Nanotubes, Nanorod and Nanosheet of TiO2 were synthesized by the normal hydrothermal method and the microwave hydrothermal method by constant temperature and aqueous NaOH concentration, each using TiO2 powder (Degussa, P25) as precursor material. These products were elucidated phases, morphologies and optical characteristics by X-ray diffraction pattern (XRD) analysis, Transmission Electron Microscopy (TEM) and Diffuse Reflectance Spectroscopy (DRS), respectively. It was found that a nanostructure varied according to a generation method. In comparison with the normal hydrothermal method found that the microwave hydrothermal method produces the nanotubes mainly. Photocatalytic activity was evaluated by the degradation of methylene blue (MB) dye under simulated solar light condition. The photocatalytic efficiency of particle structure was found to be higher as compared to other nanostructures such as sheets, rods or tubes. Morphology-dependent optical and catalytic activities of the synthesized TiO2 nanostructures were evaluated. The decrease in concentration of MB depended on adsorption mainly.

Keywords: Hydrothermal synthesis, Microwave hydrothermal synthesis, TiO2 nanotubes, Nanotube, Nanorod, Nanosheet.