Single-atom-based catalysts for photoelectrocatalysis: challenges and opportunities

Abstract

Photoelectrocatalysis (PEC) has recently emerged as a promising strategy for utilizing solar energy due to its unique features in combining the merits of electrocatalysis and photocatalysis in solar energy harvesting, charge kinetics and catalytic reactions. However, it still encounters bottlenecks of scarce reaction sites and low product selectivity, restricting its development toward practical applications. Over the past decade, single-atom-based catalysts (SACs) with atomically dispersed metal sites have demonstrated immense potential in many catalytic reactions. In comparison with their nanoparticles (NPs) or bulk counterparts, the SACs normally have enormous surface active sites and trigger unique surface reactions, which, if rationally designed, can open up wide possibilities for PEC. Here, we overview the challenges and opportunities of SACs in PEC. We first summarize the advantages of SACs in enhancing the adsorption of reactants, charge transfer, catalytic selectivity, and catalytic activity. Then we discuss the rational design of single-atom active sites in the photoelectrochemical system. In the end, challenges and perspectives regarding the fundamental research and development of single-atom catalysts in PEC are also proposed. We foresee that this timely perspective can provide some important insights for researchers in this field and accelerate the development of PEC.