Copper-triggered adjacent S sites activating for enhancing the hydrogen evolution reaction in acid media

Activating the inert basal plane of MoS 2 is considered to be an efficient strategy to enhance the HER activity of MoS 2 . Herein, the adjacent S sites in the basal plane were activated by doping cu into MoS 2 nanosheets (cu-MoS 2 ). The density functional theory (DFT) calculation and experimental results show that the electronic structure of S sites adjacent to cu was adjusted. Furthermore, the ∆GH* of adjacent S sites around cu in the basal plane is closer to zero, indicating that the adsorption of H on MoS 2 was also optimized. Benefiting from the activation of adjacent S sites around cu in the basal plane, the obtained cu-MoS 2 nanosheets exhibit a small overpotential of 172 mV to achieve 10 mA cm −2 in acid media with a low Tafel slope of 49 mV decade −1 . This strategy, which involves doping-triggered activation of adjacent inert active sites, can be expanded to other two-dimensional materials for boosting electrocatalytic activity