The Growth of TiO 2

We have investigated TiO2 nanostructures prepared by anodization in conjunction with hydrothermal method using Ti metal plates. The TiO2 nanoporus were fabricated by electrochemical anodization in a NH4F/EG4/H2O electrolyte system. Ultrasonic wave was used to clean the surface of TiO2 nanoporus in the medium of water after completing the anodization. After drying in air, the nanoporusarrays were calcined at 450 °C for 2 h in air. The TiO2 nanostructures were converted by hydrothermal in air.The TiO2 nanostructures were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). XRD patterns show the TiO2 anatase structure. SEM images indicate that the TiO2 structures depend on preparation temperatures. The density of TiO2 nanostructures increases as the time increases. The growth of TiO2 nanostructures was observed to be times dependence. The nanostructures are nanowires and nanospikes when the peraring time was 18 h, nanoflowers when the preparing time was 24h. This approach provides the capability of creating patterned 1D TiO2 nanowires at 18h. The diameter of TiO2 nanowires varies from 20 nm to 25 nm and length of several 250 nm