One-step synthesis of MoS 2 /NiS heterostructures with a stable 1T phase for an efficient hydrogen evolution reaction.

Metallic phase (1T) MoS 2 has been regarded as an ideal catalytic material for the hydrogen evolution reaction (HER) due to its high active site density and favorable electrical conductivity. However, the preparation of 1T-phase MoS 2 samples requires tough reaction conditions and 1T-MoS 2 has poor stability under alkaline conditions. In this work, 1T-MoS 2 /NiS heterostructure catalysts grown in situ on carbon cloth were prepared by a simple one-step hydrothermal method. The obtained MoS 2 /NiS/CC combines the advantages of high active site density and a self-supporting structure, achieving stable 77% metal phase (1T) MoS 2 . The combination of NiS and 1T-MoS 2 enhances the intrinsic activity of MoS 2 while the electrical conductivity is improved. These advantages enable the 1T-MoS 2 /NiS/CC electrocatalyst to have a low overpotential of 89 mV (@10 mA cm -2 ) and a small Tafel slope of 75 mV dec -1 under alkaline conditions and provide a synthetic strategy of stable 1T-MoS 2 -based electrocatalysts for the HER by a heterogeneous structure.