Synthesis and Characterization of Titania Nanostructures on Glass by Al Anodization and Sol−Gel Process

Titania nanostructures with larger surface areas are fabricated on a glass substrate by anodization of sputtered aluminum and the sol−gel process, and the structural characteristics of the nanostructures are investigated. Highly pure aluminum film (99.99%, ≈2 μm), which is deposited on a glass substrate with a conductive tin-doped indium oxide (ITO) layer, is first anodized potentiostaticly in a phosphoric acid solution to obtain porous alumina structures. The anodic alumina is then used as a host or template to synthesize porous Al 2 O 3 /TiO 2 composite nanostructures through a sol−gel process. Finally, a TiO 2 nanotubules array with contours of porous anodic alumina is fabricated on glass by removing the alumina template selectively. The resultant TiO 2 is 4−20 nm polycrystalline of anatase structure with (101) preferential orientation. Titania nanostructures have large surface areas and exhibit a high transmittance in visible light and a strong absorbance within ultraviolet range in UV−vis spectra. Moreover, the fabrication of composite TiO 2 − x SiO 2 − x TeO 2 ( x = 2.5%, 5%) nanostructures is also investigated. Addition of appropriate SiO 2 and TeO 2 to TiO 2 enhances not only the adhesion to the substrate but also the mechanical strength of the nanotubules, while showing little effect on the crystallinity and the UV−vis absorbance of TiO 2 .