Tailoring activation sites of metastable distorted 1T′-phase MoS₂ by Ni doping for enhanced hydrogen evolution

Heteroatom doping is a promising approach to enhance catalytic activity by modulating physical properties, electronic structure, and reaction pathway. Herein, we demonstrate that appropriate Ni-doping could trigger a preferential transition of the basal plane from 2H (trigonal prismatic) to 1T′ (clustered Mo) by inducing lattice distortion and S vacancy (SV) and thus dramatically facilitate its catalytic hydrogen evolution activity. It is noteworthy that the unique catalysts did possess superior catalytic performance of hydrogen evolution reaction (HER). The rate of photocatalytic hydrogen evolution could reach 20.45 mmol·g⁻¹·h⁻¹ and reduced only slightly in the long period of the photocatalytic process. First-principles calculations reveal that the distorted Ni-1T′-MoS₂ with SV could generate favorable water adsorption energy (E_ad(H₂O)) and Gibbs free energy of hydrogen adsorption (∆G_H). This work exhibits a facile and promising pathway for synergistically regulating physical properties, electronic structure, or wettability based on the doping strategy for designing HER electrocatalysts.