Hydrogen Evolution Reaction of V‐Doped MoS ₂ Monolayers

ABSTRACT Molybdenum disulfide (MoS 2 ) has emerged as a promising non‐noble metal catalyst for the hydrogen evolution reaction (HER) due to its intrinsic electrocatalytic activity. However, its practical application is hindered by the inert basal plane, low electrical conductivity, and insufficient active sites. Transition metal doping provides an effective strategy for modulating material properties, offering a viable route to enhance electrocatalytic performance. In this work, controllable doping of vanadium (V) into monolayer MoS 2 was realized through chemical vapor deposition. By tuning the mass ratio of precursors, V‐doped MoS 2 (Mo 1‐x V x S 2 ) monolayers with controlled doping concentration were successfully synthesized, and the films exhibit high crystallinity and uniformity. Electrochemical measurements demonstrated that the Mo 1‐x V x S 2 film with 33.3% doping concentration exhibits a Tafel slope of 116.65 mV/dec in H 2 SO 4 , significantly outperforming pristine MoS 2 (164.08 mV/dec). Moreover, the catalyst retained over 90% of its activity after 9000 s of continuous electrolysis, highlighting its excellent stability. Density functional theory calculations revealed that vanadium doping reduces the hydrogen adsorption free energy at basal sulfur sites and enhances charge carrier mobility. This work demonstrates the effective modulation of the electronic structure and catalytic activity of MoS 2 via vanadium doping, offering a potential approach for the design of efficient and cost‐effective HER catalysts.