confirmed its a priori expected hydrophilic nature, which is useful for the selective adsorption of water in a methanol–water vapor mixture.

TiO2 supported non-noble Ni-Fe catalysts for the high yield production of 2,5-dimethylfuran biofuel

Martyna Przydacz, Marcin Jędrzejczyk, Jacek Rogowski, Dris Ihiawakrim, Nicolas Keller, Agnieszka Ruppert
Fuel, 2024, 356, pp.129606. ⟨10.1016/j.fuel.2023.129606⟩ | Publiée le 15 janvier 2024
Article dans une revue

Abstract

The establishment of the future biorefinery schemes requires the sustainable conversion and valorisation of renewable bioresources into eco-friendly fuels and chemicals. To this end, 2,5dimethylfuran (DMF) is a promising biofuel competitive to benchmarks like ethanol due to high-value intrinsic properties. It can be produced by the catalytic hydrogenation of the 5hydroxymethylfurfural (HMF) platform molecule, one of the biobased intermediate chemicals derived from the abundant lignocellulosic biomass. We evidenced that bimetallic NiFe alloys supported on TiO2 are earth-abundant non-noble metal-based catalysts allowing the high yield production of DMF to be achieved. We showed that the preparation method and the reduction temperature of the catalyst are of prime importance, and are directly influencing the structure of the supported NiFe bimetallic particles and in consequence the catalyst behaviour. The highest yield to DMF is obtained on a catalyst prepared by co-impregnation and reduced at 500°C, that features an unperfect core/shell structure of the NiFe alloy, with a partial Fe shell surrounding an Fe-enriched Ni core. The key-feature necessary for achieving high performance lies on the surface structure of the NiFe alloy that allows for an optimum availability of highly active Ni domains. The Ni atoms were maintained highly dispersed by the presence of Fecontaining surface phases. The specific surface structure is proposed to promote the HMF adsorption through the carbonyl group, while preventing from the hydrogenation of the aromatic furan ring to maintain high selectivity.

Influence of the Pending Substituent at C1 Position of Spirobifluorene Scaffold on the Electronic Properties

Lambert J Sicard, Cyril Poriel, Sadiara Fall, Olivier Jeannin, Cassandre Quinton, Nicolas Leclerc, Joëlle Rault-Berthelot, Clement Brouillac, Nicolas Zimmermann
Materials Chemistry Frontiers, 2024, Materials Chemistry Frontiers, 8 (5), pp.1349-1361. ⟨10.1039/d3qm01106b⟩ | Publiée le 1 janvier 2024
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Abstract

1-Substituted fluorenes have emerged in recent years as being among the most efficient functional materials for phosphorescence and thermally activated delayed fluorescence OLEDs. The position C1 of the fluorene is indeed highly interesting to design functional materials with specific properties. This scaffold displays two main characteristics. First, there is a strong π-conjugation disruption between the pendant substituent attached at C1 and the substituted fluorene. Second, the specific geometry of the C1-fluorene allows through-space interactions between the substituent attached at C1 and the cofacial building unit attached at C9. However, to date, this family of organic-semi-conductors has not been intensively studied yet. In this work, we report the synthesis and the structural, electrochemical and photophysical properties of four 1-substituted spirobifluorene derivatives, constructed with widely known extended π-conjugated systems: naphthalene, anthracene, phenanthrene and pyrene at the C1 position of spirobifluorene. Using a structure–property relationship approach, we show how the nature of the substituent grafted at C1 significantly modifies the electronic properties (HOMO/LUMO energy levels, triplet state energy levels, etc.). As 1-substituted spirobifluorenes are undoubtedly very promising organic semi-conductors, such a study provides fundamental knowledge to construct future efficient organic materials for specific applications.

Electrochemical trends of a hybrid platinum and metal–nitrogen–carbon catalyst library for the oxygen reduction reaction

Alvin Ly, Eamonn Murphy, Hanson Wang, Ying Huang, Giovanni Ferro, Shengyuan Guo, Tristan Asset, Yuanchao Liu, Iryna Zenyuk, Plamen Atanassov
EES Catalysis, 2024, 2 (2), pp.624-637. ⟨10.1039/D3EY00235G⟩ | Publiée le 1 janvier 2024
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Ultrasonic chemical synthesis of zinc-manganese ferrites with improved magnetic properties.

Wafaa Azouzi, Ikram Boulahya, Jérôme Robert, Ahmed Essyed, Abdelfattah Mahmoud, Ahmed Al Shami, Dris Ihiawakrim, Hicham Labrim, Mohammed Benaissa
Ultrasonics Sonochemistry, 2024, 111, pp.107108. ⟨10.1016/j.ultsonch.2024.107108⟩ | Publiée le 1 janvier 2024
Article dans une revue

Abstract

Zinc-Manganese spinel ferrites (Zn1-xMnxFe2O4) are nowadays very attractive magnetic materials for cancer diagnostic and therapy. With the help of intense ultrasonic waves, sonochemical synthesis method was used to prepare stoichiometric and chemically homogenous nanoparticles by varying the manganese content. The crystal structure along with the size and shape of the as-prepared nanoparticles were described using XRD, TEM and FT-IR techniques, while cations distribution was carefully investigated using XPS and Mossbauer spectroscopic techniques and supported with density functional theory calculations. The crystal structure study revealed the presence of a pure single cubic spinel phase, where the unit-cell and the size were observed to decrease as the manganese incorporation was increased with clear indication of cationic redistribution and degree of inversion variations. Due to the very small variation of the total energy between different configurations, the probability of formation of a mixed phase was found to be very high in such a way that the more mixed was the phase, the more stable it was. A relevant fact was the noticed quasi-systematic ionic exchange made possible by the very short reaction times and high energy offered by the ultrasonic waves. For manganese concentrations up to 60%, the systematic ionic process started by incorporating manganese ions into octahedral sites and pushing iron ions to migrate and replace those of zinc in tetrahedral sites. Such an ionic movement was of central importance for the improvement of the magnetic properties due to the establishment of super-exchange interactions. Such an ionic engineering should definitely open the way to promising applications in biomedical imaging.

Powerful Protein Nanoreservoirs Based on Stellate Mesoporous Silica Embedded in Composite Hydrogels: From Burst Release to Retention

Joelle Bizeau, Morgane Rabineau, Julie Buisson, Theo Lucante, Cedric Leuvrey, Ksenia Parkhomenko, Philippe Lavalle, Damien Mertz
Macromolecular Chemistry and Physics, In press, ⟨10.1002/macp.202400035⟩ | Publiée le 1 janvier 2024
Article dans une revue

Abstract

In the biomaterials field, one major issue with hydrogels (HGs) loaded with active therapeutics is the spontaneous leaking of the cargo occurring rapidly, usually over several hours. However, biological processes involved in regenerative medicine would require to have a sustained drug delivery lasting over weeks/months or be triggered only when a specific biochemical stimulus (enzymatic, cellular, or antimicrobial) is applied. In this work, this challenge is addressed by demonstrating that the spontaneous protein release from an agarose HG (used as model HG) can be partially or totally blocked by the incorporation of stellate mesoporous silica (STMS) nanoparticles (NPs, ≈150 ± 28 nm size, 15 nm pore) within the HG. It is shown here that the porous silica NPs act as sub-micrometer size reservoirs ensuring precise level retention simply by playing on the amount of STMS embedded in the HG. Further, this effect is shown for various proteins demonstrating the versatility of this concept.

Molecular semiconductors with Carbazole versus Triazatruxene endcaps: A matter of self-assembly

Achref Jebnouni, Safa Teka, Benoît Heinrich, Mustapha Majdoub, Nejmeddine Smida Jaballah, Nicolas Leclerc
Journal of Molecular Structure, 2024, 1318, pp.139241. ⟨10.1016/j.molstruc.2024.139241⟩ | Publiée le 1 janvier 2024
Article dans une revue

Abstract

In this work, we describe the design and synthesis of a novel soluble conjugated molecule, CAR-TzDPP, consisting of a central diketopyrrolopyrrole core (DPP) connected to carbazole endcaps through thiazole rings. To evaluate its properties, a triazatruxene-based molecule (TAT-TzDPP) was used as a model for comparison. The electrochemical and the in-solution optical properties are in good agreement with those obtained from DFT calculations. However, the thin-film selfassemblies of CAR-TzDPP exhibited distinct differences, forming a more standard crystalline structure including insulating side-chains layers that disallowed side interactions between aromatic rings. This resulted in a reduced charge transport ability to a two-dimensional (2D) ambipolar charge transport in CAR-TzDPP, compared to the nearly isotropic unipolar charge transport in TAT-TzDPP. Despite this, CAR-TzDPP can be considered a viable alternative for device configurations requiring semiconducting pathways aligned in the substrate plane due to its simplified and high yield synthesis route, ease of processing, and reliable charge mobility in OFETs. This research highlights the significance of molecular units in small semiconducting organic molecules, not only in terms of their individual optoelectronic properties but also in terms of their self-assembly capabilities, which ultimately influence their charge transport properties.

Impact of Tannic Acid on Iron Oxide Nanosclusters Synthesized by a Polyol Solvothermal Method

Joana Vaz-Ramos, Théo Lucante, Jean-Marc Greneche, Cédric Leuvrey, Vasiliki Papaefthymiou, Spiros Zafeiratos, Anne Carton, Dominique Bégin, Stéphane Le Calvé, Sylvie Bégin-Colin
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2024, 689, pp.133658. ⟨10.1016/j.colsurfa.2024.133658⟩ | Publiée le 1 janvier 2024
Article dans une revue

Abstract

Raspberry-shaped iron oxide nanostructures (RSNs) correspond to oriented aggregated and hollow clusters of nanograins exhibiting a high saturation magnetization and a superparamagnetic behaviour. These nanostructures are promising for a wide range of applications, such as magnetic separation, catalysis, pollution control, and nanomedicine. However, for most applications, particularly nanomedecine and depollution, high colloidal stability is required, and the isoelectric point of iron oxide is around 6–7. Therefore, these nanoclusters need to be coated with a surfactant to obtain colloidal suspensions in water. Here, we have developed a one-pot polyol solvothermal synthesis process to coat these promising nanoclusters with tannic acid (TA), a natural compound with antimicrobial properties, which has been little studied with these nanoclusters. Different parameters of the synthesis were adjusted, such as the molar ratio TA:Fe, the synthesis temperature and duration. We showed that TA interferes deeply in the RSNs synthesis mechanism with the observed reduction of iron(III) to iron(II), the complexation of TA with iron, the formation of intermediate phases, as well as the growth of a parasitic iron carbonate phase and the loss of the oriented aggregation and hollowness of the iron oxide RSNs. Considering all these parameters, the optimal synthesis conditions were thus established (TA:Fe ratio = 0.010, temperature of 200◦C and duration of 10.5 h), leading to RSNs with small nanograins, a rather high surface area (82 m2/g), high saturation magnetization (74 emu/g) and good colloidal stability. By combining different characterization techniques, a new synthesis mechanism was proposed different from previously established for RSNs without TA, based on strong TA-iron oxide interfaces.

GBL/BDO pair as a bio-based Liquid Organic Carrier: Kinetic modeling of liquid phase hydrogenation and dehydrogenation over copper-based catalyst

Chaimae Qasmi, Robin Mochel, Vincent Gautier, Isabelle Champon, Sébastien Thomas, Alban Chappaz, Anne-Cécile Roger
International Journal of Hydrogen Energy, 2024, 67, pp.829-841. ⟨10.1016/j.ijhydene.2023.11.232⟩ | Publiée le 1 janvier 2024
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Abstract

The use of liquid organic hydrogen carriers (LOHC) for hydrogen storage has technical, economical, and environmental advantages. The γ-butyrolactone (GBL)/1,4-butanediol (BDO) pair is used in thiswork as a bio-based LOHC. Reaction kinetics of liquid phase GBL hydrogenation and BDO dehydrogenation have been studied using a semi-batch reactor filled with a copper based methanolcatalyst with the experiments have been performed in the temperature range of 458 to 503 K with a constant pressure of 50 and 3 bar for hydrogenation and dehydrogenation respectively Based onanalytical results, a reaction pathway including the formation of side products was proposed. This pathway includes the formation of two side-products: 4-hydroxybutyl 4-hydroxybutanoate (4-HHB) isproduced from the transesterification of GBL by BDO in both reactions; and dibutyleneglycol (DG) from the etherification of BDO in dehydrogenation. Based on experimental results, kinetic models wereestablished for hydrogenation and dehydrogenation reactions. In these models, balanced reactions with a first order were used. Estimation of kinetic parameters for both reactions allows a good prediction ofthe experimental data and results in a temperature extrapolation by an Arrhenius law. Furthermore, models are valid at short (up to 5h) and long (up to 20h) reaction times and the estimation results displayacceptable uncertainties for all the reaction temperatures.

Stimuli‐Induced Fluorescence Switching in Azine‐Containing Fluorophores Displaying Resonance‐Stabilized ESIPT Emission

Timothee Stoerkler, Gilles Ulrich, Pascal Retailleau, Sylvain Achelle, Adele D. Laurent, Denis Jacquemin, Julien Massue
Chemistry - A European Journal, In press, ⟨10.1002/chem.202402448⟩ | Publiée le 1 janvier 2024
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Abstract

This article reports the synthesis, along with structural and photophysical characterization of 2‐(2’‐hydroxyphenyl)benzazole derivatives functionalized with various azaheterocycles (pyridine, pyrimidine, terpyridine). These compounds show dual‐state emission properties, that is intense fluorescence both in solution and in the solid‐state with a range of fluorescent color going from blue to orange. Moreover, the nature of their excited state can be tuned by the presence of external stimuli such as protons or metal cations. In the absence of stimuli, these dyes show emission stemming from anionic species obtained after deprotonation (D* transition), whereas upon protonation or metal chelation, ESIPT process occurs leading to a stabilized and highly emissive K* transition. With the help of extensive ab initio calculations, we confirm that external stimuli can switch the nature of the transitions, making this series of dyes attractive candidates for the development of stimuli‐responsive fluorescent ratiometric probes.

Electrochemical oxidation of glucose in alkaline environment — A comparative study of Ni and Au electrodes

Alejandra Medrano-Banda, Erwann Ginoux, Théo Faverge, Alexandr Oshchepkov, Antoine Bonnefont, Marian Chatenet, Christophe Coutanceau, Gwénaëlle Kéranguéven, Patrick Cognet, Elena Savinova
Electrochimica Acta, 2024, pp.144159. ⟨10.1016/j.electacta.2024.144159⟩ | Publiée le 1 janvier 2024
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Abstract

The glucose oxidation reaction (GOR) was studied on Au and Ni electrodes by cyclic voltammetry (CV), rotating disk electrode (RDE) measurements coupled with Koutecky-Levich analysis, Differential Electrochemical Mass Spectrometry (DEMS), In situ Fourier Transform Infrared spectroscopy (FTIRS) and High Per-formance Liquid Chromatography (HPLC) analysis of the reaction products after electrolysis in potentiostatic mode under continuous flow conditions. This study allowed to identify the reaction products and propose tentative reaction mechanisms. On gold, glucose is adsorbed on metallic sites through its anomeric function (C1) resulting in the formation of gluconate as the main GOR product at potentials close to 0.6 V vs. RHE, with a selectivity towards gluconate close to 100% and a projected faradaic efficiency of ca. 70%. The conversion rate is rather low,close to 20%, due to poisoning of the surface, leading to a strong deactivation. At potentials above 0.8 V vs. RHE, the selectivity towards gluconate decreases and non-selective GOR oxidation proceeds through C-C bond cleavage. On nickel, the GOR occurs at high potentials (close to 1.2 V vs. RHE) on Ni(OH)2 and NiOOH sites, and proceeds through C1-C2 bond breaking, resulting in arabinose and formate. At higher potentials, the electivity towards arabinose decreases, formate being the main reaction product.

Red‐Shifting ESIPT Fluorescence by Site‐Specific Functionalization in 2‐(2’‐hydroxyphenyl)benzazole Derivatives

Timothee Stoerkler, Aymeric Nicolas, Jana El Aghar, Gilles Ulrich, Adele D. Laurent, Denis Jacquemin, Julien Massue
ChemPhotoChem, 2024, 8 (10), pp.e202400079. ⟨10.1002/cptc.202400079⟩ | Publiée le 1 janvier 2024
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Abstract

We describe the synthesis, full photophysical study, and ab initio calculations of 2-(2’-hydroxyphenyl)benzazole (HBX) fluorophores substituted, at the meta position of the phenol group, by pyridine derivatives. HBX are commonly used as model dyes to study the stimuli-induced modulation of the Excited State Intramolecular Proton Transfer (ESIPT) process. The meta-substituted fluorophores reported herein, display a photophysical profile different from the previously reported ortho- and para-substituted HBO pyridine isomers. Indeed, while all dyes undergo spontaneous deprotonation in neutral conditions, leading to highly emissive anionic species; upon protonation, ortho- and para-pyridine substitution leads to resonance-stabilized keto isomers, formed after ESIPT. Protonated meta derivatives, unable to stabilize their excited structure by such electronic delocalization process, display sizable intramolecular charge transfer (ICT) processes, translating into significantly redshifted emission. In addition, all dyes present a strong emission intensity, not only in neutral and acidic solutions, but also in the solid-state. The nature of the emissive transitions was confirmed in each case by theoretical calculations combining Time-Dependent Density Functional Theory (TD-DFT) and second-order Coupled Cluster (CC2) methods.

Biodegradable PMMA coated Zn-Mg alloy with bimodal grain structure for orthopedic applications - A promising alternative

Alia A Diaa, Nahed El-Mahallawy, Madiha Shoeib, Flavien Mouillard, Tom Ferté, Patrick Masson, Adele Carradò
Bioactive Materials, 2024, 39, pp.479--491. ⟨10.1016/j.bioactmat.2024.05.031⟩ | Publiée le 1 janvier 2024
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Abstract

The study examines the impact of microstructure and polymethyl methacrylate (PMMA) grafting on the degradability of Zn-Mg alloys. The mechanical properties of a Zn alloy containing 0.68wt% Mg and extruded at 200°C are enhanced for degradable load-bearing applications, addressing a crucial need in the field. The material exhibits a bimodal grain size distribution that is random texture, consisting of secondary phases, grains, and sub-grains. With an elongation to failure of 16%, the yield and ultimate tensile strengths are 325.9 and 414.5MPa, respectively, and the compressive yield strength is 450.5MPa. The "grafting-from" method was used to coat a few micrometers thick of PMMA on both bulk and scaffold Zn alloys to mitigate the corrosion rate. The last one is a porous structure, with a porosity of 65.8 %, considered as in the first approach of an orthopedic implant. After being immersed for 720h, the PMMA-grafted bulk alloy's corrosion rate decreased from 0.43 to 0.25mm/y. Similarly, the scaffold alloy's corrosion rate reduced from 1.24 to 0.49mm/y. These results indicate that the method employed could be used for future orthopedic applications.

Uncovering the critical function of lanthanum in CH 4 production from CO 2 using exsolved LaNiO 3 perovskite catalysts

Mathias Barreau, Davide Salusso, Jinming Zhang, Michael Haevecker, Detre Teschner, Anna Efimenko, Fabrice Bournel, Jean-Jacques Gallet, Elisa Borfecchia, Kamil Sobczak, Corinne Petit, Spyridon Zafeiratos
Journal of Materials Chemistry A, 2024, 12 (13), pp.7605-7621. ⟨10.1039/D3TA07391B⟩ | Publiée le 1 janvier 2024
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Abstract

The exsolved LaNiO 3 perovskite catalyst exhibits superior performance compared to supported Ni/La 2 O 3 attributed to the critical La–Ni arrangement differences, including Ni encapsulation and lanthana's affinity for hydroxide/carbonate formation.

Assessing Electrocatalyst‐Ionomer Interactions: HOR/HER Activity of Pt/C Catalyst Layers incorporating Poly(imidazolium)s

Kate S Fraser, Kirill Dosaev, Elena Savinova, Steven Holdcroft, Tristan Asset
ChemCatChem, 2024, 16 (2), pp.e202301304. ⟨10.1002/cctc.202301304⟩ | Publiée le 1 janvier 2024
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Abstract

In this work, a specifically designed C2‐protected poly(imidazolium) with a limited number of freely rotating phenyl groups was synthesized and studied as a binder for a commercial Pt/C electrocatalyst. The ionomer‐electrocatalyst interactions were extensively investigated in terms of kinetic and limiting current for the hydrogen oxidation reaction (HOR) and hydrogen evolution reaction (HER). A non‐monotonic evolution of the electrochemically active surface area (ECSA) was observed with the increase of the ionomer‐to‐carbon ratio. The addition of ionomer to the catalyst layer leads to an increase in stability and activity of the electrocatalyst during HOR, while substantially increasing the ionomer content leads to only a marginal decrease in ECSA. Potential phenyl adsorption and cation‐hydroxide ion‐water interactions which impart deleterious impact on electrochemical activity are minimized owing to the sterically encumbered design of the polyimidazolium which (i) limits direct molecular interaction of the imidazolium cationic ring with Pt and (ii) encumbers phenyl and imidazolium ring rotation to hinder parallel aromatic ring adsorption onto the electrocatalyst surface, hence mitigating strong adsorption/blocking interactions.

Scaling-up the use of macroscopic photo-CWPO La1-xTixFeO3/SiC alveolar foam catalyst for solar water treatment against micropollutants

Patricia García-Muñoz, Aimé Abega, Alba Hernández-Zanoletty, Didier Robert, Sixto Malato, Nicolas Keller
Chemical Engineering Journal, 2024, 498, pp.155750. ⟨10.1016/j.cej.2024.155750⟩ | Publiée le 1 janvier 2024
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Abstract

Current wastewater treatment plants are not prepared for the removal of micropollutants like phenol, pharmaceuticals and pesticides in water. As their release into the environment has adverse consequences towards the living organisms of ecosystems, the engineering of novel sustainable processes able to ultimately remove the emerging organic contaminants is an objective of paramount importance. Hereby we report for the first time on the successful scale-up of a macroscopic photo-CWPO La$_{1-x}$Ti$_x$FeO$_3$/SiC alveolar foam catalyst used at the pilot-plant scale inside a Compound Parabolic Collectors based photoreactor. The removal of a span of organic micropollutants in water matrices of different complexity was efficiently realized under natural solar radiation using H$_2$O$_2$ or persulfates as oxidizing agent. The water matrix composition affected the efficiency of the degradation process. Using H$_2$O$_2$, for a collected energy of ca. 27 KJ/mol, the rate of micropollutant removal ranged from 53 % to 95 % in distilled water depending on the micropollutant in a cocktail configuration. It was lowered to the 17–66 % range in tap water, and to the 8–42 % range in simulated urban wastewater. The results demonstrated the promise of using sodium persulfate as oxidant instead of H$_2$O$_2$, with a better efficiency towards the removal of most of the micropollutants tested. The use of the sodium persulfate oxidant allows for overcoming the drawbacks associated to the treatment of real water matrices observed using H$_2$O$_2$, as better performances were reached when increasing the water matrix complexity. Complete removal of carbamazepine and diclofenac micropollutants was reached in tap water and simulated urban wastewater for ca. 27 KJ/mol of collected energy. The degradation performances combined to the catalyst robustness make this water treatment technology promising for operating in a continuous way under natural solar light.

Synthesis and characterization of carboxylic-and amine-grafted FAU zeolites as inorganic fillers to design biocompatible composites

Thomas Menard, Baylar Zarbaliyev, Aline Echalard, Erika Bullier-Marchandin, Fanny Gens, Guy Ladam, Benoît Louis, Gaëtan Lutzweiler
Microporous and Mesoporous Materials, In press, 363, pp.112834. ⟨10.1016/j.micromeso.2023.112834⟩ | Publiée le 1 janvier 2024
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Abstract

Highlights:-Surface functionalization of FAU via APTES or TESPA allowed to graft either amine or carboxylate groups, to mediate their covalent incorporation into a gelatin hydrogel.-Thermal properties of the resulting composites were substantially improved compared with non-crosslinked conditions.-The FAU/gelatin composites were found biocompatible with respect to macrophagederived THP-1 cells.

Electrocatalysis, diverse and forever young

Tristan Asset, Alexandr Oshchepkov, Frédéric Maillard, Galina Tsirlina
Electrochimica Acta, 2024, 507, pp.145174. ⟨10.1016/j.electacta.2024.145174⟩ | Publiée le 1 janvier 2024
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Abstract

Electrocatalysis has always been evolving and diversifying. Driven by expectations of advanced practical applications, the field is incorporating increasingly complex catalytic materials and leveraging insights from advanced spectroscopic, microscopic, and diffraction techniques. A significant challenge lies in linking these innovations to the fundamentals of electrocatalysis, such as the role of the charged interface, and the effects of particle size, support, spillover of adsorbates, identification of reaction intermediates, and further specification of the overall catalytic reaction pathways. This review briefly outlines the development of the electrocatalysis field and presents representative examples addressing this challenge. In line with the purpose of this review, the selection of cited articles is curated to highlight the numerous contributions of a scientist and friend whose research exemplifies the evolution of the field over the past decades.

Influence of low level of non-metal doping on g-C3N4 performance for H2 production from water under solar light irradiation

Leila Hammoud, Clément Marchal, Valérie Caps, Joumana Toufaily, Tayssir Hamieh, Valérie Keller
International Journal of Hydrogen Energy, 2024, 51 (Part A), pp.285-300. ⟨10.1016/j.ijhydene.2023.03.284⟩ | Publiée le 1 janvier 2024
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Abstract

In this paper, a facile one step synthesis method for the preparation of C-, B-, P- and S-doped g-C3N4 by incorporation of small concentration of doping element precursor into urea during thermal polycondensation is reported leading to much lower doping levels than the ones usually reported. The as-obtained doped g-C3N4 photocatalytic materials are deeply characterized in terms of structural, morphological, surface and optical properties. Doping yields beneficial surface morphology modulation along with improved optical, electronic and photocatalytic properties. In particular, C-doped and S-doped g-C3N4 show, after deposition of gold nanoparticles (&lt;1 wt%), enhanced photocatalytic performance (at least twice as high as the undoped photocatalyst, to achieve ca. 610 μmol/h/g) for the production of H2 by water splitting under solar light in the presence of low content (1 vol%) of triethanolamine (TEOA) as sacrificial agent. The most remarkable activity results from the incorporation of traces of S dopant, mainly inserted into interplanar hollow cavities. The enhanced activity is attributed to a combination of high surface area, location of the S dopant and small size of the co-catalyst NPs, which induces enhanced visible light harvesting, enhanced charge carrier separation and enhanced proton recombination. This work highlights the benefits of the optimized low-level doping strategy to overcome the main limitations of g–C3N4–based photocatalysts.

Tio2-Few Layer Graphene and Ta-Doped Tio2 (Photo)Catalysts for Efficient and Selective Glucose Conversion in a Low Temperature Photocatalysis-Assisted Hydrothermal Process

Hamza El Marouazi, Izabela Janowska, Insaf Abdouli, Nadine Essayem, Chantal Guillard, Valérie Keller
Solar RRL, 2024, 8 (11), ⟨10.2139/ssrn.4901551⟩ | Publiée le 1 janvier 2024
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Abstract

Herein, the optimal thickness of TiO 2 , M‐doped, N‐doped, and (M:N) codoped TiO 2 (with M = Nb or Ta) nanotubes (NTs) for photoelectrochemical (PEC) water splitting is determined, in one step through local PEC analysis of electrodes with variable thickness of the photoactive material. A simple anodization method allows the growth, on a single electrode, of aligned doped TiO 2 NTs (TiO 2 ‐NTs) whose length gradually changes from 0 to 15 μm. The external quantum efficiency as a function of the NTs film thickness is measured using a small beam of UV or visible light to scan the surface and locally trigger the oxygen evolution reaction. The results provide the optimal NT layer thickness for each type of doped TiO 2 ‐NTs and demonstrate that if the (M:N) codoped TiO 2 ‐NTs have the best activity in the visible region, the optimal layer thickness is reduced compared to TiO 2 or M:doped TiO 2 ‐NTs. Additionally, by fitting the data with a model that incorporates charge carrier transfer and light absorption mechanisms in the film, it becomes possible to evaluate in operando the interfacial charge transfer, absorption coefficient, or majority carrier mean path which are important properties of semiconducting materials for PEC applications.

Titania-supported sub-nanometer sized Ru-Ni catalysts for the hydroxymethylfurfural hydrodeoxygenation

Agnieszka Ruppert, Magdalena Brzezińska, Nicolas Keller
Catalysis Today, 2024, 433, pp.114651. ⟨10.1016/j.cattod.2024.114651⟩ | Publiée le 1 janvier 2024
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Abstract

Biomass derived 2,5-dimethylfuran (DMF) is a source of biobased polymers or fuels. Key to its selective production lies in the design of efficient and stable heterogeneous catalysts. In our work we showed for the first time how the modification of a finely dispersed Ru catalyst prepared by a photon-assisted synthesis with the addition of Ni allows for the elaboration of a bimetallic Ru-Ni/TiO$_2$ catalyst with boosted performances in the 5-hydroxymethylfurfural (HMF) hydrogenation to DMF. This catalyst modification influenced the electronic properties of Ru, the particle size and the metal-support interaction, that resulted in an increase in the surface acidity of the catalyst and in the improvement of the catalytic performance. We evaluated the importance of several factors, in particular the role of a Ru-Ni interaction, the particle size change or the presence of interfacial Ru-TiO2 sites, on the activity performance of the TiO$_2$ supported bimetallic catalysts. Those combined factors led to a volcano-like efficiency curve, with an optimum catalyst displaying an equimolar Ru:Ni molar ratio

A redox-active porous polymer based on poly(imide-triazine) as a high-performance cathode for lithium-ion batteries

Refka El Oueslati, Badr Jismy, Benjamin Flamme, Nicolas Leclerc, Fouad Ghamouss, Mohamed Abarbri
Journal of Materials Chemistry A, 2024, 12 (26), pp.15866-15873. ⟨10.1039/D4TA00221K⟩ | Publiée le 1 janvier 2024
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Abstract

Organic materials are gaining increasing interest as electrode materials for Lithium Ion Batteries (LIBs) due to their molecular diversity, high capacity, low cost, environmental friendliness and durability. However, most organic electrode materials suffer from poor electronic conductivity, limited active sites and high solubility in organic electrolytes, which impede their practical use in LIB applications. To avoid these drawbacks, an insoluble redox-active porous polymer (RAPP) based on triazine and pyromellitic diimide has been prepared by a simple one-pot solvothermal polymerization method and employed as a cathode material for LiBs. The poly(imide-triazine), denoted as PIT, shows dual porosity combining micro and mesopores with a high specific surface area of about 674 m$^2$ g$^{-1}$ which facilitates electrolyte penetration and ionic transportation and provides interfacial Li storage allowing an additional capacity. Moreover, the dual-redox active sites of C[double bond, length as m-dash]N and C[double bond, length as m-dash]O groups generate more capacity. Remarkably, the LiBs assembled with the synthesized PIT cathode show continuous activation with a high discharge capacity of 233 mA h g$^{-1}$ after 300 cycles at 2 A g$^{-1}$. After an activation process, the PIT material delivers a very high discharge capacity (422 mA h g$^{-1}$ at 0.5 A g$^{-1}$), excellent rate capability (268 mA h g$^{-1}$ at 10 A g$^{-1}$) and extraordinary ultralong cycling stability keeping 65% of discharge capacity after 4000 cycles at 6 A g$^{-1}$. These unprecedented performances outperform most organic/polymeric cathode materials, making PIT a highly promising cathode material for LiBs for future electrochemical energy-storage applications.

Rapid Determination of the Optimum Thickness of Doped TiO 2 Nanotubes Layer by Local Photoelectrochemistry and Operando Properties Extraction by Data Modeling

Sébastien Vergne, Florian Gelb, Valérie Keller, Thomas Cottineau
Solar RRL, 2024, 8 (11), pp.2400156. ⟨10.1002/solr.202400156⟩ | Publiée le 1 janvier 2024
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Abstract

Herein, the optimal thickness of TiO₂, M‐doped, N‐doped, and (M:N) codoped TiO 2 (with M = Nb or Ta) nanotubes (NTs) for photoelectrochemical (PEC) water splitting is determined, in one step through local PEC analysis of electrodes with variable thickness of the photoactive material. A simple anodization method allows the growth, on a single electrode, of aligned doped TiO₂ NTs (TiO₂‐NTs) whose length gradually changes from 0 to 15 μm. The external quantum efficiency as a function of the NTs film thickness is measured using a small beam of UV or visible light to scan the surface and locally trigger the oxygen evolution reaction. The results provide the optimal NT layer thickness for each type of doped TiO₂‐NTs and demonstrate that if the (M:N) codoped TiO₂‐NTs have the best activity in the visible region, the optimal layer thickness is reduced compared to TiO₂ or M:doped TiO₂‐NTs. Additionally, by fitting the data with a model that incorporates charge carrier transfer and light absorption mechanisms in the film, it becomes possible to evaluate in operando the interfacial charge transfer, absorption coefficient, or majority carrier mean path which are important properties of semiconducting materials for PEC applications.

Difluoro Dipyridomethene Boron Complexes: Synthesis, Characterization, and Ab Initio Calculations

Carlotta Figliola, Alexandra Sutter, Thomas Papineau, Camille Chériaux, Pascal Retailleau, Denis Jacquemin, Gilles Ulrich
Journal of Organic Chemistry, In press, ⟨10.1021/acs.joc.3c02491⟩ | Publiée le 1 janvier 2024
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Abstract

Molecular engineering studies on the meso-cyano difluoro dipyridomethene boron complexes are presented and two series (a and b) of novel fluorophores are extensively studied. Halogenated derivatives were reacted under Suzuki-Miyaura or Sonogashira cross coupling reactions to introduce electron-donating or electron-withdrawing functional groups on positions 1 and 2 of the aromatic ligand. All derivatives were obtained in 14-90% yields and studied in detail by structural, photophysical and computational analyses. Both series display excellent emissive properties in solution with blue to orange fluorescence emission upon blue light absorption and promising features as solid emitters. All the spectroscopic measurements are supported and confirmed by first-principles theoretical calculations combining TD-DFT and CC2. Series b, featuring an aryl substituent onto position 1 of the aromatic core, showed significantly large Stokes shifts values.

Ni-NHC Nanoparticles in Micelles as an Effective and Reusable Catalyst for Hydrogenations and Reductive-Aminations in Water

Marta G Avello, Jorge Blas Martínez, Thierry Romero, Vasiliki Papaefthimiou, Michael J Chetcuti, Vincent Ritleng, Cuong Pham-Huu, Claude Oelschlaeger, Christophe Michon
ACS Sustainable Chemistry & Engineering, In press, ⟨10.1021/acssuschemeng.4c01636⟩ | Publiée le 1 janvier 2024
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Abstract

Nickel metallomicelles were formed through the self-assembly of NHC-olefin-coordinated nickel nanoparticles and sodium dodecyl sulfate (SDS) as a surfactant in water. The reduction of various organic compounds was catalyzed using hydrogen gas within water and without any organic cosolvent. The resulting nickel nanoparticles coordinated to NHC-olefin ligands and coated by a bilayer SDS surfactant structure proved to be effective, selective and reusable catalysts for the hydrogenations of alkenes, alkynes and nitroarenes, as well as for the reductive-aminations of aldehydes with primary amines. The hydrogenations were scaled up to 6 mmol and the catalyst was recycled over 10 runs without any significant loss of activity.

Spontaneous Modulation Doping in Semi‐Crystalline Conjugated Polymers Leads to High Conductivity at Low Doping Concentration

Aditya Dash, Shubhradip Guchait, Dorothea Scheunemann, Vishnu Vijayakumar, Nicolas Leclerc, Martin Brinkmann, Martijn Kemerink
Advanced Materials, 2023, ⟨10.1002/adma.202311303⟩ | Publiée le 26 décembre 2023
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Abstract

Abstract The possibility to control the charge carrier density through doping is one of the defining properties of semiconductors. For organic semiconductors, the doping process is known to come with several problems associated with the dopant compromising the charge carrier mobility by deteriorating the host morphology and/or introducing Coulomb traps. While for inorganic semiconductors these factors can be mitigated through (top‐down) modulation doping, this concept has not been employed in organics. Here, this work shows that properly chosen host/dopant combinations can give rise to spontaneous, bottom‐up modulation doping, in which the dopants preferentially sit in an amorphous phase, while the actual charge transport occurs predominantly in a crystalline phase with an unaltered microstructure, spatially separating dopants and mobile charges. Combining experiments and numerical simulations, this work shows that this leads to exceptionally high conductivities at relatively low dopant concentrations.

Urea oxidation reaction on Ni-based electrodes studied by electrochemical and in situ spectroscopies

Viktoriia Zemtsova
Theoretical and/or physical chemistry. Université de Strasbourg, 2023. English. ⟨NNT : 2023STRAF075⟩ | Publiée le 20 décembre 2023
Thèse

Abstract

The objectives of the work were to unveil the dependence of the activity and the products of the UOR on the structure and composition of Ni-based catalysts. We used operando XAS to investigate both the structure of the catalysts and the mean oxidation state of Ni in Ni, NiCo and NiFe catalysts during their operation, and FTIRS to detect products and intermediates formed during the UOR. The operando FTIR spectroscopy allowed us to detect several urea oxidation products on Ni, NiFe and NiCo electrodes, suggesting that the UOR follows two parallel pathways. The pathway resulting in the carbonate formation (and hence also N2 which cannot be detected with FTIRS) predominates at lower potentials, whereas the formation of nitrite and cyanate increases at higher potentials. The operando XAS measurements at Ni K-edge allowed us to detect formation of NiOOH, and decrease of its fraction in the presence of urea. The results support the EC’ (electrochemical – followed by a chemical step) UOR mechanism operating both for monometallic and for bimetallic catalysts, the role of the second component (Fe, Co) mainly related to its influence on the potential of the Ni(OH)2/NiOOH transition and hence the UOR overpotential.

Sustainable polymers and additives from waste plastics using a hybrid “chem-biotech” approach

Agathe Mouren
Polymers. Université de Strasbourg, 2023. English. ⟨NNT : 2023STRAE042⟩ | Publiée le 15 décembre 2023
Thèse

Abstract

Polyurethanes (PU) are a major family of polymers with a wide range of structures and applications. However, they are generally synthesized from fossil resources with a significant environmental impact. Renewable PU with different architectures, e.g. aromatic, cycloaliphatic and linear, have been developed in a circular bioeconomy approach, focusing on sustainable resources such as plastic waste and biomass, combining biotechnologies and chemistry (“chem-biotech” approach). The impact of the developed chemistries and the structure of the sustainable building blocks used was analyzed through the synthesized macromolecular architectures and the obtained properties. In particular, the materials synthesized in this thesis showed superior thermal and mechanical properties to their fossil counterparts, with particular chemical structures, thus also offering a wide potential of applications. In addition, synthons derived from sustainable resources were developed using a "chem-biotech" approach. Some of these have shown strong potential as antioxidants and plasticizers, to improve the processability, utilization, and overall properties of various polymeric materials such as PU. This doctoral work was carried out in the context of a very large Sino-European project (MIX-UP - Horizon 2020).

Composites de type MOF/TiO2/Au pour la photo-réduction du CO2 en phase gazeuse

Marie Duflot
Matériaux. Université de Strasbourg, 2023. Français. ⟨NNT : 2023STRAF066⟩ | Publiée le 15 décembre 2023
Thèse

Abstract

La capture et la conversion du dioxyde de carbone (CO2) en carburants propres sont devenus un enjeu majeur ces dernières années. Dans un contexte écologique, en vue de ralentir le réchauffement climatique, et énergétique considérant les ressources naturelles (énergies fossiles) qui continuent de diminuer, notre société est aujourd’hui obligée de trouver d’autres moyens pour répondre à l’incessante augmentation des besoins énergétiques. Face à cette problématique, la réduction du CO2 par photocatalyse est une solution prometteuse pour produire des carburants tels que le méthane CH4 en utilisant uniquement l’énergie solaire.Cette thèse vise à coupler les propriétés photo-réductrices du dioxyde de titane (TiO2), couramment utilisé comme semi-conducteur, avec la grande capacité à capturer le CO2 du MOF NH2-UiO-66. Des nanoparticules d’or (NP d’Au) ont également été déposées sur ces composites pour créer des jonctions MOF/TiO2/Au et augmenter ainsi leurs capacités photocatalytiques, ceci afin d’obtenir des catalyseurs capables de réduire le CO2 en phase gazeuse, en conditions humides et sous irradiation solaire.

Operando studies of the electrode/electrolyte interface using X-Ray absorption and X-Ray photoelectron spectroscopies

Benjamin Rotonnelli
Theoretical and/or physical chemistry. Université de Strasbourg, 2023. English. ⟨NNT : 2023STRAF087⟩ | Publiée le 27 novembre 2023
Thèse

Abstract

The development of new electrocatalyst associated with the oxygen evolution reaction (OER) is limited by the comprehension we have about the different phenomena occurring at the electrode/electrolyte interface. Those phenomena, related to the reaction mechanism, the catalyst transformation during its operation, ageing, degradation or simply to the ionic rearrangement at the interface due to the electrode polarization, depend on the applied potential. Due to their dynamic nature, it is necessary to study the electrochemical system during the reaction conditions (i.e. operando). X-Ray based techniques such as X-Ray absorption (XAS) and X-Ray photoelectron spectroscopies (XPS) are particularly adapted to the study of those changes, as they are sensitive to the oxidation degree and the chemical environment changes of species at the interface. In this manuscript, we illustrate the advantages, the limitations and the experimental methodology associated to those spectroscopy techniques under operando conditions through the study of 3 different electrochemical systems, and how they allow to understand electrochemical interfaces of various complexities.

Diatom and diatomite: different focus on natural media to material science path

Secou Sall, Vasiliki Papaefthimiou, Thierry Dintzer, Fabrice Vigneron, Eric Brendlé, Pierre Petit, Tom Ferte, Saliha Haddoum, Sana Labidi, Corinne Petit
2023 | Publiée le 14 novembre 2023
Pré-publication, Document de travail

Abstract

Bio-silica issued from diatom, a microalgae, is attracted increasing attention in material science thanks to its peculiar nanoarchitecture and related properties with versatile applications. The present work is a deep analysis on morphological and chemical properties of bio-silica issued from fossil origin (diatomaceous earth) and living one (algal paste). An optimization in purification protocol was performed to obtain multiparous bio-silica from its raw media with keeping its original shape entirely. Multiple characterization methods as scanning electronic microscopy (SEM), infrared spectroscopy, xray diffraction (DRX), x-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDX), nitrogen adsorption and inverse gas chromatography (IGC), were used to check the purification protocol efficiency as well as to gather accurate information on morphology and chemical composition of diatom material obtained in large amount.

Electron rich substituted β-carboline derivatives: Synthesis and photophysical properties

Corentin Maret, Sarah Chebourou, Antoinette de Nicola, Thomas Papineau, Morgane Vacher, Denis Jacquemin, Gilles Ulrich
Dyes and Pigments, 2023, 219, pp.111640. ⟨10.1016/j.dyepig.2023.111640⟩ | Publiée le 1 novembre 2023
Article dans une revue

Abstract

We report the synthesis and characterisation of known and novel analogues of β-carboline, a naturally occurring alkaloid. Striving to induce changes in the optical properties of carboline, we first focus on substitutions at position 1 before exploring other positions. The β-carbolines were synthesized using, on the one hand, post-synthetic functionalization of biosourced products and, on the other hand, total synthesis of the desired compounds. Our strategy mainly relies on the well-known Pictet-Spengler reaction, followed by aromatization using different techniques. Post functionalization were performed by Knoevenagel condensation or pallado-catalyzed cross-coupling. The measured UV-visible and fluorescence spectra show unexpected results with large shifts obtained when changing a few substituents only. For instance, the replacement of the aryl by a styryl substituent induces a bathochromic shift as large as 70 nm. This allowed controlling the position of the emission on a broad range (from 370 and 650 nm). Additionally, protonation of the compounds leads to profound changes in the spectroscopic properties. We indeed observe for some compounds a bathochromic shift in the emission as large as 200 nm upon protonation. The main experimental results are rationalized using theoretical calculations.

Design of platinum nanoflower catalyst exhibiting near-ideal local coordination in a complex shape

Alvin Ly, Tristan Asset, Eamonn Murphy, Kaustubh Khedekar, Ying Huang, Li Xing, Mingjie Xu, Hanson Wang, Raphaël Chattot, Xiaoqing Pan, Iryna V Zenyuk, Plamen Atanassov
Electrochimica Acta, 2023, 469, pp.143282. ⟨10.1016/j.electacta.2023.143282⟩ | Publiée le 1 novembre 2023
Article dans une revue

Abstract

Here, we investigate the oxygen reduction reaction activity of near-monocrystalline platinum nanoflowers presenting a low microstrain to decorrelate the contribution of (i) distorted lattice and (ii) high coordination active sites found within the platinum nanoflower pores to the specific activity enhancement. The results are discussed within the framework of previous investigations onto various catalytic nanostructures. We evidenced that the microstrain of the platinum nanoflowers stands out of the trends previously established for defective platinum-based nanostructures, where the activity is driven by lattice distortion. This indicates that (i) 'defective' structures with low lattice distortion, but high variation in coordination number, can be synthesized and (ii) that their specific activity improvement is comparable to the surface distortion approach in liquid electrolyte.

Magnetic induction assisted pyrolysis of plastic waste to liquid hydrocarbons on carbon catalyst

Cuong Duong-Viet, Lai Truong-Phuoc, Lam Nguyen-Dinh, Christophe Michon, Jean-Mario Nhut, Charlotte Pham, Housseinou Ba, Cuong Pham-Huu
Materials Today Catalysis, 2023, 3, pp.100028. ⟨10.1016/j.mtcata.2023.100028⟩ | Publiée le 1 novembre 2023
Article dans une revue

Abstract

Carbon-based catalyst can effectively crack model waste plastic based on polyolefins under contactless induction heating and yield gaseous and liquid hydrocarbons fractions at mild reaction temperatures. High catalytic performances are reached thanks to the stable catalyst bed temperature arising from the high heating rate of the induction setup. By comparison to indirect Joule heating which required much higher temperatures, contactless direct induction heating allows a compensation of the internal temperature loss during such highly endothermic process through direct heat targeting. The single carbon-based catalyst combined a high and stable activity with an extremely high stability as a function of cycling tests with pure or mixed polymers. By comparison to the acid or metal based catalysts used in plastic cracking, such low cost carbon catalyst avoids deactivation within cycling tests and therefore provides an efficient and cost-effective route for waste plastic recycling and also as chemical storage means for renewable energy.

Portable Microfluidic Analyser For Continuous Monitoring of Formaldehyde in Indoor Air

Audrey Grandjean, Damien Bazin, Anaïs Becker, Stéphane Le Calvé
Envirotech online, 2023 | Publiée le 31 octobre 2023
Article dans une revue

Abstract

At a time when pollution has become a major public health concern, reliable monitoring techniques for air quality must be available. Formaldehyde is a pollutant found mainly in indoor air. It is present in concentrations 2 to 15 times higher than those in outdoor air, with values typically ranging from 10 to 100 µg m-3 [1]. A wide variety of formaldehyde sources are present indoors: building and furnishing products, household products, domestic combustion, etc. Formaldehyde is also present in many products due to its disinfectant and conservation properties. Formaldehyde has irritating effects on the respiratory system and eye mucosa, and its involvement in allergic asthma, is well known [2]. The International Agency for Research on Cancer classified it as carcinogen in 2004. Health agencies recommended thus to reduce exposure to lowest feasible concentration: values of 19.7 µg m−3 (16 ppb) (NIOSHa) and 30 µg m-3 (24.4 ppb) (ANSESb) for long term exposure while occupational exposure limits are set at 243 µg m-3 (300 ppb) (over 8 h) and 487 µg m-3 (600 ppb) (over 15 min) under EU Directive 2019/983. Rapid, sensitive, easy-to-use, and robust continuous analysis techniques need to be developed to democratise the formaldehyde monitoring.

Transition metal and nitrogen co-doped TiO2 for broad spectrum solar light activation photocatalysis

Qingyang Xi
Other. Université de Strasbourg, 2023. English. ⟨NNT : 2023STRAF052⟩ | Publiée le 17 octobre 2023
Thèse

Abstract

Photocatalysis is a promising technology in the field of solar energy conversion, which can be used for environmental remediation and solar fuel production. In this context, the thesis presents works aiming at developing transition metal (M=Nb, Ta or W) and nitrogen co-doped TiO2 photocatalysts with broad spectrum solar light response. (M,N) co-doped TiO2 nanoparticles were synthesized via a sol-gel method followed by a thermal nitridation process in ammonia. The pre-presence of cation promoted nitrogen insertion and increased visible light absorption of the co-doped materials. By adjusting the nitridation conditions, the visible absorption could be shifted in the region before 550 nm or extended at longer wavelengths. By comparing the characterization results of (Nb,N), (Ta,N) and (W,N) co-doped TiO2, the role of cation in determining the N-doping process and defect generation was studied. Co-doped (M,N) samples synthesized with different nitriding conditions were then tested for MB degradation and water-splitting reactions. In the first case, the results showed an improvement in conversion activated by visible light, particularly for (Nb,N) co-doped TiO2. On the other hand, the Nb and Ta dopants effectively promoted the photocatalytic oxidation of water.

Development of an Improved Kinetic Model for CO2 Hydrogenation to Methanol

Siphesihle Mbatha, Sébastien Thomas, Ksenia Parkhomenko, Anne-Cécile Roger, Benoît Louis, Xiaoti Cui, Ray Everson, Henrietta Langmi, Nicholas Musyoka, Jianwei Ren
Catalysts, 2023, 13 (10), ⟨10.3390/catal13101349⟩ | Publiée le 6 octobre 2023
Article dans une revue

Abstract

The kinetics of methanol synthesis remains debatable for various reasons, such as the lack of scientifically conclusive agreement about reaction mechanisms. The focus of this paper is on the evaluation of the intrinsic kinetics of the methanol synthesis reaction based on CO 2 hydrogenation and the associated reverse water-gas shift as overall reactions. The industrial methanol synthesis catalyst, Cu/ZnO/Al 2 O 3 /MgO, was used for performing the kinetic studies. An optimal kinetic model was assessed for its ability to predict the experimental data from differential to integral conditions, contrary to the typical fitting of only the integral conditions' data (common practice, as reported in the literature). The catalyst testing and kinetic evaluations were performed at various temperatures (210-260 • C) and pressures (40-77 bar), and for different stoichiometric numbers (0.9-1.9), H 2 /CO 2 ratios (3.0-4.4) and carbon oxide ratios (0.9-1.0), in an isothermal fixed bed reactor, operated in a plug-flow mode. Experiments with CO in the feed were also generated and fitted. Different literature kinetic models with different assumptions on active sites, rate-determining steps, and hence, model formulations were fitted and compared. The original Seidel model appeared to fit the kinetic data very well, but it has twelve parameters. The modified model (MOD) we propose is derived from this Seidel model, but it has fewer (nine) parameters-it excludes CO hydrogenation, but it takes into consideration the morphological changes of active sites and CO adsorption. This MOD model, with three active sites, gave the best fit to all the data sets.

Effect of a benzothiadiazole spacer on transport properties and N-doping of naphthalene-diimidebased copolymers

Olivier Bardagot, Yann Kervella, Asma Aicha Medjahed, Stéphanie Pouget, Tamara Nunes Domschke, Alexandre Carella, Cyril Aumaître, Patrick Lévêque, Renaud Demadrille
Journal of Materials Chemistry C, 2023, 41 (11), ⟨10.1039/d3tc02816j⟩ | Publiée le 4 octobre 2023
Article dans une revue

Abstract

We report the synthesis of two n-type semiconducting polymers containing a naphthalene diimide (NDI) monomer and thiophene spacers. The two polymers differ by the introduction of an additional 2,1,3-benzothiadiazole (BTD) moiety in the polymer backbone. Although there are examples of polymers combining these two moieties, the effects of introducing the BTD as a third co-monomer on the transport properties and, in particular, the doping mechanisms of these materials have not been elucidated. We describe the optoelectronic, structural organisation and transport properties of these two polymers and investigate the effect of BTD introduction on molecular doping with N-DMBI as a dopant using UV-Vis spectroscopy, DFT modelling, cyclic voltametry, and X-ray diffraction. We show that the incorporation of a BTD unit in the polymer backbone not only improves the charge transport in organic field effect transistors but also the doping efficiency with N-DMBI as well as the conductivity and stability in the conducting state. Our results highlight the need for post-deposition annealing to optimise the N-DMBI doping of the BTD-based polymer and ultimately its conductivity and thermoelectric properties.

(M,N) codoping (M = Nb or Ta) and CoO nanoparticle decoration of TiO2 nanotubes: synergistic enhancement of visible photoelectrochemical water splitting

Thomas Favet, Sharmin Sharna, Valérie Keller, My Ali El Khakani, Thomas Cottineau
Materials today energy, 2023, 37, pp.101376. ⟨10.1016/j.mtener.2023.101376⟩ | Publiée le 1 octobre 2023
Article dans une revue

Impact of film thickness on the structural, linear and non-linear optical properties of ferroelectric Bi2FeCrO6 perovskite thin films

B. Ait Ali, A. Bouhmouche, L. Wendling, C. Hu, C. Bouillet, G. Schmerber, A.M. Saeedi, Spiros Zafeiratos, V. Papaefthimiou, R. Moubah, S. Colis
Vacuum, 2023, 216, pp.112411. ⟨10.1016/j.vacuum.2023.112411⟩ | Publiée le 1 octobre 2023
Article dans une revue

Sensitivity of the European Kingfisher (Alcedo atthis) to global change: evidence from home range features and contaminations by trace elements and organic pollutants, a case study in the marshes of Western Europe

Raphaël Musseau, Frédéric Angelier, Coraline Bichet, Maurice Millet, Céline Rousselle, Jérôme Moreau, Paco Bustamante
4th international Kingfisher conferencen, Biology, ecology & conservation, Wdecki Landscape Parc, Sep 2023, Tleń, Poland | Publiée le 28 septembre 2023
Communication dans un congrès

Abstract

This study, conducted in western France from 2018 to 2021, aimed to examine the environmental disruption risks faced by the European Kingfisher, a species of conservation concern in Europe. We focused on examining the risks associated with habitat reduction, as well as the potential exposure of the species to trace elements and organic pollutants, and the effects of these pollutions on the health of individuals. Through a GPS tracking program, our results highlight the potential importance of wetlands with reduced surface areas and shallow water for the species. Furthermore, by analysing mercury and pesticide concentrations respectively in feathers and in blood samples, we also observed significant contamination of these pollutants in birds' tissues, leading to various negative health effects. Our study highlights: i) the necessity for conservation and ecological restoration policies dedicated to small wetlands to mitigate the potential detrimental effects of global changes on the conservation status of the species, and ii) the significance of apex predators, like the European Kingfisher, as keystone species, in assessing the risks of wetland contamination by trace elements or organic pollutants.

Development of an Online Instrument for Continuous Gaseous PAH Quantification: Laboratory Evaluation and Comparison with The Offline Reference UHPLC-Fluorescence Method

Joana Vaz-Ramos, Mathilde Mascles, Anaïs Becker, Damien Bourgain, Audrey Grandjean, Sylvie Bégin-Colin, Franck Amiet, Damien Bazin, Stéphane Le Calvé
Chemosensors, 2023, Feature Papers on Section "Analytical Methods, Instrumentation and Miniaturization", 11 (9), pp.496. ⟨10.3390/chemosensors11090496⟩ | Publiée le 9 septembre 2023
Article dans une revue

Abstract

Polycyclic aromatic hydrocarbons (PAHs) are widespread environmental contaminants formed during incomplete combustion or pyrolysis of organic material. The reliable quantification of PAH in airborne samples is still difficult, costly, and time-consuming due to the use of offline techniques, including long sampling on filters/adsorbents, laboratory extraction, purification, and concentration steps before analysis. To tackle these drawbacks, this work focused on the development of a fully automatic gas chromatograph (GC) equipped with a flame ionization detector (FID) and a sample preconcentration unit (PC) for gas sampling. This instrument was validated under laboratorycontrolled conditions in the range 0-10 ng for 18 PAH. The chromatographic separation was rather satisfactory except for two PAH pairs, which were quantified together. For all compounds, the peak areas increased perfectly with the gaseous PAH concentration (R 2 &gt; 0.98), without any significant memory effect between two consecutive analyses. Considering a gaseous sample volume of 1 L, the extrapolated limits of detections (LOD) were in the range 19.9-62.6 ng/m 3 , depending on the PAH. Its analytical performances were then compared to those of the offline reference UHPLC-fluorescence method, widely used for airborne PAH monitoring. This was also compared with the very few portable or continuously operating instruments.

Development and characterization of nanofibrous membrane for the treatment of congenital diaphragmatic hernia

Rodolphe Migneret, Isabelle Talon, Emeline Lobry, Guy Schlater, Hamdi Jmal, Amane-Allah Lachkar, Nadia Bahlouli, Anne Hébraud
33rd Annual Conference of the European Society for Biomaterials, Sep 2023, DAVOS, Switzerland | Publiée le 4 septembre 2023
Poster de conférence

Abstract

Congenital Diaphragmatic Hernia (CDH) is a rare malformation, a hole in the diaphragm is formed early in the embryogenesis. For the most severe cases of CDH, a prosthesis is necessary to fill the hole in the diaphragm. The major issue is that the currently used prosthesis cannot follow the growth of the child. Their mechanical properties are not suitable in terms of stretchability and rigidity, leading to the break of the stretches and recidivism of the hernia. We aim to change the paradigm by designing a biocompatible prosthesis adapted to the disease with two distinct faces: one smooth side to impair the intestine adherence on the abdominal side and one fibrous side to enhance the cellular colonization to improve the integration of the prosthesis to the diaphragm. To follow the growth of the child, the mechanical specifications are the following: a 300 % minimum stretchability and a rigidity similar to the muscle. A medical grade elastomeric thermoplastic polyurethane (TPU) was processed using electrospinning. A semi-diluted entangled polymer solution is stretched in a jet-like form, under a strong electric field, leading to the formation of a nano-fibrous membrane on a grounded collector. Electrospinning formulation and process parameters, using a 4-needles setup , were studied to obtain fibrous membranes. Then, the preparation of bilayered membrane with a smooth film layer and a rough fibrous layer was investigated. To avoid delamination between the two layers, the membranes were fabricated in a continuous process by varying the flow rate of the solution during electrospinning. A 4-needles emiter was used to increase the production yield and its translation was optimized to ensure the thickness homogeneity of the membrane (Figure 1). It was shown that mechanical properties are impacted by the ratio of film to total thickness. A panel of membranes was thus designed varying this ratio from 0 (only fibers) to 1 (only film) allowing to modulate the mechanical properties of the membrane (tensile strength, elongation at break, Young modulus, Figure 2). The membrane exhibiting the best mechanical properties was compared with the current prosthesis. The specifications in terms of stretchability were successfully doubled (600 %) and the rigidity was considerably lowered (2.5 MPa). Further biological and mechanical tests, such as uniaxial tensile tests on the stretched membrane or bi-axial tensile tests, are currently ongoing to complete the study.

Dip and Pull X-ray photoelectron spectroscopy for operando analysis of electrochemical systems

Benjamin Rotonnelli, Tristan Asset, Jean-Jacques Gallet, Fabrice Bournel, Elena R. Savinova
74th ISE Annual Meeting, Sep 2023, Lyon, France | Publiée le 1 septembre 2023
Communication dans un congrès

Understanding the electrochemical interface in alkaline environment

Tristan Asset, Pierre-Antoine Bonnefont, Kirill A. Dosaev, Kate Fraser, Steven Holdcroft, Julien Massue, Benjamin Rotonnelli, Elena R. Savinova, Timothee Stoerkler, Jules Wolff
74th annual meeting of the International Society of Electrochemistry, Sep 2023, Lyon, France | Publiée le 1 septembre 2023
Communication dans un congrès

Tuning CH4 Productivity from Visible Light‐Driven Gas‐Phase CO2 Photocatalytic Reduction on Doped g‐C3N4/TiO2 Heterojunctions

Leila Hammoud, Clément Marchal, Christophe Colbeau-Justin, Joumana Toufaily, Tayssir Hamieh, Valérie Caps, Valérie Keller
Energy Technology, 2023, 11, ⟨10.1002/ente.202201363⟩ | Publiée le 28 août 2023
Article dans une revue

Abstract

Herein, visible light-driven gas-phase photocatalytic CO2 reduction into CH4 is tuned by designing optimized three-component Au/doped C3N4/TiO2 composite photocatalysts. The key point strategy consists in the formation of high-quality C3N4/TiO2 heterojunction by associating low containing doped graphitic carbon nitride to commercially available TiO2 UV-100. Those heterojunctions result in both visible light sensitization and increased charge-carrier separation. Further deposition of small Au nanoparticles (≈3 nm), quite exclusively onto TiO2 surfaces, mainly acts as electron trapping/cocatalytic functions without excluding surface plasmonic effects. The resulting doped g-C3N4 material exhibits enhanced visible light harvesting properties, especially in the case of C-doping. In addition, it is assumed that B– and C–C3N4 doping, leading to a more or less lower conduction band position, is the impacting factor toward total CH4 selectivity achievement. The (0.77 wt%)Au/(0.59 wt%)C–C3N4/TiO2 composite photocatalyst, exhibiting the best compromise between the various impacting factors, leads to a continuous productivity rate of CH4 of 8.5 μmol h-1 g-1 under visible light irradiation over at least 10 h. To the best of knowledge, this level of performance is unprecedented under continuous gas-phase flowing CO2 in the presence of water as reducing agent, without addition of any sacrificial agent.

Ni-doped CeO2 nanoparticles to promote and restore the performance of Ni/YSZ cathodes for CO2 electroreduction

Dingkai Chen, Jinming Zhang, Mathias Barreau, Sylwia Turczyniak-Surdacka, Olivier Joubert, Annie Le Gal La Salle, Spyridon Zafeiratos
Applied Surface Science, 2023, 611, pp.155767. ⟨10.1016/j.apsusc.2022.155767⟩ | Publiée le 15 août 2023
Article dans une revue

Abstract

Despite the considerable efforts to develop innovative electrode materials, nickel/yttria-stabilized zirconia (Ni/YSZ) electrodes are still employed in nearly all commercial and industrial solid oxide cell units. This is because Ni/YSZ cermets have good electrocatalytic activity in both electrolysis and fuel cell modes, while they are cost-effective as compared to alternative electrodes under development at the lab scale. Infiltration of nanoparticles has immersed as a promising concept to enhance the performance and robustness of conventional Ni/YSZ. Herein, we apply a relatively simple procedure to infiltrate Ni/YSZ electrodes with hexane solution containing prefabricated Ni-doped CeO2 nanoparticles. Cells with modified Ni/YSZ electrodes show a great improvement in the electrocatalytic activity and stability towards direct CO2 reduction as compared to unmodified cathodes. Besides, a single infiltration step is sufficient to achieve the optimum cell performance, streamlining the preparation process. More importantly, we show that this strategy can be equally efficient to fully reactivate previously degraded Ni/YSZ electrodes and restore their electrochemical performance at levels even higher than the initial ones. In addition, due to the high viscosity of the hexane solution, Ni-doped CeO2 nanoparticles access the entire electrode volume all the way close to the YSZ interface, while it penetrates the micro cracks between Ni and YSZ particles. In this way the electrocatalytic reaction zone is recovered, and the degraded Ni/YSZ electrode is reactivated. Physicochemical, microstructural and electrochemical characterization of the cells evinces several effects that contribute to the performance improvement of Ni/YSZ after infiltration, such as the enhanced surface reducibility of Ni and the amelioration of charge transfer processes within the electrode. The simplicity of the proposed infiltration method and the significant promotion in CO2 electroreduction activity, advocate it as a cost-efficient strategy to improve or regenerate conventional Ni/YSZ electrodes without significantly altering the already well-established fabrication process.

X-ray Photoelectron Spectroscopy in Catalysis: Impact and Historical Background

Spyridon Zafeiratos
Applications of X-ray Photoelectron Spectroscopy to Catalytic Studies, 21, WORLD SCIENTIFIC (EUROPE), pp.1-11, 2023, Catalytic Science Series, ⟨10.1142/9781800613294_0001⟩ | Publiée le 12 août 2023
Chapitre d'ouvrage

Method development for the LC-MS/MS determination of C60 and C70 fullerenes and their functionalized derivatives in airborne particulate matter, settled dust and soot

Mathieu Galmiche, Eden Esslinger, Olivier Delhomme, Philippe Schaeffer, Estelle Motsch, Emmanuelle Leize-Wagner, Yannis-Nicolas François, Maurice Millet
International Journal of Mass Spectrometry, 2023, 490, pp.117072. ⟨10.1016/j.ijms.2023.117072⟩ | Publiée le 1 août 2023
Article dans une revue

Abstract

This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

In situ/operando X-ray absorption and photoelectron spectroscopies applied to water-splitting electrocatalysis

Benjamin Rotonnelli, Marie-Sophie Dias Fernandes, Fabrice Bournel, Jean-Jacques Gallet, Benedikt Lassalle-Kaiser
Current Opinion in Electrochemistry, 2023, 40, pp.101314. ⟨10.1016/j.coelec.2023.101314⟩ | Publiée le 1 août 2023
Article dans une revue

Abstract

The production of hydrogen by water electrolysis allows storing electrical energy into chemical bonds, therefore providing a convenient and carbon-free option to regulate the intermittency of renewable energy sources. The large-scale use of this process requires efficient catalysts, which are currently based on noble metals such as iridium (for the oxygen evolution reaction) and platinum (for the hydrogen evolution reaction). Efforts are being undertaken to decrease the amount of catalysts required in electrolyzers, while maintaining their efficiency. These efforts are backed up by fundamental studies describing the structure of the catalysts, the critical reaction intermediates involved and their failure modes. Such information can be collected during the reaction with synchrotron-based techniques, such as X-ray photoelectron and X-ray absorption spectroscopies. We give here an overview of the potential of these techniques and of their application to the water electrolysis reaction.

Self-powered dynamic glazing based on twisted-nematic liquid crystals and organic photovoltaic layers

Thomas Heiser, Sadiara Fall, Yuhan Zhong, Jing Wang, Thomas Ducatel, Martin Brinkmann, Nicolas Leclerc, Nicolas Brouckaert, Thomas Regrettier, Olzhas Ibraikulov, Malgosia Kaczmarek
SPIE Organic Photonics + Electronics, 2023, 20-24 August 2023, San Diego, California, United States, Aug 2023, San Diego, United States. SPIE, 2023, ⟨10.1117/12.2676830⟩ | Publiée le 1 août 2023
Poster de conférence

Applications of X-ray Photoelectron Spectroscopy to Catalytic Studies

Spyridon Zafeiratos
WORLD SCIENTIFIC (EUROPE), 21, 2023, Catalytic Science Series, ⟨10.1142/q0392⟩ | Publiée le 22 juillet 2023
Ouvrages

Non-fused BODIPY-based acceptor molecules for organic photovoltaics

Fabien Ceugniet, Amina Labiod, Denis Jacquemin, Benoit Heinrich, Fanny Richard, Patrick Lévêque, Gilles Ulrich, Nicolas Leclerc
Journal of Materials Chemistry C, 2023, ⟨10.1039/d3tc02039h⟩ | Publiée le 13 juillet 2023
Article dans une revue

Abstract

Thanks to the rise of efficient push-pull non-fullerene acceptors (NFAs), bulk-heterojunction organic solar cells have reached a high level of competitiveness with maximum power conversion efficiency over 18% for binary active layers. A common thread of most of these NFAs is the presence of a central unit with several fused aromatic rings. Although this design is very effective in achieving high planarity of the conjugated system, it requires the development of a complex chemistry. In the present work, we designed and synthesized a new series of NFAs, called BTTs, by using the uncommon BODIPY unit as central electron accepting unit and avoiding the intricate chemistry of fused aromatic units. All 6 new BTT molecules exhibit very low optical bandgaps (below 1.5 eV), very high extinction coefficients and a LUMO level deep enough to be used as NFA with some of the most efficient electron-donor molecules. The appropriate halogenation of the cyanoindanone electron acceptor end units with chlorine or fluorine atoms allows the fine tuning of the energy levels. Despite the unfavorable edge-on orientation of these new BTTs, the most efficient derivative led to one of the best PCEs obtained so far with a BODIPY-based NFA of around 6%.

Interplay between Dual-State and Aggregation-Induced Emission with ESIPT Scaffolds Containing Triphenylamine Substituents: Experimental and Theoretical Studies

Timothée Stoerkler, Gilles Ulrich, Adèle Laurent, Denis Jacquemin, Julien Massue
Journal of Organic Chemistry, 2023, 88 (13), pp.9225-9236. ⟨10.1021/acs.joc.3c00806⟩ | Publiée le 7 juillet 2023
Article dans une revue

Synthèse de nanocomposites à base de nitrure de carbone graphitique, de dioxyde de titane et de nitrure de bore pour la photo-production de H2 et la photo-réduction de CO2

Leila Hammoud
Chimie théorique et/ou physique. Université de Strasbourg, 2023. Français. ⟨NNT : 2023STRAF028⟩ | Publiée le 4 juillet 2023
Thèse

Abstract

Inspirée de la photosynthèse naturelle, la photocatalyse hétérogène est une technologie respectueuse de l’environnement qui consiste à convertir le CO2 en composés valorisables, et à produire de l’H2 décarboné à l’aide de l’énergie solaire abondante et renouvelable. Dans ce cadre, ce projet s’est focalisé sur le développement de systèmes photocatalytiques à base de TiO2, de g-C3N4 et de BN poreux. Le rendement photocatalytique de ces systèmes vis-à-vis de la photo-production d’H2 sous lumière solaire à partir de l’eau et de la photoréduction de CO2 par l’eau en phase gazeuse sous lumière solaire et visible a été amélioré : (1) en dopant le g-C3N4 et le BN par des éléments non métalliques pour une meilleure absorption de la lumière visible, (2) en créant des hétérojonctions g-C3N4 dopés/TiO2, g-C3N4 dopés/BN et BN/TiO2 pour une meilleure séparation des charges photogénérées et (3) en décorant les systèmes ainsi obtenus par des métaux. Une étude particulière de l’effet de la taille, de la teneur, de la composition et de la structure de nanoparticules d’alliage (Au-Pt) sur les performances photocatalytiques sous illumination visible a aussi été investiguée.

[Ru(bpy)3]2+-functionalized polydopamine-coated polyurethane foam as an easily reusable macroscopic heterogeneous catalyst for visible-light photocatalysis

Han Peng, Thierry Romero, Vasiliki Papaefthimiou, Philippe Bertani, Vincent Ritleng
Molecular Catalysis, 2023, 545, pp.113183. ⟨10.1016/j.mcat.2023.113183⟩ | Publiée le 1 juillet 2023
Article dans une revue

Abstract

An easy-to-handle, highly reusable and efficient [Ru(bpy)3] 2+-based heterogeneous photocatalyst was obtained by post-functionalization of a polydopamine-coated open cell polyurethane foam (PDA@PUF) via a silanization process of the mussel-inspired adhesive layer with 3-(triethoxysilyl)propan-1-amine (APTES), followed by an EDC-mediated coupling with [2,2'-bipyridine]-4-carboxylic acid and further complexation with [Ru(bpy)2Cl2] (bpy = 2,2'-bypyridine). The successful covalent grafting of APTES on the PDA layer of PUF and functionalization all over the foam surface with [Ru(bpy)3] 2+ was suggested by 29Si CP-MAS NMR, XPS, ICP-AES and SEM-EDX. The macroscopic photocatalyst proved effective in model benzylic amine homocouplings and cross dehydrogenative couplings under visible-light irradiation and molecular oxygen, showing good functional group tolerance and excellent reusability in an easy-to-carry "dip-and-play" mode for at least six runs. Impressively, an improvement of the catalytic performances was even observed in both reactions, which most likely results from a modification of the uppermost layer of polydopamine throughout the successive cycles that renders the photocatalyst more accessible.

Side chains in organic conjugated materials, a key parameter

Nicolas Leclerc, Olzhas A Ibraikulov, Pablo Durand, Huiyan Zeng, Benoît Heinrich, Thomas Heiser, Patrick Lévêque, Martin Brinkmann, Stéphane Méry
SCF 2023 (Société Chimique de France), Jun 2023, Nantes, France | Publiée le 26 juin 2023
Communication dans un congrès

Ionic Nickel Embedded in Ceria with High Specific CO 2 Methanation Activity

Mathias Barreau, Davide Salusso, Juan Li, Jinming Zhang, Elisa Borfecchia, Kamil Sobczak, Luca Braglia, Jean‐jacques Gallet, Piero Torelli, Hua Guo, Sen Lin, Spyridon Zafeiratos
Angewandte Chemie International Edition, 2023, 62 (25), ⟨10.1002/anie.202302087⟩ | Publiée le 19 juin 2023
Article dans une revue

Abstract

Abstract CO 2 hydrogenation to methane is gaining increasing interest as one of the most promising ways to store intermittent renewable energy in the form of chemical fuels. Ni particles supported on CeO 2 represent a highly efficient, stable and inexpensive catalyst for this reaction. Herein, Ni‐doped CeO 2 nanoparticles were tested for CO 2 methanation showing an extremely high Ni mass‐specific activity and CH 4 selectivity. Operando characterization reveals that this performance is tightly associated with ionic Νi and Ce 3+ surface sites, while formation of metallic Ni does not seem to considerably promote the reaction. Theoretical calculations confirmed the stability of interstitial ionic Ni sites on ceria surfaces and highlighted the role of Ce‐O frustrated Lewis pair (FLP), Ni‐O classical Lewis pair (CLP) and Ni‐Ce pair sites to the activation of H 2 and CO 2 molecules. To a large extent, the theoretical predictions were validated by in situ spectroscopy under H 2 and CO 2 : H 2 gaseous environments.

MOF-based nanomaterials for photocatalytic CO2 reduction and H2 production

Maria Anagnostopoulou
Theoretical and/or physical chemistry. Université de Strasbourg, 2023. English. ⟨NNT : 2023STRAF018⟩ | Publiée le 16 juin 2023
Thèse

Abstract

Over the past few years, global warming has become more and more evident. Excessive greenhouse gas emissions are the main cause. CO2 is one of the greenhouse gases, whose increase on the atmosphere is attributed to the destabilization of carbon cycle and the anthropogenic emissions (i.e., industry, transport). In order to tackle this problem, the decrease of CO2 emissions by energetic transition towards environmental-friendly resources and the CO2 conversion to other high-added value chemicals, is suggested. In this direction, photocatalysis is introduced as a promising and environmentally friendly pathway, by reducing CO2 into other chemicals, which can be used as fuels-so called solar fuels (CH4, CO, H2). Except for the presence of sunlight, the presence of photocatalysts is also prerequisite. Actually, the most commonly studied photocatalysts present some shortcomings. Therefore, this thesis aims to couple MOFs materials with commonly used semiconductors (g-C3N4, TiO2), aiming to obtain composite materials with photocatalytic properties superior to their bare counterparts.

Tailoring the 3D porous structure of conducting PEDOT:PSS gels via ice-templating

Quentin Weinbach, Naoures Hmili, Emma Gottis, Guillaume Fleith, Jérôme Combet, Vasiliki Papaefthimiou, Vincent Malesys, Emmanuel Denys, Laurent Simon, Marc Schmutz, Alain Carvalho, Doru Constantin, Laure Biniek
Journal of Materials Chemistry C, 2023, 11 (23), pp.7802-7816. ⟨10.1039/D3TC01110K⟩ | Publiée le 15 juin 2023
Article dans une revue

Abstract

Well-controlled gelation of fibrillar PEDOT:PSS and growth of ice crystals yield robust anisotropic macroporous materials with a tuned pore size. The honey-comb like structure is at the origin of the low thermal conductivity.

Solid-state emitters presenting a modular excited-state proton transfer (ESIPT) process: recent advances in dual-state emission and lasing applications

Martyna Durko-Maciag, Gilles Ulrich, Denis Jacquemin, Jaroslaw Mysliwiec, Julien Massue
Physical Chemistry Chemical Physics, 2023, 25 (22), pp.15085-15098. ⟨10.1039/D3CP00938F⟩ | Publiée le 7 juin 2023
Article dans une revue

Abstract

This review aims at providing a broad readership about recent advances in the fields of dual solution-solid emitters and lasing applications based on organic dyes displaying an excited-state intramolecular proton transfer (ESIPT) process.

Elaboration de matériaux multifonctionnels : application à l'hydrogénation catalytique du CO$_2$ en méthanol et dimethyl éther (DME)

Vincent Gautier, Audrey Hertz, Albin Chaise, Anne-Cécile Roger
GECat 2023 - Groupe d'Etude sur la Catalyse, Jun 2023, Dunkerque, France. 2023 | Publiée le 6 juin 2023
Poster de conférence

Abstract

L'hydrogénation catalytique du CO$_2$ en méthanol et DME avec de l'hydrogène (synthétisé à partir d'énergie bas-carbone) a pour objectif d'apporter une alternative durable aux hydrocarbures fossiles. Cependant, d'importantes quantité d'eau générées au cours de la réaction limitent les rendements de production et dégradent prématurément le catalyseur. Pour répondre à ce problème, l'utilisation de membranes capables de séparer sélectivement l'eau au sein du réacteur catalytique a fait ses preuves dans la littérature.

The runt of ammonia production by N2 reduction: Electrocatalysis in aqueous media

Tristan Asset
Current Opinion in Electrochemistry, 2023, 39, pp.101301. ⟨10.1016/j.coelec.2023.101301⟩ | Publiée le 1 juin 2023
Article dans une revue

Understanding the Role of Poly(imidazolium) Ionomers in Alkaline Fuel Cell and Electrolyzer Applications – Ionomer Impact on the Hydrogen Evolution and Oxidation Reactions

Kate Fraser, Tristan Asset, Kirill A. Dosaev, Elena R. Savinova, Steven Holdcroft
CSC 2023, Jun 2023, Vancouver, Canada | Publiée le 1 juin 2023
Communication dans un congrès

Grafting of Crown Ether and Cryptand Macrocycles on Large Pore Stellate Mesoporous Silica for Sodium Cation Extraction

Paula Duenas-Ramirez, Caroline Bertagnolli, Robin Weiss, Joëlle Bizeau, Loïc Jierry, Philippe Choquet, Ariane Zaloszyc, Sylvie Bégin-Colin, Damien Mertz
Molecules, 2023, 28 (12), pp.4622. ⟨10.3390/molecules28124622⟩ | Publiée le 1 juin 2023
Article dans une revue

Abstract

Regulation of the sodium cations level in the case of renal failure diseases is a very challenging task for clinicians, and new pollutant extractors based on nanomaterials are emerging as potential treatments. In this work, we report different strategies for the chemical functionalization of biocompatible large pore mesoporous silica, denoted stellate mesoporous silica (STMS), with chelating ligands able to selectively capture sodium. We address efficient methods to covalently graft highly chelating macrocycles onto STMS NPs such as crown ethers (CE) and cryptands (C221) through complementary carbodiimidation reactions. Regarding sodium capture in water, C221 cryptand-grafted STMS showed better capture efficiency than CE-STMS due to higher sodium atom chelation in the cryptand cage (Na+ coverage of 15.5% vs. 3.7%). The sodium selectivity was hence tested with C221 cryptand-grafted STMS in a multi-element aqueous solution (metallic cations with the same concentration) and in a solution mimicking peritoneal dialysis solution. Results obtained indicate that C221 cryptand-grafted STMS are relevant nanomaterials to extract sodium cations in such media and allow us to regulate their levels.

Corrigendum to “Neonicotinoids: Still present in farmland birds despite their ban, Chemosphere, 321, April 2023, 138091”

Elva Fuentes, Agathe Gaffard, Anaïs Rodrigues, Maurice Millet, Vincent Bretagnolle, Jérôme Moreau, Karine Monceau
Chemosphere, 2023, 325, pp.138344. ⟨10.1016/j.chemosphere.2023.138344⟩ | Publiée le 1 juin 2023
Article dans une revue

Selection of green solvents for organic photovoltaic cells applying reverse engineering methodology

Ivonne Rodriguez Donis, Jing Wang, Sophie Thiebaud-Roux, Vincent Gerbaud, Nicolas Leclerc, Patrick Lévêque, Olzhas A Ibraikulov, Markus Kohlstädt, Thomas Heiser
RRB23. International Conference on Renewable Resources & Biorefineries, May 2023, Riga, Lithuania | Publiée le 31 mai 2023
Communication dans un congrès

Optimizing chain alignment and preserving the pristine structure of single-ether based PBTTT helps improve thermoelectric properties in sequentially doped thin films

Martin Brinkmann, Huiyan Zeng, Pablo Durand, Shubhradip Guchait, Laurent Herrmann, Celine Kiefer, Benoît Heinrich, Nicolas Leclerc
E-MRS Spring meeting 2023, EMRS, May 2023, Strasbourg, France | Publiée le 29 mai 2023
Communication dans un congrès

Inter-annual variation of physiological traits between urban and forest great tits

Agnès Saulnier, Josefa Bleu, Anne Boos, Maurice Millet, Sandrine Zahn, Pascale Ronot, Islah El Masoudi, Emilio R Rojas, Pierre Uhlrich, Mirella del Nero, Sylvie Massemin
Comparative Biochemistry and Physiology - Part A: Molecular and Integrative Physiology, 2023, 279, pp.111385. ⟨10.1016/j.cbpa.2023.111385⟩ | Publiée le 1 mai 2023
Article dans une revue

Abstract

Urbanization is characterized by rapid environmental changes such as an increase in building surface, in pollution, or a decrease in invertebrate abundance. For many bird species, morphological and physiological differences have been observed between urban and rural individuals that seem to reflect a negative impact of urban life on the health and fitness of individuals. Studies on passerine birds also showed important differences between populations and species in their responses to the urban environment. We propose to test physiological differences between urban and forest individuals over 3 years to understand whether the observed patterns are constant or subject to variations across years. For this purpose, we assessed the health parameters of adults and fledgling of great tits, Parus major, living in an urban and in a forest site in the Eurometropole of Strasbourg, for three years. Bird health was estimated with morphological parameters (body condition and size) and also with physiological parameters (oxidative status and telomere length). Our results showed lower body condition of urban fledglings regardless of the year, but no site effects on telomere length. On the contrary, for adult breeders, urban individuals had longer telomeres than forest ones except for one year which coincide with bad weather conditions during reproduction where no difference was detected. Urban birds also had higher antioxidant capacity whatever the years. These results suggest that cities act as a filter in which only good quality individuals survive and achieve successful reproduction regardless of year, whereas in the forest the selection occurs only during harsh weather years.

(Invited) Core-Shell Fe 3 O 4 @CoFe 2 O 4 Spinel Nanoparticles for the Oxygen Evolution Reaction in Alkaline Media

Lisa Royer, Iryna Makarchuk, Tristan Asset, Benjamin Rotonnelli, Benoit Pichon, Antoine Bonnefont, Elena Savinova
243rd ECS Meeting, May 2023, Boston (MA), United States. pp.2066-2066, ⟨10.1149/MA2023-01362066mtgabs⟩ | Publiée le 1 mai 2023
Communication dans un congrès

Abstract

Transition metal oxides have attracted much attention as promising anode materials for anion exchange membrane water electrolysis (AEMWE). Herewith we introduce core-shell nanoparticles comprised of a Fe 3 O 4 core and a CoFe 2 O 4 shell as prospective catalysts for the oxygen evolution reaction (OER) at the cathode of an AEMWE. We show that confining the active component in a thin (~1-2 nm) shell and taking advantage from the core-shell synergistic interaction allows one to reach an exceptional OER activity of 2800 A at 1.65 V vs. RHE per gram of cobalt [1]. We further show that to correctly determine the OER activity, it is necessary to study the OER in a wide interval of the catalyst loadings [2]. To shed light of the origin of the aforementioned synergistic effect between the core and the shell, the Fe 3 O 4 @CoFe 2 O 4 nanoparticles were investigated using operando near edge X-ray absorption fine structure (NEXAFS) spectroscopy in a total electron yield (TYE) detection mode, under potential and during the OER conditions [3] . We documented a strong influence of the Fe3O4 core on the redox behavior of the CoFe2O4 shell under the OER conditions. Contrary to the previously studied Co 3 O 4 anode, whose surface at high potentials has been shown to transform into CoOOH [4], the shell of the Fe 3 O 4 @CoFe 2 O 4 nanoparticles maintains its spinel structure with Co(II) stabilized by the Fe(III) of the core. The results suggest the occurrence of a cation-redox OER mechanism involving cooperative redox behavior between Co and Fe atoms. It is remarkable that the core-shell structure is essentially preserved under the OER conditions. Figure 1. Left-hand side: cartoon showing the composition of the core-shell nanoparticle and charge transfer from Co to Fe occurring under positive polarization. Right-hand side: Fe L-edge difference spectra acquired at 1.2, 1.4 and 1.8 V vs RHE (the reference itself taken at 1.0 V vs. RHE). Reproduced from Ref. [3]. Finally, we study the influence of the shell composition by replacing Co by Ni on the OER activity and stability of core-shell nanoparticles. Acknowledgements The authors are indebted to S. Hettler and R. Arenal of INMA (Zaragoza, Spain), S. Holdcroft of SFU (Vancouver, Canada) and J. Velasco-Vélez of Alba Synchrotron facility (Spain) for their cooperation. We thank the HZB für Materialien und Energie for the allocation of synchrotron radiation beamtime. Financial support from Jean-Marie-Lehn foundation is gratefully acknowledged. REFERENCES [1] L. Royer, S. Hettler, R. Arenal, T. Asset, B. Rotonnelli, A. Bonnefont, E. Savinova, B. Pichon, submitted. [2] L. Royer, J. Guehl, M. Zilbermann, T. Dintzer, C. Leuvrey, B. Pichon, E. Savinova, A. Bonnefont, submitted. [3] L. Royer, A. Bonnefont, T. Asset, B. Rotonnelli, J. Velasco-Vélez, S. Holdcroft, S. Hettler, R. Arenal, B. Pichon, E. Savinova, ACS Catalysis, https://doi.org/10.1021/acscatal.2c04512. [4] F. Reikowski, F. Maroun, I. Pacheco, T. Wiegmann, P. Allongue, J. Stettner, O. Magnussen, ACS Catal. 2019, 9 (5), 3811–3821; https://doi.org/10.1021/acscatal.8b04823. Figure 1

Residues of glyphosate, AMPA and glufosinate in soils, earthworms and wild small mammals in arable landscapes: a new case of “emerging organic contaminants”?

Clémentine Fritsch, Colette Bertrand, Brice Appenzeller, Olivier Delhomme, Maurice Millet, Marjolaine Bourdat-Deschamps, Sylvie Nélieu, Michaël Coeurdassier, Renaud Scheifler, Sabrina Gaba, Vincent Bretagnolle, Céline Pelosi
SETAC Europe 33rd Annual Meeting, Apr 2023, Dublin, Ireland. 2023 | Publiée le 30 avril 2023
Poster de conférence

ACTRIS - CiGas side-by-side interlaboratory comparison of new and classical techniques for formaldehyde measurement in the nmol/mol range

Therese Salameh, Emmanuel Tison, Evdokia Stratigou, Sébastien Dusanter, Vincent Gaudion, Marina Jamar, Ralf Tillmann, Franz Rohrer, Benjamin Winter, Teresa Verea, Amalia Muñoz, Fanny Bachelier, Véronique Daele, Audrey Grandjean
EGU 2023, Apr 2023, Vienne (AUT), Austria. ⟨10.5194/egusphere-egu23-17535⟩ | Publiée le 23 avril 2023
Communication dans un congrès

Abstract

Formaldehyde is an important hazardous air pollutant, classified as carcinogenic to humans by the International Agency for Research on Cancer (IARC). It is emitted directly by many anthropogenic and natural sources, and formed as a secondary product from volatile organic compounds (VOCs) photo-oxidation. Formaldehyde is, as well, a significant source of radicals in the atmosphere resulting in ozone and secondary organic aerosols formation. Routine measurements of formaldehyde in regulatory networks within Europe (EMEP) and USA (EPA Compendium Method TO 11A) rely on sampling with DNPH (2,4-Dinitrophenylhydrazine)- impregnated silica cartridges, followed by analysis with HPLC (High-performance liquid chromatography). In the framework of the EURAMET-EMPIR project « MetClimVOC » (Metrology for climate relevant volatile organic compounds: http://www.metclimvoc.eu/), the European ACTRIS (Aerosol, Cloud and Trace Gases Research InfraStructure: https://www.actris.eu/) Topical Centre for Reactive Trace Gases in-situ Measurements (CiGas), IMT Nord Europe unit – France, organized a side-by-side intercomparison campaign in Douai-France, dedicated to formaldehyde measurement in a low amount fraction range of 2 - 20 nmol/mol, from 30 May to 8 June 2022. The objectives of the intercomparison are to evaluate the instruments metrological performance under the same challenging conditions, and to build best practices and instrumental knowledge. Here, we present the results from the intercomparison, where ten instruments belonging to seven different techniques were challenged with the same formaldehyde gas mixture generated either from a cylinder or from a permeation system, in different conditions (amount fractions, relative humidity, interference, blanks, etc.), flowing through a high-flow (up to 50 L/min) Silcosteel-coated manifold. The advantages/drawbacks of the techniques will be discussed.

Influence of the catalyst layer thickness on the determination of the OER activity of Fe3O4@CoFe2O4 core-shell nanoparticles

Lisa Royer, Julie Guehl, Maud Zilbermann, Thierry Dintzer, Cédric Leuvrey, Benoit Pichon, Elena Savinova, Antoine Bonnefont
Electrochimica Acta, 2023, 446, pp.141981. ⟨10.1016/j.electacta.2023.141981⟩ | Publiée le 1 avril 2023
Article dans une revue

CeO 2 Frustrated Lewis Pairs Improving CO 2 and CH 3 OH Conversion to Monomethylcarbonate

Davide Salusso, Giorgio Grillo, Maela Manzoli, Matteo Signorile, Spyridon Zafeiratos, Mathias Barreau, Alessandro Damin, Valentina Crocellà, Giancarlo Cravotto, Silvia Bordiga
ACS Applied Materials & Interfaces, 2023, 15 (12), pp.15396-15408. ⟨10.1021/acsami.2c22122⟩ | Publiée le 29 mars 2023
Article dans une revue

Effect of Nitrogen Defects on Pt Nanoparticle Dispersion and Stability Studied by Electron Microscopy Paired with Machine Learning Image Processing for Probing Catalyst–Support Interactions

Margaret Fitzgerald, Hanson Wang, Alvin Ly, Jayson Foster, Matthew Sorrells, Tristan Asset, Plamen Atanassov, Svitlana Pylypenko
ACS Applied Nano Materials, 2023, 6 (7), pp.5313-5324. ⟨10.1021/acsanm.2c05414⟩ | Publiée le 22 mars 2023
Article dans une revue

Optimization of NH2-UiO-66/TiO2/Au composites for enhanced gas-phase CO2 photocatalytic reduction into CH4

Marie Duflot, Clément Marchal, Valérie Caps, Vincent Artero, Konstantinos Christoforidis, Valérie Keller
Catalysis Today, 2023, 413- 415, pp.114018. ⟨10.1016/j.cattod.2023.01.025⟩ | Publiée le 15 mars 2023
Article dans une revue

Abstract

Here we report on the optimization of NH2-UiO-66/TiO2/Au (ca. 1.5 wt%) composite photocatalysts applied to gas phase CO2 photocatalytic reduction in presence of water as reducing agent by varying NH2-UiO-66/TiO2 ratio and pH during synthesis. It is shown that 10 wt% NH2-UiO-66/TiO2/Au (at pH=7) composite leads to the best cumulated CH4 production rate of 136 mu mol/gcatalyst with 70% electronic selectivity over 5 h of continuous test. This composite exhibits the best compromise between MOF surface area and thus CO2 adsorption sites, visible light photons absorption capacity and a large interface contact area, which ensured preferable metal(Zr)-to-metal(Ti) charge carrier. Au deposition by impregnation/chemical reduction in also required to perform CO2 photoreduction, and may presumably act as electron traps, co-catalyst or surface plasmon resonator.

Densité de probabilité de présence ou densité d'énergie de la particule libre ?

Christian Preziosa
2023 | Publiée le 11 mars 2023
Pré-publication, Document de travail

Development of biodegradable and biobased multiphase films for single-use containers used in bioprocesses

Alexis Morinval
Polymers. Université de Strasbourg, 2023. English. ⟨NNT : 2023STRAE001⟩ | Publiée le 10 mars 2023
Thèse

Abstract

After a continuous growth of plastics production since the 1950s, it is time to take charge of the environmental aspects related to these indispensable materials with unique properties. This requires taking into account the beginning (resources) and the end (circularity) of their life cycle, especially by using biobased and biodegradable polymers. In this thesis, renewable films are developed and analyzed for applications to packaging used in biotechnologies. Compatibilized multilayer films based on plasticized starch and a polyester have been coextruded and characterized in order to evaluate their properties and their suitability for the targeted field. In this context, starch and a biodegradable polyester were chemically modified to develop thermoreversible Diels-Alder reactions at the interface. These modified polymers allowed to improve the properties, especially mechanical, of these systems. The thiol-Michael click addition and the disulfide bond exchange have also been studied for the future development of dynamic compatibilized systems with possible end-of-life treatments allowing an easier recycling.

Heteroaryl‐Substituted Bis‐Anils: Aggregation‐Induced Emission (AIE) Derivatives with Tunable ESIPT Emission Color and pH Sensitivity

Timothée Stoerkler, Pascal Retailleau, Gilles Ulrich, Denis Jacquemin, Julien Massue
Chemistry - A European Journal, 2023, 29 (14), ⟨10.1002/chem.202203766⟩ | Publiée le 7 mars 2023
Article dans une revue

Abstract

Abstract The two‐step synthesis, structural, and photophysical properties of a series of heteroaryl‐substituted bis‐anil derivatives presenting aggregation‐induced emission (AIE) coupled with an excited‐state intramolecular proton transfer (ESIPT) process is described. The fluorescence color of the aggregates can be fine tuned by changing the electronic nature of the peripheral substitution, leading to a wide range of emission wavelengths (from green to the near infra‐red). Moreover, upon introduction of strong electron‐withdrawing groups such as cyano (CN), a competition between ESIPT and deprotonation is observed leading to the emission of the anionic species at low water percentage. This observation led to the synthesis of an additional mixed AIE fluorophore, functionalized by methoxy groups on one side and cyano groups on the other side. Upon addition of water, this dye displays first anionic emission, followed by typical AIE/ESIPT red fluorescence upon formation of the aggregates. TD‐DFT calculations on selected AIE dyes were performed to rationalize the nature of the emissive transitions in these derivatives.

Influence of the solid titanium source on the activity of La1−xTixFeO3 photo-CWPO catalysts under UV-A light

Patricia Garcia-Muñoz, Fernando Fresno, Christophe Lefevre, Didier Robert, Nicolas Keller
Catalysis Today, 2023, 413-415, pp.113974. ⟨10.1016/j.cattod.2022.12.005⟩ | Publiée le 1 mars 2023
Article dans une revue

Abstract

In the search for more efficient low-temperature catalysts able to oxidise biorecalcitrant pollutants in water, the selective substitution of La3+ by Ti3+ cations was reported to boost the UV-A light driven activity of LaFeO3 orthoferrites as H2O2-mediated photo-CWPO catalysts. La1-xTixFeO3 catalysts with 0 < x < 0.11 were obtained by a modified Pechini sol–gel route via the addition of a solid source of titanium during the synthesis. By using a span of crystallized and amorphous TiO2, the influence of the titanium source on the substitution rate in the orthoferrite network and on the performances of the catalysts under UV-A light was demonstrated using the degradation of 4-chlorophenol as test reaction. The amorphous content of the TiO2 precursor is proposed to be the key factor driving the substitution of La3+, the largest substitution of 11% being obtained using a dried sol-gel TiO2 precursor. We suggest that the substitution proceeds during the thermal treatment via a solid-solid diffusion between TiO2 and the amorphous LaFeO3 before it crystallises. The catalyst robustness was influenced by the TiO2 nature. Small size Ti-LaFeO3 crystallites strongly lowered or blocked the Fe release, while no improvement was observed for large size crystallites vs. the pristine material, what was associated to a poor homogenization of the titanium in the network. We showed that the mineralization activity was proportional to the substitution rate of La1-xTixFeO3 catalysts, while a similar relationship could be drawn for the degradation activity only in the case of highly robust catalysts with pure heterogeneous surface reactions.

Solar hydrogen production from ethanol-water vapours over metal/TiO2 photocatalysts supported on β-SiC alveolar foams

Patricia García-Muñoz, Javier Ivanez, Víctor de la Peña O’shea, Nicolas Keller, Fernando Fresno
Catalysis Today, 2023, 413-415, pp.113987. ⟨10.1016/j.cattod.2022.12.018⟩ | Publiée le 1 mars 2023
Article dans une revue

Abstract

In this work, we have explored the feasibility of alveolar open-cell β-SiC foams as catalyst support for solar hydrogen production. For that purpose, Pt and Ru nanoparticles have been obtained, by means of photoassisted synthesis, on TiO2-coated foams and tested in gas-phase hydrogen production from water-ethanol mixtures in a tubular reactor coupled to a compound parabolic solar collector (CPC). Subnanometre-sized metal or metal/oxide nanoparticles are obtained for Pt/TiO2/SiC and Ru/TiO2/SiC foams, respectively, where co-catalyst nanoparticles decorate the TiO2 coating which in turn is attached to the SiC foam through an amorphous SiO2 washcoat formed by SiC pre-calcination. In solar photocatalytic reactions, all of the assayed foam-supported photocatalysts are active for the production of hydrogen, with Pt/TiO2 ones being the most active and foam pore size exerting little influence on hydrogen outcome. In the best conditions, 14% UV-to-hydrogen (equivalent to 0.49% solar-to-hydrogen) conversion efficiency, with photonic efficiency higher than 30%, is attained.

Lysosomes targeting pH activable imaging‐guided photodynamic agents

Carlotta Figliola, Halina Anton, Christophe Sutter, Camille Chériaux, Alexandra Sutter, Valérie Mazan, Mourad Elhabiri, Pascal Didier, Denis Jacquemin, Gilles Ulrich
ChemBioChem, 2023, 24 (2), ⟨10.1002/cbic.202300139⟩ | Publiée le 23 février 2023
Article dans une revue

Abstract

Photodynamic therapy (PDT) is a photochemistry-based medical treatment combining light at a specific wavelength and a photosensitizer (PS) in the presence of oxygen. Application of PDT as a conventional treatment is limited and clearly the approval in clinics of new PS is challenging. The selective accumulation of the PS in the targeted malignant cells is of paramount importance to reduce the side effects that are typical of the current worldwide approved PS. Here we report a new series of aniline-and iodine-substituted BODIPY derivatives (1-3) as promising lysosome-targeting and pHresponsive theranostic PS, which displayed a significant in vitro light-induced cytotoxicity, efficient imaging properties and low dark toxicity (for 2 and 3). These compounds were obtained in few reproducible synthetic steps and good yields. Spectroscopic and electrochemical measurements along with computational calculations confirmed the quenching of the emissive properties of the PS, while both fluorescence and 1 O2 emission were obtained only under acidic conditions inducing amine protonation. The pKa values and pH-dependent emissive properties of 1-3 being established, their cellular uptake and activation in the lysosomal vesicles (pH ≈ 4-5) were confirmed by their colocalization with the commercial LysoTracker deep red and light-induced cytotoxicity (IC50 between 0.16 and 0.06 µM) against HeLa cancer cells.

Cobalt tris(4-vinylphenyl)corrole: out of the frying pan into the polymer

Nicolas Desbois, W. Ryan Osterloh, Dimitri Sabat, Camille Monot, Stéphane Brandès, Michel Meyer, Capucine Chaar, Louise Hespel, Laurent Lebrun, Rachid Baati, François Estour, Claude Gros
Chemical Communications, 2023, 59 (15), pp.2098-2101. ⟨10.1039/d2cc06872a⟩ | Publiée le 16 février 2023
Article dans une revue

Abstract

A novel cobalt corrole bearing 4-vinylphenyl groups at the 5,10,15-meso-positions of the macrocycle has been synthesized from tris(4-bromophenyl)corrole using a Suzuki coupling reaction. The spectral and electrochemical properties are reported in CH2Cl2 along with its ability to form a highly stable six-coordinate complexand cross-linked corrole-based polymer in a 59% yield.

(NHC-olefin)-nickel(0) nanoparticles as catalysts for the (Z)-selective semi-hydrogenation of alkynes and ynamides

Marta G. Avello, Stéphane Golling, Lai Truong-Phuoc, Loic Vidal, Thierry Romero, Vasiliki Papaefthymiou, Nathalie Gruber, Michael Chetcuti, Frederic Leroux, Morgan Donnard, Vincent Ritleng, Cuong Pham-Huu, Christophe Michon
Chemical Communications, 2023, 59, pp.1537. ⟨10.1039/D2CC05302K⟩ | Publiée le 7 février 2023
Article dans une revue

Abstract

Nickel(0) nanoparticles coordinated to NHC ligands bearing a N-coordinated cynnamyl moiety were readily prepared by reduction of a [NiCpBr(NHC-cynnamyl)] complex with methyl magnesium bromide. The combination of a strong sigma-donor NHC ligand with a pi-coordinating appended cinnamyl moiety likely prevents nickel(0) nanoparticles aggregation to larger inactive species, and allows the effective and (Z)-selective semi-hydrogenation of alkynes and ynamides.

Combining Associative and Dissociative Dynamic Linkages in Covalent Adaptable Networks from Biobased 2,5-Furandicarboxaldehyde

Matteo Andrea Lucherelli, Antoine Duval, Luc Averous
ACS Sustainable Chemistry & Engineering, 2023, 11 (6), pp.2334-2344. ⟨10.1021/acssuschemeng.2c05956⟩ | Publiée le 2 février 2023
Article dans une revue

Tailoring Structure and Acidity of ZSM-5 Zeolite by Algae Carbon Modification: Promoting Effect in the MTO Reaction

Yu Zhang, B Louis
Microporous and Mesoporous Materials, 2023, ⟨10.1016/j.micromeso.2023.112431⟩ | Publiée le 1 février 2023
Article dans une revue

Abstract

A biochar obtained from algae (Trachydiscus minutus, TRA) with rich surface functional groups and metal ions was used as a hard template to efficiently synthesize modified ZSM-5 zeolites with high external surface area (ESA) and mild acidity. Compared with pristine ZSM-5, which exhibited an ESA of 121 m 2 /g, TRA/ZSM-5 modified with algal carbon yielded an ESA of 171 m 2 /g. In addition, the catalytic lifetime of TRA/ZSM-5 zeolite in the methanol-to-hydrocarbons (MTH) reaction was significantly improved compared with H-ZSM-5: TRA/ZSM-5 maintained a methanol conversion > 95% during 16 h (at 400 o C, WHSV=8h-1), whilst H-ZSM-5 could only last for 10 h. After further optimization, the lifespan of TRA/ZSM-5 could be further enhanced to 24 h. Finally, it could be shown that the presence of hydrophilic functional groups and heteroelements were the key parameters to enhance the ESA and reduce the Brønsted acidity of the zeolite.

The role of the gold–platinum interface in AuPt/TiO2 -catalyzed plasmon-induced reduction of CO2 with water

Leila Hammoud, Claire Strebler, Joumana Toufaily, Tayssir Hamieh, Valérie Keller, Valérie Caps
Faraday Discussions, 2023, 242, pp.443-463. ⟨10.1039/D2FD00094F⟩ | Publiée le 31 janvier 2023
Article dans une revue

Abstract

Bimetallic gold–platinum nanoparticles have been widely studied in the fields of nanoalloys, catalysis and plasmonics. Many preparation methods can lead to the formation of these bimetallic nanoparticles (NPs), and the structure and related properties of the nanoalloy often depend on the preparation method used. Here we investigate the ability of thermal dimethylformamide (DMF) reduction to prepare bimetallic gold–platinum sub-nm clusters supported on titania. We find that deposition of Pt preferentially occurs on gold. Formation of sub-nm clusters (vs. NPs) appears to be dependent on the metal concentration used: clusters can be obtained for metal loadings up to 4 wt% but 7–8 nm NPs are formed for metal loadings above 8 wt%, as shown using high resolution transmission electron microscopy (HRTEM). X-ray photoelectron spectroscopy (XPS) shows electron-rich Au and Pt components in a pure metallic form and significant platinum enrichment of the surface, which increases with increasing Pt/Au ratio and suggests the presence of Au@Pt core–shell type structures. By contrast, titania-supported bimetallic particles (typically &gt;7 nm) obtained by sodium borohydride (NaBH4) reduction in DMF, contain Au/Pt Janus-type objects in addition to oxidized forms of Pt as evidenced by HRTEM, which is in agreement with the lower Pt surface enrichment found by XPS. Both types of supported nanostructures contain a gold–platinum interface, as shown by the chemical interface damping, i.e. gold plasmon damping by Pt, found using UV-visible spectroscopy. Evaluation of the materials for plasmon-induced continuous flow CO2 reduction with water, shows that: (1) subnanometer metallic clusters are not suitable for CO2 reduction with water, producing hydrogen from the competing water reduction instead, thereby highlighting the plasmonic nature of the reaction; (2) the highest methane production rates are obtained for the highest Pt enrichments of the surface, i.e. the core–shell-like structures achieved by the thermal DMF reduction method; (3) selectivity towards CO2 reduction vs. the competing water reduction is enhanced by loading of the plasmonic NPs, i.e. coverage of the titania semi-conductor by plasmonic NPs. Full selectivity is achieved for loadings above 6 wt%, regardless of the NPs composition and alloy structure.

Nanoalloy catalysis and magnetic and optical properties: general discussion

Christine M. Aikens, Hakim Amara, Vincenzo Amendola, Francesca Baletto, Stephan Barcikowski, Noelia Barrabés, Valérie Caps, Fuyi Chen, Daojian Cheng, Vana Chinnappa Chinnabathini, Emmanuel Cottancin, Isaac Daniel, Kobe de Knijf, Alessandro Fortunelli, Didier Grandjean, Graham Hutchings, Ewald Janssens, Robert Jones, Christian Kuttner, Alexander Large, Éric Marceau, Marcelo Mariscal, Pinkie Ntola, Jonathan Quinson, Mzamo Shozi, Swathi Swaminathan, Mona Treguer-Delapierre, Lichang Wang, Hans-Christian Weissker, Miguel Jose Yacaman, Yufei Zhang
Faraday Discussions, 2023, 242, pp.522-541. ⟨10.1039/d2fd90088b⟩ | Publiée le 31 janvier 2023
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Élaboration de capteurs de type microleviers optiques avec des nanostructures multi-échelles pour la détection de composés organophosphorés

Jean-Philippe Brach
Autre. Université de Strasbourg, 2023. Français. ⟨NNT : 2023STRAE004⟩ | Publiée le 20 janvier 2023
Thèse

Abstract

La conception de systèmes de détection sensibles, sélectifs et fiables reste un défi majeur pour défendre les civils et militaires de menaces chimiques. Ce projet s’est porté sur l’usage de capteur de type microlevier pour répondre à la menace d’attaques aux agents neurotoxiques. Le principe de ces capteurs repose sur le changement de leur fréquence de résonance suite à l’adsorption d’analytes à leur surface. Cependant, l’élaboration de nanostructures à la surface du capteur présentant des interactions favorables avec les agents neurotoxiques est nécessaire pour améliorer leur sensibilité. Ainsi, cette thèse rapporte l’élaboration de nanostructures multi-échelles à la surface des microleviers, afin d’améliorer leur surface de capture. Ces nanostructures ont été élaborées en deux étapes : (1) avec la croissance de nanofils de TiO2 à la surface des microleviers, puis, (2) avec le greffage de nanoparticules de MOF UiO-66 à la surface des nanofils de TiO2. Les performances en détection des capteurs de type microlevier nanostructurés ont été évaluées avec un simulant du gaz Sarin, le Diméthylméthylphosphonate (DMMP).

Silver Nanowire Electrodes Integrated in Organic Solar Cells with Thick Active Layer Based on a Low-Cost Donor Polymer

Issoufou Ibrahim Zamkoye, Johann Bouclé, Nicolas Leclerc, Bruno Lucas, Sylvain Vedraine
Solar RRL, 2023, 7 (2), pp.2200756. ⟨10.1002/solr.202200756⟩ | Publiée le 1 janvier 2023
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Abstract

Transparent electrodes are a key component in the manufacturing of optoelectronic devices such as LEDs, touch screens, and solar cells. The transparent electrode commonly used in this field is based on indium tin oxide (ITO). It contains indium, which is an expensive, rare, difficult to extract and depleting element, hence the need to find an alternative. Silver Nanowire (AgNW) electrodes are one of the best alternatives due to their excellent electrical, optical, and mechanical properties. In this work we show that embedding AgNWs between two layers of ZnO nanoparticles (ZnONPs) leads to superior optical and electrical performance. The validation of the ZnONPs /AgNWs/ ZnONPs (ZAZ) electrode using the reference PF2:PC70BM organic active layer, known to resent a long carrier lifetime, in inverted solar cell architectures shows an increased absorption of the active layer. This enhancement is due to the electrical field resulting from plasmonic resonance since the absorption is proportional to the square of the electric field amplitude. Through photoluminescence spectroscopy, we also observed a shorter exciton lifetime in PF2 in the presence of AgNWs. All these processes lead to improved photovoltaic performance compared to ITO-based reference, with 39% increase in photocurrent and 33% increase of overall power conversion efficiency.

Enantiopure natural deep eutectic solvents for metal–organic framework chiral induction

Renata A. Maia, Audrey Fluck, Catalin Maxim, Benoît Louis, Stéphane Baudron
Green Chemistry, 2023, 25 (22), pp.9103-9108. ⟨10.1039/D3GC02993J⟩ | Publiée le 1 janvier 2023
Article dans une revue

Abstract

A green alternative approach to the chiral induction of a metal–organic framework (MOF) has been explored using the natural deep eutectic solvents (DES) proline : thymol (1 : 7) and menthol : thymol (1 : 1). These solvents have been successfully employed for the preparation of the MIL-103 MOF and lead to an enantioenrichment of the porous material when used in enantiopure form, as demonstrated by circular dichroism.

Neonicotinoids: Still present in farmland birds despite their ban

Elva Fuentes, Agathe Gaffard, Anaïs Rodrigues, Maurice Millet, Vincent Bretagnolle, Jérôme Moreau, Karine Monceau
Chemosphere, 2023, 321, pp.138091. ⟨10.1016/j.chemosphere.2023.138091⟩ | Publiée le 1 janvier 2023
Article dans une revue

Abstract

Neonicotinoids (neonics) are the most widely used insecticides worldwide and are considered to be of low risk to non-target organisms such as vertebrates. Further, they are reported to be rapidly excreted and metabolized, reducing their potential toxicity. Nevertheless, growing evidence of adverse effects of neonics on farmland bird species raise questions about the purported harmless nature of these pesticides. We attempted to search for pesticide residues in species of different trophic levels and at different life stages, by using multiple bird monitoring programs on a Long-Term Socio-Ecological Research (LTSER) platform. Three passerine birds-the blackbird (Turdus merula), cirl bunting (Emberiza cirlus), and common nightingale (Luscinia megarhynchos)-that feed on seeds and invertebrates were monitored during their reproductive period, and the grey partridge (Perdix perdix) that feeds on seeds was monitored during its wintering period. We also monitored chicks of an apex predator-the Montagu's harrier (Circus pygargus)-that preys mostly upon common voles but also upon insects. We found that the birds' blood samples showed presence of residues of five neonics: three banned since 2018 in France-clothianidin, thiacloprid, and thiamethoxam-and two-dinotefuran and nitenpyram-used for veterinary purposes only. While none of these neonics was detected in blackbirds, all were present in grey partridges. Clothianidin was detected in all species, except blackbirds. Concentrations of the three banned neonics were similar or higher than concentrations found in birds monitored elsewhere before the ban. These findings raise questions about the persistence of neonics within the environment and the mode of exposure to wild fauna. Future investigations on the sublethal effects of these neonics on life-history traits of these farmland birds may help in providing a better understanding of the effects of exposure of bird populations to these insecticides, and also to the consequent effect on human health.

Nanoplastics are potentially more dangerous than microplastics

Virender K Sharma, Xingmao Ma, Eric Lichtfouse, Didier Robert
Environmental Chemistry Letters, 2023, 21 (4), pp.1933 - 1936. ⟨10.1007/s10311-022-01539-1⟩ | Publiée le 1 janvier 2023
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Abstract

Nanoplastics are probably much more dangerous for living organisms than microplastics because they are more abundant and reactive. They can potentially reach more remote locations and penetrate in living cells. Here we compare nanoplastics with microplastics and engineered nanoparticles, with focus on formation, size, reactivity, mobility, biofilms, and interactions with microbes, pollutants and natural organic matter.

Highly dispersed Rh single atoms over graphitic carbon nitride as a robust catalyst for the hydroformylation reaction

Lole Jurado, Jerome Esvan, Ligia Luque-Álvarez, Luis Bobadilla, José Odriozola, Sergio Posada-Pérez, Albert Poater, Aleix Comas-Vives, M. Rosa Axet
Catalysis Science & Technology, 2023, 13 (5), pp.1425-1436. ⟨10.1039/D2CY02094G⟩ | Publiée le 1 janvier 2023
Article dans une revue

Abstract

Rhodium-catalysed hydroformylation, effective tool in bulk and fine-chemical synthesis, predominantly uses soluble metal complexes. For that reason, the metal leaching and the catalyst recycling are still the major drawbacks of this process. Single-atom catalysts have emerged as a powerful tool to combine the advantages of both homogeneous and heterogeneous catalysts. Since using an appropriate support material is key to create stable, finely dispersed, single-atom catalysts, here we show that Rh atoms anchored on graphitic carbon nitride are robust catalysts for the hydroformylation reaction of styrene.

Electrocatalysis (2023): Sore spots in the electrocatalyis research

Elena Savinova, Galina Tsirlina
Current Opinion in Electrochemistry, 2023, 40, pp.101317. ⟨10.1016/j.coelec.2023.101317⟩ | Publiée le 1 janvier 2023
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Aggregation-Induced Enhanced Emission of a Dimethylacridan Substituted Pyrimidine Derivative

Julien Massue, Lacina Diarra, Ioannis Georgoulis, Arnaud Fihey, Françoise Robin-Le Guen, Gilles Ulrich, Mihalis Fakis, Sylvain Achelle
ChemPhotoChem, 2023, 7 (9), pp.e202300085. ⟨10.1002/cptc.202300085⟩ | Publiée le 1 janvier 2023
Article dans une revue

Abstract

A pyrimidine chromophore bearing an acridan fragment was synthesized and its photophysical properties were studied. In solution, this compound is characterized by an important positive emission solvatochromism with a shift of 5800 cm(-1) between nonpolar heptane and dichloromethane (DCM) associated with large Stokes shifts (up to 9100 cm(-1) in DCM). Mono-exponential fluorescence decays are observed in heptane whereas more complicated bi- or three-exponential decays are observed in more polar solvents due to an interplay between locally excited and charge transfer excited state. Additionally, an aggregation-induced enhanced emission process was demonstrated in THF/water mixtures. At low temperature (77 K), in a polymethylmethacrylate (PMMA) thin film, the presence of an accessible triplet state (T1) was demonstrated, which was not observed in solution. Finally, we show that it is possible to protonate the chromophore in thin film leading to panchromatic dual emission

Performant removal of creatinine using few-layer-graphene/alginate beads as a kidney filter

Kamel Shoueir, Ahmed M Wahba, Hamza El Marouazi, Izabela Janowska
International Journal of Biological Macromolecules, 2023, 242 (4), pp.124936. ⟨10.1016/j.ijbiomac.2023.124936⟩ | Publiée le 1 janvier 2023
Article dans une revue

Abstract

Reduction of renal function, such as creatinine adsorption is one of the most common and dangerous diseases. Dedicated to this issue, developing high-performance, sustainable, and biocompatible adsorbing materials is still challenging. Herein, barium alginate (BA) and BA containing few-layer graphene (FLG/BA) beads were synthesized in water from sodium alginate, also acting as bio-surfactant in in-situ exfoliation of graphite to FLG. The physicochemical characteristics of the beads demonstrated an excess of barium chloride used as a cross-linker. The efficiency and sorption capacity (Q e) of creatinine removal increase with processing duration reaching 82.1, 99.5 %, and 68.4, 82.9 mg. g-1 for BA and FLG/BA, respectively. The thermodynamic parameters detect the enthalpy change (ΔH o) of about-24.29 and-36.11 kJ. mol-1 and the entropy change (ΔS o) of around-69.24 and-79.46 kJ. mol-1 for BA and FLG/BA, respectively. During the reusability test, the removal efficiency decreases from the optimal first cycle to 69.1 and to 88.3 % in the sixth cycle for BA and FLG/BA, revealing superior stability of FLG/BA. The MD calculations confirm a higher adsorption capacity of FLG/BA composite compared to BA alone, clearly confirming a strong structure-property relation.

Heterogeneous Oriented Structure model of thermoelectric transport in conducting polymers

Patrice Limelette, Nicolas Leclerc, Martin Brinkmann
Scientific Reports, 2023, 13 (1), pp.21161. ⟨10.1038/s41598-023-48353-5⟩ | Publiée le 1 janvier 2023
Article dans une revue

Abstract

Understanding transport phenomena in conducting polymers (CP) is a main issue in order to optimize their performance and despite intense investigations, the influence of their microstructure remains controversial. By analyzing the thermoelectric measurements performed on highly oriented and non-oriented CP films, we show that an Heterogeneous Oriented Structure (HOSt) model considering both ordered and disordered domains is able to account for the thermoelectric transport in CP. This model unveils the key role of the crystallinity, the anisotropy and the alignment degree of these domains. It points out the importance of the thermal conductivity in the interpretation of the thermopower α and explains the frequently observed electrical conductivity σ cut-off in the α - σ curves due to the disordered domains. By varying the alignment degree depending on the orientation and the anisotropy according to the face-on or the edge-on polymers conformation, the HOSt model successfully describes the overall measured thermoelectric properties by demonstrating its applicability to a wide variety of both oriented and non-oriented CP.

Non-platinum group metal anode catalysts for alkaline fuel cells

Alexandr Oshchepkov, Antoine Bonnefont, Guillaume Braesch, Elena Savinova, Marian Chatenet
Pascal Brault et Alain Dollet. Encyclopédie ISTE SCIENCES, Wiley, 2023 | Publiée le 1 janvier 2023
Chapitre d'ouvrage

Polydopamine-Coated Polyurethane Foam as a Structured Support for the Development of an Easily Reusable Heterogeneous Photocatalyst Based on Eosin Y

Han Peng, Thierry Romero, Philippe Bertani, Vincent Ritleng
Catalysts, 2023, 13 (3), pp.589. ⟨10.3390/catal13030589⟩ | Publiée le 1 janvier 2023
Article dans une revue

Abstract

An easy-to-handle eosin Y-based heterogeneous photocatalyst was prepared by postfunctionalization of a polydopamine-coated open cell polyurethane foam (PDA@PUF) via the silanization of the adhesive layer with 3-(triethoxysilyl)propan-1-amine (APTES) and the subsequent EDC-mediated coupling of the resulting amino-functionalized foam with eosin Y. The obtained macroscopic material, EY-APTES@PDA@PUF, showed good efficiency and excellent reusability, in an easy-to-carry "dip-and-play" mode for at least six runs as photocatalyst for the aerobic oxidation of 2-methyl-5-nitroisoquinolin-2-ium iodide to the corresponding isoquinolone. Subsequent investigation of the catalytic efficiency of EY-APTES@PDA@PUF for the oxidation of sulfides to sulfoxides, however, evidenced non-negligible eosin Y leaching, leading to a progressive deactivation of the catalytic foam in this case. Two alternative synthetic protocols for the preparation of the macroscopic photocatalyst were next explored to avoid eosin Y leaching. In both cases however, cycling tests also highlighted a progressive deactivation of the catalytic foams in sulfide-to-sulfoxide oxidation reactions.

Core–shell Fe3O4 @CoFe2O4 nanoparticles as high-performance anode catalysts for enhanced oxygen evolution reaction

Lisa Royer, Iryna Makarchuk, Simon Hettler, Raul Arenal, Tristan Asset, Benjamin Rotonnelli, Antoine Bonnefont, Elena Savinova, Benoit Pichon
Sustainable Energy & Fuels, 2023, 7 (14), pp.3239-3243. ⟨10.1039/d3se00130j⟩ | Publiée le 1 janvier 2023
Article dans une revue

Abstract

Water electrolysis is a promising and environmentally friendly means for renewable energy storage. Recent progress in the development of anion exchange membranes (AEMs) has provided new perspectives for high-performance anode catalysts based on transition metal oxides (TMOs) for the sluggish anodic oxygen evolution reaction (OER). Here, we report on core–shell nanoparticles (Fe3O4@CoFe2O4) which allow combining an electrocatalytic shell (CoFe2O4) with a conductive core (Fe3O4). Such an original approach significantly minimizes critical Co content in the catalyst and avoids addition of unstable conductive carbon black. The core–shell nanoparticles outperform Co(1−x)Fe(2+x)O4 nanoparticles and show an exceptional OER activity per Co unit mass (2800 A gcobalt−1 at 1.65 V vs. RHE) suggesting synergistic interaction between the core and the shell. Along with the core–shell structure, the size of the Fe3O4 core is a critical parameter, with a large conductive Fe3O4 core being beneficial for OER enhancement

Photocatalytic Synthesis of Hydrogen Peroxide from Molecular Oxygen and Water

Patricia Garcia-Munoz, Laura Valenzuela, Deborah Wegstein, Tobias Schanz, Girlie Eunice Lopez, Agnieszka Ruppert, Hynd Remita, Jonathan Bloh, Nicolas Keller
Topics in current chemistry, 2023, 381 (4), pp.15. ⟨10.1007/s41061-023-00423-y⟩ | Publiée le 1 janvier 2023
Article dans une revue

Abstract

Hydrogen peroxide is a powerful and green oxidant that allows for the oxidation of a wide span of organic and inorganic substrates in liquid media under mild reaction conditions, and forms only molecular water and oxygen as end-products. Hydrogen peroxide is therefore used in a wide range of applications, for which the well-documented and established anthraquinone autoxidation process is by far the dominating production way at the industrial scale. That method being highly energy-consuming and environmentally-costly, the search for more sustainable synthesis methods is of high interest. To this end, the article reviews the basis and the recent development of the photocatalytic synthesis of hydrogen peroxide. Different oxygen reduction and water oxidation mechanisms are discussed, as well as several kinetic models, and the influence of the main key reaction parameters is itemized. A large range of photocatalytic materials is reviewed, with emphasis on titania-based photocatalysts and on high-prospect graphitic carbon nitride based systems that take advantage of advanced bulk and surface synthetic approaches. Strategies for enhancing the performances of solar-driven photocatalysts are reported, and the search for new, alternative, photocatalytic materials is detailed. Finally, the promise of in-situ photocatalytic synthesis of hydrogen peroxide for water treatment and organic synthesis is described, as well as its coupling with enzymes and the direct in-situ synthesis of other technical peroxides.

Phosphate Capture Enhancement Using Designed Iron Oxide-Based Nanostructures

Paula Dueñas Ramírez, Chaedong Lee, Rebecca Fedderwitz, Antonia R Clavijo, Débora P P Barbosa, Maxime Julliot, Joana Vaz-Ramos, Dominique Begin, Stéphane Le Calvé, Ariane Zaloszyc, Philippe Choquet, Maria a G Soler, Damien Mertz, Peter Kofinas, Yuanzhe Piao, Sylvie Begin-Colin
Nanomaterials, 2023, 13 (3), pp.587. ⟨10.3390/nano13030587⟩ | Publiée le 1 janvier 2023
Article dans une revue

Abstract

Phosphates in high concentrations are harmful pollutants for the environment, and new and cheap solutions are currently needed for phosphate removal from polluted liquid media. Iron oxide nanoparticles show a promising capacity for removing phosphates from polluted media and can be easily separated from polluted media under an external magnetic field. However, they have to display a high surface area allowing high removal pollutant capacity while preserving their magnetic properties. In that context, the reproducible synthesis of magnetic iron oxide raspberry-shaped nanostructures (RSNs) by a modified polyol solvothermal method has been optimized, and the conditions to dope the latter with cobalt, zinc, and aluminum to improve the phosphate adsorption have been determined. These RSNs consist of oriented aggregates of iron oxide nanocrystals, providing a very high saturation magnetization and a superparamagnetic behavior that favor colloidal stability. Finally, the adsorption of phosphates as a function of pH, time, and phosphate concentration has been studied. The undoped and especially aluminum-doped RSNs were demonstrated to be very effective phosphate adsorbents, and they can be extracted from the media by applying a magnet.

Mouse Models of Mineral Bone Disorders Associated with Chronic Kidney Disease

Ariane Zaloszyc, Julie Bernardor, Justine Bacchetta, Gilles Laverny, Claus Peter Schmitt
International Journal of Molecular Sciences, 2023, 24 (6), pp.5325. ⟨10.3390/ijms24065325⟩ | Publiée le 1 janvier 2023
Article dans une revue

Abstract

Patients with chronic kidney disease (CKD) inevitably develop mineral and bone disorders (CKD-MBD), which negatively impact their survival and quality of life. For a better understanding of underlying pathophysiology and identification of novel therapeutic approaches, mouse models are essential. CKD can be induced by surgical reduction of a functional kidney mass, by nephrotoxic compounds and by genetic engineering specifically interfering with kidney development. These models develop a large range of bone diseases, recapitulating different types of human CKD-MBD and associated sequelae, including vascular calcifications. Bones are usually studied by quantitative histomorphometry, immunohistochemistry and micro-CT, but alternative strategies have emerged, such as longitudinal in vivo osteoblast activity quantification by tracer scintigraphy. The results gained from the CKD-MBD mouse models are consistent with clinical observations and have provided significant knowledge on specific pathomechanisms, bone properties and potential novel therapeutic strategies. This review discusses available mouse models to study bone disease in CKD.

Ethanol Dry Reforming over Bimetallic Ni‐Containing Catalysts Based on Ceria‐Zirconia for Hydrogen Production

Valeria Fedorova, Yulia Bespalko, Marina Arapova, Ekaterina Smal, Konstantin Valeev, Igor Prosvirin, Vladislav Sadykov, Ksenia Parkhomenko, Anne-Cecile Roger-Charbonniere, Mikhail Simonov
ChemCatChem, 2023, 15 (10), pp.e202201491. ⟨10.1002/cctc.202201491⟩ | Publiée le 1 janvier 2023
Article dans une revue

Abstract

Mixed Ce−Zr oxides with a fluorite structure were synthesized by the solvothermal method in a supercritical medium of isopropanol. The prepared mixed oxides Ce$_{0.5}$Zr$_{0.5}$O2 and Ce$_{0.75}$Zr$_{0.25}$O$_2$ were used as supports for 5 wt%Ni and bimetallic 2.5 wt%Ni + 2.5 wt%Co catalysts. The catalysts were fully characterized (specific surface area, morphology, particle size, phase composition, surface atomic composition) and tested in ethanol dry reforming. The dependences of the conversion of C$_2$H$_5$OH and CO$_2$, the yield of CO and H$_2$, and the H$_2$/CO ratio were estimated. The effect of the supported metals interaction and the effect of Ce/Zr ratio in the support on the catalytic activity were shown. The presence of nickel in the composition of the catalyst is necessary for high catalytic activity. It has been shown that the addition of cobalt cannot contribute to increase the catalytic activity and stability, but helps to decrease the deposition of carbon and significantly reduces the rate of carbon formation during ethanol dry reforming comparing to the monometallic nickel material.

Impact of Regioregularity on Alignment and Thermoelectric Properties of Sequentially Doped and Oriented Films of Poly(3-hexylthiophene)

Shubhradip Guchait, Laurent Herrmann, Karim Kadri, Nicolas Leclerc, François Tran-Van, Martin Brinkmann
ACS Applied Polymer Materials, 2023, 5 (7), pp.5676-5686. ⟨10.1021/acsapm.3c00972⟩ | Publiée le 1 janvier 2023
Article dans une revue

Abstract

Alignment of conjugated polymers such as regioregular poly(3-hexylthiophene-2,5-diyl) (rr-P3HT) is an effective means to enhance charge transport and thermoelectric properties of thin films doped with F4TCNQ. In this contribution, we investigate the impact of P3HT regioregularity (RR) on the alignment achieved in thin films by high temperature rubbing and the resulting thermoelectric properties in sequentially doped and aligned films. Structure and thermoelectric properties in doped P3HT thin films are investigated by a combination of transmission electron microscopy (electron diffraction), polarized UV-vis-NIR spectroscopy and thermoelectric measurements. Despite limited thermomechanical properties, rubbing at 165°C generates order and alignment in 71%RR P3HT (R71-P3HT) with a typical lamellar stacking of P3HT chains similar to that of the smectic-like phase of RR-P3HT. Order is further enhanced in aligned R71-P3HT films by doping with F4TCNQ. Intercalation of dopants in the ordered domains of R71-P3HT induces a reorganization of polythiophene backbones within individual -stacks with lattice parameter variations equivalent to those observed for RR-P3HT. Despite ordering induced by both rubbing at 165°C and doping, charge conductivity of oriented R71-P3HT in the chain direction remains 50-times below that of oriented RR-P3HT. The strong blue-shift of the polaronic bands in R71-P3HT versus RR-P3HT indicates that polarons are strongly localized in both ordered and amorphous zones of R71-P3HT, explaining the modest charge conductivity of 3-4 S/cm observed in the chain direction.

From Lignins to Renewable Aromatic Vitrimers based on Vinylogous Urethane

Lisa Sougrati, Antoine Duval, Luc Avérous
ChemSusChem, 2023, 16 (23), pp.e202300792. ⟨10.1002/cssc.202300792⟩ | Publiée le 1 janvier 2023
Article dans une revue

Abstract

During the two last decades, covalent adaptable networks (CANs) have proven to be an important new class of polymer materials combining the main advantages of thermoplastics and thermosets. For instance, materials can undergo reprocessing cycles by incorporating dynamic covalent bonds within a cross-linked network. Due to their versatility, renewable resources can be easily integrated into these innovative systems to develop sustainable materials, which can be related to the context of the recent development of a circular bioeconomy. Lignins, the main renewable sources of aromatic structures, are major candidates in the design of novel and biobased stimuli-responsive materials such as vitrimers due to their high functionality and specific chemical architectures. In the aim of developing recyclable lignin-based vinylogous urethane (VU) networks, an innovative strategy was elaborated in which lignin was first modified into liquid polyols and then into polyacetoacetates. Resulting macromonomers were integrated into aromatic VU networks and fully characterized through thermal, mechanical, and rheological experiments. Viscoelastic behaviors of the different aromatic vitrimers exhibited fast stress-relaxations (e. g., 39 s at 130 °C) allowing easy and fast mechanical reprocessing. A thermomechanical recycling study was successfully performed. Then, the developed strategy enabled the fabrication of healable biobased aromatic vitrimers with tunable structures and properties.

Photocatalytic Efficiency of Suspended and Immobilized TiO2 P25 for Removing Myclobutanil, Penconazole and Their Commercial Formulations

Ignace Christian M’bra, Nicolas Keller, Albert Trokourey, Didier Robert
Photocatalysis: Research and Potential, 2023, 1 (1), pp.1-10. ⟨10.35534/prp.2023.10004⟩ | Publiée le 1 janvier 2023
Article dans une revue

Magnetic few-layer graphene nanocomposites for the highly efficient removal of benzo(a)pyrene from water

Joana Vaz-Ramos, Dominique Bégin, Paula Duenas-Ramirez, Anaïs Becker, Mathieu Galmiche, Maurice Millet, Sylvie Bégin-Colin, Stéphane Le Calvé
Environmental science‎.Nano, 2023, 10 (6), pp.1660 - 1675. ⟨10.1039/d3en00047h⟩ | Publiée le 1 janvier 2023
Article dans une revue

Abstract

Regarding the importance of water pollution by persistent organic pollutants and the need for innovative processes to extract them efficiently, we designed magnetic few-layer graphene-based composite nanomaterials (CNs) for high removal from water of a particularly toxic polycyclic aromatic hydrocarbon (PAH): benzo(a)pyrene (BaP). The CNs were prepared in a one-step polyol solvothermal synthesis process by introducing few-layer graphene coated with tannic acid in the reaction medium of iron oxide nanostructures. The synthesis was reproducible and allowed obtaining a large amount of magnetic CNs, which can be easily and quickly magnetically removed from aqueous medium. BaP adsorption on CNs was studied for an initial BaP aqueous concentration of 1-5000 μg L −1. A very low amount of CNs (5 mg L −1) was sufficient and effective to have a very high and fast BaP adsorption in comparison with previous studies reporting an adsorbent amount of 5-1000 mg L −1. Removal efficiencies of 99.95 ± 0.01% in water with 1% ethanol as co-solvent were reached in minutes. The presence of iron oxide was observed to not affect the adsorption capacity of CNs. The volume percentage of ethanol in the water media influenced the removal efficiency of BaP by the CNs. With 50 vol% ethanol necessary to obtain an adsorption isotherm, the adsorption follows Langmuir's law with a maximum adsorption capacity q max = 69.45 ± 5.20 mg g −1 and a Langmuir isotherm constant K L = 1.92 ± 0.54 L mg −1. These CNs, compared with other BaP and PAH adsorbents, are clearly very promising for BaP removal from polluted media.

Multisustainable Approach. Ternary Photocatalytic Composite: Fe x O 3 /Albumin/Few Layer Graphene in H 2 Production via Photo-reforming of Methanol

Kamel Shoueir, Mathias Barreau, Walid Baaziz, Izabela Janowska
ACS Sustainable Chemistry & Engineering, 2023, 11 (42), pp.15171-15177. ⟨10.1021/acssuschemeng.3c04186⟩ | Publiée le 1 janvier 2023
Article dans une revue

Abstract

To address the energy requirements via an optimally sustainable way is of high interest. The ternary hybrid based on natural protein, few layer graphene and a non-precious metal component is obtained by rapid and green method bypassing high-temperature calcination. Its significant activity in H 2 production via photoreforming of methanol is related to the factors combining the nanosized related quantum confinement effect and small band gap, lifted-up conduction band edge and enhanced reducibility of Fe x O 3 nanoparticles (size up to 2nm). The albumin homogenously decorating FLG surface helps in the catalyst dispersion, reduction of photogenerated charges recombination and MeOH adsorption. Fe x O 3 /Album/FLG shows great photostability and superior activity to TiO 2 based catalysts of reference.

New development in carbon-based electrodes and electrolytes for enhancement of supercapacitor performance and safety

Sirine Zallouz, Sergey Pronkin, Jean-Marc Le Meins, Cuong Pham-Huu, Camélia Matei Ghimbeu
Renewable Energy Production and Distribution Volume 2 in Advances in Renewable Energy Technologies, Elsevier, pp.353-408, 2023, ⟨10.1016/B978-0-443-18439-0.00011-2⟩ | Publiée le 1 janvier 2023
Chapitre d'ouvrage

Abstract

This book chapter presents an overview on the electrode materials and electrolytes used in supercapacitors. The working principles, the mechanisms of charge storage, and the configuration of supercapacitors are briefly discussed. A first focus is on electrode materials relying on different charge storage mechanisms, i.e., electrochemical double-layer carbon materials and pseudocapacitive transition-metal oxides and metal-sulfides materials. The last part focuses on the electrolytes used in supercapacitors. Classical liquid electrolytes are reviewed and the development of gel- and solid-like electrolytes is presented. The advantages, current limitations, and challenges of electrodes and electrolytes are also addressed.

Modified Co/TiO2 catalysts for CO2 hydrogenation to fuels

Canio Scarfiello, Katerina Soulantica, Simon Cayez, Aurélien Durupt, Guillaume Viau, Nolwenn Le Breton, Athanassios Boudalis, F.C. Meunier, Guillaume Clet, Mathias Barreau, Davide Salusso, Spiros Zafeiratos, Doan Pham Minh, Philippe Serp
Journal of Catalysis, 2023, 428, pp.115202. ⟨10.1016/j.jcat.2023.115202⟩ | Publiée le 1 janvier 2023
Article dans une revue

Abstract

The direct CO2 conversion to liquid fuels by catalytic hydrogenation (CO2-based Fischer-Tropsch synthesis, FTS), is a sustainable approach to reduce CO2 emissions. This challenging reaction proceeds through tandem catalysis involving reverse water gas shift reaction to produce CO and subsequent traditional CO-FTS. Unmodified Co-based catalysts allow performing the reaction at low temperatures (&lt; 250 °C), albeit producing mainly methane. In this study, we modified a commercial TiO2-P25 support by NaBH4 reduction so as to introduce controlled amounts of promoters and oxygen vacancies (Ov). The modified and unmodified supports were used to prepare Co-based catalysts, which were evaluated for CO2-based FTS at 220-250 °C and 20 bar. The promoted catalysts outperform the one prepared on commercial TiO2 in terms of activity and selectivity towards C5+. Detailed characterizations of the catalysts were performed to decipher the role of promoters. We show that, besides improving CO2 activation and limiting H2 activation, the presence of alkali on the support allows a modulation of hydrogen spillover in the system. The best catalyst in terms of activity and selectivity is the one for which sodium is deposited in sufficient amount to modulate the hydrogen spillover, which allows an optimal surface C/H ratio on cobalt.

Direct Evidence of Dynamic Metal Support Interactions in Co/TiO2 Catalysts by Near-Ambient Pressure X-ray Photoelectron Spectroscopy

Davide Salusso, Canio Scarfiello, Anna Efimenko, Doan Pham Minh, P. Serp, Katerina Soulantica, Spyridon Zafeiratos
Nanomaterials, 2023, 13 (19), pp.2672. ⟨10.3390/nano13192672⟩ | Publiée le 1 janvier 2023
Article dans une revue

Abstract

The interaction between metal particles and the oxide support, the so-called metal–support interaction, plays a critical role in the performance of heterogenous catalysts. Probing the dynamic evolution of these interactions under reactive gas atmospheres is crucial to comprehending the structure–performance relationship and eventually designing new catalysts with enhanced properties. Cobalt supported on TiO2 (Co/TiO2) is an industrially relevant catalyst applied in Fischer−Tropsch synthesis. Although it is widely acknowledged that Co/TiO2 is restructured during the reaction process, little is known about the impact of the specific gas phase environment at the material’s surface. The combination of soft and hard X-ray photoemission spectroscopies are used to investigate in situ Co particles supported on pure and NaBH4-modified TiO2 under H2, O2, and CO2:H2 gas atmospheres. The combination of soft and hard X-ray photoemission methods, which allows for simultaneous probing of the chemical composition of surface and subsurface layers, is one of the study’s unique features. It is shown that under H2, cobalt particles are encapsulated below a stoichiometric TiO2 layer. This arrangement is preserved under CO2 hydrogenation conditions (i.e., CO2:H2), but changes rapidly upon exposure to O2. The pretreatment of the TiO2 support with NaBH4 affects the surface mobility and prevents TiO2 spillover onto Co particles.

Analytical Development for the Assessment of Pesticide Contaminations in Blood and Plasma of Wild Birds: The Case of Grey Partridges (Perdix Perdix)

Anaïs Rodrigues, Agathe Gaffard, Jérôme Moreau, Karine Monceau, Olivier Delhomme, Maurice Millet
SSRN : Social Science Research Network, 2023, 1687, pp.463681. ⟨10.1016/j.chroma.2022.463681⟩ | Publiée le 1 janvier 2023
Article dans une revue

Abstract

In this study, blood and plasma of grey partridges ( Perdix perdix) were analyzed to assess their potential contamination by plant protection products (PPP) and especially pesticide compounds.The group of pesticides selected is composed of a huge variety of compounds. Therefore, in this study, two methods were optimized and validated to analyze 104 compounds including herbicides, insecticides, fungicides and photoprotectors or synergists.Various extraction methods found in the literature were compared and adapted for the extraction of pesticides from blood and plasma. After extraction, samples were concentrated then injected for quantification simultaneously in LC-MS/MS and ATD-GC/MS/MS with an automatic thermal desorption step (ATD).Both LC-MS/MS and ATD-GC/MSMS analyses were performed using the MRM mode with 2 mass transitions for each compound.For both analytical methods, calibrations in triplicate were done by spiking within clean matrices using deuterated internal standard as ISTD. Evaluation of reproducibility, repeatability and determination of extraction yields were also performed with satisfactory results for most compounds then LOD and LOQ were determined with good sensibility results. LODs varied from 0.005 to 0.035 pg mg -1 and LOQs from 0.017 to 0.116 pg mg -1 for both matrices and methods.The two distinct analytical methods were then successfully applied to 70 blood samples and 35 plasma samples.

Continuous real-time monitoring of formaldehyde over 5 weeks in two French primary schools: identification of the relevant time resolution and the most appropriate ventilation scenario

Claire Trocquet, Irene Lara-Ibeas, Anaïs Becker, Aurélie Schulz, Pierre Bernhardt, Vincent Person, Béatrice Cormerais, Stéphanette Englaro, Stéphane Le Calvé
Air Quality, Atmosphere & Health, 2023, 16 (6), pp.1091 - 1115. ⟨10.1007/s11869-023-01328-x⟩ | Publiée le 1 janvier 2023
Article dans une revue

Abstract

An intensive field campaign was conducted to monitor indoor air formaldehyde in two French elementary schools for 5 weeks, where the experimental conditions were modified every week. Formaldehyde concentration was monitored using two portable laboratory prototypes with a detection limit of 1 μg m −3 and a temporal resolution of 2 s. Carbon dioxide concentration, temperature (T), and relative humidity (RH) were also recorded over the whole field campaign. To take advantage of continuous measurement of formaldehyde for post-data analysis, these 2-s raw formaldehyde concentrations were then used to recalculate the average values for several time steps, i.e., 1 min, 10 min, 1 h, and 1 day. This paper highlights that a time resolution of 10 min is sufficient and well adapted to monitor most of the variations of formaldehyde concentrations observed in these two classrooms. The weekly mean formaldehyde concentrations calculated were in the ranges of 25.6-33.8 μg m −3 and 14.7-26.8 μg m −3 for schools 1 (S1) and 2 (S2), respectively, once excluded an unwanted painting event in S1. The results obtained were in excellent agreement with those determined by using the reference method based on DNPH derivatization. The results also revealed that building materials and furniture were two significant formaldehyde emission sources. Unlike most of the studies found in the literature in which formaldehyde is monitored using passive sampling, continuous measurements allowed us to estimate real children's exposure. When considering only the children's occupation time, a significant decrease in average formaldehyde concentration ranging between 20 and 34 % was observed for weeks 4 and 5 when the occupants followed specific strategies for natural ventilation. Opening the windows as soon as the CO 2 exceeds the thresholds appears to be the most efficient way to limit exposure to formaldehyde in the two investigated schools. The findings of this paper demonstrate the importance of continuous and accurate formaldehyde measurements with at least 10-min time resolution which could serve as a roadmap for future developments of formaldehyde low-cost sensors.

Mechanosynthesis of MAPbI3@Graphite Composites with Active Interfaces and Promising Photodetection Properties

Yihui Cai, Dominique Bégin, Charles Sidhoum, Adrien Girault, Thomas Fix, Christophe Lefevre, Wissal Belayachi, Aziz Dinia, Daniele Preziosi, Mathieu Gallart, Pierre Gilliot, Eric Gros-Daillon, Ferdinand Ledee, Ovidiu Ersen, Clément Sanchez, Sylvie Bégin-Colin
Chemistry of Materials, 2023, 35 (23), pp.10188-10205. ⟨10.1021/acs.chemmater.3c02418⟩ | Publiée le 1 janvier 2023
Article dans une revue

Abstract

Three-dimensional (3D) hybrid perovskites (HPs) are currently a key player in optoelectronic applications and, beyond the traditional photovoltaic applications, have also other great potentials as light-emitting diodes, lasers, photocatalysts, and photo- and X-ray detectors. However, despite the excellent performance of 3D HPs, certain HPs such as methylammonium lead iodide (CH3NH3PbI3 named MAPbI3) lack long-term environmental stability because they are very sensitive to humidity and degrade under oxygen and light exposures. Moreover, MAPbI3 films or single crystals or powders are mainly produced from precursor mixture methods and suffer some drawbacks such as the formation of intermediate phases with solvents affecting their performance. To face some of those problems, we have optimized the synthesis of MAPbI3 via a green solvent-free mechanosynthesis process, which also provides large amounts of powders, and to enhance its chemical stability, we have mixed MAPbI3 with graphite, which also granted the possibility to combine the different electronic properties of both components. The mechanosynthesis parameters have been optimized for both systems to minimize the defect amount, and their structural, optical, and electronic properties have been characterized. High-resolution transmission electron microscopy (HRTEM) and in situ HRTEM highlighted common crystallographic orientations between MAPbI3 nanograins (∼10 nm) in aggregates of mechanosynthesized (MS) powders. The band gap values and photoluminescence (PL) properties of mechanosynthesized MAPbI3 are in good agreement with the ones reported for MAPbI3 synthesized by chemical methods. A decrease in PL intensity related to the introduction of defects is observed with a longer grinding time, confirming that the selected grinding conditions were optimal. These mechanosynthesis conditions of MAPbI3 were found also suitable to obtain MAPbI3@Graphite composites with different amounts of graphite. A homogeneous distribution of few-layer graphite within the MAPbI3 matrix was noticed in powder-compacted wafers. Graphite-enhanced Raman scattering was observed with the composite with 5 wt % graphite showing its strong resistance to photodegradation and suggesting a charge transfer between graphite and MAPbI3. Such charge transfer is also in agreement with the quenching of the PL with an increasing amount of graphite. Further analysis of time-resolved PL decays confirmed, supported by X-ray detection results, that the presence of graphite impacted the charge transfer. The presence of graphite would induce a local modification of the Coulomb interaction, “attracting” the charge carriers at the graphite and MAPbI3 interfaces and thus favoring the charge separation and transport. In addition, the composite with 5 wt % graphite exhibited promising photodetection properties with a photoresponsivity of 1.5 × 103 A/W and an effective quantum effect of around 4.4 × 106 % at 400 nm with a light power of 330 nW. This high photoconductive gain matches with the trapping of one type of charge carrier, while the other one is multiplied via injection from the contact electrodes, thus contributing even more to the photoconductivity. These results highlighted that the mechanosynthesis, which is green and efficient in providing large amounts of powders, is suitable to design homogeneous MAPbI3@Graphite composites with strong interactions between graphite and MAPbI3 favoring an improved charge transfer and amplification of the photocurrent that will be very promising for photodetection applications.

Styrylpyrimidine chromophores with bulky electron-donating substituents: experimental and theoretical investigation

Maxime Hodée, Julien Massue, Sylvain Achelle, Arnaud Fihey, Denis Tondelier, Gilles Ulrich, Françoise Robin Le Guen, Claudine Katan
Physical Chemistry Chemical Physics, 2023, 25, pp.32699. ⟨10.1039/D3CP03705C⟩ | Publiée le 1 janvier 2023
Article dans une revue

Abstract

Styrylpyrimidine with bulky 9,9-dimethylacridan, phenoxazine and phenothiazine electron-donating fragment were designed. Thermally activated delayed fluorescence (TADF) properties were expected for these structures. These chromophores exhibit peculiar emission properties. For 9,9-dimethylacridan and phenoxazine derivatives, a single emission highly sensitive to the polarity is observed in solution whereas for phenothiazine derivative a dual emission is observed in solution and is attributed to the coexistence of quasi-axial (Qax) and quasi-equatorial (Qeq) conformers. This study intends to understand with theoretical and experimental works, why the studied chromophores do not exhibit TADF properties, contrary to what was expected. The absence of phosphorescence both at room temperature and 77K tends to indicate the impossibility to harvest triplet states in these systems. Wave-function based calculations show that for both conformers of the three chromophores the S1-T1 splitting is significantly larger than 0.2 eV. The second triplet state T2 of Qeq conformers is found very close in energy to the singlet S1 state, but S1 and T2 states possess similar charge transfer characters. This prevents efficient spin-orbit coupling between the states, which is consistent with the absence of TADF.

Self-powered dynamic glazing based on nematic liquid crystals and organic photovoltaic layers for smart window applications

Sadiara Fall, Jing Wang, Thomas Regrettier, Nicolas Brouckaert, Olzhas A Ibraikulov, Nicolas Leclerc, Yaochen Lin, Mohammed Ibn Elhaj, Lachezar Komitov, Patrick Lévêque, Yuhan Zhong, Martin Brinkmann, Malgosia Kaczmarek, Thomas Heiser
ACS Applied Materials & Interfaces, 2022, 15 (3), pp.4267-4274. ⟨10.1021/acsami.2c21727⟩ | Publiée le 20 décembre 2022
Article dans une revue

Stockage d’hydrogène par de nouveaux vecteurs liquides biosourcés (LOHC)

Chaimae Qasmi
Autre. Université de Strasbourg, 2022. Français. ⟨NNT : 2022STRAF025⟩ | Publiée le 20 décembre 2022
Thèse

Abstract

Les LOHC sont des liquides organiques permettant de stocker le surplus de l’énergie électrique renouvelable sous forme d’une énergie chimique (H2) via la réaction d’hydrogénation d’un liquide déchargé en H2. Cette énergie peut être déstockée en cas de besoin via la réaction de déshydrogénation du liquide chargé en H2. Dans ce travail, un système catalytique unique (même réacteur et catalyseur) est étudié pour l'hydrogénation/déshydrogénation d’un couple de LOHC biosourcé (GBL/BDO) pour le stockage stationnaire de l’H2. Après des tests effectués en réacteur semi-batch sur différents catalyseurs aux différentes propriétés physico-chimiques, un catalyseur à base de cuivre présentant une activité et sélectivité élevées dans les deux sens de la réaction est sélectionné. Des modèles cinétiques sont développés et implémentés dans un modèle de réacteur continu triphasique à lit fixe catalytique. Finalement, les résultats de modélisation cinétique et réacteur ont présentés un accord satisfaisant avec les résultats expérimentaux obtenus.

Sustainable cycloaliphatic polyurethanes: from synthesis to applications

Agathe Mouren, Luc Avérous
Chemical Society Reviews, 2022, 52 (1), pp.277-317. ⟨10.1039/D2CS00509C⟩ | Publiée le 15 décembre 2022
Article dans une revue

Abstract

Polyurethanes (PUs) are a versatile and major polymer family, mainly produced via polyaddition between polyols and polyisocyanates. A large variety of fossil-based building blocks is commonly used to develop a wide range of macromolecular architectures with specific properties. Due to environmental concerns, legislation, rarefaction of some petrol fractions and price fluctuation, sustainable feedstocks are attracting significant attention, e.g., plastic waste and biobased resources from biomass. Consequently, various sustainable building blocks are available to develop new renewable macromolecular architectures such as aromatics, linear aliphatics and cycloaliphatics. Meanwhile, the relationship between the chemical structures of these building blocks and properties of the final PUs can be determined. For instance, aromatic building blocks are remarkable to endow materials with rigidity, hydrophobicity, fire resistance, chemical and thermal stability, whereas acyclic aliphatics endow them with oxidation and UV light resistance, flexibility and transparency. Cycloaliphatics are very interesting as they combine most of the advantages of linear aliphatic and aromatic compounds. This original and unique review presents a comprehensive overview of the synthesis of sustainable cycloaliphatic PUs using various renewable products such as biobased terpenes, carbohydrates, fatty acids and cholesterol and/or plastic waste. Herein, we summarize the chemical modification of the main sustainable cycloaliphatic feedstocks, synthesis of PUs using these building blocks and their corresponding properties and subsequently present their major applications in hot-topic fields, including building, transportation, packaging and biomedicine.

Mn (III)-containing compounds : synthesis and electrocatalytic properties in the oxygen reduction reaction

Kirill Dosaev
Other. Université de Strasbourg, 2022. English. ⟨NNT : 2022STRAF028⟩ | Publiée le 14 décembre 2022
Thèse

Abstract

The oxygen reduction reaction (ORR) attracts close attention of researchers since it underlies manytechnologically important processes. Despite significant recent advances, there are still importantfundamental gaps in understanding the key steps of the ORR and factors affecting its kinetics. Thethesis is devoted to (i) the study of the influence of the composition of the Mn spinel oxides on theirstability and ORR activity, and (ii) the effect of electrolyte composition (pH and Na+ concentration)on the Mn oxide/electrolyte interface and on the ORR kinetics. While Mn3O4 is unstable under theORR conditions, Mn (II) substitution by red-ox inactive cations allows to enhance spinel stability,MgMn2O4 being the most stable in all stress tests. Results of the second part of the work show a stronginfluence of pH and concentration of Na+ ions on the electrochemical behavior of manganese oxides.The strongest effect is discovered for MnOOH, which exhibits significant enhancement of the ORRkinetics with the cation concentration. This is ascribed to the increase in the kinetics of the O-O bondbreakingstep in the H2O2 intermediate.

Environmental friendly approaches to optimize ZSL-5 zeolite for the MTO reaction

Yu Zhang
Theoretical and/or physical chemistry. Université de Strasbourg, 2022. English. ⟨NNT : 2022STRAF071⟩ | Publiée le 9 décembre 2022
Thèse

Abstract

ZSM-5 zeolites are promising candidates for the MTO reaction due to their unique properties, such as numerous and adjustable acid sites, high surface area, and excellent shape selectivity. Nevertheless, increase the lifetime, decrease the cost as well as avoid the pollution remain critical targets for the modification of ZSM-5 zeolite. Based on these demands, in this Thesis, modified ZSM-5 zeolites were designed by in situ hydrothermal synthesis method, using biochars as hard template and perlites as supports, respectively. Both raw materials (biochar and perlite) come from nature, and contain abundant heteroelements. Biochars, as hard template, provide high external surface area for the zeolite; The perlite could not only be used as support material but also as Al source for the zeolite. In addition, the heteroelements present in biochars and perlites exhibited remarkable ability to adjust acidity for the preparation of ZSM-5 zeolite.In summary, the high external surface area, moderate Brønsted acidity of biochar/ZSM-5 zeolite and excellent diffusion efficiency of perlite/ZSM-5 zeolite led to powerful catalytic properties.

Reproductive differences between urban and forest birds across the years: importance of environmental and weather parameters

Agnès Saulnier, Josefa Bleu, Anne Boos, Maurice Millet, Sandrine Zahn, Pascale Ronot, Islah El Masoudi, Emilio Rojas, Pierre Uhlrich, Mirella del Nero, Sylvie Massemin
Urban Ecosystems, 2022, ⟨10.1007/s11252-022-01305-9⟩ | Publiée le 7 décembre 2022
Article dans une revue

Abstract

Urban environments pose many challenges to wildlife, not least for insectivorous passerines. Numerous studies have reported on the negative effects of urbanization on reproduction in these species. However, depending on the taxa and cities studied, no particular or positive effects have been reported. This may be related to the different levels of urban environmental stressors. As unfavorable weather can have deleterious effects on birds (e.g. lower prey availability and higher costs of pollutants), annual variations in the differences observed between sites could be related to synergetic effects between the urban environment and weather conditions. In this context, we studied the reproduction of great tit (Parus major) at two sites (urban and forest) over four years. First, we quantified pollution, prey availability, and vegetal cover at each site to characterize each environment. Second, we measured the effects of site and weather conditions on tit reproductive success to determine if the influence of weather is higher in the city. Except for the fledging rate, reproductive parameters were lower in the city than in the forest whatever the year probably because of poorer food availability and a predominance of non-vegetated areas in cities. The fledging rate and the nestling number in the urban environment were positively correlated to temperatures during rearing whereas there was no significant correlations in the forest. These results support the hypothesis of additive effects of urban constraints and weather that limit bird productivity in cities.

La plasmonique et les électrodes à base de nanofils d’argent pour des cellules solaires organiques

Issoufou Ibrahim Zamkoye, Johann Bouclé, Nicolas Leclerc, Bruno Lucas, Sylvain Vedraine
SPIC 2022 : Quatrième congrès national Sciences et Technologies des systèmes pi-conjugués, Dec 2022, Saint Malo, France | Publiée le 5 décembre 2022
Communication dans un congrès

Improving catalytic performance via induction heating: selective oxidation of H 2 S on a nitrogen-doped carbon catalyst as a model reaction

Wei Wang, Cuong Duong Viet, Lai Truong Phuoc, Tri Truong-Huu, Hoang M. Nguyen, Lam Nguyen-Dinh, Yuefeng Liu, Cuong Pham Huu
New Journal of Chemistry, 2022, 47 (3), pp.1105-1116. ⟨10.1039/D2NJ04897C⟩ | Publiée le 1 décembre 2022
Article dans une revue

Highly vertical 3D bio-inspired hierarchical and multiscale superstructures on microcantilever for gas sensing of organophosphorous agents

Guillaume Thomas, Valérie Keller, Denis Spitzer
Applied Materials Today, 2022, 29, pp.101667. ⟨10.1016/j.apmt.2022.101667⟩ | Publiée le 1 décembre 2022
Article dans une revue

Le photovoltaïque organique est-il crédible pour alimenter des nœuds IoT ?

Patrick Lévêque, Ashkan Pourmoslemi, Roman Adamski, Nicolas Leclerc, Vincent Frick
SPIC 2022 (Science et Technologie des Systèmes pi-Conjugués), St Malo, France, décembre 2022, Dec 2022, St Malo, France | Publiée le 1 décembre 2022
Communication dans un congrès

Fe-doped olivine and char for in-bed elimination of gasification tars in an air-blown fluidised bed reactor coupled with oxidative hot gas filtration

Miguel Ruiz, Adam Schnitzer, Claire Courson, Guillain Mauviel
Carbon Resources Conversion, 2022, 5 (4), pp.271-288. ⟨10.1016/j.crcon.2022.07.004⟩ | Publiée le 1 décembre 2022
Article dans une revue

Abstract

Gasification experiments were carried out in a pilot scale fluid bed reactor operated under allothermal mode and low fluidisation regime with iron-doped olivine and char as catalyst for in-situ tar abatement. The catalyst combination resulted in a reduction of 50% in the overall tar yield with respect to the reference values. Furthermore, the integration of an oxidative Hot Gas Filtration unit downstream the gasification reactor led to a further reduction in overall tar yield and relatively clean gas was obtained (approx. 1 g/Nm 3 , benzenefree). The tar dew point of the resulting producer gas was estimated to 80 • C, only 40 • C above the threshold value recommended for its valorisation in standard internal combustion engines. Moreover, catalyst elutriation and char holdup took place to a large extent inside the reactor. The analysis of catalyst samples at different Time-On-Stream (TOS) revealed: (i) a considerable loss of iron oxides during the first hour of test because of the interparticle mechanical attrition (mostly surface abrasion) and partial reduction of hematite to magnetite and wustite but, stable composition at higher TOS, (ii) the loss of the iron oxide coverage of Fe/olivine particles and the formation of agglomerates with increasing TOS and, (iii) the amount of carbon deposited in the surface of the Fe/olivine particles increased with TOS, but in any case, these carbon deposits can be completely oxidized above 650 • C.

Synthesis of Ni-doped ceria nanoparticles and their unusual surface reduction in hydrogen

M. Barreau, Dingkai Chen, Jinming Zhang, V. Papaefthimiou, Corinne Petit, E. Borfecchia, S. Turczyniak-Surdacka, K. Sobczak, Davide Salusso, S. Mauri, L. Braglia, P. Torelli, Spiros Zafeiratos
Materials Today Chemistry, 2022, 26, pp.101011. ⟨10.1016/j.mtchem.2022.101011⟩ | Publiée le 1 décembre 2022
Article dans une revue

Abstract

This work presents an original approach to preparing pure and Ni-doped CeO2 nanoparticles (NPs) that can be directly drop-casted on a substrate or calcined to form powders. The reduction of the NPs in H2 is very different than the one usually anticipated for supported Ni–CeO2 catalysts. In situ soft X-ray absorption and infrared spectroscopies revealed that the reduction of Ce4+ into Ce3+ in H2 proceeds via simultaneous oxidation of Ni2+ ions into Niδ+ (2&lt;δ&lt;3). Comparison with reference samples indicates that Ce4+ ions reduction is promoted over Ni-doped CeO2 NPs, whereas that of Ni2+ is hindered. Theoretical simulation of Ni L-edge spectra suggested that Ni dopant into ceria is in a square planar four-coordinate environment, in contrast to the familiar octahedral symmetry of bulk nickel oxides. Our results reveal that the surface chemistry of Ni-doped CeO2 is quite distinct as compared to that of the individual bulk oxides, which potentially can lead to a different performance of this material, notably in catalytic applications.

Pd-functionalized polydopamine-coated polyurethane foam: a readily prepared and highly reusable structured catalyst for selective alkyne semi-hydrogenation and Suzuki coupling under air

Han Peng, Xiong Zhang, Vasiliki Papaefthimiou, Cuong Pham-Huu, Vincent Ritleng
Green Chemistry, 2022, ⟨10.1039/d2gc03283j⟩ | Publiée le 29 novembre 2022
Article dans une revue

Abstract

A polyurethane foam (PUF) was coated with a thin layer of polydopamine (PDA), and Pd strongly anchored onto PDA via simple immersion of PDA@PUF in a hydro-alcoholic solution of Pd(NH 3) 4 Cl 2 •H 2 O at room temperature under air to afford a Pd@PDA@PUF foam. XPS showed the absence of initial reduction of palladium despite the redox properties of PDA, and HR-SEM and SEM-EDX suggested a coordination of evenly dispersed Pd(II) ions by the catechol moieties of the PDA layer, thus resulting in a single atom-type dispersion of the active phase. The "dip-and-play" catalytic pattern of Pd@PDA@PUF and high dispersion of Pd on the surface guaranteed high activity, selectivity and reusability in alkyne semi-hydrogenation and in Suzuki coupling under air without prior reduction procedures. Self-enhancing properties, observed in recycling and control experiments, were explained by XPS as the chelated Pd(II) ions were gradually reduced to isolated coordinated Pd(0) atoms under hydrogenation or Suzuki coupling reaction conditions.

UiO-66/TiO2 nanostructures as adsorbent/photocatalytic composites for air treatment towards dry dimethyl methylphosphonate-laden air flow as a Chemical Warfare Agent analog

Nina Rouvière, Jean-Philippe Brach, Tom Honnecker, Konstantinos Christoforidis, Didier Robert, Valérie Keller
Catalysis Today, 2022, ⟨10.1016/j.cattod.2022.11.021⟩ | Publiée le 19 novembre 2022
Article dans une revue

Tuning CO 2 hydrogenation selectivity on Ni/TiO 2 catalysts via sulfur addition

Carole Le Berre, Andrea Falqui, Alberto Casu, Tekalign Debela, Mathias Barreau, Christopher Hendon, Philippe Serp
Catalysis Science & Technology, 2022, 12 (22), pp.6856-6864. ⟨10.1039/D2CY01280D⟩ | Publiée le 14 novembre 2022
Article dans une revue

Abstract

In the context of CO2 valorization, the possibility of shifting the selectivity of Ni catalysts from CO2 methanation to reverse water gas shift reaction could be economically attractive provided that the catalyst presents sufficient activity and stability. Remarkably, the addition of sulfur (0.2–0.8% w/w) to nickel on a Ni/TiO2 catalyst induces a complete shift in the catalyst selectivity for CO2 hydrogenation at 340 °C from 99.7% CH4 to 99.7% CO. At an optimal Ni/S atomic ratio of 4.5, the productivity of the catalyst reaches 40.5 molCO2 molNi−1 h−1 with a good stability. Density functional theory (DFT) calculations performed on various Ni surfaces reveal that the key descriptor of selectivity is the binding energy of the CO intermediate, which is related to the local electron density of surface Ni sites.

Core-shell cobalt iron oxide nanoparticles for the electrocatalysis of the oxygen evolution reaction

Lisa Royer
Other. Université de Strasbourg, 2022. English. ⟨NNT : 2022STRAF023⟩ | Publiée le 8 novembre 2022
Thèse

Abstract

This thesis studies a novel type of catalyst aiming for lowering the overpotential of the oxygen evolution reaction in alkaline media while replacing the noble metals oxide commonly used in acidic media by transition metal oxides. This catalyst combines the conductive properties of a magnetite core (Fe3O4) and the electrocatalytic activity of a cobalt ferrite shell using core-shell Fe3O4@CoFe2O4 nanoparticles. The electrochemical properties of these nanoparticles have been systematically studied modifying the core size and the shell thickness. The particles presenting a core diameter superior to 12nm reached an activity of 2800 A.g-1cobalt at 1.65 V vs. RHE which is by far superior to the activity reported in the literature for similar catalysts. The transformations occurring at the surface of the catalyst during the oxygen evolution reaction have been studied operando by NEXAFS thanks to synchrotron radiation. This technique allowed the study the evolution of the metal cation oxidation state and evidenced a synergy between the Fe (II) in the core and the Co (II) in the shell during the OER. Moreover, transmission electron microscopy revealed that the core-shell structure was preserved during the OER and that it allows to prevent the formation of CoOOH in the potential range of the OER.

Not Just Another Methanation Catalyst: Depleted Uranium Meets Nickel for a High‐Performing Process Under Autothermal Regime

Lai Truong Phuoc, Jean Mario Nhut, Sécou Sall, Giulia Tuci, Andrea Rossin, Vasiliki Papaefthimiou, Cuong Duong Viet, Corinne Petit, Mehdi Arab, Alex Jourdan, Loic Vidal, Giuliano Giambastiani, Cuong Pham Huu
ChemSusChem, 2022, ⟨10.1002/cssc.202201859⟩ | Publiée le 4 novembre 2022
Article dans une revue

Abstract

Ni-based catalysts prepared through impregnation of depleted uranium oxides (DU) have successfully been employed as highly efficient, selective, and durable systems for CO2 hydrogenation to substituted natural gas (SNG; CH4 ) under an autothermal regime. The thermo-physical properties of DU and the unique electronic structure of f-block metal-oxides combined with a nickel active phase, generated an ideal catalytic assembly for turning waste energy back into useful energy for catalysis. In particular, Ni/UOx stood out for the capacity of DU matrix to control the extra heat (hot-spots) generated at its surface by the highly exothermic methanation process. At odds with the benchmark Ni/γ-Al2 O3 catalyst, the double action played by DU as a "thermal mass" and "dopant" for the nickel active phase unveiled the unique performance of Ni/UOx composites as CO2 methanation catalysts. The ability of the weakly radioactive ceramic (UOx ) to harvest waste heat for more useful purposes was demonstrated in practice within a rare example of a highly effective and long-term methanation operated under autothermal regime (i. e., without any external heating source). This finding is an unprecedented example that allows a real step-forward in the intensification of "low-temperature" methanation with an effective reduction of energy wastes. At the same time, the proposed catalytic technology can be regarded as an original approach to recycle and bring to a second life a less-severe nuclear by-product (DU), providing a valuable alternative to its more costly long-term storage or controlled disposal.

On the evolution of oxidative etching of few layer graphene (FLG) in FLG /TiO2 nanocomposites. Interfacial dipole signature and chemical shift in C1s X-ray photoemission spectra

Hamza El Marouazi, Valérie Keller, Izabela Janowska
Surfaces and Interfaces, 2022, 36, pp.102510. ⟨10.1016/j.surfin.2022.102510⟩ | Publiée le 1 novembre 2022
Article dans une revue

Abstract

We present the effect of oxidative etching in FLG/TiO2 hybrids on FLG edges chemistry/morphology addressing also the catalytic activity of TiO2 NPs. According to the XPS and TGA analysis the oxidation degree strongly depends on TiO2:FLG ratio. The preparation of two series of FLG/TiO2 hybrids via sol-gel method and in-situ oxidation permitted to correctly describe and distinguish the chemical composition, core shift and charge distribution in C1s XPS with Ti2p peak as reference. Such analysis is challenging in carbon materials due the overlapping of C1s peaks from the sample and adventitious carbon reference. We claim the formation of interfacial dipole as possible direct signature of charge transfer from TiO2 to FLG. A downward shift of C1s (sp2C) up to 1.4 eV is measured and contributions of non sp2C are determined in the composites. The modifications related to the oxidation are supported by TEM/SEM observations, and referred to non-catalytic oxidation and oxidation in mechanically mixed components.

Near Ultra-Violet absorbers for transparent organic solar cells

Chaima Mahmoudi, Wenziz Muzuzu, Sadiara Fall, Yuhan Zhong, Christophe Melart, Patrick Lévêque, Thomas Heiser, Nejmeddine Smida Jaballah, Mustapha Majdoub, Nicolas Leclerc
Dyes and Pigments, 2022, 207, pp.110752. ⟨10.1016/j.dyepig.2022.110752⟩ | Publiée le 1 novembre 2022
Article dans une revue

Abstract

We describe the synthesis of two new dumbbell-shaped small molecules used as near ultraviolet absorbers for transparent organic solar cell application. The electron-donor TAT units, sandwiching the central chromophore, constitute very efficient π-stacking platforms that are nevertheless highly soluble thanks to the presence of three alkyl chains. The TAT units are used in combination, with a small central electron donor unit, either a carbazole or a thieno[3,2-b]thiophene (TT) unit. The two new dumbbell-shaped small molecules including only electron-donor units are strongly absorbing in the near UV range, due to the reduced electronic conjugation. Combined with a suitable hole mobility, the most conjugated thieno[3,2-b]thiophene-based derivative, when used as electrondonor component in a bulk heterojunction organic solar cell, exhibits a 48% of average visible transmittance with a power conversion efficiency close to 2%.

Pesticides in the Indoor Environment of Residential Houses: A Case Study in Strasbourg, France

Josephine Al-Alam, Alexandre Sonnette, Olivier Delhomme, Laurent Alleman, Patrice Coddeville, Maurice Millet
International Journal of Environmental Research and Public Health, 2022, 19 (21), pp.14049. ⟨10.3390/ijerph192114049⟩ | Publiée le 1 novembre 2022
Article dans une revue

Abstract

Indoor environmental exposure to pesticides has become one of the major concerns that might adversely affect human health and development. People spend most of their lifetime in enclosed indoor environments where they might inhale harmful toxic chemicals, such as pesticides, dispersed either in particulate or in a gas phase. In this study, an assessment of pesticide contamination in indoor environments was conducted. The study covered nine houses during one year, starting from February 2016 and ending in February 2017, in which both air and dust samples were assessed for their potential contamination with 50 pesticides. The results showed that all the assessed houses were contaminated by several pesticides, especially with the allethrin pesticide (detection frequency (DF) = 100%). The highest pesticide contamination was detected in the spring/summer season when it reached an average of around 185 ng g−1 and 186.4 ng sampler−1 in the collected dust and air samples, respectively. The potential contamination of pyrethroid insecticides within all the targeted samples revealed by this study stresses the importance of minimizing the use of such indoor treatments as part of the efficient prevention and control of human exposure to pesticides.

Are Fe–N–C Electrocatalysts an Alternative to Pt-Based Electrocatalysts for the Next Generation of Proton Exchange Membrane Fuel Cells?

Xiong Zhang, Lai Truong-Phuoc, Tristan Asset, Sergey Pronkin, Cuong Pham-Huu
ACS Catalysis, 2022, 12 (22), pp.13853-13875. ⟨10.1021/acscatal.2c02146⟩ | Publiée le 27 octobre 2022
Article dans une revue

Abstract

Notable progresses have been made for low Pt-based and Fe-N-C electrocatalysts for proton exchange membrane fuel cells (PEMFCs) applications. Particularly, the research and development of cost-effective Fe-N-Cs have witnessed significant improvements in the recent years, due to the need of an alternative candidate to the scare, and expensive, platinum. Numerous studies have been exploring the design and optimization of Fe-N-Cs and generally make simple performance comparison with commercial Pt/C catalysts on the basis of rotating disk electrode (RDE) and/or membrane electrode assembly (MEA), thus arguing that said materials are comparable, or could even surpass, Pt/C electrocatalysts. The resulting question, i.e. 'are Fe-N-Cs an alternative to Pt-based electrocatalysts in PEMFCs?' is the centerpiece of this review. Here, the interconnectedness and differences between Fe-N-Cs and Pt-based materials are discussed from fundamental insights to applications in PEMFCs, covering the oxygen reduction reaction (ORR) mechanism, the nature of active sites and its effect on the intrinsic activity, the rational design of catalyst layer, the electrocatalysts performances in PEMFCs and their durability in operating conditions. This review provides a global picture of the current research state in the field of PEMFCs electrocatalysts, focusing onto the two most important types of cathode materials and aiming to shed light on the potential of Fe-N-Cs as replacement for Pt-based catalysts along with pointing out the research directions toward the next generation of PEMFCs.

Développements analytiques pour la spéciation chimique organique et metaprotéomique des particules et des poussières

Mathieu Galmiche
Chimie analytique. Université de Strasbourg, 2022. Français. ⟨NNT : 2022STRAF043⟩ | Publiée le 14 octobre 2022
Thèse

Abstract

Les aérosols et les poussières sont des sources d’exposition à une grande diversité de composants chimiques et biologiques. Pour mieux les caractériser, plusieurs développements analytiques ont été entrepris dans cette thèse.Une méthode GC-MS/MS a été développée pour analyser simultanément 79 Composés Aromatiques Polycycliques. Elle a permis de quantifier ces composés dans des particules d’échappement de moteur diesel, des aérosols d’un parking, ou encore des poussières de logements urbains.Une méthode LC-MS/MS a été développée pour analyser les fullerènes. Celle-ci a pu être validée, mais aucun fullerène n’a été détecté dans les échantillons environnementaux étudiés.Un screening métaprotéomique de la fraction biologique des aérosols et des poussières a été mis au point. La méthode d’extraction des protéines a été optimisée. Des analyses bottom-up ont ensuite été réalisées afin de vérifier l’identité des protéines extraites.Ces développements analytiques visent à atteindre une meilleure connaissance des fractions chimiques et biologiques des aérosols et des poussières.

A recent advance on partial evaporating organic Rankine cycle: experimental results on an axial turbine

Guillaume Lhermet, Nicolas Tauveron, Nadia Caney, Quentin Blondel, Franck Morin
Energies, 2022, 15 (20), pp.7559. ⟨10.3390/en15207559⟩ | Publiée le 13 octobre 2022
Article dans une revue

Abstract

The organic Rankine cycle (ORC) technology is an efficient way to convert low-grade heat from renewable sources or waste heat for power generation. The partial evaporating organic Rankine cycle (PEORC) can be considered as a promising alternative as it can offer a higher utilization of the heat source. An experimental investigation of a small ORC system used in full or partial evaporation mode is performed. First characterized in superheated mode, which corresponds to standard ORC behavior, a semi-empirical correlative approach involving traditional non-dimensional turbomachinery parameters (specific speed, pressure ratio) can accurately describe one-phase turbine performance. In a second step, two-phase behavior is experimentally investigated. The efficiency loss caused by the two-phase inlet condition is quantified and considered acceptable. The turbine two-phase operation allows for an increase in the amount of recovered heat source. The ability to operate in two phases provides a new degree of flexibility when designing a PEORC. The semi-empirical correlative approach is then completed to take into account the partially evaporated turbine inlet condition. The qualitative description and the quantitative correlations in the one-phase and two-phase modes were applied to different pure working fluids (Novec649TM, HFE7000 and HFE7100) as well as to a zeotropic mixture (Novec649TM/HFE7000).

Fe Atom—Mixed Edges Fractal Graphene via DFT Calculation

Lobna Aloui, Thierry Dintzer, Izabela Janowska
ChemEngineering, 2022, 6 (5), pp.79. ⟨10.3390/chemengineering6050079⟩ | Publiée le 8 octobre 2022
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Abstract

The stability of small fractal graphene models with two different symmetries and Fe atoms at their mixed edges is addressed by density functional theory (DFT) calculations. Four kinds of edge configurations and Fe atom localizations are determined depending on the model. The edges have mixed configuration, the zig-zag and “intra-zig-zag” in symmetrical structures and armchair and zig-zag type in the architectures with rotational symmetry. The rotational symmetry graphene exhibits slightly higher stability per carbon atom compared to the symmetrical model, while the localization of Fe atoms is more favorable at armchair and “inversed zigzag” than at zigzag type carbon termination. Larger graphene structures with rotational symmetry were observed previously via experimental cutting of graphene with Fe nanoparticles (NPs).

TiO2 supported Co catalysts for the hydrogenation of γ-valerolactone to 2methyltetrahydrofuran: influence of the support

Emilia Soszka, Marcin Jędrzejczyk, Christophe Lefèvre, Dris Ihiawakrim, Nicolas Keller, Agnieszka Ruppert
Catalysis Science & Technology, 2022, 12 (19), pp.5802-5813. ⟨10.1039/d2cy01044e⟩ | Publiée le 3 octobre 2022
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Abstract

2-Methyltetrahydrofuran (MTHF) is considered as one of the most promising green fuel alternatives that could be obtained from renewable lignocellulosic biomass through the catalytic hydrogenation of the γ-valerolactone (GVL) platform molecule. In the current work, we report on the ability of earth-abundant non-noble metal Co catalysts supported on TiO2 to be used efficiently for the synthesis of MTHF. The activity of TiO2-supported Co catalysts in the hydrogenation of GVL to 2-MTHF was investigated, and several key factors with significant influence on the reaction have been identified and discussed. Among them, we pointed out the crucial role of the titania support as a versatile tool able to drive the properties of the supported metallic cobalt nanoparticles and consequently the activity of the catalysts. In addition to the necessary catalyst acidity, we showed that the catalyst performances were related to the Co particle size and to the metal–support interaction, both properties being highly dependent on the composition of the titania support. We demonstrated the beneficial co-presence of both anatase and rutile crystalline phases within the TiO2 support, and we proposed that the nature of the crystalline phase not only influences the Co particle size and the catalyst acidity but also allows tuning the SMSI effect for achieving optimum performances in 2-MTHF synthesis.

Emerging high-prospect applications in photothermal catalysis

Ana Iglesias-Juez, Fernando Fresno, Juan Coronado, James Highfield, Agnieszka Ruppert, Nicolas Keller
Current opinion in green and sustainable chemistry, 2022, 37, pp.100652. ⟨10.1016/j.cogsc.2022.100652⟩ | Publiée le 1 octobre 2022
Article dans une revue

Abstract

This article updates the most appealing progresses from the last years in the fast-expanding, burgeoning research field that is photothermal heterogeneous catalysis. We provide an overview of significant advances realized in less-scrutinized, albeit high-prospect, reactions, namely in the valorization of bio-resources, the methane activation, the ammonia synthesis, and the molecular oxygen activation for selective oxidations. Regardless of whether the light-induced reaction mechanisms are electron-or heat-driven, we show that synergistic (cooperative) effects upon a suited dual-mode thermal/photonic excitation in photothermal catalysis allow for the greening of the catalytic processes, through the acceleration of the reaction rates to get shorter reaction times under fixed conditions, the orientation of reaction selectivities, the enhancement of the catalyst stability and/or the softening of the reaction conditions.

Ceria nanoparticles as promoters of CO2 electroreduction on Ni/YSZ: An efficient preparation strategy and insights into the catalytic promotion mechanism

Dingkai Chen, Mathias Barreau, Sylwia Turczyniak-Surdacka, Kamil Sobczak, Marcin Strawski, Annie Le Gal La Salle, Anna Efimenko, Detre Teschner, Corinne Petit, Spyridon Zafeiratos
Nano Energy, 2022, 101, pp.107564. ⟨10.1016/j.nanoen.2022.107564⟩ | Publiée le 1 octobre 2022
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Abstract

Since many decades nickel yttria-stabilized zirconia cermet (Ni/YSZ) has been the most frequently used fuel electrode material for high temperature solid oxide cells (SOCs). However, in recent years there has been considerable effort to improve the Ni/YSZ performance through surface engineering. In this work, we report a simple strategy to apply nanosized un-doped (CeOx) and Ni-doped (NiCeOy) ceria particles into porous Ni/YSZ cermet electrodes via infiltration from hexane solution. Detailed characterization of the particles in their solution revealed differences in the ease of agglomeration, with NiCeOy nanoparticles being better dispersed and thus forming smaller aggregates. This property is critical for the effectiveness of the solution in filling the pores of Ni/YSZ cermet and the consequent ceria deposition. In particular, morphological and microstructural characterization reveals that NiCeOy nanoparticles decorate uniformly the pores of Ni/YSZ backbone, deep up to the interface with the electrolyte. More importantly, this can be done with relatively high ceria loading per infiltration/co-firing step. Electrochemical tests demonstrate that infiltrated Ni/YSZ fuel electrodes have improved I-V performance in CO2 electrolysis as compared to pristine Ni/YSZ. Synchrotron-based operando NAP-XPS experiments using both soft and tender X-rays revealed the formation of an ultrathin Ni-Ce3+ layer on the electrode surface, which can rationalize the ameliorated CO2 electrolysis performance.

Eliminer les microplastiques

Eric Lichtfouse, Didier Robert, Chuanyi Wang
Le CNRS en Chine, 2022, 36, pp.47-50 | Publiée le 1 octobre 2022
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Abstract

Les microplastiques sont des contaminants qui ont été identifiés récemment dans les organismes vivants et dans la plupart des milieux naturels dans le monde entier. Cette présence pose un problème de santé car d’une part, certains microplastiques sont toxiques, et d’autre part, ils transportent d’autres contaminants et des microbes pathogènes. C’est également un problème de changement climatique car la plupart des plastiques proviennent du pétrole, et donc leur dégradation augmente la teneur en CO2 de l’atmosphère. Cet article présente l'origine et la formation des microplastiques, ainsi que les méthodes pour les éliminer des eaux contaminées, notamment par photocatalyse.

Optimizing chain alignment and preserving the pristine structure of single-ether based PBTTT helps improve thermoelectric properties in sequentially doped thin films

Martin Brinkmann, Pablo Durand, Shubhradip Guchait, Laurent Herrmann, Celine Kiefer, Nicolas Leclerc, Huiyan Zeng
Journal of Materials Chemistry C, 2022, ⟨10.1039/D2TC03600B⟩ | Publiée le 28 septembre 2022
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Abstract

Doped polymer semi-conductors are of central interest in material science for their interesting charge transport and thermoelectric properties. Polymer alignment and crystallization are two means to enhance thermoelectric parameters (charge...

Ru based photothermal catalysts for formic acid dehydrogenation and CO2 methanation

Francisco Javier Ivanez Castellano
Other. Université de Strasbourg, 2022. English. ⟨NNT : 2022STRAF057⟩ | Publiée le 15 septembre 2022
Thèse

Abstract

This work is centered on the study of ruthenium-based catalysts for their use in photothermal catalysis. For this purpose, different experiments have been elaborated focusing from their synthesis method to their applications for obtaining hydrogen or CO2 conversion via methanation. The study of the different materials, under different conditions and on different reactions shows that the photothermal effect, mainly generated by ruthenium, can contribute to an improvement of the catalytic properties. The results affirm a direction of selectivity to the desired reactions while increasing the catalytic activity at lower temperatures thanks to light irradiation. This work opens up the use of photothermal catalysts for more sustainable processes in the energy and industrial sectors.

Développements analytiques pour l'évaluation des contaminations aux produits phytosanitaires dans différentes matrices : étude des transferts vers les populations riveraines et les organismes vivants

Anais Rodrigues
Chimie analytique. Université de Strasbourg, 2022. Français. ⟨NNT : 2022STRAF061⟩ | Publiée le 13 septembre 2022
Thèse

Abstract

Dans un contexte environnemental d’une pollution des pesticides, ces travaux de thèse ont eu comme objectifs principaux le développement de différentes méthodes analytiques pour l’évaluation des contaminations aux pesticides dans différentes matrices (environnementales et biologiques).Les premières matrices étudiées sont des matrices environnementales à savoir de l’air et des poussières domestiques. Le but était de développer une méthodologie de prélèvement combinée pour l’analyse d’air et de poussières dans des habitations de riverains de zones de culture et notamment des vignes.Les secondes matrices que nous avons étudiées sont le sang et le plasma de perdrix grises (Perdix perdix). L’objectif était de développer deux méthodes d’extractions et de quantifications des pesticides potentiellement présents dans ces matrices afin d’évaluer la potentielle contamination d’oiseaux d’élevage par ces composés.Les résultats obtenus pour ces deux études ont permis de dresser une première approche de l’évaluation des contaminations aux pesticides que ce soit chez les riverains ou dans des organismes vivants tels que les oiseaux.

Simultaneous Monitoring of Outdoor PAHs and Particles in a French Peri-Urban Site during COVID Restrictions and the Winter Saharan Dust Event

Farhan Ramadzan Nursanto, Joana Vaz-Ramos, Olivier Delhomme, Sylvie Bégin-Colin, Stéphane Le Calvé
Atmosphere, 2022, 13 (9), pp.1435. ⟨10.3390/atmos13091435⟩ | Publiée le 5 septembre 2022
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Abstract

The presence of polycyclic aromatic hydrocarbons (PAHs) and particulate matter (PM) in air is known to provoke deleterious effects on human health. This work focused on the monitoring of PM and PAHs in the air over four weeks in a peri-urban site in Strasbourg (France), using a three-stage cascade impactor and a particle analyser allowing PM1, PM2.5 and PM10 discrimination. Meteorological conditions were monitored to study their influence on the pollutant levels. The average PM10 concentration of the cascade impactor and particle analyser varied from 11.8 to 80.2 µg/m3 and 10.6 to 220.2 µg/m3, respectively. The PAH total concentration ranged in 1.1–7.6 ng/m3 and a predominance of 5- and 6-ring PAHs was observed. PAHs were also more abundant in finer particles (PM1). Specifically, identified PAHs are traffic tracers suggesting that vehicular emission was one of its main sources. Two pollution episodes, associated with either a Saharan dust wind episode or traffic pollution, were observed, and led to PM10 and PM2.5 surpassing the daily limit values established by the European Union despite the traffic limitations according to the COVID restrictions. The total PAH concentrations were the highest during these periods suggesting PAHs might be bound to and transported via dust particles.

Impact of urea-based deep eutectic solvents on Mg-MOF-74 morphology and sorption properties

Michaël Teixeira, Renata A. Maia, Sangaraju Shanmugam, Benoît Louis, Stéphane Baudron
Microporous and Mesoporous Materials, 2022, 343, pp.112148. ⟨10.1016/j.micromeso.2022.112148⟩ | Publiée le 1 septembre 2022
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High yield production of 2-methyltetrahydrofuran biofuel with reusable Ni-Co catalysts

Emilia Soszka, Marcin Jȩdrzejczyk, Nicolas Keller, Agnieszka Ruppert
Fuel, 2022, 332 (part 2), pp.126118. ⟨10.1016/j.fuel.2022.126118⟩ | Publiée le 1 septembre 2022
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Abstract

The sustainable production of environmentally-friendly alternative fuels from renewable resources is one of the worldwide high-prospect strategies for future biorefinery schemes. 2methyltetrahydrofuran (2-MTHF) that can be obtained from renewable sources such as lignocellulosic biomass is considered as an ideal green fuel competitive to benchmarks products due to high-value properties like high energy density. In our work we showed that bimetallic Ni-Co/g-Al2O3 catalysts with an appropriate amount of Ni are worth robust, reusable and cheap earth-abundant non-noble metals-based catalysts enabling the high yield production of 2-MTHF. The factors allowing the activity to be strongly boosted compared to the monometallic counterparts while keeping a high selectivity to the targeted 2-MTHF product were identified and discussed. Among the key factors we identified the role of the Ni-Co interaction allowing the Ni availability at the surface of the catalyst to be enhanced. Additionally, the surface acidity was recognized as another important factor. Silica supported catalysts were selective towards the 1,4-pentanediol (1,4-PDO) intermediate obtained by GVL dehydration, while more acidic g-Al2O3 was pushing the reaction further towards 2-MTHF. The synthesis parameters were optimized in terms of reduction temperature (500°C) and Ni:Co ratio (1:4) on the most active g-Al2O3 supported catalyst.

Atmospheric dispersion modelling of gaseous emissions from Beirutinternational airport activities

Tharwat Mokalled, Stéphane Le Calvé, Nada Badaro-Saliba, Maher Abboud, Rita Zaarour, Wehbeh Farah, Jocelyne Adjizian-Gérard
Aims Environmental Science, 2022, 9 (5), pp.553 - 572. ⟨10.3934/environsci.2022033⟩ | Publiée le 1 septembre 2022
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Abstract

The projected increase of civil aviation activity, the degradation of air quality and the location of Beirut Airport embedded in a very urbanized area, in addition to the special geography and topography surrounding the airport which plays a significant role in drawing emissions to larger distances, demanded anassessment of the spatial impact of the airport activities on the air quality of Beirut and its suburbs. This is the first study in the Middle East region that model pollutant concentrations resulting from an international airport's activities using an advanced atmospheric dispersion modelling system in a country with no data. This followed validation campaigns showing very strong correlations (r = 0.85) at validation sites as close as possible to emission sources. The modelling results showed extremely high NO2 concentrations within the airport vicinity, i.e., up to 110 µg•m-3 (which is greater than the World Health Organization annual guidelines) posing a health hazard to the workers in the ramp. The major contribution of Beirut-Rafic Hariri International Airport to the degradation of air quality was in the airport vicinity; however, it extended to Beirut and its suburbs in addition to affecting the seashore area due to emissions along the aircraft trajectory; this isan aspect rarely considered in previous studies. On the other hand, elevated volatile organic compound levels were observed near the fuel tanks and at the aerodrome center. This study provides (i) a methodology to assess pollutant concentrations resulting from airport emissions through the use 554 of an advanced dispersion model in a country with no data; and (ii) a tool for policy makers to better understand the contribution of the airport's operations to national pollutant emissions, which is vital for mitigation strategies and health impact assessments.

Development of a biomimetic bioreactor for regenerative endodontics research

Aurélien Louvrier, Marie Kroemer, Lisa Terranova, Florent Meyer, Marion Tissot, Edouard Euvrard, Florelle Gindraux, Christophe Meyer, Gwenaël Rolin
Journal of Tissue Engineering and Regenerative Medicine, 2022, ⟨10.1002/term.3346⟩ | Publiée le 25 août 2022
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Abstract

In the context of regenerative endodontics research with the development of biomaterials, this work aimed to develop and test a prototype biomimetic bioreactor of a human tooth. The bioreactor was designed to reproduce a shaped dental canal connected with a cavity reproducing the periapical region and irrigated through two fluidic channels intended to reproduce the apical residual vascular supply. A test biomaterial composed of polylactic acid/polycaprolactone-tannic acid (PLA/PCL-TA) was produced by electrospinning/electrospraying and calibrated to be inserted in a dental canal. This biomaterial was first used to evaluate its imbibition capacity and the oximetry inside the bioreactor. Then, Dental Pulp Stem Cells (DPSCs) were cultured on PLA/PCL-TA cones for 1–3 weeks in the bioreactor; afterward cell adhesion, proliferation, and migration were histologically assessed. Complete imbibition biomaterial was obtained in 10 min and oximetry was stable over time. In the bioreactor, DPSCs were able to adhere, proliferate and migrate onto the surface and inside the biomaterial. In conclusion, this bioreactor was used successfully to test a biomaterial intended to support pulp regeneration and constitutes a new in vitro experimental model closer to clinical reality.

Simplified green-emitting single-layer phosphorescent organic light-emitting diodes with an external quantum efficiency > 22%

Fabien Lucas, Clément Brouillac, Sadiara Fall, Nicolas Zimmerman, Denis Tondelier, Bernard Geffroy, Nicolas Leclerc, Thomas Heiser, Christophe Lebreton, Emmanuel Jacques, Cassandre Quinton, Joëlle Rault-Berthelot, Cyril Poriel
Chemistry of Materials, 2022, 34 (18), pp.8345-8355. ⟨10.1021/acs.chemmater.2c01909⟩ | Publiée le 3 août 2022
Article dans une revue

Abstract

Nowadays, phosphorescent organic light-emitting diodes (PhOLEDs) is a widespread technology, in which all the high-performance devices are constructed on a stack of different organic layers called multi-layer devices (ML-PhOLEDs). Thanks to these functional layers, the injection, the transport, and the recombination of holes and electrons in the emissive layer (EML) are significantly improved, allowing to reach high performances. In this technology, the ideal devices are the single-layer PhOLEDs (SL-PhOLEDs), with a very simple stack only constituted by the electrodes and the EML. These devices are simple, very easy to fabricate, and can hence significantly decrease their costs. Nevertheless, removing the functional layers of an OLED drastically decreases the performances and there is, so far, only a few examples of high-performance SL-PhOLEDs. Thus, in SL-PhOLEDs, the role of the functional layer should be performed by the EML, which should allow an excellent injection, transport, and recombination of holes and electrons. In this work, thanks to a rational molecular design of the EML, we report a green-emitting SL-PhOLED, displaying a very high external quantum efficiency of 22.7%. The EML of this device is constructed on the barely studied Ir(ppy)2acac phosphor and a high efficiency host material possessing a Donor-spiro-Acceptor design. This performance is, to the best of our knowledge, the highest reported to date for SL-PhOLEDs (all colors considered). Through a structure/property/device performance relationship study combining morphological (AFM), photophysical (time-resolved spectroscopy) and charge transport studies, we show that the EML presents all the required characteristics such as smooth surface, quick radiative deactivation, and ambipolarity. In addition, the comparison with Ir(ppy)3, the most famous green emitter used in PhOLEDs, highlights the high potential of Ir(ppy)2acac. The impact of the phosphorescent emitter on the ambipolarity of the charge transport is particularly evidenced.

Photo-degradation in bulk heterojunction organic solar cells using a fullerene or a non-fullerene derivative electron acceptor

Amina Labiod, Olzhas A Ibraikulov, Sylvie Dabos-Seignon, Stéphanie Ferry, Benoît Heinrich, Stéphane Méry, Sadiara Fall, Thomas Heiser, Clément Cabanetos, Nicolas Leclerc, Patrick Lévêque
Organic Electronics, 2022, 107, pp.106549. ⟨10.1016/j.orgel.2022.106549⟩ | Publiée le 1 août 2022
Article dans une revue

Abstract

The use of Non-Fullerene Acceptors (NFAs) in the active layer of organic solar cells (OSCs) has made it possible to exceed 18% conversion efficiency. However, OSCs still present stability issues under operational conditions that need to be surpassed for their industrialization. In this work, we investigated binary and ternary blends to examine their efficiency and their stability as active layers of OSCs. We used a fluorinated polymer (PF2) as an electron donor and two different electron acceptors, a fullerene derivative (PC 71 BM) and a NFA (EH-IDTBR). We demonstrated that using EH-IDTBR instead of PC 71 BM leads to a decrease in efficiency attributed to the low out-of-plane electron mobility measured in the blend. However, using EH-IDTBR as single electron-acceptor significantly enhanced the OSCs stability under continuous illumination. Ternary blends were tested to reach simultaneously a high efficiency and a long-term stability. The best efficiency/stability compromise appeared to be when using EH-IDTBR only as electron-acceptor. We identified changes in the main charge-carrier recombination mechanism in photo-degraded devices from bimolecular in low EH-IDTBR content blends to trap-assisted in high EH-IDTBR ones. Finally, the blend morphology at a nanometer scale appeared as stable in high EH-IDTBR content blends while photo-degradation impacted significantly the morphology of the low EH-IDTBR content blend.

Détermination de la teneur des polluants organiques et des métaux lourds dans les poissons provenant des baies de la côte de Dakar (Soumbédioune et Hann)

Cheikh Tidiane Dione
Chimie analytique. Université de Strasbourg; Université Cheikh Anta Diop (Dakar, Sénégal ; 1957-..), 2022. Français. ⟨NNT : 2022STRAF042⟩ | Publiée le 23 juillet 2022
Thèse

Abstract

Dans ce travail, nous nous sommes proposés d’étudier la contamination, de certaines espèces de poissons provenant des côtes de la région de la Dakar, par les métaux lourds et les polluants organiques (pesticides, PCBs et HAPs). Les échantillons de poissons sont prélevés entre 2018 et 2021 dans les sites de Hann et de Soumbédioune, qui abritent des canaux d’évacuation, des eaux usées, traversant une bonne partie de la ville. Ces sites ont été choisis à cause des activités qui s’y déroulent. Les espèces de poissons collectées dans ces deux sites sont côtières et commercialisées. Les ETM ont été dosés par la spectrophotométrie à l’aide du photomètre PF-11. Une méthode basée sur l'extraction QuEChERS et la chromatographie gazeuse couplée à la spectrométrie de masse (GC/MSMS) a été développée pour la détermination des polluants organiques. La méthode développée présente de bons taux de récupération, une bonne précision, une bonne sensibilité et une bonne linéarité. Elle présente une bonne répétabilité et une reproductibilité. Les teneurs en métaux trouvées dans les deux sites sont nettement inférieures aux normes établies par la FAO et la CEE. Cependant les teneurs en pesticides dépassent largement la LMR (EC, 2018) dans les aliments. De même, les concentrations des HAPs et des PCBs sont supérieures aux limites, admises, définies par l'Union Européenne (UE) (30μg.Kg-1). Ainsi la présence de ces composés, dans ces espèces, pourrait être associée aux facteurs biotiques et anthropiques. Cela peut être dû à leurs habitats spécifiques et leurs habitudes alimentaires. Il faut noter que les POPs peuvent rester pendant de longues périodes dans les milieux aquatiques, être transférés dans les chaînes alimentaires, s’accumuler dans les organes des poissons et enfin atteindre les consommateurs. Cette étude a montré la présence des polluants organiques persistants et de métaux lourds dans les poissons provenant des sites de Hann et de Soumbédioune. Elle prouve aussi le danger réel que présente cette partie du littoral dakarois qui est constitué de zones utilisées pour la pêche et le débarquement de produits halieutiques.

Chemical design of high performance SPR biosensor based on a dielectric nanoparticle assembly supported onto a gold thin film

Pier Berling, Mathias Dolci, Spyridon Zafeiratos, Thomas Gehin, Cédric Leuvrey, Céline Kiefer, Déborah Wagner, Fouzia Boulmedais, Benoit P Pichon
Sensors & Diagnostics, 2022, 1, pp.1069 - 1079. ⟨10.1039/d2sd00069e⟩ | Publiée le 19 juillet 2022
Article dans une revue

Abstract

The SPR system is a very efficient tool to investigate original and highly efficient biosensors and to study molecular recognition mechanisms. We report on the design of an original nano-architecture which consists of iron oxide nanoparticle assemblies supported on gold thin films and which acts as a very efficient SPR sensor. The build-up of the sensor consists of a three-step CuAAC "click" reaction process which allows the selective and easy preparation of a robust platform. Iron oxide nanoparticles allow the label-free detection of targeted proteins thanks to their high sensitivity to slight variations in the refractive index in the vicinity of the SPR sensor surface. We investigated the very well-known biotin/streptavidin couple in order to study the selectivity of biomolecular binding of our sensor platform. The nonspecific adsorption of proteins was suppressed by using oligo ethylene oxide (EO) chains. A study of the kinetics revealed the remarkably low limit of detection (down to 1.1 nM) which is ascribed to the enhanced accessibility of biotin groups and to the biotin/SA affinity (2.45 × 10 7 M). Indeed, the high radius of curvature of the nanoparticles avoids steric hindrance of the biotin groups and the flexibility of the EO linkers favors their mobility in an aqueous medium. An optimized sensing platform was built by taking advantage of the adequate surface functionalization of iron oxide nanoparticle assemblies supported on a gold thin film. Sens. Diagn.

Sterically Hindered 2‐(2’‐Hydroxyphenyl)benzoxazole (HBO) Emitters: Synthesis, Spectroscopic Studies, and Theoretical Calculations

Timothée Stoerkler, Thibault Pariat, Adèle Laurent, Denis Jacquemin, Gilles Ulrich, Julien Massue
European Journal of Organic Chemistry, 2022, 2022 (30), pp.e202200661. ⟨10.1002/ejoc.202200661⟩ | Publiée le 12 juillet 2022
Article dans une revue

Abstract

We describe various synthetic pathways to introduce sterically hindered substituents (mesityl, 2,4,6-triisopropylphenyl, anthracene) to the proton donor side of excited-state intramolecular proton transfer (ESIPT)-capable 2-(2’-hydroxyphenyl) benzoxazole (HBO) fluorophores. Two original synthetic approaches were investigated in order to synthesize seven HBO derivatives. Optimization studies concluded that electron rich and bulky phosphine ligands are required to ensure completion of the Suzuki-Miyaura cross-coupling reaction involving a bulky aromatic boronic acid. The photophysical properties of all dyes revealed a strong influence of the nature of the solvent on the optical properties, as protic solvents tend to stabilize enol tautomers and induce dual emission. Our studies confirmed that, unlike the majority of organic dyes, ESIPT fluorophores do not undergo π-stacking in the solid-state. The nature of the excited-states was explored by ab initio calculations.

Endogeic earthworms facing pesticide residues in agricultural landscapes: bioaccumulation and population risk assessment

Audrey Barranger, Romain Georges, Olivier Delhomme, Maurice Millet, Florent Lafay, Emmanuelle Vulliet, Gaëlle Daniele, Françoise Binet
12th International Symposium on Earthworm Ecology, Jul 2022, Rennes, France | Publiée le 10 juillet 2022
Poster de conférence

33% PCE enhancement in Organic Solar Cells integrating Silver Nanowire Electrodes

Issoufou Ibrahim Zamkoye, Johann Bouclé, Nicolas Leclerc, Bruno Lucas, Sylvain Vedraine
15th International Symposium on Flexible Organic Electronics (ISFOE22), Jul 2022, Thessaloniki, Greece | Publiée le 4 juillet 2022
Communication dans un congrès

Optimization of the continuous coprecipitation in a microfluidic reactor: Cu-based catalysts for CO2 hydrogenation into methanol

Valentin l'Hospital, Svetlana Heyte, Sébastien Paul, Ksenia Parkhomenko, Anne-Cécile Roger
Fuel, 2022, 319, pp.123689. ⟨10.1016/j.fuel.2022.123689⟩ | Publiée le 1 juillet 2022
Article dans une revue

Investigation of the stability of the boron-doped diamond support for Co3O4-based oxygen evolution reaction catalysts synthesized through in situ autocombustion method

Gwénaëlle Kéranguéven, Ivan Filimonenkov, Elena Savinova
Journal of Electroanalytical Chemistry, 2022, 916, pp.116367. ⟨10.1016/j.jelechem.2022.116367⟩ | Publiée le 1 juillet 2022
Article dans une revue

Abstract

In this work we studied the anodic stability of nanostructured Boron-Doped Diamond (BDD) in view of its eventual utilisation as support for metal oxide–carbon composites prepared by the In Situ Autocombustion (ISAC) method. The anodic behaviour of the BDD was investigated by the rotating ring-disc electrode (RRDE) method in 1 M NaOH electrolyte to determine its corrosion current and compare the latter with that of the commercial Vulcan XC-72 carbon from Cabot and Sibunit pyrolytic carbon, the latter known for its high stability against electrochemical corrosion. The BDD has proven to be significantly more stable than either the Sibunit or the Vulcan carbon. The Co3O4-BDD and Co3O4-Sibunit composites prepared by the ISAC method were then tested as catalysts of the oxygen evolution reaction (OER). The Co3O4-BDD composites appear to be competitive electrocatalysts for the OER in alkaline medium, showing activity comparable to the literature and much higher support stability towards oxidation. Further research is required to decrease the size of Co3O4 spinel nanoparticles and improve their distribution over the BDD support and hence increase the mass-specific OER activity of the BDD-based ISAC composites.

Eco‐Friendly Needleless Electrospinning and Tannic Acid Functionalization of Polyurethane Nanofibers with Tunable Wettability and Mechanical Performances

Andrea Dodero, Maila Castellano, Silvia Vicini, Anne Hébraud, Emeline Lobry, Jean Mario Nhut, Guy Schlatter
Macromolecular Materials and Engineering, 2022, 307 (6), ⟨10.1002/mame.202100823⟩ | Publiée le 28 juin 2022
Article dans une revue

Abstract

Electrospinning is the leading process allowing the fabrication of polymeric nanofibrous membranes and mats. Unfortunately, it generally requires the solubilization of the polymer in a toxic solvent causing health and environmental issues during the production. Here, it is demonstrated that polyurethane (PU) fibrous membranes can be produced by electrospinning and then, moreover, functionalized using water as the only solvent for each processing step. Waterborne polyurethane in the form of a dispersion is firstly electrospun using poly(ethylene oxide) (PEO) as template polymer. After removing PEO via a washing cycle in water, the membranes show physico-chemical properties influenced by the initial polymeric component ratio with greater mechanical performances and hydrophobicity observed at a higher PU amount. Aqueous solutions of bio-based tannic acid (TA) are then employed to modify the surface properties of the membranes. The high amount of galloyl units per TA molecule allows its efficient anchoring on the fiber surface through supramolecular hydrogen bonding. By varying the TA amount and the order of washing cycle, the wettability can be tuned expanding the application range of the membranes. Finally, their efficient electrospinning at high flow-rate using a home-made needleless emitter paves the way for industrial production via full environmentally green processing.

para-Azaquinodimethane based quinoidal polymers for opto-electronic applications: Impact of donor units on opto-electronic properties

Bharath Dyaga, Sasikumar Mayarambakam, Olzhas A Ibraikulov, Nicolas Zimmermann, Sadiara Fall, Olivier Boyron, Thomas Heiser, Nicolas Leclerc, Nicolas Berton, Bruno Schmaltz
Materials Advances, 2022 | Publiée le 22 juin 2022
Article dans une revue

Abstract

para-azaquinodimethane (p-AQM) based quinoidal-donor (Q-D) alternating copolymers offer a unique opportunity to investigate the properties of quinoidal polymers. It was however reported that the bandgap increases with increasing number of donor aryl units, as a result of a weakening of the quinoidal character in the polymer backbone. To overcome this issue, herein two new polymers were designed and synthesized by incorporating fused donor (PAQM2T-TT) and vinylene linker (PAQM2T-TVT) units, following a strategy of enhanced backbone planarity. The thiophene-containing polymers PAQM3T and PAQM4T were also synthesized for better understanding of the influence of structural variations. Thus, in comparison with PAQM3T and PAQM4T, PAQM2T-TT and PAQM2T-TVT exhibited slight red shift in spite of having more extended donor units, which is consistent with enhanced planarity and quinoidal character as suggested by DFT calculations. It is also found that the different donor units have a limited impact on the HOMO energy level of the p-AQM copolymers. Transport properties are measured by field effect transistors, and the photovoltaic properties of these p-AQM based polymers are reported for the first time, as electron donor materials in inverted configuration devices. PAQM2T-TVT containing thiophene vinylene thiophene comonomer exhibits planar structure leading to a hole mobility of 3.8×10-2 cm-2 V s-1. When combined with a fullerene acceptor in solar cells, PAQM2T-TVT polymer exhibited a highest PCE of 2.32%.

Examination of C12A7 electride work function and surface composition by means of XPS, UPS and thermionic emission measurements

Antonio Gurciullo, Vasiliki Papaefthimiou, Paul Lascombes, Stéphane Mazouffre, Fabian Plaza, Angel Post
37th International Electric Propulsion Conference, Jun 2022, Cambridge, United States | Publiée le 19 juin 2022
Communication dans un congrès

Abstract

The work functions of LaB6 and C12A7:e-samples have been estimated by thermionic emission measurements and compared with ultraviolet photoelectron spectroscopy (UPS) data. In addition to this, the surface composition of the samples is characterized by X-ray photoelectron spectroscopy (XPS). Consistent work function values of 3.2-3.3 eV have been measured for clean LaB6 samples. A wider range of values has been measured with the C12A7:e-sample, where a work function of 2.4-2.8 eV and 3.2 eV is estimated when using a setup for thermionic emission and UPS, respectively.

The use of industrial molasses waste in the performant synthesis of fewlayer graphene (and its Au/Ag nanoparticles nanocomposites): Photocatalytic and supercapacitance applications

Kamel Shoueir, Anurag Mohanty, Izabela Janowska
Journal of Cleaner Production, 2022 | Publiée le 1 juin 2022
Article dans une revue

Abstract

In view of clean environment, the industry needs to address multiple demands at different levels of production and processes via the sustainable approach including recycling or smart use of produced waste. On the other hand, a development and success of green energy requires the crucial materials synthesized via efficient, sustainable methodology. Herein, we present the green, simple, easily scalable, fast, and highly efficient synthesis of few-layer graphene (FLG) and its composites with Au and Ag nanoparticles using a waste. The FLG synthesis based on the exfoliation of graphite occurs in water in the presence of industrial co-product, molasses, which next shows also performant reductive properties during Ag and Au NPs formation. The decreased size of NPs deposited on FLG indicates the synergetic effect of molasses and FLG, exhibiting the add role of FLG/molasses as metal stabilizer species. The NPs/FLG composites 2 are efficient photocatalysts in degradation of organic contaminant, bisphenol (BisA), in the presence of peroxy-monosulfate (PMS) activator. The Au/FLG (PVDF) and Ag/FLG (PVDF) based electrodes reveal as well relatively high gravimetric capacitance, 205 Fg-1 and 729 Fg-1. The presented approach is much worthy to be further applied in the synthesis of other layered materials as well as other non-noble supported metallic systems.

Engineering catalytic dephosphorylation reaction for endotoxin inactivation

Meng Gao, Xi Liu, Zhenzhen Wang, Hui Wang, Tristan Asset, Di Wu, Jun Jiang, Qianqian Xie, Shujuan Xu, Xiaoming Cai, Jia Li, Weili Wang, Huizhen Zheng, Xingfa Gao, Nikolai Tarasenko, Benjamin Rotonnelli, Jean-Jacques Gallet, Frédéric Jaouen, Ruibin Li
Nano Today, 2022, 44, pp.101456. ⟨10.1016/j.nantod.2022.101456⟩ | Publiée le 1 juin 2022
Article dans une revue

Abstract

Although lives have been saved due to the discovery of endotoxin removal methods including solvent extraction and affinity adsorption, they have limitations in treatment capacity, efficiency or costs. Endotoxin contaminations still result in a large number of deaths in global every year. This necessitates a mechanistic breakthrough for endotoxin removal or inactivation. Herein, we engineered a dephosphorylation reaction on endotoxins by a synthetic nanozyme (CeO2) to attenuate the toxicity. CeO2 prepared in phosphate-free hydrothermal reaction selectively and efficiently catalyzed the breaking of P-O bonds in endotoxins. Catalytic depletion of phosphates from endotoxins attenuated their binding with Toll-like receptors, NF-κB activation and pro-inflammatory cytokine release. Airborne LPS was, for the first time, inactivated (98%) by this facile dephosphorylation reaction. A CeO2 integrating column displayed a 16-fold higher treatment capacity than commercial resins to aqueous endotoxins (water and protein solution). Overall, our findings offer a different mechanistic insight for removal of endotoxins.

Self-activated Photovoltaic Liquid Crystal Light Modulators

Yaochen Lin, Sadiara Fall, Nicolas Brouckaert, Nina Podoliak, Malgosia Kaczmarek, Giampaolo D’alessandro, Nicolas Leclerc, Thomas Heiser
International Workshop on Emerging Solar Energy Materials and Applications, May 2022, Porquerolles, France | Publiée le 30 mai 2022
Communication dans un congrès

MOF side chains as sources of supramolecular interactions: organic pollutant extraction from water

Nizami Israfilov, Karel Soukup, Benoit Louis, Jean-Marc Planeix
New Journal of Chemistry, 2022, 46 (19), pp.8967-8970. ⟨10.1039/D2NJ00273F⟩ | Publiée le 16 mai 2022
Article dans une revue

Abstract

Polyethylene glycol-modified terphenyl tetracarboxylic ligands were used for the preparation of copper-based MOFs: SUM-102 and SUM-103. The influence of side chains on the stability and adsorption capacities was investigated. Compared to the simpler analogue-NOTT-101, these MOFs, in particular SUM-103, exhibit high stability in water. Also, side chains do not affect the thermostability. The extraction capacity of organic cationic and anionic dyes was demonstrated by adsorption experiments carried out in water. SUM-103 showed a high Langmuir adsorption capacity of methylene blue in an aqueous solution (194 ± 4 mg g−1 at 30 °C).

Fe-N-C catalysts toward electrocatalytic oxygen reduction reaction

Xiong Zhang
Other. Université de Strasbourg, 2022. English. ⟨NNT : 2022STRAF014⟩ | Publiée le 13 mai 2022
Thèse

Abstract

Fe-N-C electrocatalyst is becoming a challenging research topic with great expectations for the next-generation energy devices due to its high intrinsic ORR activity comparable to platinum group metals (PGM) electrocatalyst. However, a high effective preparation strategy with improved catalytic performance and high robustness, employing noncritical components is of great importance for the development of Fe-N-C electrocatalyst, and the identification nature of active site for pyrolytic Fe-N-C material is still a topic of heated debate due to potential presence of multiple active sites.In this work we developed catalysts with N-decorated single atom Fe catalysts in porous carbon by high temperature pyrolysis using cost-effective, non-toxic raw components. Systematic variation of composition of N, and C precursors and various structuring agents, as well as conditions of different steps allowed us to determine the optimal parameters for a multi-step synthesis. Various characteristic technologies, including TGA/TPD-MS, Raman, BET, XRD, XPS, HAADF-STEM and XAS have been applied to study the composition and structure of synthesized Fe-N-C catalysts. The electrocatalytic performance of the catalysts were studied by (R)RDE measurements and accelerated durability tests. This study allowed us to demonstrate that Fe-N-C electrocatalysts with optimized structure and composition provide stable 4e- oxygen electroreduction performance in 0.1 M KOH electrolyte with activity outperforming benchmark 20% Pt/C catalysts. Most importantly, the nature of active sites and structure-performance correlation of as-obtained electrocatalysts are systematically investigated. The work aims to provide fundamental understanding of Fe-N-C catalyst from both material design and natura of active sites which is believed to favor the development of next generation electrocatalyst for fuel cell technology.

How Halogenation Impacts the Polymer Backbone Conformation: Learning from Combination of Solid-state MAS NMR and X-Ray Scattering

Théodore Olla, Ribal Jabbour, Amina Labiod, Olivier Boyron, Stéphane Méry, Benoit Heinrich, Thomas Heiser, Denis Jacquemin, Patrick Lévêque, Anne Lesage, Nicolas Leclerc
Advanced Functional Materials, 2022, ⟨10.1002/adfm.202204929⟩ | Publiée le 12 mai 2022
Article dans une revue

Abstract

Over the last decade, halogenated semiconducting polymers have attracted considerable interest due to their outstanding optoelectronic properties. Thus, most today's OPV benchmark organic semiconductors are halogenated materials, either electron donor polymers or non-fullerene acceptor (NFA) small molecules. However, the nature and position of the substituted halogen atoms in halogenated semiconducting polymers impact, through self-assembly modification, on their optoelectronic properties in a way which is 2 difficult to predict. Yet, the solid-state self-assembling of this materials has been shown to be a key parameter towards high charge transport properties and photovoltaic efficiencies. In this context, there is still a need to develop analytical methods that will enable an atomicscale structural characterization of these materials as function of the halogenation. In this manuscript, we explore the solid-state nuclear magnetic resonance (NMR) under magic angle spinning (MAS) as a tool to investigate the local structure and supramolecular organization of a series of conjugated polymers, specially designed for this study. Through a comprehensive study using complementary techniques including MAS-NMR, small and wideangle X-ray scattering (SWAXS) and molecular modelling investigations, we have definitely succeeded in determining the molecular conformation of these polymers in relation to their chemical composition.

Hetero-substituted αβ-fused BODIPY

Fabien Ceugniet, Quentin Huaulmé, Alexandra Sutter, Denis Jacquemin, Nicolas Leclerc, Gilles Ulrich
Chemistry - A European Journal, 2022, ⟨10.1002/chem.202200130⟩ | Publiée le 2 mai 2022
Article dans une revue

Abstract

Here we report the synthesis and properties of heterosubtituted αβfused BODIPY fluorophores. The compounds were obtained in good yields by sequential and selective Stille cross-coupling reactions from 2,3,5,6-tetrahalo-BODIPY, allowing the introduction of different subtituents at the 3,5 and 2,6 positions of the BODIPY ring. The final fused compounds were synthesized using oxidative cyclisation with ferrous chloride. The fully fused compounds show a strong bathochromically shifted emission along with a hyperchromic shift of the absorption maxima. The fluorescence quantum yields remain relatively large for compounds emitting in this wavelength range. Computational studies are planned to fully understand the photophysical behaviors of these dyes.

Long-Term Anxiety-like Behavior and Microbiota Changes Induced in Mice by Sublethal Doses of Acute Sarin Surrogate Exposure

Sabine François, Stanislas Mondot, Quentin Gerard, Rosalie Bel, Julie Knoertzer, Asma Berriche, Sophie Cavallero, Rachid Baati, Cyrille Orset, Gregory Dal Bo, Karine Thibault
Biomedicines, 2022, 10 (5), pp.1-21. ⟨10.3390/biomedicines10051167⟩ | Publiée le 1 mai 2022
Article dans une revue

Abstract

Anxiety disorder is one of the most reported complications following organophosphorus (OP) nerve agent (NA) exposure. The goal of this study was to characterize the long-term behavioral impact of a single low dose exposure to 4-nitrophenyl isopropyl methylphosphonate (NIMP), a sarin surrogate. We chose two different sublethal doses of NIMP, each corresponding to a fraction of the median lethal dose (one mild and one convulsive), and evaluated behavioral changes over a 6-month period following exposure. Mice exposed to both doses showed anxious behavior which persisted for six-months post-exposure. A longitudinal magnetic resonance imaging examination did not reveal any anatomical changes in the amygdala throughout the 6-month period. While no cholinesterase activity change or neuroinflammation could be observed at the latest timepoint in the amygdala of NIMP-exposed mice, important modifications in white blood cell counts were noted, reflecting a perturbation of the systemic immune system. Furthermore, intestinal inflammation and microbiota changes were observed at 6-months in NIMP-exposed animals regardless of the dose received. This is the first study to identify long-term behavioral impairment, systemic homeostasis disorganization and gut microbiota alterations following OP sublethal exposure. Our findings highlight the importance of long-term care for victims of NA exposure, even in asymptomatic cases.

Photovoltaic spatial light modulators for self-powered smart windows

Yuhan Zhong, Jing Wang, Sadiara Fall, Yaochen Lin, Nicolas Brouckaert, Chaima Mahmoudi, Wenziz Muzuzu, Nicolas Leclerc, Malgosia Kaczmarek, Martin Brinkmann, Thomas Heiser
Organic Electronics and Photonics: fundamentals and devices III - SPIE Photonics Europe, May 2022, Strasbourg, France | Publiée le 1 mai 2022
Communication dans un congrès

Poly(imidazolium) ionomers influence on the hydrogen evolution and oxidation reaction

Tristan Asset, Kate Fraser, Elena R. Savinova, Steven Holdcroft
2nd Meeting of the CNRS French Hydrogen Federation, May 2022, Aussois, France | Publiée le 1 mai 2022
Communication dans un congrès

Near-infrared Responsive Nanocomposite Hydrogels Made from Enzyme-Coated Carbon Nanotubes@ Large Pore Mesoporous Silica for Remotely Triggered Drug Delivery

Bing Li, Alexandre Adam, Miryam Criado-Gonzalez, Loïc Jierry, Joëlle Bizeau, Alain Chaumont, Sebastien Harlepp, Christophe Mélart, Sylvie Begin-Colin, Dominique Begin, Damien Mertz
Materialia, 2022, 22, pp.101414. ⟨10.1016/j.mtla.2022.101414⟩ | Publiée le 1 mai 2022
Article dans une revue

Abstract

The design of smart nanocomposite supramolecular scaffolds for tissue engineering or anticancer applications, able to release drugs under external fields is currently a challenge. Such architectures require not only strong interactions between the polymer matrix and externally responsive nanomaterials, but also an efficient strategy for the loading and release of drugs. Herein, we address an original approach to trigger the self-assembly of peptide hydrogel from enzyme-coated carbon-based nanocomposites which act as initiators and cross-linking points of the resulting nanocomposite hydrogel. Carbon nanotubes (CNTs), chosen given their photothermal behavior under near infrared (NIR) light, were coated with large pore (&gt; 10 nm) mesoporous silica (CNT@LPMS) which are very suitable for a high loading of enzymes. Then, based on an original isobutyramide (IBAM)-mediated coating, a huge amount of alkaline phosphatase (AP) (&gt; 100% wt) was immobilized within the large pores allowing the localized growth of peptide nanofibrous network resulting in supramolecular hydrogel. The incorporation of Doxorubicin (DOX) during the hydrogelation process leads to a reservoir material of anti-cancer agents whose release is photothermally triggered by the NIR light-induced hyperthermia temperature. Combination of rheological studies and molecular simulations indicate an original mechanism in which DOX is included within the peptide nanofibers.

Diabetic kidney disease versus non‐diabetic kidney disease in type 2 diabetic patients on dialysis: An observational cohort

Arnaud Delautre, Thierry Hannedouche, Cécile Couchoud, José Guiserix, Damiano Cerasuolo, François Chantrel, Jonas Martzloff, Nicolas Keller, Thierry Krummel
Endocrinology, Diabetes & Metabolism, 2022, 5 (4), ⟨10.1002/edm2.281⟩ | Publiée le 30 avril 2022
Article dans une revue

Abstract

Abstract Background All chronic kidney diseases in diabetic patients are not diabetic kidney diseases. The objective was to compare the clinical characteristics, survival and access to transplantation in diabetic patients starting dialysis and classified either as diabetic kidney disease (DKD) or non‐diabetic kidney disease in diabetic patients (NDKD). Methods We used the nationwide French REIN registry to analyse baseline clinical characteristics at dialysis inception and outcomes defined as kidney transplantation, deaths and their causes. The probability of death or transplantation was analysed using a multivariate Cox model and the Fine and Gray competing for risk model (sdHT). Results We included 65,136 patients from January 2009 to December 2015 with a median follow‐up of 31 months. The cumulative incidence of kidney transplantation over eight years was 46.9% (44.8–48.9) in non‐diabetic patients (ND), higher than the 19.3% (17.5–21.2) in the DKD group and 22.2% (18.4–26.7) in the NDKD group. The risk of death was significantly higher in the NDKD group than in the DKD group, even after accounting for the competing risk of transplantation (NDKD/sdHR 1.22; 95%CI 1.18–1.27; p < 0.005 vs. DKD/sdHR 1.12; 95%CI 1.08–1.16; p < 0.005 with adjustment for age, sex, major adverse cardiovascular events, cancer and chronic respiratory failure, compared to ND). Conclusions In diabetic patients starting dialysis, patients in the DKD group had reduced access to kidney transplantation. NDKD patients had a higher risk of mortality than DKD. The distinction between DKD and NDKD should be accounted for in the plan of care of diabetic patients starting dialysis.

Redox Transitions in Pseudocapacitor Materials: Criteria and Ruling Factors

Sergey N. Pronkin, Nina Yu. Shokina, Cuong Pham-Huu
Redox Chemistry - From Molecules to Energy Storage [Working Title], IntechOpen, 2022, ⟨10.5772/intechopen.104084⟩ | Publiée le 23 avril 2022
Chapitre d'ouvrage

Abstract

Pseudocapacitance is a phenomenon of charge storage involving redox transitions at the electrode/electrolyte interface. As the result of an electrode potential modulation, one or few components of the electrode and/or electrolyte change its/their oxidation states. The redox reaction may be confined to the interface or propagate into the bulk of the electrode material, thus significantly increasing the charge (and energy) capacitance of the material. The rate and the reversibility of the interfacial redox reaction are the key factors determining the efficiency of charge storage due to pseudocapacitance phenomena. The influence of the characteristics of the interfacial redox reaction on the efficiency of charge storage in pseudocapacitive materials is considered in the current chapter. In particular, the similarities and the differences between the charge storage in batteries and pseudocapacitors are discussed. The analysis of the pseudocapacitive behavior of electrode material using the impedance spectroscopy is presented.

Thermocatalytic Hydrogenation of CO2 to Methanol Using Cu-ZnO Bimetallic Catalysts Supported on Metal–Organic Frameworks

Zama G Duma, Xoliswa Dyosiba, John Moma, Henrietta W Langmi, Benoit Louis, Ksenia Parkhomenko, Nicholas M Musyoka
Catalysts, 2022, 12 (4), ⟨10.3390/catal12040401⟩ | Publiée le 5 avril 2022
Article dans une revue

Abstract

The thermocatalytic hydrogenation of carbon dioxide (CO2) to methanol is considered as a potential route for green hydrogen storage as well as a mean for utilizing captured CO2, owing to the many established applications of methanol. Copper–zinc bimetallic catalysts supported on a zirconium-based UiO-66 metal–organic framework (MOF) were prepared via slurry phase impregnation and benchmarked against the promoted, co-precipitated, conventional ternary CuO/ZnO/Al2O3 (CZA) catalyst for the thermocatalytic hydrogenation of CO2 to methanol. A decrease in crystallinity and specific surface area of the UiO-66 support was observed using X-ray diffraction and N2-sorption isotherms, whereas hydrogen-temperature-programmed reduction and X-ray photoelectron spectroscopy revealed the presence of copper active sites after impregnation and thermal activation. Other characterisation techniques such as scanning electron microscopy, transmission electron microscopy, and thermogravimetric analysis were employed to assess the physicochemical properties of the resulting catalysts. The UiO-66 (Zr) MOF-supported catalyst exhibited a good CO2 conversion of 27 and 16% selectivity towards methanol, whereas the magnesium-promoted CZA catalyst had a CO2 conversion of 31% and methanol selectivity of 24%. The prepared catalysts performed similarly to a CZA commercial catalyst which exhibited a CO2 conversion and methanol selectivity of 30 and 15%. The study demonstrates the prospective use of Cu-Zn bimetallic catalysts supported on MOFs for direct CO2 hydrogenation to produce green methanol.

Exciton lifetime in donor-acceptor-donor planar dumbbell-shaped triazatruxene-thienopyrroledione derivatives

Jiang Jing, Émilie Steveler, Nicolas Leclerc, Anthony d'Aléo, Benoit Heinrich, Wilfried Uhring, Thomas Heiser
2022 SPIE Photonics Europe, Apr 2022, Strasbourg, France. pp.1214904, ⟨10.1117/12.2615963⟩ | Publiée le 3 avril 2022
Communication dans un congrès

Abstract

Organic semiconductor materials such as planar conjugated small molecules are of great interest to the photovoltaic community. In thin films, the exciton and charge carrier dynamics, which are crucial to photovoltaic device operation, depend in a non-trivial way on the organic molecular structure and on the molecular organization in the solid state. Recently, the exciton diffusion has been found to strongly depend on the crystalline order of the organic thin films. This work presents the study of the exciton lifetime in an innovative class of molecular semiconductors able to present different crystalline order. This family of molecules has a “dumbbell-shaped” structure based on triazatruxene units that act as a π-stacking platform. Such molecules with different side-chains have been found to self-assemble into various crystalline and liquid crystalline phases. We have studied the steady-state photoluminescence and the exciton lifetime for several triazatruxene-based derivatives with different side-chains, in solution and in thin films for different solid state phases. In solution, the fluorescence lifetime corresponds to the reference value that can be obtained without intermolecular interaction. In thin films, we measured the exciton lifetime for different molecular structures in order to correlate the exciton dynamics with the molecular stacking. The results reveal a significant increase in the exciton lifetime with the enhancement of the structural order.

Direct borohydride fuel cells: A selected review of their reaction mechanisms, electrocatalysts, and influence of operating parameters on their performance

Alexandr Oshchepkov, Antoine Bonnefont, Gaël Maranzana, Elena R Savinova, Marian Chatenet
Current Opinion in Electrochemistry, 2022, 32, pp.100883. ⟨10.1016/j.coelec.2021.100883⟩ | Publiée le 1 avril 2022
Article dans une revue

Abstract

Direct borohydride fuel cells (DBFC) oxidize an easily-stored energy-dense borohydride fuel (sodium borohydride: NaBH4), that in theory reacts ca. 400 mV below H2 and produce 8 electrons per BH4anion. However, the borohydride oxidation reaction (BOR) does not fully meet these promises in practice: the electrocatalyst nature, structure and state-of-surface, and the operating conditions (pH, BH4concentration, temperature, fluxes) noticeably influence the BOR kinetics and mechanism. Nickel and platinum-based catalysts both have assets for the BOR. DBFCs can only yield decent performance if their separator combines high ionconductivity and efficient separation of the reactants; cation-exchange membranes, anionexchange membranes, bipolar membranes and porous separators all have their own advantages and drawbacks. Besides the anode, the choice of separator must consider the DBFC cathode reaction, where oxygen (air) or hydrogen peroxide are reduced, provided adapted catalysts are used. All these aspects drive the DBFC performance and stability/durability.

Surface oxidation of Ni-cermet electrodes by CO2 and H2O and how to moderate it

Dingkai Chen, Mathias Barreau, Thierry Dintzer, Sylwia Turczyniak-Surdacka, Fabrice Bournel, Jean-Jacques Gallet, Spyridon Zafeiratos
Journal of Energy Chemistry, 2022, 67, pp.300-308. ⟨10.1016/j.jechem.2021.10.002⟩ | Publiée le 1 avril 2022
Article dans une revue

Abstract

The oxidation of porous Ni-yttria-stabilized zirconia (YSZ) and Ni-gadolinia-doped ceria (GDC) ceramic-metal (cermet) electrodes in H2O and CO2 atmospheres was studied by near-ambient pressure X-ray photoelectron spectroscopy (NAP-XPS). We show that the oxidation of nickel by the two gases is not similar, as is commonly believed, but it depends on the ceramic type. Nickel is vulnerable to oxidation in H2O but it resists to CO2 in Ni-GDC, as compared to the Ni-YSZ electrode. Inspired by this observation we conceptualize and fabricate Ni-YSZ electrodes modified by ceria nanoparticles, which show significantly higher resistance to CO2 oxidation as compared with conventional Ni-YSZ electrodes. The preparation of tailor-made cermet electrodes with identical bulk/mechanical characteristics but very different surface properties offers a promising fabrication strategy for high-performance and durability solid oxide electrolysis cells for CO2 conversion.

Diazine-based thermally activated delayed fluorescence chromophores

Sylvain Achelle, Maxime Hodée, Julien Massue, Arnaud Fihey, Claudine Katan
Dyes and Pigments, 2022, 200, pp.110157. ⟨10.1016/j.dyepig.2022.110157⟩ | Publiée le 1 avril 2022
Article dans une revue

Abstract

Diazines are electron deficient six-membered aromatic rings heterocycles which have successfully been employed in the design of a wide range of push-pull chromophores for various applications in the field of organic electronics and optoelectronics. For instance, some have been specifically designed to be inserted in the electroluminescent emission layer of organic light emitting diodes (OLED). OLED technology has continuously evolved and is currently used in industry for display and lighting purposes, offering many advantages including low turn-on voltage and power consumption. In the prospect to further reduce energy waste, a third generation of OLED based on thermally activated delayed fluorescence (TADF), which allows harvesting both triplet and singlet excitons, attracts increasing attention from the scientific community. In this review, we provide a comprehensive overview of the present status of diazine-based dyes developed for TADF. The pyrimidine core is by far the most used and has demonstrated deep blue, blue or sky-blue and green emission when combined with carbazole, acridan and phenoxazine fragments, respectively. Further design of TADF emitters is desirable to afford red OLED and both the pyrazine and pyridazine cores have been scarcely explored.

Development of a Portable and Modular Gas Generator: Application to Formaldehyde Analysis

Anaïs Becker, Nathaly Lohmann, Christophe Serra, Stéphane Le Calvé
Chemosensors, 2022, ⟨10.3390/chemosensors10040131⟩ | Publiée le 31 mars 2022
Article dans une revue

The use of pseudo‐MRM for a sensitive and selective detection and quantification of polycyclic aromatic compounds by tandem mass spectrometry

Mathieu Galmiche, Anaïs Rodrigues, Estelle Motsch, Olivier Delhomme, Yannis‐nicolas François, Maurice Millet
Rapid Communications in Mass Spectrometry, 2022, 36 (13), ⟨10.1002/rcm.9307⟩ | Publiée le 30 mars 2022
Article dans une revue

Abstract

Rationale: Multiple Reaction Monitoring (MRM) is a sensitive and selective detection mode for target trace-level analysis. However, it requires the fragmentation of labile bonds which are not present in molecules such as Polycyclic Aromatic Hydrocarbons (PAHs) and their heterocyclic derivatives (PANHs, PASHs). Methods: We present the application of an alternative tandem mass spectrometry (MS/MS) mode called "pseudo-MRM" for the GCMS/MS analysis of Polycyclic Aromatic Compounds (PACs). This mode is based on the monitoring of transitions with no mass loss between the precursor and the product ion. Pseudo-MRM peak areas were compared with those of classic MRM on three different mass spectrometers: two triple quadrupoles and an ion trap. Results: For all non-polar PACs studied here (PAHs, PANHs and PASHs), the pseudo-MRM transition was always the most intense. The classic MRM transitions exhibited peak areas 2 to 5 times lower. On the contrary, for the functionalized PACs (oxygenated and nitrated PAHs), classic MRM was favored over pseudo-MRM. These observations were confirmed on two triple quadrupoles (QqQs), and the real-world applicability of pseudo-MRM on QqQs was validated by the successful analysis of Diesel PM. However, a comparison with an ion trap showed that pseudo-MRM was never favored on that instrument, which caused fragmentation of non-polar PACs in MS/MS. Conclusions: The results of this study show an important gain in sensitivity when using pseudo-MRM instead of MRM for non-polar PACs on QqQ instruments. The selectivity of MRM is preserved in pseudo-MRM by applying non-zero collision energies to which only these non-polar PACs are resistant, not the isobaric interferences. No interference issue was observed when analyzing Diesel PM, a complex matrix, with our pseudo-MRM method. Therefore, we advise for a broader use of this MS/MS mode for trace-level determination of non-polar PAHs.

Elaboration de matériaux multifonctionnels, application à l’hydrogénation catalytique du CO2 en méthanol et DME

Vincent Gautier, Albin Chaise, Audrey Hertz, Anne-Cécile Roger
37ème réunion annuelle du GFZ, Mar 2022, Vogüé, France | Publiée le 29 mars 2022
Poster de conférence

Lignin as a Bio-Sourced Secondary Template for ZSM-5 Zeolite Synthesis

Camila Gomes Flores, Helena Schneider, Benoit Louis
Catalysts, 2022, 12 (4), ⟨10.3390/catal12040368⟩ | Publiée le 24 mars 2022
Article dans une revue

Abstract

The aim of this study was to investigate the effect of the addition of lignin as a sacrificial agent in ZSM-5 zeolite synthesis. Peculiar growths of ZSM-5 crystals leading to various textural properties were observed. Hence, the behavior in acid-catalyzed conversion of methanol into hydrocarbons (MTH) shifted from high selectivity toward olefins (>55%) to the sole formation of dimethyl ether (DME). Lignin acted as a bio-sourced secondary template (BSST), impacting the zeolite crystals’ shape and, thus, their physicochemical properties.

Homo and Heteronuclear Layered Simple Hydroxides for CO2 electroreduction catalysis

Juan Aguirre-Araque, Mélanie Guyot, Ali Tarhini, S. Chardon-Noblat, Cyrille Costentin, Cedric Leuvrey, Christine Mousty, Vanessa Prevot, Pierre Rabu, Spiros Zafeiratos, Guillaume Rogez
Réunion du Groupe Français d’Étude des Composés d’Insertion, Mar 2022, Sète (34200), France | Publiée le 14 mars 2022
Poster de conférence

Investigation of interactions between organophosphorus compounds and TiO₂ modified microcantilevers for molecule detection in air

Urelle Biapo, Valérie Keller, Philippe Bazin, Thomas Cottineau
Materials Advances, 2022, 3, pp.3600 - 3609. ⟨10.1039/d1ma01064f⟩ | Publiée le 8 mars 2022
Article dans une revue

Abstract

In order to develop a detector working in the gas phase for organophosphorus molecules, resonant microcantilever surfaces were chemically modified with pristine and functionalized TiO 2 nanorods. By using a solvothermal synthesis method a homogeneous film, composed of nanorods with square facets, covering completely the surface of the levers was obtained. The synthesized rods mainly exhibit [110] oriented crystals and this facet has especially demonstrated a high loading ability for grafted sensing molecules. Experimental results showed that the sensing response is three times higher when the TiO 2 sensor is functionalized with amine terminated molecules while no significant response is observed for bare cantilevers exposed to a DMMP simulant. The in situ IR analysis highlighted the formation of hydrogen bonds between the characteristic groups of DMMP and the TiO 2 surface at room temperature. The strength of this bond depends on the chemical groups present at the oxide surface. Molecules containing hydroxyl or amino functions form stronger hydrogen interactions with the OP simulant compared to the fluorine group. The kinetics of adsorption are characterized by a fast initial reaction followed by gradual slowing to a steady-state for all the samples.

Exchange bias at the organic/ferromagnet interface may not be a spinterface effect

Garen Avedissian, Jacek Arabski, Jennifer A Wytko, Jean Weiss, Vasiliki Papaefthimiou, Guy Schmerber, Guillaume Rogez, Eric Beaurepaire, Christian Meny
Applied Physics Reviews, 2022, 9 (1), pp.011417. ⟨10.1063/5.0054524⟩ | Publiée le 14 février 2022
Article dans une revue

Abstract

Exchange bias is a physical effect that is used in many spintronic devices like magnetic read heads, MRAMS, and most kinds of magnetic sensors. For the next generation of fully organic devices, molecular exchange bias, if existing, could have a huge impact for developing mechanically soft and environment friendly devices. The observation of molecular exchange bias has been reported recently in hybrid systems where a metallic ferromagnet is exchanged biased by an organic film, and it is considered to be a spinterface effect. To understand this effect, we investigate if the molecular exchange bias exists in Co/metal tetra-phenyl porphyrin hybrid bilayer systems. Molecular exchange bias is never observed when the samples are properly encapsulated, and when exchange bias is eventually observed, it is not a spinterface effect, but it results from air-driven partial oxidation of the cobalt film transforming part of the metallic cobalt into a cobalt oxide that is well known to induce exchange bias effects. Surprisingly, oxidation is very difficult to prevent even by using very thick metallic encapsulating layers. A similar effect is observed in the Co/metal-phthalocyanine bilayer system showing that molecular exchange bias is not a spinterface effect also in the hybrid system in which this effect was originally discovered.

3D Multiscale Analysis of the Hierarchical Porosity in Coscinodiscus Sp Diatoms using a Combination of Tomographic Techniques

Othmane Darouich, Walid Baaziz, Dris Ihiawakrim, Charles Hirlimann, Danièle Spehner, Patrick Schultz, Hedwige Poncet, Virgile Rouchon, Sana Labidi, Corinne Petit, Pierre Levitz, Ovidiu Ersen
Nanoscale Advances, 2022, 4 (6), pp.1587 - 1598. ⟨10.1039/d1na00691f⟩ | Publiée le 4 février 2022
Article dans une revue

Abstract

A full 3D analysis of the hierarchical porosity in Coscinodiscus sp. diatom structures was carried out by using a multiscale approach that combines three advanced volumetric imaging techniques with resolutions and fields of view covering all the porous characteristics of such complex architectures: electron tomography, "slice and view" approach that uses a dual-beam microscope (FIB-SEM), and array tomography consisting of serial imaging of ultrathin specimen sections. This multiscale approach allowed the whole porosity network to be quantified and provided an unprecedented structural insight into these natural nanostructured materials with internal organization ranging from micrometer to nanometer. The analysed species is made of several nested layers with different pore sizes, shapes and connectivities and characterized by the presence of interconnected pores structured in various ways. The first evidence of the presence of a nanometric porosity made of ellipsoidal pores in the siliceous diatom frustules is also provided.

Study of the water sorption and barrier performances of potato starch nano-biocomposites based on halloysite nanotubes

Nadège Follain, Jiawei Ren, Eric Pollet, Luc Avérous
Carbohydrate Polymers, 2022, 277, pp.118805. ⟨10.1016/j.carbpol.2021.118805⟩ | Publiée le 1 février 2022
Article dans une revue

Peptide Hydrogels Assembled from Enzyme-Adsorbed Mesoporous Silica Nanostructures for Thermoresponsive Doxorubicin Release

Bing Li, Miryam Criado-Gonzalez, Alexandre Adam, Joëlle Bizeau, Christophe Mélart, Alain Carvalho, Sylvie Bégin, Dominique Bégin, Loïc Jierry, Damien Mertz
ACS Applied Nano Materials, 2022, 5 (1), pp.120-125. ⟨10.1021/acsanm.1c03959⟩ | Publiée le 28 janvier 2022
Article dans une revue

Abstract

The development of nanocomposite supramolecular hydrogels, which can be activated by local or external stimuli (pH, redox, enzyme, heat), is highly promising for various applications including implantable materials for antitumor or tissue engineering applications. Here, we show that large pore stellate mesoporous silica modified with isobutyramide grafts allow &gt;100% wt. loading of enzymes, which ensures through the enzyme-assisted self-assembly an easy, rapid, and efficient way to design smart thermoresponsive nanocomposite supramolecular hydrogels. The typical temperature increase (42 °C), which may be induced by hyperthermia anticancer treatments, leads to the controlled-release of doxorubicin encapsulated in the resulting peptide self-assembled material.

Deciphering the Exceptional Performance of NiFe Hydroxide for the Oxygen Evolution Reaction in an Anion Exchange Membrane Electrolyzer

Li Wang, Viktoriia A. Saveleva, Mohammad J Eslamibidgoli, Denis Antipin, Corinne Bouillet, Indro Biswas, Aldo S Gago, Seyed S Hosseiny, Pawel Gazdzicki, Michael H Eikerling, Elena R Savinova, K. Andreas Friedrich
ACS Applied Energy Materials, 2022, 5 (2), pp.2221 - 2230. ⟨10.1021/acsaem.1c03761⟩ | Publiée le 19 janvier 2022
Article dans une revue

Abstract

Hydrogen production via water electrolysis with renewable electricity as input will be crucial for the coming defossilized energy age. Herein, we report an anion exchange membrane electrolyzer using Fe-doped Ni hydroxide as an anode catalyst that is on par with proton exchange membrane electrolyzers in terms of the performance, 2 A cm -2 at 2.046 V and 50 °C. We found that Fe doping stabilizes the α-Ni(OH) 2 phase, which is key to ensure the fast Ni(OH) 2 /NiOOH redox transition and the subsequent fast reaction between Ni 3+/4+ and the electrolyte (OH -), resulting in the excellent oxygen evolution reaction activity of Fe-doped Ni hydroxide. Spin-polarized DFT + U computations reveal that the local arrangement of Fe 3+ with Ni 3+/4+ plays a crucial role in enabling the high OER activity on the (001) facet of this anode catalyst.

Single ether-based side chains in conjugated polymers: Towards power factors of 2.9 mW/m . K 2

Pablo Durand, Huiyan Zeng, Till Biskup, Vishnu Vijayakumar, Viktoriia Untilova, Céline Kiefer, Benoît Heinrich, Laurent Herrmann, Martin Brinkmann, Nicolas Leclerc
Advanced Energy Materials, 2022, 12 (2), pp.2103049. ⟨10.1002/aenm.202103049⟩ | Publiée le 13 janvier 2022
Article dans une revue

Abstract

Combining side chain engineering and controlled alignment of PBTTT is an effective strategy to produce oriented thin films with improved thermoelectric performances when doped sequentially with the acceptor molecule F 6 TCNNQ. The substitution of linear alkyl side-chains (n-C 12) with a chain of identical length including an ether function (n-C 7 OC 4) leads to a new class of slightly polar PBTTT polymers, preserving the ease of synthesis and air stability of alkylated PBTTTs. This sidechain modification improves the structural order of PBTTT backbones and the thermomechanical properties of the polymer. It then can be oriented by high temperature rubbing up to 240°C to reach very high dichroic ratios up to 20 thanks to enhanced cohesive forces within side-chain layers. The side chain polarity of n-C7OC4 helps to tune the polymer-dopant interactions. A multi-technique approach demonstrates that F6TCNNQ dopants are randomly oriented in the disordered side chain layers of n-C7OC4 with some evidence of dopant clustering. The combination of improved alignment and random orientation of intercalated F6TCNNQ dopants helps reach a very high charge conductivity o = 5.104 S/cm and a record power factors PF = 2.9 mWm-1K-2 in the polymer chain direction.

Graphite Felt-Sandwiched Ni/SiC Catalysts for the Induction Versus Joule-Heated Sabatier Reaction: Assessing the Catalyst Temperature at the Nanoscale

Lai Truong-Phuoc, Cuong Duong-Viet, Giulia Tuci, Andrea Rossin, Jean-Mario Nhut, Walid Baaziz, Ovidiu Ersen, Mehdi Arab, Alex Jourdan, Giuliano Giambastiani, Cuong Pham-Huu
ACS Sustainable Chemistry & Engineering, 2022, 10 (1), pp.622-632. ⟨10.1021/acssuschemeng.1c07217⟩ | Publiée le 10 janvier 2022
Article dans une revue

Abstract

The paper describes a series of graphite felt-sandwiched kNi/SiC composites at variable metal loading (k = 10, 15, and 20 wt %) and their application as catalysts for the CO2 methanation process (Sabatier reaction) under two distinct and conceptually different heating setups: Joule heating versus induction heating (IH). A comparative analysis carried out on all catalysts from this series operated under the two heating configurations has unveiled the superior performance of radiofrequency (RF)-heated (IH) catalysts in the process. Most importantly, it has offered a practical tool to map the gap existing between the macroscopic temperature value measured at the catalyst bed using a remote-sensing thermometer (pyrometer) and that (real) of the excited metal nano-objects (Ni NPs) directly engaged in the RF-heated catalytic process. Besides the evident advantages of IH technology applied to the methanation process in terms of process rates (λ) already under nominally low reaction temperatures, the virtual absence of any thermal inertia and the subsequent fast modulation of the temperature at the catalytic bed demonstrate unique features of this heating technology in terms of process safety (cold-reactor walls) and reduction of energy wastes (neither pre- and postcatalyst heating of reagents and products nor that of the whole reactor volume and its peripheral walls).

Adsorption of gaseous formaldehyde on Y zeolites and on metal-organic frameworks

Anaïs Becker, Nizami Israfilov, Elise Ehrstein, Irene Lara-Ibeas, Jean-Marc Planeix, Benoît Louis, Stéphane Le Calvé
Microporous and Mesoporous Materials, 2022, 343, pp.112136. ⟨10.1016/j.micromeso.2022.112136⟩ | Publiée le 1 janvier 2022
Article dans une revue

Abstract

Formaldehyde is a known carcinogen and a major indoor air pollutant, which has led the authorities to regulate its levels in the air. To reduce indoor airborne concentrations, several strategies can be adopted, namely the reduction of emissions or the elimination of this pollutant by different depollution processes. Among them, adsorption on highly porous solid materials remains one of the most efficient strategy. This study aims to provide experimental data on formaldehyde adsorption capacity over different microporous materials at realistic levels (~164 ppb), being representative of the performance of the investigated materials in a real environment. For that purpose, gaseous formaldehyde breakthrough experiments were performed under laboratory-controlled conditions over several porous solids: focusing on cation-exchanged zeolites and metalorganic frameworks (MOFs). These materials were fully characterized in terms of textural and structural properties. Cu-based MOFs acted as more promising HCHO adsorbents than zeolites, exhibiting at least one order of magnitude higher adsorption capacity under realistic indoor conditions. Among MOFs, SUM-102 (Strasbourg University Material) exhibited the highest surfacic adsorption capacity (0.52 μg HCHO m − 2), yielding more than 1 kg HCHO adsorbed per m 3 sorbent being superior to the zeolite family by at least one order of magnitude.

Green synthesis of biobased soft foams by Aza-Michael reaction

Guilhem Coste, Claire Negrell, Luc Averous, Sylvain Caillol
ACS Sustainable Chemistry & Engineering, 2022, 10 (26), pp.8549-8558. ⟨10.1021/acssuschemeng.2c01885⟩ | Publiée le 1 janvier 2022
Article dans une revue

Abstract

The world has been facing a major resources crisis for few decades. In order to tackle with such environmental issues, new solutions have to be found in order to replace fossil resources by more sustainable, biobased resources. One of the most promising biobased resources are vegetable oils which are used as building blocks for renewable polymers synthesis. Industrial productions and the corresponding chemical structures make oleo-chemistry very attractive. Nevertheless, such building blocks have to compete with usual petrol-based monomers. Hence, this work focuses on the development of new foams in order to replace toxic isocyanate-based polyurethanes foams. Different efficient soft foams were obtained for the first time by Aza Michael reactions, using acrylated soybean oils and biobased amines, with an original chemical blowing system. Properties of the foams have been studied in order to determine the influence of the different structures in terms of morphologies, glass transition, hardness or deformation…. Homogeneous open cells foams with a pore size from 0.1 to 0.5 mm were obtained. Flexible foams were obtained with glass transition form-20 °C to-7 °C. These soft foams demonstrated a time recovery about few seconds and exhibited similar properties to equivalent commercial fossil-polyurethane foams, without the use of highly toxic chemicals.

Methods of sampling and sample preparation for detection of microplastics and nanoplastics in the environment

Quiteria Tornero, Marie-Antoinette Dzuila, Didier Robert, Nicolas Keller, Jorge Rodríguez-Chueca, Patricia Garcia-Muñoz
Current Developments in Biotechnology and Bioengineering Microplastics and Nanoplastics: Occurrence, Environmental Impacts and Treatment Processes, Elsevier, pp.79-97, 2022, ⟨10.1016/B978-0-323-99908-3.00004-X⟩ | Publiée le 1 janvier 2022
Chapitre d'ouvrage

Abstract

Microplastics and nanoplastics are a new type of emerging pollutant that appears in the environment. The difference between those two is based on the particle size. The studies about microplastics and nanoplastics have recently increased because of the growing social awareness and because of the biological effects they provoke. To clarify these effects, proper sampling and identification methods are required. The lack of standard methods up to now makes the studies and the comparisons hard. This chapter provides an overview of the main existing methods of sampling, sample preparation, and the identification of debris comprise of microplastics (MPs) and nanoplastics (NPs) in nature. In conclusion, the methods employed for these purposes depend on the type of material, the size, and the matrix in which the polymer is involved.

Glyphosate, AMPA and glufosinate in soils and earthworms in a French arable landscape

C. Pelosi, C. Bertrand, V. Bretagnolle, M. Coeurdassier, O. Delhomme, M. Deschamps, S. Gaba, M. Millet, S. Nélieu, C. Fritsch
Chemosphere, 2022, 301, pp.134672. ⟨10.1016/j.chemosphere.2022.134672⟩ | Publiée le 1 janvier 2022
Article dans une revue

Abstract

Although Glyphosate-based herbicides are often marketed as environmentally friendly and easily biodegradable, its bioavailability and risks to wildlife raise significant concerns. Among non-target organisms, earthworms which live in close contact with the soil can be directly exposed to pesticides and harmed. We investigated soil contamination and the exposure of earthworms to glyphosate, its metabolite AMPA, and glufosinate in an arable landscape in France, both in treated (i.e. temporary grasslands and cereal fields under conventional farming), and nontreated habitats (i.e. hedgerows, permanent grasslands and cereal fields under organic farming) (n = 120 sampling sites in total). Glyphosate, AMPA and glufosinate were detected in 88%, 58% and 35% of the soil samples, and in 74%, 38% and 12% of the earthworm samples, respectively. For both glyphosate and AMPA, concentrations in soils were at least 10 times lower than predicted environmental concentrations. However, the maximum glyphosate soil concentration measured (i.e., 0.598 mg kg⁻¹) was only 2 to 3 times lower than the concentrations revealed to affect earthworms (survival and avoidance) in the literature. These compounds were found both in conventional and organic farming fields, thus supporting a recent study, and for the first time they were detected in hedgerows and grasslands. However, glyphosate and AMPA were more frequently detected in soils from cereal fields and hedgerows than in grasslands, and median concentrations measured in soils from cereal fields were significantly higher than in the two other habitats. Bioaccumulation of glyphosate and AMPA in earthworms was higher than expected according to the properties of the molecules. Our findings raised issues about the high occurrence of glyphosate and AMPA in soils from cropped and more natural areas in arable landscapes. They also highlight the potential for transfer of these molecules in terrestrial food webs as earthworms are prey for numerous animals.

Excited-State Intramolecular Proton Transfer Dyes with Dual-State Emission Properties: Concept, Examples and Applications

Timothée Stoerkler, Thibault Pariat, Adèle Laurent, Denis Jacquemin, Gilles Ulrich, Julien Massue
Molecules, 2022, 27 (8), pp.2443. ⟨10.3390/molecules27082443⟩ | Publiée le 1 janvier 2022
Article dans une revue

Abstract

Dual-state emissive (DSE) fluorophores are organic dyes displaying fluorescence emission both in dilute and concentrated solution and in the solid-state, as amorphous, single crystal, polycrystalline samples or thin films. This comes in contrast to the vast majority of organic fluorescent dyes which typically show intense fluorescence in solution but are quenched in concentrated media and in the solid-state owing to π-stacking interactions; a well-known phenomenon called aggregation-caused quenching (ACQ). On the contrary, molecular rotors with a significant number of free rotations have been engineered to show quenched emission in solution but strong fluorescence in the aggregated-state thanks to restriction of the intramolecular motions. This is the concept of aggregation-induced emission (AIE). DSE fluorophores have been far less explored despite the fact that they are at the crossroad of ACQ and AIE phenomena and allow targeting applications both in solution (bio-conjugation, sensing, imaging) and solid-state (organic electronics, data encryption, lasing, luminescent displays). Excited-State Intramolecular Proton Transfer (ESIPT) fluorescence is particularly suitable to engineer DSE dyes. Indeed, ESIPT fluorescence, which relies on a phototautomerism between normal and tautomeric species, is characterized by a strong emission in the solid-state along with a large Stokes’ shift, an enhanced photostability and a strong sensitivity to the close environment, a feature prone to be used in bio-sensing. A drawback that needs to be overcome is their weak emission intensity in solution, owing to detrimental molecular motions in the excited-state. Several strategies have been proposed in that regard. In the past few years, a growing number of examples of DSE-ESIPT dyes have indeed emerged in the literature, enriching the database of such attractive dyes. This review aims at a brief but concise overview on the exploitation of ESIPT luminescence for the optimization of DSE dyes properties. In that perspective, a synergistic approach between organic synthesis, fluorescence spectroscopy and ab initio calculations has proven to be an efficient tool for the construction and optimization of DSE-ESIPT fluorophores.

Blue-Emitting 2-(2′-Hydroxyphenyl)benzazole Fluorophores by Modulation of Excited-State Intramolecular Proton Transfer: Spectroscopic Studies and Theoretical Calculations

Maxime Munch, Erika Colombain, Timothée Stoerkler, Pauline Vérité, Denis Jacquemin, Gilles Ulrich, Julien Massue
Journal of Physical Chemistry B, 2022, 126 (10), pp.2108-2118. ⟨10.1021/acs.jpcb.2c00383⟩ | Publiée le 1 janvier 2022
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Abstract

This article describes the synthesis, spectroscopic studies, and theoretical calculations of nine original fluorophores based on the 2-(2′-hydroxyphenyl)benzazole (HBX) scaffold, functionalized at the 4-position of the phenol ring by ethynyl-extended aniline moieties. HBX dyes are well-known to display an excited-state intramolecular proton transfer (ESIPT) process, owing to a strong six-membered hydrogen bond in their structure that allows for an enol/keto tautomerism after photoexcitation. Appropriate electronic substitution can perturb the ESIPT process, leading to dual fluorescence, both excited tautomers emitting at specific wavelengths. In the examples described herein, it is demonstrated that the proton transfer can be finely frustrated by a modification of the constitutive heteroring, leading to a single emission band from the excited enol or keto tautomer or a dual emission with relative intensities highly dependent on the environment. Moreover, the nature of the functionalization of the N-alkylated aniline moiety also has a significant importance on the relative excited-state stabilities of the two tautomers in solution. To shed more light on these features, quantum chemical calculations by the density functional theory are used to determine the excited-state energies and rationalize the experimental spectroscopic data.

Preparation of Supported Metal Single-Atom Catalysts on Carbon Supports

Camila Rivera-Cárcamo, P. Serp
Philippe Serp; Doan Pham Minh. Supported Metal Single Atom Catalysis, Wiley, 101-144 (Chap. 3), 2022, 9783527348442 | Publiée le 1 janvier 2022
Chapitre d'ouvrage

Abstract

In this chapter, we review the most representative synthesis methods for the preparation of single-atom catalysts on carbon supports. We identify key parameters in each of the different protocols and address some of the stabilization mechanisms. Special attention is paid to the correlation between the structure and the catalytic properties of the different active sites (M–C, M–N–C, etc.). Both technical and theoretical aspects of the synthetic approaches are discussed with the intention to give an insight into the advantages and drawbacks when choosing a specific method.

The Potential Use of Aqueous Extract of Ulva lactuca seaweed for the Control of the Post-Harvest Citrus Green Mold, in vivo and in vitro conditions

Joséphine Al-Alam, Douaa Salim, Ziad Fajloun, Maurice Millet, Asma Chbani
Arabian Journal of Medicinal & Aromatic Plants, 2022, 8 (1), pp.155-170 | Publiée le 1 janvier 2022
Article dans une revue

Abstract

Seaweed liquid extracts (SLE) were assessed as natural antifungal products for the control of the post-harvest citrus green mold Penicillium digitatum. The SLE of a green alga, Ulva lactuca, at different concentration (25, 50, 100 and 200 g L-1) were evaluated for their inhibitory potential of the in vivo development of P. digitatum on fresh oranges and of the in vitro conidia germination and tube elongation of the mold on potato dextrose broth (PDB). The study of their effects on fungus viability on malt extract agar (MEA) was also evaluated. The results revealed that the assessed SLE at 50 and 100 g L-1 allowed a potential inhibition of the fungus viability and development. The U. lactuca liquid extract at 50 g L-1 allowed a complete in vivo protection of the oranges from the mold for the total duration of the study and a 90 % inhibition of spore germination. Moreover, the chemical characterization of the extract showed valuable content in polysaccharides and mainly in ulvan, known for its antifungal effects. These findings could be highly promising to develop an eco-friendly, safe and effective product for citrus fruit post-harvesting protection.

Dispiroacridine-indacenobisthiophenes positional isomers: Impact of the bridge on the physicochemical properties

Jean-David Peltier, Benoît Heinrich, Bertrand Donnio, Olzhas A Ibraikulov, Thomas Heiser, Nicolas Leclerc, Joëlle Rault-Berthelot, Cyril Poriel
Materials Chemistry Frontiers, 2022, 6, pp.225-236. ⟨10.1039/D1QM01393A⟩ | Publiée le 1 janvier 2022
Article dans une revue

Abstract

We report the influence of positional isomerism on the electronic (electrochemical HOMO/LUMO energy levels), photophysical and physical properties (molecular organization, crystallinity and phase transitions) and charge transport properties of dispiroacridine-indacenobisthiophene positional isomers. The isomers differ from the central indacenobisthiophene (IDT) core, which displays either para or meta linkages. We show that the spiro-connected phenylacridine bridges have a significant influence on all these properties and particularly on the charge transport mobility values, which were found to be higher in the meta isomer than in the para isomer. This finding is different to what was reported in literature for other couples of IDT-based isomers and shows the key role played by the spiro-connected fragments in these molecular systems.

Comparison of two Analytical Systems for Continuous Monitoring of ppb to ppm-levels of Formaldehyde in Air

Audrey Grandjean, Damien Bazin, Franck Amiet, Stéphane Le Calvé
Chemical Engineering Transactions, 2022, 95, pp.67-72. ⟨10.3303/CET2295012⟩ | Publiée le 1 janvier 2022
Article dans une revue

Abstract

Accurate and continuous monitoring of indoor air quality is crucial to understand and prevent airborne diseases, since humans spend most of their routine time indoors. Aldehydes are of particular interest as they are irritants and usually present in indoor air at concentrations from 2 to 10 times higher than in outdoor air. Formaldehyde, the most abundant one, is classified as carcinogenic category 1B under European Regulation (EC) No 1272/2008. In indoor air, aldehydes mainly originate from construction materials such as plywood, insulating materials and paints. Some aldehydes have a pungent and fruity odour at high concentrations but may be undetected at low concentration. To be able to implement preventive measures, there is a need for continuous, fast, accurate and robust techniques for quantification of aldehydes in indoor air. In this work, two different systems which have been developed for monitoring of formaldehyde and other aldehydes are presented: a portable microdevice based on the derivatization of formaldehyde for continuous fluorometric detection, and an Automatic Gas 2D-chromatograph equipped with a thermodesorption unit and flame ionization detector (auto-TD-GC-FID). These techniques were compared under laboratory-controlled measurements. The portable microdevice specifically quantifies formaldehyde down to ppb levels. It is compact and uses a specific aqueous reagent to convert formaldehyde into a fluorescent product, 100 mL enabling a continuous monitoring for 4 days. The auto-TD-GC-FID is an automatic gas chromatograph permitting formaldehyde and acetaldehyde quantification from ppb to ppm levels. It runs continuously with successive 15min cycles. This instrument only requires a power supply and gas generators or gas cylinders of hydrogen, air, and nitrogen. Our experimental results demonstrate that both analytical devices quantify formaldehyde accurately.

Effect of deposition conditions on the properties of Ni-Mo-W coatings as electrocatalysts for hydrogen evolution reaction

Houda Boudjehem, Hayet Moumeni, Abderrafik Nemamcha, Sergey Pronkin, Jean Luc Rehspringer
Journal of Applied Electrochemistry, 2022, 52 (2), pp.217-229. ⟨10.1007/s10800-021-01615-4⟩ | Publiée le 1 janvier 2022
Article dans une revue

Abstract

Ni-Mo-W electrocatalysts have been prepared by electrodeposition on a copper substrate in a bath with different Na2WO4 center dot 2H(2)O concentrations (0.01-0.1 M) and pH values (4 and 7.5). The chemical composition, surface morphology, and crystalline structure of the as-prepared electrocatalysts were followed by scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), and X-ray diffraction (XRD) techniques. The chronopotentiometry and electrochemical impedance spectroscopy (EIS) methods were conjointly used to investigate the Ni-Mo-W electrocatalysts' activity for hydrogen evolution reaction (HER) in alkaline medium. As estimated by EDX results, Ni is the major element in all the synthesized Ni-Mo-W deposits, and Mo and W contents are pH and Na2WO4 center dot 2H(2)O concentrations dependent. The XRD results reveal the formation of a nanocrystalline FCC-Ni(Mo, W) solid solution at pH 4, while at pH 7.5, the deposits present an amorphous structure. The deposits prepared at pH 4 have homogeneous surface with a needle-like morphology but at pH 7.5, a cracked morphology with a uniform and regular porous structure is observed. According to the electrochemical analyses, the Ni-Mo-W electrocatalyst developed at pH 7.5 and [WO42-] = 0.01 M with maximum Mo and minimum W contents was found to be the best electrode material for HER in alkaline media. This electrocatalyst exhibits low overpotential, eta, and charge-transfer resistance, R-ct, values associated to higher values for the double-layer capacitance, C-dl, and the roughness factor, R-f.

2,3-Butanediol as a Biobased Chain Extender for Thermoplastic Polyurethanes: Influence of Stereochemistry on Macromolecular Architectures and Properties

Antoine Duval, Alexandru Sarbu, Florent Dalmas, David Albertini, Luc Averous
Macromolecules, 2022, 55, pp.5371-5381. ⟨10.1021/acs.macromol.2c00671⟩ | Publiée le 1 janvier 2022
Article dans une revue

Color-Tunable Multifunctional Excited-State Intramolecular Proton Transfer Emitter: Stimulated Emission of a Single Dye

Martyna Durko-Maciag, Denis Jacquemin, Gilles Ulrich, Julien Massue, Jaroslaw Mysliwiec
Chemistry - A European Journal, 2022, 28 (44), pp.e202201327. ⟨10.1002/chem.202201327⟩ | Publiée le 1 janvier 2022
Article dans une revue

Abstract

Since the 1970s the Excited-State Intramolecular Proton Transfer chromophores were regarded as good materials for laser action generation due to their inherent four-level photocycle. The excitation-dependent properties of these compounds enable light amplification from two distinct forms: both enol and keto, making it possible to obtain dual fluorescenceemission. Herein, we report that a third option is plausible: for the first time stimulated emission was realized with a deprotonated ESIPT molecule based on a novel rigidified 2-(2'-hydroxyphenyl)benzothiazole derivative, triggering the possibilityto fabricate real-time tunable active material. Through the rational engineering of the ratio of each emissive species, a redgreen-blue device was fabricated with the possibility of white light generation. The degenerated two-wave mixing setup was applied to construct a continuously tunable Distributed Feedback laser.

Silver Nanowire Electrodes and Plasmonic Resonance influences on PF2:PC70BM Organic Solar Cells

Ibrahim Issoufou, Bernard Ratier, Johann Bouclé, Nicolas Leclerc, Bruno Lucas, Sylvain Vedraine
ICSM 2022, 2022, Glasgow, France | Publiée le 1 janvier 2022
Poster de conférence