Defects Enhance the Electrocatalytic Hydrogen Evolution Properties of MoS2 -based Materials.

MoS2 have recently emerged as alternatives to noble metals as electrocatalysts for the hydrogen evolution reaction (HER) owing to their abundance and low cost. Considering the shortcomings of MoS2 , including insufficient active sites, inert basal plane, and poor conductivity, the electrocatalytic hydrogen evolution properties of MoS2 can be improved in three ways: activating the inert basal plane to improve intrinsic activity, increasing active edge sites, and improving the conductivity. Defects can adjust the surface electronic structure of the crystal to bring the hydrogen adsorption free energy closer to zero. Therefore, current research has mainly used S-vacancies to activate the inert basal surface of MoS2 ; used edge defects to increase the number of active sites; and used defective conductive carbon supports to improve the conductivity of MoS2 -based catalysts. This review introduces researches on improving the performance of MoS2 for HER by considering the purpose, characterization, and preparation of defects.