Engineering W/Mo-modified Ni3S2 with local crystalline/disordered interfacial domains for efficient alkaline hydrogen evolution

W/Mo-modified Ni 3 S 2 features local crystalline/disordered interfacial domains. • The electrode requires 101 mV at 10 mA cm −2 with a 69.9 mV dec −1 Tafel slope. • Stable HER operation is maintained for 100 h at 100 mA cm −2 . • DFT suggests modulated H* adsorption energetics and a lower water dissociation barrier. The rational engineering of crystalline/disordered interfacial domains with tailored electronic properties represents a promising strategy for developing high-performance electrocatalysts for the hydrogen evolution reaction (HER). Herein, a three-dimensional self-supported W/Mo-modified Ni 3 S 2 -based electrocatalyst with local crystalline/disordered interfacial domains (Ni 3 S 2 @W:Mo-0.2:0.2) is fabricated through a facile hydrothermal strategy. Structural characterizations support the coexistence of crystalline Ni 3 S 2 domains and adjacent Ni-containing W/Mo/O-associated disordered regions, while the combined experimental and theoretical results suggest interfacial electronic regulation and enhanced alkaline HER kinetics. The local interfacial structure is associated with interfacial charge-transfer behavior. Consequently, the electrode requires an average overpotential of 101.00 ± 1.73 mV at 10 mA cm −2 in 1 M KOH, together with improved apparent kinetics, reduced charge-transfer resistance, and stable operation at 100 mA cm −2 for 100 h. The enhanced activity arises from the combined contributions of accessible surface area, ECSA-normalized apparent specific activity, and charge-transfer kinetics. Density functional theory (DFT) calculations suggest modulated H* adsorption energetics and a lower water dissociation barrier. Gas chromatography (GC) analysis quantitatively confirms sustained H 2 generation. This work provides insights into interfacial engineering and electronic structure regulation for advanced electrocatalyst design. Download: Download high-res image (215KB) Download: Download full-size image