Engineering Mott–Schottky Heterojunction Au^δ+/1T-MoS_1.76 Electrocatalyst for Boosting Hydrogen Evolution Reaction

The hydrogen evolution reaction (HER) with MoS 2 as the electrocatalyst typically suffers from its inert kinetics due to the unsuitable adsorption capability of MoS 2 toward hydrogen. To address this issue, we herein successfully design and synthesize a Mott–Schottky (M–S) heterojunction Au δ+ /MoS 1.76 electrocatalyst by integrating interfacial chemistry, phase engineering, and S-vacancy implantation and demonstrate that Au δ+ /MoS 1.76 has superior HER activity and good stability with a low overpotential (∼90 mV) and a low Tafel slope (∼47 mV dec –1 ). Density functional theory calculation indicates that engineering of the Au δ+ /MoS 1.76 M–S interface can naturally endow MoS 1.76 with more negative charges, effectively regulating the MoS 2 electronic structure, stabilizing the 1T metallic phase, and optimizing Gibbs free energy of H adsorption. This work provides an alternative strategy to modify the electronic structure of transition-metal dichalcogenides and deepens our understanding of catalytic behavior of MoS 2 toward HER.