Template synthesis and characterization of CdS/TiO2 coaxial nanocables for photocatalysis in visible light

CdS/TiO2 coaxial nanocables was synthesized through electrodeposition method with the assistant of porous anodic aluminum oxide (AAO) template. The obtained samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDX). The morphology results show that the external diameter of CdS/TiO2 coaxial nanocables is approximately 100 nm and the wall thickness is almost 20 nm, indicating that the TiO2 nanotubes are fully filled with CdS nanowires. The photo response shows that doping CdS nanowire arrays (NWAs) into TiO2 nanotube arrays (NTAs) could expand the spectral response of TiO2 from ultraviolet region to the visible light region. Meanwhile, compared with pure TiO2 NTAs, the CdS/TiO2 coaxial nanocables displayed an improved photodegradation efficiency for Rhodamine B (RhB) from 47.77 to 98.86%. As for the photocatalytic activity of hydrogen production, the H2 production evolution rate of CdS/TiO2 coaxial nanocables was 8.7 times higher than that of TiO2 NTAs within 200 min reaches as 1256 μmol/h. The enhancement of photocatalysis activity indicates that CdS/TiO2 coaxial nanocables has a potential application in photocatalytic field.