MXene-supported copper-molybdenum sulfide nanostructures as catalysts for hydrogen evolution

The development of efficient and low-cost sustainable electrocatalytic hydrogen precipitation materials is an effective way to support the reduction of fossil fuel use. In recent years, in order to overcome the problem of the poor electrical conductivity of transition metal chalcogenides (TMCs), carbon-based materials and the MXene family have become popular TMC carriers. In this work, Cu₂MoS₄/Ti₃C₂T_x-30% materials with a special structure were synthesized for the first time via a simple and friendly solvothermal method. We successfully grew Cu₂MoS₄ in situ on a MXene (Ti₃C₂T_x) via solvent heating, and Cu₂MoS₄/Ti₃C₂T_x-30% was bonded together by electrostatic adsorption to form a special structure. Its overpotential is 103 mV lower than that of pure Cu₂MoS₄ at a current density of 10 mA cm^-2 in an acidic medium (0.5 M H₂SO₄). At the same time, under the same conditions, the Tafel slope is 37 mV dec^-1 lower than that of pure Cu₂MoS₄. Critically, the heterostructure retains high catalytic activity within 20 h. All of this is attributed to the special structure of Cu₂MoS₄/Ti₃C₂T_x-30%, resulting in increased conductivity, electrochemically active surface area (ECSA), and stability. This provides new ideas for future discoveries relating to the synthesis of non-precious transition metal two-dimensional composites. (authors)