Controlled Growth of Cu2–xS Sheet-like Nanoshells and Cu2–xS–CdS p-n Junctions on Au Nanorods with Coupled Plasmon Resonances and Enhanced Photocatalytic Activities
In this study, we propose an approach to grow Cu2–xS sheet-like nanoshells on Au nanorods with the aid of Ag2S auxiliary templates. Ag2S semi-shells are first grown on the side-surface of Au nanorods, then Cu2–xS sheet-like nanoshells are selectively grown on the opposite side, which is beneficial to improve the controllability of the growth sites of Cu2–xS sheet-like nanoshells. The Cu2–xS–CdS p-n junctions grown on Au nanorods are produced by replacing Ag+ with Cd2+ on the basis of the as-prepared Au/(Cu2–xS–Ag2S), so 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 Au/(Cu2–xS–CdS) heterorods is obtained and it is about 1.62 and 1.22 times that of Au/Cu2–xS and Au/CdS. The improved photocatalytic performance of Au/(Cu2–xS–CdS) heterorods are attributed to the effective charge carriers at the interfaces of CdS–Au, Cu2–xS–Au and Cu2–xS–CdS p-n junction. Our findings provide a strategy for the optimal design of plasmon-exciton heterostructures with improved photocatalytic activity.