Hierarchical few-layer fluorine-free Ti3C2TX (T = O, OH)/MoS2 hybrid for efficient electrocatalytic hydrogen evolution

Abstract

As an eco-friendly and renewable energy source, hydrogen energy has attracted widespread attention. MoS₂ nanomaterials are typical catalysts for the electrocatalytic hydrogen evolution reaction (HER), but their performances are limited by their poor conductivity and spontaneous agglomeration. Here, we prepared few-layer fluorine-free Ti₃C₂T_X (T = O, OH) as a conductive substrate of MoS₂ for HER catalysis, and the as-prepared hybrid catalyst exhibits high catalytic activity with a small overpotential of 139 mV at −10 mA cm⁻², a Tafel slope of 78 mV dec⁻¹, and a negligible decay after 3000 cycles at a scan rate of 100 mV s⁻¹ in an acidic solution. The excellent performance in HER activity can be attributed to the improved electrical conductivity, increased O active sites and optimized 2D mass-transport channels of the unique few-layer fluorine-free structure. Interestingly, the few-layer fluorine-free Ti₃C₂T_X/MoS₂ catalyst also performs well under neutral and alkaline conditions. This work demonstrates that few-layer fluorine-free Ti₃C₂T_X (T = O, OH) can be used as an excellent conductive substrate to further improve the HER performances of other nanoscale electrocatalysts.