Atomically dispersed metal cocatalysts for solar energy conversion

Abstract

The pursuit of clean and sustainable energy has become more urgent than ever. Photocatalysis is a potential approach to convert highly sustainable solar energy into promising fuels. Additionally, effective and robust cocatalysts are crucial factors in facilitating rapid photogenerated charge separation/charge transfer, widespread absorption and highly photoactive reactions and achieving efficient solar-to-chemical energy conversion. In this review, we summarize the recent advances in efficient cocatalysts provided with atomic metal sites, including single-atom metal cocatalysts (SAMCs) and atomic cluster metal cocatalysts (ACMCs). First, we present a general definition of atomic metal sites to improve our understanding of the structure–activity correlations at the atomic scale. Then, a brief description of advanced characterization techniques is given to distinguish the atomic metal sites. After introducing the atomic metal sites, regulating strategies for the enhancement of photocatalysis, such as electronic metal–support interaction (EMSI), atomic alloy strategy and confinement strategy, the advantages and disadvantages of each type of atomic metal sites and the solar energy conversion applications (water splitting, CO₂ reduction, N₂ reduction, etc.) are highlighted. Finally, the prospective and a summary of the comparison of different atomic metal sites as well as the potential development direction of photocatalysts in the future are outlined.