Single Atom Extracting Photoexcited Holes for Key Photocatalytic Reactions

Abstract Recent advances on material science result in the emerging concept of single atom catalysts as highly efficient photocatalysts to optimize the conversion efficiency of solar energy into chemicals/fuels. After more than five decades of research, severe electron–hole recombination remains the key bottleneck restricting the photocatalytic reactions. Particularly, the sluggish hole extraction/migration kinetic seriously suppresses the charge separation/transport. Thus, accelerating hole transfer kinetics emerges as the effective route to boost the photocatalytic processes. Nevertheless, to the best of our knowledge, a timely review, which focuses on single atom extracting photogenerated hole for important photocatalytic reactions, is still missing. Thus, this review summarizes the latest achievement of hole extraction in single‐/dual‐single atom photocatalysts for key energy/environment‐related reactions (e.g., water splitting, Carbon dioxide (CO 2 ) reduction, Nitrogen (N 2 ) fixation, and wastewater treatment/pollutant degradation). Particularly, this review introduces the important role of advanced ex/in situ characterizations for exploring charge kinetics. It also offers new insights into accurate design of advanced single‐/dual‐single atom photocatalysts with optimized electron/hole transfer kinetics for key energy/environmental‐related applications.