Synthesis of plasmonic Au-CuS hybrid nanocrystals for photothermal transduction and chemical transformations

Plasmonic Au-copper sulfides hybrid nanocrystals are of great interest for both fundamental research and application in optoelectronics, catalysis, and biomedicine, in which a precise and high-yield synthesis of the hybrid nanocrystals is required. Herein, we investigated colloidal synthesis of Au-CuS hybrid nanocrystals based on a seed-mediated method. Different from previously reported deposition of Cu-rich Cu chalcogenides, we found that decreasing the Cu-S reaction rate is critical for the deposition of relatively S-rich CuS on Au seeds in high yield, which can be achieved by using a chlorobenzene solution containing a small amount of oleylamine as the solvent. The influence of the S/Cu feed molar ratio and reaction temperature on the formation of Au-CuS hybrid nanocrystals has also been investigated. The obtained Au-CuS hybrids showed better photothermal transduction efficiency over CuS nanocrystals prepared under identical conditions. In addition, Au-CuS hybrids could be used as templates to synthesize Au-CuInS2 and Au-Cu2ZnSnS4 hybrid nanocrystals via subsequent reactions with In or Zn/Sn precursors at high temperature. These results provide insight into the critical parameters governing the growth of Au-copper sulfides hybrid nanostructures, which can be useful for the design of other noble metal-semiconductor hybrid nanostructures