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

The hydrogen evolution reaction (HER) with MoS2 as theelectrocatalyst typically suffers from its inert kinetics due to theunsuitable adsorption capability of MoS2 toward hydrogen.To address this issue, we herein successfully design and synthesizea Mott-Schottky (M-S) heterojunction Au delta+/MoS1.76 electrocatalyst by integrating interfacial chemistry,phase engineering, and S-vacancy implantation and demonstrate thatAu(delta+)/MoS1.76 has superior HER activityand good stability with a low overpotential (similar to 90 mV) and alow Tafel slope (similar to 47 mV dec(-1)). Density functionaltheory calculation indicates that engineering of the Au delta+/MoS1.76 M-S interface can naturally endow MoS1.76 with more negative charges, effectively regulating theMoS(2) electronic structure, stabilizing the 1T metallicphase, and optimizing Gibbs free energy of H adsorption. This workprovides an alternative strategy to modify the electronic structureof transition-metal dichalcogenides and deepens our understandingof catalytic behavior of MoS2 toward HER.