Confining TungstenDisulfide Quantum Dots on MXeneNanosheets Enables Efficient Hydrogen Evolution Reaction

Zero-dimensional (0D) tungsten disulfide quantum dots (WS₂ QDs) with an active edge structure are considered as promising cathode catalysts toward the hydrogen evolution reaction (HER), while their serious agglomeration phenomenon and intrinsic semiconducting property largely restrain the overall electrocatalytic performance. To circumvent these barriers, here we adopt a convenient and cost-effective method to confine ultrafine WS₂ QDs on the surface of two-dimensional (2D) Ti₃C₂T_<i>x</i> MXene nanosheets (WS₂ QDs/Ti₃C₂T_<i>x</i>) through a controllable assembly process. Because of the unique structural characteristics, such as large specific surface area, homogeneous WS₂ QDs dispersion, stable 0D/2D heterointerfaces, and excellent electrical conductivity, the resultant WS₂ QDs/Ti₃C₂T_<i>x</i> electrocatalyst demonstrates prominent HER capacities in terms of a low onset potential, a small Tafel slope, and dependable long-term durability, which are superior to those of bare WS₂ QDs and Ti₃C₂T_<i>x</i> electrocatalysts.