Computational Screening of Pre- and Post-Transition Metal Oxides and Sulfides for Photocatalytic Hydrogen Generation

Discovering efficient and scalable photocatalysts for water splitting is a major challenge for the sustainable production of carbon-free hydrogen. In this presentation, we tackle that challenge and expand the list of known water-splitting photocatalysts using data-intensive screening based on accurate first-principles calculations of band gaps, band edges, and free energies of electrochemical decomposition. Building on previous studies [1,2] which show that inserting pre-transition (<i>s</i>-block) metals in binary metal oxides can improve redox activity while preserving solar absorption, we specifically target the family of post-transition (<i>p</i>-block) metal oxides. We analyze the influence of adding <i>s</i>-block cations on the band gaps and band edges of these materials and on their photocatalytic efficiency. Based on this analysis, we screen 109 ternary metal oxides and identify nine candidates, among which two appear to not have been previously proposed as water-splitting photocatalysts [3]. We then extend these results to the family of ternary <i>s</i>- and <i>p</i>-block metal sulfides, leading to the discovery of additional photoactive compounds, which warrants further studies [4].<br/><br/>[1] Xiong et al., <i>Energy Environ. Sci.</i> (2021) 14, 2335-2348. DOI: 10.1039/D0EE02984J<br/>[2] Katz et al., <i>Adv. Energy Mater.</i> (2022) 2201869. DOI: 10.1002/aenm.202201869<br/>[3] Gelin et al., submitted to <i>PRX Energy</i> (2023). arxiv:2303.03332<br/>[4] Katz et al., submitted to <i>ACS Energy Letters</i> (2023)