Synthesis and Photocatalytic Properties of Ce-Doped TiO2 Nanotube Arrays via Anodic Oxidation

Ce-doped TiO2 nanotube arrays (TNAs) were prepared successfully through one-step anodic oxidation methods. The structural and morphological features of the TNAs were monitored by x-ray diffraction and field emission scanning electron microscopy with energy dispersive spectroscopy. Ultraviolet-visible light absorption spectra showed the light absorption performances of TiO2 nanotubes in both ultraviolet (UV) and visible light regions. Also, the photocatalytic activities of these samples were measured by the photodegradation rate of methylene blue (MB). The result indicated that doping a moderate amount of cerium ions into TNAs increased the absorption of both ultraviolet light and visible light obviously. However, the excess amount of doping ions would destroy the tubular structure severely and decrease the specific surface area of TNAs sharply. It could directly lead to the decreasing of photocatalytic activitity of TNAs. Furthermore, the best photodegradation rate of the Ce-doped TNAs on MB reached to 95.6%, which had a huge improvement comparing with pure TNAs.