Doping of MoS2 basal planes with transition metals for hydrogen evolution: Linking electronic structure, hydrogen adsorption, and catalytic activity

Activating the comparatively inactive basal plane of molybdenum disulfide (MoS 2 ) is a promising strategy for improving hydrogen evolution reaction (HER) catalysis, but transition-metal effects cannot be captured by a single descriptor. This study compares substitutional Mn-, Zn-, and Co-doped MoS 2 using a common 3 × 3 × 1 density-functional-theory framework and analytical re-analysis of structural, band-gap, density-of-states (DOS), and hydrogen-interaction data. All dopants preserved the global lattice dimensions while strongly restructuring the electronic states. Relative to pristine MoS 2 (2.07 eV), clean-system band gaps decreased to 0.13, 0.02, and 0.42 eV for Mn–MoS 2 , Zn–MoS 2 , and Co–MoS 2 , corresponding to reductions of 93.72%, 99.03%, and 79.71%, respectively. Although Zn produced the greatest band-gap narrowing, Mn showed the strongest qualitative DOS activation near the Fermi level. Co exhibited the largest hydrogen-induced electronic response, with its band gap increasing from 0.42 to 0.81 eV (+92.86%), together with the lowest reported hydrogen-interaction metric (6.47 eV). Literature benchmarking supports these dopant-specific trends. Overall, Zn favors gap engineering, Mn enhances Fermi-level state availability, and Co shows pronounced hydrogen-responsive behavior, demonstrating that HER screening should integrate complementary electronic and hydrogen-interaction descriptors rather than rely on band-gap reduction alone for rational basal-plane catalyst design strategies.