Disclosing the active integration structure and robustness of a pseudo-tri-component electrocatalyst toward alkaline hydrogen evolution

Designing multicomponent integration catalysts(MICs)has been a promising strategy for improving electrocatalytic hydrogen evolution reaction(HER)due to the highly active interfaces as well as electronic synergy.Nevertheless,many fundamental questions such as their actual active species and the influence on long-term stability remain to be answered.Herein,we present the structural evolution from a pseudotri-component electrocatalyst of nitrogen-doped carbon supported nickel/vanadium nitride/vanadium oxide(Ni-VN-V_(2)O_(3)/NC)nanorods to the heterostructural nickel/vanadium nitride(Ni-VN/NC)nanosheets during chemical or electrochemical processes.The self-reconstructed Ni-VN/NC exhibits a robust stability under alkaline conditions,while maintaining initial efficient HER activity with a low overpotential of 76 mV at the current density of 10 mA cm^(-2).Theoretical calculations and quasi-in-situ spectroscopic technology unveil the redistribution of electrons on the synergistic active interface,which synchronously optimizes the affinities for hydrogen,hydroxide,and water molecules,thereby remarkably accelerating the HER kinetics by reducing the barrier of Volmer step.