Hydrogen Evolution Catalyzed by A Sub-Stoichiometric Molybdenum Sulfide Two-Dimensional Structure

M. Yang, J.W. Chai, S.J. Wang, D.Z. Chi
Institute of Materials Research and Engineering,

Keywords: 2D materials, hydrogen evolution reaction, catalyst, MoS2


Molybdenum disulfide has been demonstrated as a promising catalyst for hydrogen evolution reactions (HER). However, its performance is limited by fractional active edge sites and the strong dependence on hydrogen coverage. In this study, we report the synthesis of a new class of two-dimensional (2D) sub-stoichiometric molybdenum sulfide on sulfur-enriched substrate, constructed from Mo6S8 chevrel building blocks. We reveal that the basal plane of this sub-stoichiometric molybdenum sulfide 2D structure is chemically reactive towards HER as evidenced by an optimum Gibbs free energy and a low reaction overpotential. More interestingly, the HER performance is insensitive to hydrogen coverages and can be improved under compressive in-plane biaxial strains. Our results suggest an improved HER performance of sub-stoichiometric molybdenum sulfide due to its chemical reactive basal plane, and also a way to tune the performance.