Liquid-phase epitaxial growth of two-dimensional semiconductor hetero-nanostructures

Although many two-dimensional (2D) hybrid nanostructures are being prepared, the engineering of epitaxial 2D semiconductor hetero-nanostructures in the liquid phase still remains a challenge. The preparation of 2D semiconductor hetero-nanostructures by epitaxial growth of metal sulfide nanocrystals, including CuS, ZnS and Ni₃S₂, is achieved on ultrathin TiS₂ nanosheets by a simple electrochemical approach by using the TiS₂crystal and metal foils. Ultrathin CuS nanoplates that are 50-120 nm in size and have a triangular/ hexagonal shape are epitaxially grown on TiS₂nanosheets with perfect epitaxial alignment. ZnS and Ni₃S₂nanoplates can be also epitaxially grown on TiS₂nanosheets. As a proof-of-concept application, the obtained 2D CuS-TiS₂composite is used as the anode in a lithium ion battery, which exhibits a high capacity and excellent cycling stability.