Dual-phase MoS₂/MXene/CNT ternary nanohybrids for efficient electrocatalytic hydrogen evolution

Two-dimensional (2D) molybdenum disulfide (MoS₂) has been recognized as a potential substitution of platinum (Pt) for electrochemical hydrogen evolution reaction (HER). However, the broad adoption of MoS₂ is hindered by its limited number of active sites and low inherent electrical conductivity. In this work, we employed a one-step solvothermal synthesis technique to construct a ternary hybrid structure consisting of dual-phase MoS_2, titanium carbide (Ti₃C₂) MXene, and carbon nanotubes (CNTs), and demonstrated synergistic effects for active site exposure, surface area enlargement, and electrical conductivity improvement of the catalyst. The dual-phase MoS₂ (DP-MoS₂) is directly formed on the MXene with CNTs acting as crosslinks between 2D islands. The existence of edge-enriched metallic phase MoS₂, the conductive backbone of MXene along with the crosslink function of CNTs clearly improves the overall HER performance of the ternary nanocomposite. Moreover, the integration of MoS₂ with MXene not only increases the interlayer distance of the 2D layers but also partially suppresses the MXene oxidation and the 2D layer restacking, leading to good catalytic stability. As a result, an overpotential of 169 mV and a low Tafel slope of 51 mV/dec was successfully achieved. This work paves a way for 2D-based electrocatalyst engineering and sheds light on the development of the next-generation noble metal-free HER electrocatalysts.