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

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.