Rapid advances in antimony triselenide photocathodes for solar hydrogen generation

One of the paramount challenges for realizing practical solar hydrogen production is the development of a low-cost semiconductor that is suitable for large-area and high-performance photoelectrochemical devices. Antimony triselenide (Sb₂Se₃) has emerged as a nearly ideal semiconductor material that satisfies nearly all requirements for effectively generating hydrogen using solar energy. In this report, we highlight the extraordinary characteristics of Sb₂Se₃ relative to the myriad of other emerging semiconductors, in terms of cost, band gap, optoelectronic properties, photocorrosion stability, and processability. Additionally, we discuss recent studies on Sb₂Se₃ photocathodes with a focus on their intrinsic properties, use of co-catalysts, and top and bottom interface engineering for enhanced performance. Unresolved issues and future research directions will also be discussed briefly. We believe that the rapid advances in Sb₂Se₃-photocathode water splitting over the past three years suggest a positive outlook for the cost-effective production of solar hydrogen.