Ultrathin NiPt Single-Atom Alloy for Synergistically Accelerating Alkaline Hydrogen Evolution

Single-atom Pt-based catalysts display a promising strategy to enhance the atomic utilization of noble metals while attaining desirable electrocatalytic properties. Moreover, rationally selecting the substrate helps optimize the water dissociation energy as well as promote H* conversion. Herein, we dispersed monoatomic Pt with ultralow content onto porous nickel nanosheets to accelerate the reaction kinetics of the hydrogen evolution reaction in an alkaline medium. Density functional theory calculations reveal that the synergistic effects between Ni–Ni and Ni–Pt sites are jointly responsible for the highly efficient hydrogen evolution reaction (HER) catalysis. Besides, ultrathin nanosheets with a porous structure of Ni substantially provide further enhancement. Consequently, the obtained NiPt alloy catalyst displays exceptional alkaline HER activity with a low overpotential of 18 mV at the specific current density of 10 mA cm–2 and a Tafel slope of 45 mV dec–1, which significantly outperform the commercial Pt/C. This work provides valuable guidelines for the proper design and construction of single-atom alloy catalysts.