Interfacial Electronic Structure Modulation and Surface Reconstruction in (Ni, Co)Se2/MoSe2 Mott-Schottky Heterojunction for pH-Universal Hydrogen Evolution.

Achieving efficient hydrogen evolution across the entire pH range remains challenging because distinct reaction environments require fundamentally different interfacial catalytic properties. Herein, a (Ni, Co)Se2/MoSe2 heterostructure was rationally constructed on carbon cloth through a hydrothermal-selenization strategy to regulate the interfacial electronic structure and optimize hydrogen evolution reaction (HER) kinetics. Benefiting from the formation of a Mott-Schottky heterointerface, pronounced charge redistribution and electronic coupling are achieved, leading to optimized hydrogen adsorption/desorption behavior and accelerated interfacial charge transfer. As a result, the optimized catalyst only requires overpotentials of 36, 83, and 67 mV to achieve 10 mA cm-2 in acidic, alkaline, and neutral electrolytes, respectively, together with enhanced long-term stability over 100 h at 50 mA cm-2 under alkaline conditions. Density functional theory (DFT) calculations further reveal that the heterointerface induces d-band-center modulation and weakens the excessive interaction with hydrogen intermediates, thereby facilitating hydrogen desorption and reducing the HER energy barrier. In addition, in situ Raman and post-catalytic characterizations demonstrate that surface reconstruction under alkaline conditions further contributes to the dynamic evolution of catalytically active sites. This study provides a general strategy for designing high-performance electrocatalysts capable of adapting to diverse reaction environments.