Fabrication and optical properties of TiO₂nanowire arrays made by sol gel electrophoresis deposition into anodic alumina membranes

Ordered TiO 2 nanowire arrays have been successfully fabricated into the nanochannels of a porous anodic alumina membrane by sol–gel electrophoretic deposition. After annealing at 500°C, the TiO 2 nanowire arrays and the individual nanowires were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED) and x-ray diffraction (XRD). SEM and TEM images show that these nanowires are dense and continuous with a uniform diameter throughout their entire length. XRD and SAED analysis together indicate that these TiO 2 nanowires crystallize in the anatase polycrystalline structure. The optical absorption band edge of TiO 2 nanowire arrays exhibits a blue shift with respect of that of the bulk TiO 2 owing to the quantum size effect.