Decorating Co3+-rich Na0.96CoPO4 with silver nanoparticles as a high-efficiency catalyst for oxygen evolution reaction

Abstract

Developing oxygen evolution reaction catalysts with high activity and robust stability represents a critical precondition for the large-scale application of electrochemical hydrogen production. In this study, a novel composite catalyst (Ag@Na0.96CoPO4) consisted of Na-ion-deficient Na0.96CoPO4 matrix and Ag nanoparticles modifiers are well-designed to efficiently catalyse the OER. Cation defect engineering applied to the Na0.96CoPO4 matrix can modulate the oxidation state and electronic structure of Co species, thereby improving the intrinsic activity. Subsequently, Ag nanoparticles are deposited onto the surface of Na0.96CoPO4 via a solution infiltration method. The engineering of Ag modification not only promotes charge transfer, but also further modulates the electronic structure of Co. Benefitting from the tailored electronic structure of Co, the improved intrinsic activity together with the strengthened interaction between Na0.96CoPO4 substrate and Ag nanoparticles modifiers, the Ag@Na0.96CoPO4 composite displays an excellent catalytic activity with a low overpotential of 276 mV at the current density of 10 mA cm-2, markedly superior to the commercial IrO2 of 318 mV.