In this paper, a simple, efficient and environmental friendly method was proposed to fabricate TiO2/CdS nanotube arrays. The composite nanotubes with a core-shell coaxial structure were fabricated via a simple method of liquid deposition and double diffusion using anodic aluminum oxide (AAO) templates. The photocatalytic properties of the nanotube arrays (TiO2, TiO2/CdS) were confirmed by the degradation of methyl orange (MO) under UV irradiation. Compared to bare TiO2 nanotube arrays, TiO2/CdS composite nanotube arrays showed improved photocatalytic performance: The degradation efficiency of TiO2/CdS and TiO2 nanotube arrays towards methyl orange was 65% and 39%, respectively.

SiO2/TiO2 nano-hybrid particles were successfully prepared by hydrothermal method by using titanium tetrafluoride (TiF4) as the titanium source, silicon dioxide as template. The factors of hydrothermal temperature and hydrothermal time on the morphologies and photocatalytic activity of SiO2/TiO2 nano-spheres were systematically discussed in this paper. The structures and properties of the SiO2/TiO2 nano-hybrid particles were studied by some techniques such as SEM, TEM, XRD and BET analysis. The results indicated that TiO2 prepared by hydrothermal method were anatase crystal, and in the form of polycrystalline. The formation mechanism of SiO2/TiO2 nano-hybrid particles was also discussed.