Photocatalyst for Overall Solar Water Splitting—Semiconducting Scandium/Yttrium-Chalcohalides

Solar-driven photocatalytic water splitting stands as a pivotal technology for the production of hydrogen, representing a significant step towards sustainable and renewable energy solutions. This presentation highlights the potential of two-dimensional materials as photocatalysts with tunable electronic properties for superior photocatalytic performance. Utilizing first-principle calculations, we have discovered a series of scandium/yttrium chalcohalide monolayers (ScSeCl, ScSeBr, ScSeI, ScTeI, YTeCl, YTeBr, and YTeI) in the α phase, showcasing promising characteristics for overall solar water splitting. These materials exhibit optimal band gaps and band edge positions, aligning well with the visible light region of the solar spectrum. Our findings indicate a notable increase in visible light response with the number of layers, particularly in α-ScTeI, where the absorption intensity increases from 15% in the monolayer to 45% in the seven-layer configuration. Moreover, monolayer and bulk α-ScTeI demonstrate advantageous properties such as low exciton binding energy, elevated carrier mobility, and prolonged hot carrier cooling time, positioning them as exceptional candidates for photocatalytic applications. This research underscores the potential of van der Waals scandium/yttrium chalcohalides as high-efficiency photocatalysts for solar water splitting. The results presented here motivate further experimental research to develop scalable and cost-effective strategies for green hydrogen production, contributing to the global shift towards clean energy.