Department of Chemistry, Tongji University, Singping Road 1239, 20092 Shanghai, P. R. China.
Chemphyschem. 2010 Nov 15;11(16):3491-8. doi: 10.1002/cphc.201000371.
A novel TiO(2) nanotube array/CdS nanoparticle/ZnO nanorod (TiO(2) NT/CdS/ZnO NR) photocatalyst was constructed which exhibited a wide-absorption (200-535 nm) response in the UV/Vis region and was applied for the photoelectrocatalytic (PEC) degradation of dye wastewater. This was achieved by chemically assembling CdS into the TiO(2) NTs and then constructing a ZnO NR layer on the TiO(2) NT/CdS surface. Scanning electron microscopy (SEM) results showed that a new structure had been obtained. The TiO(2) NTs looked like many "empty bottles" and the ZnO NR layer served as a big lid. Meanwhile the CdS NPs were encapsulated between them with good protection. After being sensitized by the CdS NPs, the absorption-band edge of the obtained photocatalyst was obviously red-shifted to the visible region, and the band gap was reduced from its original 3.20 eV to 2.32 eV. Photoelectric-property tests indicated that the TiO(2) NT/CdS/ZnO NR material maintained a very high PEC activity in both the ultraviolet (UV) and the visible region. The maximum photoelectric conversion efficiencies of TiO(2) NT/CdS/ZnO NR were 31.8 and 5.98% under UV light (365 nm) and visible light (420-800 nm), respectively. In the PEC oxidation, TiO(2) NT/CdS/ZnO NR exhibited a higher removal ability for methyl orange (MO) and a high stability. The kinetic constants were 1.77×10(-4) s(-1) under UV light, which was almost 5.9 and 2.6 times of those on pure TiO(2) NTs and TiO(2) NT/ZnO NR, and 2.5×10(-4) s(-1) under visible light, 2.4 times those on TiO(2) NT/CdS.
构建了一种新型 TiO(2) 纳米管阵列/CdS 纳米颗粒/ZnO 纳米棒（TiO(2) NT/CdS/ZnO NR）光催化剂，该催化剂在紫外/可见区域具有宽吸收（200-535nm）响应，并应用于光电催化（PEC）降解染料废水。这是通过将 CdS 化学组装到 TiO(2) NT 中，然后在 TiO(2) NT/CdS 表面构建 ZnO NR 层来实现的。扫描电子显微镜（SEM）结果表明，已经获得了一种新结构。TiO(2) NT 看起来像许多“空瓶”，而 ZnO NR 层则充当大盖子。同时，CdS NPs 被它们包裹着，得到了很好的保护。在被 CdS NPs 敏化后，所得光催化剂的吸收带边缘明显红移到可见光区，带隙从原来的 3.20eV 降低到 2.32eV。光电性能测试表明，TiO(2) NT/CdS/ZnO NR 材料在紫外（UV）和可见光区均保持很高的 PEC 活性。TiO(2) NT/CdS/ZnO NR 在紫外光（365nm）和可见光（420-800nm）下的最大光电转换效率分别为 31.8%和 5.98%。在 PEC 氧化中，TiO(2) NT/CdS/ZnO NR 对甲基橙（MO）具有更高的去除能力和更高的稳定性。动力学常数在紫外光下为 1.77×10(-4) s(-1)，几乎是纯 TiO(2) NTs 和 TiO(2) NT/ZnO NR 的 5.9 和 2.6 倍，在可见光下为 2.5×10(-4) s(-1)，是 TiO(2) NT/CdS 的 2.4 倍。
