Double transition metal carbide MXene Ti2VC2Tx/MoS2-CNTs hybrids as efficient self-supporting electrocatalyst for enhanced hydrogen evolution

Molybdenum disulphide (MoS2) has been widely studied as a potential alternative to Pt/C catalysts for hydrogen evolution reactions (HER) in acidic conditions. However, the limited electron transfer capability and poor conductivity restrict further improvement of the HER activity. Herein, a novel bimetallic Ti2VC2Tx MXene/MoS2 heterojunction was fabricated by hydrothermal method. In addition, hydroxylated carbon nanotubes (CNTs) was incorporated to increase its conductivity and structural stability. The as-prepared Ti2VC2Tx/MoS2-CNTs electrocatalyst was characterized and the HER performance were investigated in acidic media. The effects of different weight ratio of Ti2VC2Tx to ammonium molybdate tetrahydrate (AMT), catalyst mass loading, and CNTs dosage on the HER activities of Ti2VC2Tx/MoS2-CNTs were optimized. The optimal electrocatalyst exhibits superior HER properties in 0.5 M H2SO4 electrolyte with an overpotential of 183 mV at a current density of 10 mA center dot cm(-2), a Tafel slope of 83 mV center dot dec(-1), a double-layer capacitance (C-dl) value of 160 mF cm(-2), as well as satisfactory long-term stability. This study provides an intentional exploration for developing bimetallic MXene based HER electrocatalysis application.