Single-atom and Cluster Photocatalysis:Competition and Cooperation

Photocatalytic technology has been considered as a promising and sustainable technology to convert solar energy to storable chemical energy. With active sites (single metal atoms and clusters) atomically dispersed on the semiconductor, the mass and charge transfer in photocatalysis can be significantly promoted, and the photocatalytic performance can be remarkably improved. However, it is still controversial whether clusters or single-atoms are the real active sites in catalysts. In this review, the recent advances in single-atom photocatalysis are briefly introduced, with the competition and synergy of single-atoms and clusters analyzed and discussed. Then, the state-of-the-art technologies in the identification and characterization of single-atoms and clusters as photocatalytic active sites are presented. Finally, the future development of single-atoms/clusters synergistic photocatalysis in solar-chemical energy conversions such as water splitting and CO2 reduction is prospected.