Ni-MoS2@B-Ti3C2纳米异质结构制备及其电催化析氢性能

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

摘要:

采用硼掺杂碳化钛（B-Ti₃C₂，MXene结构）纳米片作为基底，经水热反应原位生长Ni掺杂二硫化钼（Ni-MoS₂），成功制备了系列Ni掺杂的Ni-MoS₂@B-Ti₃C₂纳米异质结构电催化剂，并对其成分、结构及电催化析氢性能进行了表征与评价。结果表明，1%Ni-MoS₂@B-Ti₃C₂明显优于其它Ni含量的异质结构电催化剂，碱性环境下达到10 mA·cm^-2电流密度仅需130 mV，Tafel斜率为91.8 mV·dec^-1，且能稳定运行12 h以上。理论计算进一步阐明，Ni掺杂有效优化了边缘硫位点的氢吸附自由能，结合MXene载体的强电子相互作用，协同降低了析氢反应能垒。

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.