Molybdenum carbide MXene embedded with nickel sulfide clusters as an efficient electrocatalyst for hydrogen evolution reaction

Molybdenum-based MXene materials (Mo2CTx) have recently demonstrated great potential in electrocatalytic hydrogen production. Herein, we fabricated a novel NiS/Mo2CTx hybrid via chemical etching in an NH4F/HCl solution followed by solvothermal reactions, where nickel sulfide (NiS) clusters were embedded between the interlayers of Mo2CTx. The intrinsic structure and electrochemical properties were experimentally investigated to explore the potential of an electrocatalyst for hydrogen evolution. As expected, the heterostructure by embedding NiS into the Mo2CTx MXene interlayers not only brings about large electrochemical surface areas with abundant active site exposure but also enhances the intrinsic kinetics to facilitate the electrolysis process. Electrochemical tests revealed that the NiS/Mo2CTx catalyst exhibited the HER performance with a small overpotential of 157 mV to drive the current density of 10 mA cm−2 and long-term stable durability, which are superior to that of pristine Mo2CTx MXene and nickel sulfides. This study can provide a synthetic strategy for designing and developing Mo2CTx MXene-based electrocatalysts for hydrogen production.