CdS nanoparticles decorated anatase TiO2 nanotubes with enhanced visible light photocatalytic activity

One-dimensional nanotubes are promising nanostructured materials for environmental applications. In this study, CdS nanoparticles decorated anatase TiO2 nanotubes were fabricated using an alkaline hydrothermal combined surface precipitation method. The structure and properties of the prepared samples were characterized by XRD, TEM, UV-vis/DRS, N-2 adsorption-desorption and XPS. It was found that the as-synthesized CdS/TNTs consisted of anatase TiO2 nanotubes and cubic phase CdS, CdS nanoparticles were highly dispersed on the tube walls of TNTs. In comparison with P25 and TNTs, CdS/TNTs exhibited strong visible light absorption at about 550 nm. Compared to P25, TNTs, CdS nanoparticles and CdS/TiO2, CdS/TNTs exhibited obviously enhanced visible light (lambda > 420 nm) photocatalytic activity in the decomposition of Rh B and MO. This could be attributed to the synergic effects of some factors, such as the excellent crystallinity, electronic band structure, strong absorption in the visible light region, high specific surface area and large pore size. Based on the results of the study, the mechanism of photocatalysis on CdS/TNTs under visible light is also discussed. (C) 2015 Elsevier B.V. All rights reserved.