Prussian blue functionalized MIL-101(Cr)-SO3H for Cs+ ion capture for the management of contaminated water

International audienceThis study investigates the property of Metal-Organic Frameworks (MOFs) grafted with Prussian blue analogs (PBA) for the efficient removal of Cs+ ions from aqueous solutions. MIL-101(Cr)-SO3H-PBA material was synthesized using a two-step process: hydrothermal reaction between monosodium 2-sulfoterephthalic acid (BDC-SO3Na) and chromium oxide (CrO3) to produce MIL-101(Cr)-SO3H, followed by grafting with CuK2[Fe(CN)6] (PBA). Both materials were characterized using XRD, IR, N2 sorption and Raman spectroscopy. The results confirmed the conservation of MOF porosity after functionalization and the successful incorporation of PBA. Batch adsorption experiments were conducted to evaluate Cs+ removal performance of the adsorbents. The study examined contact time (up to 1440 min), pH (2, 7 and 11), initial Cs+ concentration (from 9 ppb to 1800 ppm) and competing ions. The resistance of the porous solids under drastic conditions involving gamma radiation (from 0.5 MGy up to10 MGy) was also investigated.MIL-101(Cr)-SO3H-PBA exhibited a maximum Cs⁺ adsorption capacity of 242 mg.gMOF-1, compared to 161 mg.gMOF-1 for pristine MIL-101(Cr)-SO3H and showed high selectivity toward Cs+ in the presence of competing ions (Na+, K+, Mg2+, Ca2+, Sr2+). MI-101(Cr)-SO3H-PBA also demonstrates remarkable stability under radiation and alkaline conditions, maintaining 95% efficiency, whereas the performance of pristine MIL-101(Cr)-SO3H material decreased significantly (7.5-fold decrease).Cette étude examine les propriétés des structures métal-organiques (MOF) greffées avec des analogues du bleu de Prusse (PBA) pour l'élimination efficace des ions Cs+ des solutions aqueuses. Le matériau MIL-101(Cr)-SO3H-PBA a été synthétisé selon un procédé en deux étapes : réaction hydrothermale entre l'acide 2-sulfotéréphtalique monosodique (BDC-SO3Na) et l'oxyde de chrome (CrO3) pour produire du MIL-101(Cr)-SO3H, suivie d'un greffage avec du CuK2[Fe(CN)6] (PBA). Les deux matériaux ont été caractérisés par DRX, IR, sorption de N2 et spectroscopie Raman. Les résultats ont confirmé la conservation de la porosité des MOF après fonctionnalisation et l'incorporation réussie du PBA. Des expériences d'adsorption par lots ont été menées pour évaluer les performances d'élimination du Cs+ des adsorbants. L'étude a examiné le temps de contact (jusqu'à 1 440 min), le pH (2, 7 et 11), la concentration initiale en Cs+ (de 9 ppb à 1 800 ppm) et les ions concurrents. La résistance des solides poreux à des conditions extrêmes impliquant un rayonnement gamma (de 0,5 MGy à 10 MGy) a également été étudiée.Le MIL-101(Cr)-SO3H-PBA a montré une capacité d'adsorption maximale de Cs+ de 242 mg.gMOF-1, contre 161 mg.gMOF-1 pour le MIL-101(Cr)-SO3H, et a montré une forte sélectivité pour le Cs+ en présence d'ions concurrents (Na+, K+, Mg2+, Ca2+, Sr2+). Le MI-101(Cr)-SO3H-PBA présente également une stabilité remarquable dans des conditions de rayonnement et alcalines, maintenant une efficacité de 95 %, tandis que les performances du matériau MIL-101(Cr)-SO3H ont diminué de manière significative (diminution de 7,5 fois)

Photocatalytic properties of La₂Ti₂O₇ synthesized by glycine-assisted sol-gel method and its impact on intestinal and blood-brain barriers

International audienceThe La₂Ti₂O₇ photocatalyst, synthesized using a glycine-assisted sol-gel method, demonstrates excellent efficiency in the photodegradation of both anionic dyes, such as Naphthol Green B and Eosin Y, and cationic dyes like Crystal Violet, at a pH of 5.8 under UV irradiation. Kinetic studies reveal that the degradation process follows first-order kinetics, specifically described by the Langmuir-Hinshelwood model. Additionally, this photocatalyst has been successfully utilized for the photoreduction of Cr(VI) to Cr(III). Mott-Schottky analysis of La₂Ti₂O₇ confirms its n-type semiconductor behavior and provides insights into its flat band potential. The conduction and valence band levels were determined experimentally through flat band potential measurements and optical band gap analysis, showing good agreement with theoretical values obtained from the Mulliken electronegativity approach. Furthermore, photocurrent transient response measurements under both UV and solar excitation reveal a higher photocurrent density in the UV spectral region, consistent with the material's absorption characteristics. This suggests the photocatalyst's potential applicability in treating various pollutants, making it a promising candidate for wastewater remediation. For the first time, to the best of our knowledge, the impact of La₂Ti₂O₇ toxicity on the human body was also investigated. Specifically, its effects were studied on the human intestinal barrier and a human in vitro blood-brain barrier model. The results indicate no cytotoxicity at concentrations ranging from 0.1 to 1 μg.mL−1, highlighting its potential as a safe and effective material for environmental and biomedical applications

Mission accomplished? A post-assessment of EU ETS impact on power sector emissions reduction

International audienceThe debate on the capacity of the European Union Emissions Trading System (EU ETS) to effectively induce CO emissions reduction is still ongoing. This is particularly noteworthy in the case of the power sector, where numerous decarbonization policies overlap. This paper contributes to this discussion by leveraging a methodological approach that circumvents the challenges of constructing credible counterfactuals for causal inference and allows for disentangling the impact of the EU ETS from other measures on the power sector’s abatement efforts, alongside influencing factors such as weather. Specifically, we employ a Bayesian structural time series (BSTS) model, conceptually related to synthetic control techniques, to assess the effectiveness of the three completed phases of the EU ETS (2005-2020) in reducing CO emissions in the power sector across 24 Member States. We analyze the policy implementation effect over the course of each phase by comparing actual power sector emissions with counterfactual estimates derived from contemporaneous predictors related to such emissions. The results indicate a statistically significant emissions reduction in the second and third phases, with no significant reduction in the first phase. The power sector’s centrality to the EU ETS, and its critical role in our economies emphasize the importance of our findings in evaluating emissions reduction objectives

MIL-101(Cr)-SO3H fonctionnalisé au bleu de Prusse pour la capture des ions Cs+ dans la gestion des eaux contaminées.

International audienceThis study investigates the property of Metal-Organic Frameworks (MOFs) grafted with Prussian blue analogs (PBA) for the efficient removal of Cs+ ions from aqueous solutions. MIL-101(Cr)-SO3H-PBA material was synthesized using a two-step process: hydrothermal reaction between monosodium 2-sulfoterephthalic acid (BDC-SO3Na) and chromium oxide (CrO3) to produce MIL-101(Cr)-SO3H, followed by grafting with CuK2[Fe(CN)6] (PBA). Both materials were characterized using XRD, IR, N2 sorption and Raman spectroscopy. The results confirmed the conservation of MOF porosity after functionalization and the successful incorporation of PBA. Batch adsorption experiments were conducted to evaluate Cs+ removal performance of the adsorbents. The study examined contact time (up to 1440 min), pH (2, 7 and 11), initial Cs+ concentration (from 9 ppb to 1800 ppm) and competing ions. The resistance of the porous solids under drastic conditions involving gamma radiation (from 0.5 MGy up to10 MGy) was also investigated.MI-101(Cr)-SO3H-PBA exhibited a maximum Cs+ adsorption capacity of 242 mg.gMOF-1, compared to 161 mg.gMOF-1 for pristine MIL-101(Cr)-SO3H and showed high selectivity toward Cs+ in the presence of competing ions (Na+, K+, Mg2+, Ca2+, Sr2+). MI-101(Cr)-SO3H-PBA also demonstrates remarkable stability under radiation and alkaline conditions, maintaining 95% efficiency, whereas the performance of pristine MIL-101(Cr)-SO3H material decreased significantly (7.5-fold decrease).Cette étude examine la propriété des Metal-Organic Frameworks (MOF) greffés avec des analogues de bleu de Prusse (PBA) pour l'élimination efficace des ions Cs+ des solutions aqueuses. Le matériau MIL-101(Cr)-SO3H-PBA a été synthétisé en deux étapes : une réaction hydrothermale entre l'acide 2-sulfotéréphtalique monosodique (BDC-SO3Na) et l'oxyde de chrome (CrO3) pour produire le MIL-101(Cr)-SO3H, suivie d'un greffage avec du CuK2[Fe(CN)6] (PBA). Les deux matériaux ont été caractérisés par DRX, IR, sorption de N2 et spectroscopie Raman. Les résultats ont confirmé la conservation de la porosité du MOF après fonctionnalisation et l'incorporation réussie du PBA. Des expériences d'adsorption en mode batch ont été menées pour évaluer la performance des adsorbants en matière d'élimination du Cs+. L'étude a examiné le temps de contact (jusqu'à 1440 min), le pH (2, 7 et 11), la concentration initiale en Cs+ (de 9 ppb à 1800 ppm) et l'effet des ions compétiteurs. La résistance des solides poreux dans des conditions drastiques impliquant un rayonnement gamma (de 0,5 MGy jusqu'à 10 MGy) a également été étudiée.Le MIL-101(Cr)-SO3H-PBA a présenté une capacité d'adsorption maximale du Cs+ de 242 mg.gMOF-1, contre 161 mg.gMOF-1 pour le MIL-101(Cr)-SO3H non modifié, et a montré une sélectivité élevée pour le Cs+ en présence d'ions compétiteurs (Na+, K+, Mg2+, Ca2+, Sr2+). Le MIL-101(Cr)-SO3H-PBA a également démontré une stabilité remarquable sous rayonnement et en conditions alcalines, maintenant une efficacité de 95 %, tandis que la performance du matériau MIL-101(Cr)-SO3H non modifié a diminué de manière significative (une réduction de 7,5 fois)

Critical material and regional inequality: Material demand under diverging decarbonization pathways in China’s power sector

International audienceChina's power sector decarbonization is crucial for global climate goals. However, regional disparities in decarbonization pathways and material demands arise due to differences in resource endowment, economic development, and policy support. This study develops an integrated assessment model to evaluate critical material demand for decarbonizing China's power sector under four scenarios: Business-as-Usual (BAU), Renewable Energy (RE), Carbon Capture and Storage (CCS), and Advanced Nuclear (AN). The results show significant provincial variations, with eastern provinces favoring wind and solar, while western and coal-dependent regions rely on hydropower or CCS. Nationally, material demand peaks in the CCS scenario by 2060, especially for structural materials like copper (2250 Mt) and nickel (445 Mt). Functional materials such as silicon and indium see significant demand increases under PV-driven transitions, with silicon reaching 9300 kt and indium 14.2 Mt by 2060 in the RE scenario. These findings highlight the need for region-specific policies, long-term material supply planning, and addressing material demand imbalances for a sustainable energy transition

Climate shocks and banking sector stability: Evidence from El Niño southern oscillation

International audienceThis study introduces a novel ex ante approach to assess the short-term impact of climate shocks on banking sector stability by examining the effect of El Niño Southern Oscillation (ENSO) on banking sector distance-to-default. Using dynamic panel data econometric modeling, we investigate the macroeconomic implications of ENSO-induced climate shocks, such as El Niño and La Niña events, on banking sector stability in 51 countries across three regions particularly exposed to the consequences of ENSO oscillations (East Asia and Pacific, Latin America and the Caribbean, and Sub-Saharan Africa) during the period 2000–2020. Our findings show that the adverse effects of these climate shocks on banking sector stability are unevenly distributed among countries, with more pronounced and robust adverse effects of El Niño events in the short-term, particularly in Latin America and the Caribbean and, to a lesser extent, Sub-Saharan Africa. We also document the short-term adverse effects of La Niña events for Latin American and the Caribbean countries. Further estimates suggest that the increase in non-performing loans is a key transmission channel linking El Niño events to banking sector stability. As global warming should intensify the frequency and magnitude of ENSO's cyclical pattern, these findings can help estimate the potential adverse effects of climate change-related natural disasters on banking sector stability and inform future mitigation and adaptation policies

Turning a solar cell into a catalyst: (Ag,Cu)(In,Ga)Se₂ p–n junction enabling ambient dry reforming of methane

International audiencePhotocatalysis driven by solar energy offers a sustainable alternative to thermocatalysis for methane valorization, however large-scale deployment remains limited by catalyst efficiency and scalability. Meanwhile, photovoltaic technologies, though highly developed for electricity generation, still face challenges in costly energy storage and underutilized potential in direct solar-to-chemical energy conversion. In this context, CIGS thin-film solar cells emerge as promising candidates for photocatalytic applications due to their strong light absorption, tunable electronic properties, and industrial scalability. In the present work, we use a thin-film CIGS solar cell plates, re-designed as a monolithic photocatalyst, to drive DRM under ambient conditions. A 2 µm ptype (Ag,Cu)(In,Ga)Se2 (ACIGS) absorber deposited on a soda-lime glass/Mo substrate is overcoated with an ntype CdS layer, forming a p-n junction that couples strong light absorption with built-in charge separation. Under irradiation, ACIGS/CdS plates produce > 2 mmol g cat -1 syngas with ≈ 85 % CO selectivity at ambient conditions, without any external electric power or thermal input. Mechanistic evidence indicates deep CH4 dissociation to surface carbon and hydrogen, with subsequent CO2 reduction by surface carbon to CO. The catalytic plates are air-regenerable under light and exhibit notable stability. Turning a solar-cell design into the catalytic junction tackles efficiency and manufacturing hurdles for CH4/CO2 conversion. Because CIGS and CdS processes already exist at industrial scale, this approach provides a practical route to deployable solar chemical hardware; further gains are expected from junction optimization and selective co-catalysts

Another World Is Possible—It Is Already Here: A Review and Research Agenda on Alternative Organizing

International audienceAmid multiple crises on a planetary scale, alternative organizing offers plural possibilities for reconfiguring societal relations and bringing into being a more livable world. Despite growing interest, the literature on alternative organizing remains fragmented, marked by a narrow and selective integration of disciplinary and geographic knowledge communities. This fragmentation leads to ambiguities and contradictions in concepts and theory development. To address these issues, we review 50 years of research on alternative organizing, following three steps. First, we map the genealogy of research on alternative organizing, identify its relations with institutional orders, and distinguish key perspectives. Second, we develop an integrative framework that (a) identifies three constitutive dimensions of alternative organizing—imaginaries, alterity, and subjectivities—and (b) synthesizes the processes, frictions, and outcomes for societal transformation. Drawing on this framework, we suggest avenues to attune to the ways alternative organizing unsettles dominant orders and cultivates the present and future, other-wise

Phase engineering in NaNbO₃ thin films fabricated by PLD: Strain, substrate and temperature role on the Q FE – P AFE phase transition

International audienceThis study explores precise control over ferroelectric (Q) and antiferroelectric (P) phase transitions in NaNbO3 (NNO) thin films, essential for sustainable electronic applications. Epitaxial NNO layers (10–290 nm) were grown via Pulsed Laser Deposition (PLD) onto SrTiO3 (001) and NdGaO3 (110)/(101). X-ray diffraction and reciprocal-space mapping show films deposited at 600 °C nucleate as a fully strained Q phase; beyond a thickness of about 45 nm on NdGaO3, they relax into the P phase. Elevated deposition temperature (750 °C) facilitates early partial relaxation of the Q-phase and promotes nucleation and growth of the P-phase, evident from distinctive morphologies observed by Atomic Force Microscopy (AFM). Conductive AFM further links structural phases to their distinct electrical signatures, showcasing ferroelectric hysteresis in Q-phase regions and more complex loops in P/Q mixed-phase domains. Notably, on NdGaO3 (101), we demonstrate distinct single-phase growth; by selecting deposition temperature, we obtain exclusively the Q or P phase, without mixed states. These results provide insights into controlling structural transitions in NNO thin films, guiding their future development for sustainable electronics, energy storage, piezoelectric microdevices, and multifunctional systems

When cost metafrontiers are nonconvex in the outputs, then the production metafrontier is nonconvex: the price of a convexification strategy

International audienceMetafrontier analysis is widely used to account for technological heterogeneity among producers. The approach involves combining a number of group-specific production possibilities sets to form a production possibilities metaset. Even though the union of the group sets normally results in a nonconvex metaset, most authors proceed as if this metaset is convex. Kerstens, O’Donnell and Van de Woestyne (2019) obtain new results on the union operator on sets under various assumptions and empirically illustrate that the popular convexification strategy is highly questionable. In this paper we transpose their results on the union operator from a production to a cost context: this is new. We then explore the extent to which convexity of the cost function is corroborated using a newly developed test. Furthermore, we check to which extent a convexification strategy is tenable when estimating a cost metafrontier. We use an original banking data set from China and the USA to illustrate the main issues. We establish that the cost function is not convex in the outputs for China and that the convexification strategy leads to potentially-biased estimates of the cost metafrontier and associated measures of efficiency