Basal Plane Activation of MoS₂ by the Substitutional Doping of Vanadium toward Electrocatalytic Hydrogen Generation

Substitutional doping of vanadium (V) in MoS2 monolayers (MS) is shown to enhance the electrocatalytic hydrogen evolution (HER) activity of MS. In this report, the basal plane activation of MS toward HER via V-doping (VMS) is demonstrated both experimentally and theoretically. Single crystal electrochemical microcell based HER studies are conducted. The overpotential to achieve 10 mA cm–2 HER current density is ∼466 mV for MS, where it is reduced to ∼130 mV for optimum V-doped (1 atomic %) MS (VMS-L). Further enhancement in the V content (∼9 atomic %) increases the overpotential to ∼312 mV, despite the enhancement of its electrical conductivity. The overpotential obtained for VMS-L is better than the best reported values of 1T MoS2, and hence, here we demonstrate a thermodynamically stable VMS system with enormous HER performance in comparison to the other reported doped MoS2 structures.