Molybdenum Disulfide/Titanium Carbide MXene Heterostructure with Mixed-Phase Coupling and Moiré Superlattice Interface for Highly Efficient Alkaline Hydrogen Evolution

The development of efficient and earth-abundant hydrogen evolution reaction (HER) electrocatalysts is critical for advancing sustainable hydrogen production.In this study, we report a Molybdenum Disulfide/Titanium Carbide MXene (MoS2/Ti3C2Tx) heterostructure that integrates mixed-phase MoS2 nanosheets with an interfacial moiré superlattice, achieving high intrinsic HER activity and stability under alkaline conditions.The catalyst is synthesized via a hydrothermal method, producing vertically aligned MoS2 nanosheets on Ti3C2Tx substrates to form a tightly coupled sandwich-like heterointerface.Structural characterization reveals (i) a well-defined MoS2/Ti3C2Tx interface, (ii) coexistence of metallic and semiconducting MoS2 domains, and (iii) periodic moiré fringes at the interface.Electrochemical measurements in 1.0 M KOH show that the heterostructure exhibits an onset overpotential of ~90 mV, a low η10 of 138 mV, and a Tafel slope of 65 mV•dec -1 , outperforming pristine MoS2, Ti3C2Tx, and even commercial Pt/C under high current density (η100 = 342 mV).Density functional theory (DFT) calculations indicate that the optimized heterointerface exhibits near-thermoneutral hydrogen adsorption (ΔG*H ≈ 0.65 eV) and enhanced interfacial charge delocalization, which synergistically facilitate rapid charge transfer and efficient H + adsorption/desorption.These findings highlight a promising strategy combining mixed-phase engineering, MXene coupling, and moiré superlattice design, offering new insights for the development of cost-effective, high-performance HER electrocatalysts for alkaline water splitting.