Synthesis and characterization of CdTe nanoparticle-sensitized TiO2 nanotube arrays for photocatalysis

CdTe nanoparticle-sensitized TiO 2 nanotube arrays (CdTe/TiO 2 NTAs) were prepared by combining the sol–gel method with the electrodeposition method by the aid of anodic aluminum oxide template. The morphology, structure and composition of the materials were characterized by scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffraction (XRD). The photo response and photocatalytic activity of the materials were investigated by UV–Vis absorption spectroscopy. The results show that the pore diameter of the TiO 2 nanotubes is about 120 nm and the wall thickness is approximately 30 nm. CdTe nanoparticles are deposited both inside and in the tube-to-tube voids of the TiO 2 nanotubes. XRD analyses identify the anatase structure of TiO 2 nanotubes and cubic sphalerite structure of CdTe. Compared with pure TiO 2 nanotube film, the CdTe/TiO 2 NTAs display a significant increase in absorption coefficient in the visible light and a higher activity for photodegrading Rhodamine B under Xe lamp irradiation with an increase from 34 to 88%. The results also show that CdTe/TiO 2 NTAs exhibit better photoelectrochemical performance than TiO 2 NTAs.