Single Atom Catalysts for Photoelectrochemical Water Splitting

Abstract Single atom catalysts (SACs) have attracted increasing attention in electrocatalysis due to their unprecedented catalytic activity with excellent atomic utilization efficiency derived from unique electronic states and coordination environments. In photoelectrochemical (PEC) water splitting, atomically dispersed metal catalysts anchored to photoelectrodes offer the breakthrough to outperform the conventional thin‐film PEC catalysts by enlarging the catalytic sites and facilitating photogenerated charge carrier kinetics. Herein, we present a comprehensive review of SAC‐incorporated photoelectrodes for efficient PEC water splitting. Firstly, the representative characterization techniques for the identification of SACs and investigations in respect of photogenerated charge carrier kinetics and photon‐to‐current efficiency will be discussed. Then, we will introduce the state‐of‐the‐art PEC‐SACs classified into noble metal, non‐noble metal, and dual metal SACs. Finally, critical outlooks to realize the full potential of SACs in photoelectrocatalysis will be highlighted.