Engineering Mott–Schottky Heterojunction Auδ+/1T-MoS1.76 Electrocatalyst for Boosting Hydrogen Evolution Reaction

Abstract

The hydrogen evolution reaction (HER) with MoS2 as the electrocatalyst typically suffers from its inert kinetics due to the unsuitable adsorption capability of MoS2 toward hydrogen. To address this issue, we herein successfully design and synthesize a Mott–Schottky (M–S) heterojunction Auδ+/MoS1.76 electrocatalyst by integrating interfacial chemistry, phase engineering, and S-vacancy implantation and demonstrate that Auδ+/MoS1.76 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 Auδ+/MoS1.76 M–S interface can naturally endow MoS1.76 with more negative charges, effectively regulating the MoS2 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 MoS2 toward HER.