The interfacial Ni–O–V linkages drive built−in fields for high−efficiency alkaline hydrogen evolution

The hydrogen evolution reaction (HER) is hindered by sluggish Volmer step kinetics and intrinsic scaling relations among reaction intermediates. Herein, we report a density functional theory (DFT)-guided interfacial engineering strategy that integrates VO x into metallic Ni anchored on porous NiSe 2 to create Ni–O–V linkages that generate built-in electric fields and multitype active sites. DFT simulations show that these interfacial linkages promote charge redistribution, facilitate water activation and lower the water-dissociation barrier at Ni–O–V sites, while the downward shift of the Ni d -band center tunes H binding toward thermoneutrality. Guided by theory, we fabricated a self-supported NiVO x /NiSe 2 heterostructure electrode through a combination of electrochemical deposition and solvothermal selenization. As anticipated, such a heterostructure electrode delivers superior HER activities, requiring an overpotential of only 48 mV to achieve 10 mA cm −2 , a small Tafel slope of 44.2 mV dec −1 , a high Faradaic efficiency of 97%, and long-term durability. • DFT−guided NiVO x /NiSe 2 heterostructure with Ni–O–V linkages was developed for the first time. • Interfacial Ni–O–V linkages create built-in electric fields to enhance water activation and optimize H adsorption. • The heterostructure electrode exhibits superior alkaline HER performance. • The mechanism behind the superior performance is clarified.