Preparation of Ni-MoS₂@B-Ti₃C₂ Nano-Heterostructures and Their Electrocatalytic Hydrogen Evolution Performance

Abstract:

A series of Ni-doped Ni-MoS₂@B-Ti₃C₂ nano-heterostructure electrocatalysts were prepared by in-situ growth of Ni-doped molybdenum disulfide (Ni-MoS₂) via hydrothermal reaction on boron-doped titanium carbide (B-Ti₃C₂, MXene structure) nanosheets as the substrate. The composition, structure, and electrocatalytic hydrogen evolution performance of the catalysts were characterized and evaluated. Results show that the 1%Ni-MoS₂@B-Ti₃C₂ heterostructure outperforms other catalysts with varying Ni contents. In alkaline media, it requires only 130 mV to achieve a current density of 10 mA·cm^-2, exhibits a Tafel slope of 91.8 mV·dec^-1, and maintains stable operation for over 12 h. Theoretical calculations further clarify that Ni doping effectively optimizes the hydrogen adsorption free energy of edge sulfur sites toward zero, which, combined with the strong electronic interaction of the MXene substrate, synergistically reduces the energy barrier for the hydrogen evolution reaction.