Abstract: The titania nanowire arrays with good orientation and a shape of strings of candied haws were prepared using a highly ordered porous anodic alumina (PAA) template by the sol-electrophoresis method. X-ray diffraction and scanning electron microscopy were applied to characterize the titania nanowire arrays. The crystalline phase of the titania nanowires is anatase. The diameter of the nanowires is uniformly distributed and is consistent with the pore size of PAA. The periodic concave-convex structure was found in each nanowire. The photocatalytic activity of the titania nanowires was measured by degradation of a methyl orange solution. Compared with the TiO2 film on glass, the titania nanowire arrays have higher photocatalytic activity. Under the condition of 1 h irradiation, the degradation ratio of methyl orange increases to 93.6%, much higher than that of TiO2 film on glass (53.4%). Using this method, the self-immobilization of the titania photocatalyst can be easily achieved. In addition, the mechanism of the high photocatalytic activity is discussed.

Key words: titania nanowire arrays, porous anodic alumina template, sol-electrophoresis, methyl orange, photocatalytic degradation