Synergistic Low-Pt Modification and Ni Doping Facilitate the MoS2 Phase Transition for Accelerating the Hydrogen Evolution Reaction

Metal-phase MoS2 (1T-MoS2) is considered a promising candidate as a catalyst for the hydrogen evolution reaction (HER). However, the instability of 1T-MoS2 limits its electrocatalytic activity. Herein, we first synthesized 1T-MoS2 with excellent HER catalytic performance by a simple one-pot hydrothermal strategy of introducing the d-electron-rich transition metal atom Ni into MoS2. A bimetallic monatomic catalyst (Pt@1T-MoS2–Ni) was also prepared by modifying 1T-MoS2–Ni with Pt single atoms (Pt SAs). Experiments show that the electron transfer caused by Ni doping leads to the 1T phase transition, and the modification of Pt SAs further improves the electrical conductivity. These two factors synergistically modulate the electronic composition of MoS2 and increase the number of reactive sites. In consequence, the Pt@1T-MoS2–Ni catalyst exhibits significantly enhanced HER activity, achieving an overpotential as low as 76 mV at 10 mA/cm2 with the corresponding Tafel slope of only 46 mV/dec. Moreover, the current attenuation is negligible within 12 h, surpassing the performance of MoS2. This study offers ideas for improving the efficiency and stability of 1T-MoS2 catalyst designs.