Metal single atom photocatalysts for sunlight-driven hydrogen production: Recent and future development

Photocatalytic hydrogen evolution has been considered the most compelling approach for green hydrogen technology. Heretofore, restricted light adsorption, fast charge recombination, and limited surface-active sites have been considered as bottle-neck issues, causing poor catalytic performance. In this context, metal single atom-incorporated photocatalysts have attracted tremendous attention for their ability to overcome these obstacles while maximizing atomic metal utilization efficiency. The presented perspective aims at highlighting the cutting-edge development of metal single-atom photocatalysts. Indeed, the formation manner and features of metal single atom- anchored photocatalysts are presented. Also, various preparation methods employed to deploy metal atoms onto parent materials are unveiled. Furthermore, recent outstanding metal single atom- anchored semiconductors, which are precious, transition, dual metal single atom- decorated are discussed in detail. In addition, it is also expected to pave the way for the next generation of photocatalysts for sunlight-driven hydrogen generation and contribute to fill the missing puzzles in the picture of green hydrogen production.