Mo-Doped Sulfur-Vacancy-Rich V1.11S2 Nanosheets for Efficient Hydrogen Evolution

High-performance low-cost hydrogen evolution electrocatalysts are urgently demanded for hydrogen production by water splitting. Herein, we report that an efficient defect engineering strategy, NaBH4 treatment, was employed to promote the HER activity of pre-synthesized Mo-doped V1.11S2 nanosheets. The abundant sulfur vacancies enable Mo-doped V1.11S2 petaloid nanosheets with a low overpotential of 160 mV and a small Tafel slope of 46.2 mV dec(-1) at 10 mA cm(-2) to drive the HER, as well as excellent long-term stability in 0.5 mol L-1 H2SO4. The outstanding electrocatalytic performance can be attributed to the large electrochemical surface area and low charge transfer resistance.