Single-Atom Catalysts for Electrochemical Water Splitting

High-efficiency electrocatalysts with superior activity and stability are crucial to practical applications in water splitting, including the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). Downsizing the conventional nanoparticle catalyst to single atoms and constructing single-atom catalysts (SACs) is a rapidly emerging research focus. Because of the involvement of unique single-atom active moieties and the strong metal–support interactions arising from interfacial bonding, SACs as promising alternatives to noble metal-based nanoparticle catalysts exhibit profound power in the HER and OER. Here, we present a perspective on the exciting advances of SACs for HER and OER applications, with an emphasis on innovative synthetic strategies and an in-depth understanding of the structure–activity relationship through a combination of systematic characterization and theoretical studies. Finally, the challenges and some of the critical issues in this field are addressed.