The H₂O Dissociation and Hydrogen Evolution Performance of Monolayer MoS₂ Containing Single Mo Vacancy: A Theoretical Study

The molybdenum disulfide (MoS ₂ ), as a promising and nonprecious catalyst, has attracted growing interest towards the hydrogen production, especially the dissociation of water and the hydrogen evolution reaction (HER). However, the known active sites are limited to edges and one primitive cell missing vacancies. Herein, the potential catalytic activities of Mo-vacancies in the inert basal plane of MoS ₂ are investigated by means of first-principle density functional theory (DFT) calculations. Mo-vacancies was found to have the promising catalytic activities for the splitting of H ₂ O and have the comparable or even better catalytic activities for the HER, in compared with the precious Pt. Moreover, the catalytic activities of these active sites are well understood in terms of the analysis of the adsorption energy, the total and partial density states (DOS, PDOS), and the Bader charge transfer. Our theoretical works suggest that formation of the specified vacancy defects on the inert basal plane will enhance the catalytic activities of MoS ₂ for the dissociation of H ₂ O and the HER, which improves the efficiency of hydrogen production.