Substitutional VSn nanodispersed in MoS$_2$ film for Pt-scalable catalyst

TL;DR

This paper introduces a novel VSn-doped MoS2 catalyst with enhanced hydrogen evolution reaction performance, achieved by atomic-level engineering of transition metal dichalcogenides to improve catalytic activity and stability.

Contribution

It demonstrates the synthesis of VSn nanodispersed in MoS2, showing scalable catalytic performance and providing insights into atomic-level engineering of TMdCs for better HER activity.

Findings

Achieved high current density of 1000 mA/cm² at 0.6 V

Exhibited excellent cycle stability for HER

Identified efficient electron transfer mechanisms near vanadium sites

Abstract

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, we propose metallic vanadium sulfide (VSn) nanodispersed in a semiconducting MoS2 film (V-MoS2) as an efficient catalyst. During synthesis, vanadium atoms are substituted into hexagonal monolayer MoS2 to form randomly distributed VSn units. The V-MoS2 film on a Cu electrode exhibits Pt-scalable catalytic performance; current density of 1000 mA cm-2 at 0.6 V, overpotential of -0.06 V at a current density of 10 mA cm-2 and exchange current density of 0.65 mA cm-2 at 0 V with excellent cycle stability for hydrogen-evolution-reaction (HER). The high intrinsic HER performance of V-MoS2 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 adds insight into ways to engineer TMdCs at the atomic-level to boost intrinsic catalytic activity for hydrogen evolution.