Interfacial Structure Modulation Triggering Dual Sites Synergy for Industrial-Grade Water Electrolysis

Anion exchange membrane water electrolysis (AEMWE) is recognized as a promising technology for green hydrogen production. The development of high-performance non-noble-metal-based (NNM) electrocatalysts is crucial for its industrial-scale deployment. However, in alkaline media, they typically face a critical challenge in simultaneously activating water molecular and optimizing hydrogen species adsorption, resulting in sluggish water dissociation kinetics. Herein, we engineer a NiS/Ni₃S₂ heterojunction with strong interfacial interaction via a facile cathodic polarization method. Theoretical and experimental analyses reveal a synergistic dual-site mechanism of hydrogen evolution reaction: Ni sites promote H₂O adsorption through upshifted d-band center, serving as the primary water dissociation centers; concurrently, S sites optimize the hydrogen binding energy by accepting interfacial charges, facilitating H* adsorption/desorption. This dual-site mechanism significantly lowers the energy barrier of the Volmer step. Impressively, in AEMWE tests the resultant NiS/Ni₃S₂@W requiring only 1.73 and 1.68 V to reach a current density of 1 A cm^-2 at 60°C and 80°C, respectively. Furthermore, it can maintain stable operation for over 1 000 h at 1.5 A cm^-2 and exhibits robust tolerance under dynamic fluctuating conditions. This work provides a reliable interface engineering strategy for designing efficient electrocatalysts for industrial-grade water electrolysis.