The introduction of heteroatoms is a widely employed
strategy for
electrocatalysis of transition metal dichalcogenides (TMDs). This
approach activates the inactive basal plane, effectively boosting
the intrinsic catalytic activity. However, the effect of atomic configurations
incorporated within the TMDs’ lattice on catalytic activity
is not thoroughly understood owing to the lack of controllable synthetic
approaches for highly doped TMDs. In this study, we demonstrate a
facile approach to realizing heavily doped MoS2 with a
high doping concentration above 16% via intermediate-reaction-mediated
chemical vapor deposition. As the V doping concentration increased,
the incorporated V atoms coalesced in a manner that enabled both the
basal plane activation and electrical conductivity enhancement of
MoS2. This accelerated the kinetics of the hydrogen evolution
reaction (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, surpassing
the pristine and single-atom-doped counterparts. This study provides
an intriguing pathway for engineering the atomic doping configuration
of TMDs to develop efficient 2D nanomaterial-based electrocatalysts