Controlled growth of Cu <sub/>2a??x</sub> S sheet-like nanoshells and Cu <sub/>2a??x</sub> Sa??CdS pa??n junctions on Au nanorods with coupled plasmon resonances and enhanced photocatalytic activities

摘要： In this study, we propose an approach to grow Cu2?xS sheet-like nanoshells on Au nanorods with the aid of Ag2S auxiliary templates. The Ag2S semi-shells are first grown on the side-surface of the Au nanorods and then, the Cu2?xS sheet-like nanoshells are selectively grown on the opposite side, which is beneficial for improving the controllability of the growth sites of the Cu2?xS sheet-like nanoshells. The Cu2?xS–CdS p–n junctions grown on Au nanorods are produced by replacing Ag+ with Cd2+ in the as-prepared Au/(Cu2?xS–Ag2S), so that Au/(Cu2?xS–CdS) heterorods with non-central symmetric shells of Cu2?xS–CdS p–n junctions are formed. By carefully adjusting the effective thickness of the Cu2?xS–CdS junctions, the optimized photocatalytic activity of the Au/(Cu2?xS–CdS) heterorods is obtained, and it is about 1.62 and 1.22-fold that of Au/Cu2?xS and Au/CdS, respectively. The improved photocatalytic performance of the Au/(Cu2?xS–CdS) heterorods is attributed to the effective charge carriers at the interfaces of CdS–Au, Cu2?xS–Au and the Cu2?xS–CdS p–n junction. Our findings provide a strategy for the optimal design of plasmon–exciton heterostructures with improved photocatalytic activity.