Dual‐Site Assisted Efficient Alkaline Hydrogen Evolution Reaction on NiS/VS ₂ @NF

ABSTRACT Engineering non‐noble metal heterostructure interfaces with multiple active sites is a promising strategy to overcome scaling relationships and enhance multistep reactions. Herein, a dual‐site heterogeneous catalyst of NiS/VS 2 @NF is developed by wrapping VS 2 on NiS bacillar structures supported on nickel foam, which promotes alkaline hydrogen evolution reaction (HER) at high current densities. In situ spectroscopic analysis and theoretical calculations revealed that strong interaction of V and Ni at the interface generates a distinctive electronic environment where both metal sites facilitate water adsorption, electron‐deficient V sites expedite water dissociation, electron‐rich Ni sites promote OH desorption, and V and Ni sites together help to streamline hydrogen coupling and the subsequent release via the Volmer‐Heyrovsky pathway. The as‐prepared NiS/VS 2 @NF requires only 222 and 279 mV to reach 0.5 and 1 A cm −2 , respectively, in 1 m KOH, and exhibits negligible change in current density over 140 h of continuous operation at −0.2 V RHE . This performance is not only better than that of Pt/C@NF, but also surpasses most of the recently reported transition metal sulfide‐based materials. This work offers critical insights into designing advanced catalysts for high‐performance alkaline HER and understanding their mechanism, with implications extending to a broad range of electrochemical applications.