uO和CuS量子点修饰单晶TiO2纳米棒阵列及光电转化性能表征

In this paper, the decoration of TiO2 nanorod arrays with CuO and CuS quantum dots (QDs) was carried out through the dipping and deposition process. CuO and CuS QDs dispersed evenly on the surface of nanorods, and the particle size increased with the concentration of Cu2+ in reactants. In addition, CuS particles were much larger and more aggregated than CuO nanoparticles. The crystallinity of TiO2 was tetragonal rutile phase, and had no obvious changes before and after the QD sensitization, and no typical peaks of the QDs containing Cu(II) could be observed. Under the irradiation of solar simulator, the photocurrent response of the composite system can be improved both by the deposition of CuO or CuS QDs and the highest photocurrent densities were around 5 and 3.5 times of the TiO2, respectively, indicating that the photoinduced charge separation and transmission were certainly promoted by the introduction of these cupric QDs. The deposition of high concentraition QDs would result in the growth and aggregation of the grains, which may hinder the charge transfer between the QDs and TiO2, thus reduced the photocurrent. Furthermore, the improvement of photoelectrical activity and stability of TiO2 sensitized by CuO were always higher than that of CuS, which can be due to large and aggregated CuS QDs and the production of more stable Cu2S resulted from capturing the photogenerated electrons under the illumsination.