Interfacial Structural and Electronic Regulation of MoS2 for Promoting Its Kinetics and Activity of Alkaline Hydrogen Evolution.

The alkaline hydrogen evolution reaction (HER) of MoS2 is hampered by its sluggish water dissociation kinetics as well as limited edge sites. Herein, Ni3S2/MoS2 is fabricated as a model catalyst to highlight interfacial structural and electronic modulations of MoS2 for realizing its high performance in the alkaline HER. Experiments and density functional theory results demonstrate that the coupled Ni3S2 species can not only promote the adsorption and dissociation of H2O to boost the alkaline HER kinetics but also tailor the inert plane of MoS2 to create abundant unsaturated edge-like active sites, while the interfacial electron interaction can regulate the band gaps and Gibbs free energy of hydrogen adsorption of MoS2 to improve the electron conductivity as well as HER activity. Moreover, field emission scanning electron microscopy, transmission electron microscopy, Raman, ex situ synchrotron radiation X-ray absorption, and X-ray photoelectron spectroscopy results reveal the excellent structural stability of Ni3S2/MoS2 during the HER. As expected, the target Ni3S2/MoS2 achieves an ultralow overpotential of 68 mV at 10 mA cm-2, a fast alkaline HER kinetics, and remarkable durability. The proposed concept of interfacial structural and electronic reorganization could be extended to develop other functional materials.