Charge Transfer of Interfacial Catalysts for Hydrogen Energy

Abstract

The development of multifunctional non-precious transition metal electrocatalysts is technologically significant in hydrogen and oxygen electrochemistry but challenging. Here we exploit interface engineering to construct a novel interface catalyst of Ni3N and Co2N that exhibits multifunctional hydrogen and oxygen electrochemical activities in alkaline media. The interface catalysts of Ni3N/Co2N show superior bifunctional activity for hydrogen electrochemistry comparable to the state-of-the-art Pt catalyst, as well as high oxygen evolution reaction activity. Furthermore, the multifunctional Ni3N/Co2N interface electrocatalysts demonstrate excellent applications in water splitting for H2 generation and a highly stable Swagelok-type Ni–H battery for H2 utilization. Density functional theory calculations further confirm that the interfacial charge transfer from Ni to Co and N in Ni3N/Co2N efficiently enhances the dissociative adsorption of H2 and optimizes the adsorption configurations and binding energies of the intermediate hydrogen and hydroxide in the multifunctional reactions.