不对称沉积合成PdS-CdSe@CdS-Au一维纳米异质结构及其光解水制氢性能

Abstract Charge separation is a crucial problem in photocatalysis. We used a wet-chemical method to synthesize asymmetrically tipped PdS-CdSe-seeded CdS (CdSe@CdS)-Au nanorod (NR) heterostructures (HCs). In these HCs, electrons and holes are rapidly separated and transported to opposite ends of the NRs by internal electric fields. Their ultraviolet-visible absorption spectra showed strong electronic coupling between both tips and the CdS body. PdS-CdSe@CdS-Au achieved a H2 production rate of ca. 1100 μmol in 5 h; this is two orders of magnitude greater than the rate achieved with Au-CdSe@CdS NRs with only one tip. PdS-CdSe@CdS-Au NRs can withstand 4 h of photoirradiation, compared to 1.5 h for CdSe@CdS NRs, indicating that the photostability of PdS-CdSe@CdS-Au is much better than that of CdS. The greatly improved photocatalytic activity and stability are attributed to efficient charge separation and rapid charge transport in the PdS-CdSe@CdS-Au HCs.