Upconversion photocatalyst for H 2 production by water splitting Janyce Beaurain 1,2 , Gilles Ledoux 1 , Shashank Mishra 2 , Adel Mesbah 2 , Benoit Mahler 1 1 Institut lumière matière (ILM),UMR5306 Université Lyon 1-CNRS, Université de Lyon69622 Villeurbanne, France, 2 Institut de Recherche sur la catalyse et l’environnement (Ircelyon), UMR5256 Université Lyon 1-CNRS, Université de Lyon69622 Villeurbanne, France Photocatalysis offers a sustainable route for solar fuel production by directly converting sunlight into chemical energy, knowing that Earth receives enough solar energy in one hour to meet the world energy consumption for an entire year 1 . Photocatalytic water splitting, utilizing sunlight to convert water into hydrogen and oxygen, is emerging as a promising method for producing green hydrogen. Recent developments have demonstrated near- perfect conversion yields under ultraviolet light 2 and the feasibility of scaling up production using photocatalyst sheets in a 100 m 2 outdoor prototype reactor 3 . Despite these advancements, current solar-to-hydrogen energy conversion (STH) efficiencies remain below 5%, necessitating further research into visible light-responsive photocatalysts 4 . Recently, it has been demonstrated that Y 2 Ti 2 O 5 S 2 , a narrow bandgap semiconductor, achieves stable photocatalytic water splitting under visible light when loaded with co-catalysts and with fine-tuned reaction conditions 5 . However, the solid-state synthesis of this material leads to micron-sized particles with defects, which limit its photocatalytic performance because of charges recombination. Moreover, Y 2 Ti 2 O 5 S 2 can only absorb photons up to 650 nm, which represents only 50% of the solar spectrum. Our project aims at optimizing the synthesis of this promising material to obtain defect-free nanoparticles, and to incorporate an internal upconversion functionality via rare earth doping. By converting the low energy infrared photons into higher energy photons within the photocatalyst matrix, the material’s STH efficiency could be enhanced by taking maximum advantage of the whole solar spectrum, including infrared photons. References 1. Carrillo, A. J., González-Aguilar, J., Romero, M., & Coronado, J. M. (2019). Solar Energy on Demand: A Review on High Temperature Thermochemical Heat Storage Systems and Materials. Chemical Reviews, 119(7), 4777‑4816. https://doi. org/10.1021/acs.chemrev.8b00315 2. Takata, T. et al. (2020). Photocatalytic water splitting with a quantum efficiency of almost unity. Nature, 581, 411–414. https:// doi.org/10.1038/s41586-020-2278-9 3. Nishiyama, H. et al. (2021). Photocatalytic solar hydrogen production from water on a 100-m2 scale. Nature, 598, 304–307. https://doi.org/10.1038/s41586-021-03907-3 4. Hisatomi, T. et al. (2024). Photocatalytic water splitting for large-scale solar-to-chemical energy conversion and storage. Frontiers in Science, 2. https://doi.org/10.3389/fsci.2024.1411644 5. Wang, Q. et al. (2019). Oxysulfide photocatalyst for visible-light-driven overall water splitting. Nat. Mater., 18, 827–832. https://doi.org/10.1038/s41563-019-0399-z
P14
© The Author(s), 2025
Made with FlippingBook Learn more on our blog