Doughty-electronegative heteroatom-induced defective MoS₂ for the hydrogen evolution reaction

Producing hydrogen through water electrolysis is one of the most promising green energy storage and conversion technologies for the long-term development of energy-related hydrogen technologies. MoS₂ is a very promising electrocatalyst which may replace precious metal catalysts for the hydrogen evolution reaction (HER). In this work, doughty-electronegative heteroatom defects (halogen atoms such as chlorine, fluorine, and nitrogen) were successfully introduced in MoS₂ by using a large-scale, green, and simple ball milling strategy to alter its electronic structure. The physicochemical properties (morphology, crystallization, chemical composition, and electronic structure) of the doughty-electronegative heteroatom-induced defective MoS₂ (N/Cl-MoS₂) were identified using SEM, TEM, Raman, XRD, and XPS. Furthermore, compared with bulk pristine MoS₂, the HER activity of N/Cl-MoS₂ significantly increased from 442 mV to 280 mV at a current of 10 mA cm^-2. Ball milling not only effectively reduced the size of the catalyst material, but also exposed more active sites. More importantly, the introduced doughty-electronegative heteroatom optimized the electronic structure of the catalyst. Therefore, the doughty-electronegative heteroatom induced by mechanical ball milling provides a useful reference for the large-scale production of green, efficient, and low-cost catalyst materials.