title: Weakened negative effect of Au/TiO2photocatalytic activity by CdS quantum dots deposited under UV-vis light illumination at different intensity ratios.
abstract: Herein, we demonstrate experimentally the coexistence of photocatalytic dual opposite roles of Au nanoparticles in a UV-vis light irradiated Au/TiO2system. We have investigated that the photocatalytic performance curves of Au/TiO2and CdS/Au/TiO2for degradation of methylene blue (MB) all present a V-shape with different radiation power ratios. However, through the comparison of photocatalytic activities of Au/TiO2and CdS/Au/TiO2by statistics and mathematical simulation, we propose qualitatively that the deposition of CdS used as a photosensitizer could extend the Au/TiO2light absorption range and weaken the negative effect of Au/TiO2. Compared with Au/TiO2, it is proven indirectly that the photo-excited electrons of CdS/Au/TiO2transfer from CdS to Au, and then to TiO2. Furthermore, we discuss the photocatalytic dual opposite roles of Au nanoparticles between CdS and TiO2, the positive effect includes localized surface plasmon resonance (LSPR) and Schottky barrier (SB), and the negative effect is that Au nanoparticles can be used as a new charge-carrier recombination center. In addition, we have analyzed that the dual opposite relationship of Au/TiO2under the irradiation of mixed-light could be regulated by changing the intensity ratio of visible to UV light as well.
authors.affiliation: NEST Lab, Department of Chemistry, Shanghai University, Shanghai 200444, People's Republic of China. shinexq@shu.edu.cn xujiaqiang@shu.edu.cn.
authors.forename: Kang
authors.initials: K
authors.lastname: Song
authors.affiliation: NEST Lab, Department of Chemistry, Shanghai University, Shanghai 200444, People's Republic of China. shinexq@shu.edu.cn xujiaqiang@shu.edu.cn.
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Wang
authors.affiliation: NEST Lab, Department of Chemistry, Shanghai University, Shanghai 200444, People's Republic of China. shinexq@shu.edu.cn xujiaqiang@shu.edu.cn.
authors.forename: Qun
authors.initials: Q
authors.lastname: Xiang
authors.affiliation: NEST Lab, Department of Chemistry, Shanghai University, Shanghai 200444, People's Republic of China. shinexq@shu.edu.cn xujiaqiang@shu.edu.cn and State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, People's Republic of China.
authors.forename: Jiaqiang
authors.initials: J
authors.lastname: Xu