Formation Mechanistism Study of TiO₂ Film Comprising Nanotubes and Nanoparticles

A novel titanium dioxide (TiO₂) film comprising both nanotubes and nanopaticles was fab-ricated by an anodization process of the modified titanium. The local electric field at the anodized surface was simulated and its influence on the morphology of the TiO₂ film was discussed. The results show that the electric field strength is enhanced by the covering. The growth rate of TiO₂ increases with the assist of the local electric field. However, TiO₂ dis-solution is hindered since the local electric field prevents TiF₆^6- from diffusing. It means that the balance condition for the formation of nanotubes is broken, and TiO₂ nanoparticles are formed. Moreover, the crystal structure of the TiO₂ film was confirmed using X-ray diffraction and Raman analysis. The anatase is a main phase for the proposed film.