Engineering the Local Atomic Configuration in 2H TMDs for Efficient Electrocatalytic Hydrogen Evolution

The introduction of heteroatoms is a widely employedstrategy forelectrocatalysis of transition metal dichalcogenides (TMDs). Thisapproach activates the inactive basal plane, effectively boostingthe intrinsic catalytic activity. However, the effect of atomic configurationsincorporated within the TMDs' lattice on catalytic activityis not thoroughly understood owing to the lack of controllable syntheticapproaches for highly doped TMDs. In this study, we demonstrate afacile approach to realizing heavily doped MoS2 with ahigh doping concentration above 16% via intermediate-reaction-mediatedchemical vapor deposition. As the V doping concentration increased,the incorporated V atoms coalesced in a manner that enabled both thebasal plane activation and electrical conductivity enhancement ofMoS(2). This accelerated the kinetics of the hydrogen evolutionreaction (HER) through the reduced Gibbs free energy of hydrogen adsorption,as evidenced by experimental and theoretical analyses. Consequently,the coalesced V-doped MoS2 exhibited superior HER performance,with an overpotential of 100 mV at 10 mA cm(-2), surpassingthe pristine and single-atom-doped counterparts. This study providesan intriguing pathway for engineering the atomic doping configurationof TMDs to develop efficient 2D nanomaterial-based electrocatalysts.