Substitutional Vanadium Sulfide Nanodispersed in MoS(2) Film for Pt‐Scalable Catalyst

Among transition metal dichalcogenides (TMdCs) as alternatives for Pt‐based catalysts, metallic‐TMdCs catalysts have highly reactive basal‐plane but are unstable. Meanwhile, chemically stable semiconducting‐TMdCs show limiting catalytic activity due to their inactive basal‐plane. Here, metallic vanadium sulfide (VS(n)) nanodispersed in a semiconducting MoS(2) film (V–MoS(2)) is proposed as an efficient catalyst. During synthesis, vanadium atoms are substituted into hexagonal monolayer MoS(2) to form randomly distributed VS(n) units. The V–MoS(2) film on a Cu electrode exhibits Pt‐scalable catalytic performance; current density of 1000 mA cm(−2) at 0.6 V and overpotential of −0.08 V at a current density of 10 mA cm(−2) with excellent cycle stability for hydrogen‐evolution‐reaction (HER). The high intrinsic HER performance of V–MoS(2) is explained by the efficient electron transfer from the Cu electrode to chalcogen vacancies near vanadium sites with optimal Gibbs free energy (−0.02 eV). This study provides insight into ways to engineer TMdCs at the atomic‐level to boost intrinsic catalytic activity for hydrogen evolution.