Confining Tungsten Disulfide Quantum Dots on MXene Nanosheets Enables Efficient Hydrogen Evolution Reaction

Zero-dimensional (0D) tungsten disulfide quantum dots (WS 2 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 WS 2 QDs on the surface of two-dimensional (2D) Ti 3 C 2 T x MXene nanosheets (WS 2 QDs/Ti 3 C 2 T x ) through a controllable assembly process. Because of the unique structural characteristics, such as large specific surface area, homogeneous WS 2 QDs dispersion, stable 0D/2D heterointerfaces, and excellent electrical conductivity, the resultant WS 2 QDs/Ti 3 C 2 T x 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 WS 2 QDs and Ti 3 C 2 T x electrocatalysts.