Synthesis of Different TiO_2 Nanostructures and Their Physical Properties

Titanium dioxide (TiO_2) nanosheet, nanorod and nanotubes are synthesized using chemical vapor deposition (CVD) and anodizing processes. TiO_2 nanosheets are grown on Ti foil which is coated with Au catalyst in CVD, TiO_2 nanorods are synthesized on treated Ti foil with HCl by CVD, and TiO_2 nanotubes are prepared by the three-step anodization method. Scanning electron microscopy shows the final TiO_2 structures prepared using three processes with three different morphologies of nanosheet, nanorod and nanotube. X-ray diffraction verifies the presence of TiO_2. TiO_2 sheets and rods are crystalized in rutile phase, and TiO_2 tubes after annealing turn into the anatase crystal phase. The optical investigations carried out by diffuse reflection spectroscopy reveal that the morphology of TiO_2 nanostructures influencing their optical response and band gap energy of TiO_2 is changed for different TiO_2 nanostructures.