Electron redistribution assisted enhanced hydrogen evolution activity of NbSe2–NiSe nanoheterostructures

Nanoheterostructures (NHSs) based on transition metal dichalcogenides (TMDs) play a vital role in regulating catalytic properties through electronic structure modulation, increased active site density, and improved electrical conductivity. However, the significance of electronic structures at the metal–metal interfacial contacts of TMD-based NHSs in catalysis remains largely unexplored. In this study, we demonstrate the design of NbSe₂–NiSe NHSs featuring metal–metal interfaces for the electrocatalytic hydrogen evolution reaction (HER). By combining experimental and theoretical studies, we establish synergistic interactions between NiSe nanoplates and NbSe₂ nanosheets (NSs), leading to electron redistribution and a consequent reduction in overpotential values of NbSe₂–NiSe NHSs for HER. Gibbs free energy calculations (ΔG_H*) using density functional theory (DFT) show a pronounced reduction in the energy barrier for hydrogen at the heterojunction owing to the formation of a built-in electric field at the interfaces. Our findings elucidate the role of metal–metal interfacial contacts in modulating the catalytic activity of Nb-based NHSs by establishing a method to comprehensively investigate the factors that dictate electrocatalytic characteristics.