Photo-catalytic activity of titanium dioxide thin films prepared by micro-plasma oxidation method

Microporous titanium dioxide thin films have been fabricated on titanium plates by the micro-plasma oxidation method with different current density (5, 10 and 15 A/dm²). X-Ray diffraction, scanning electronic microscopy and UV-Vis spectrophotometry was used to characterize the films. The results indicate that the number and size of micropores and the crystallinity of the anatase and rutile TiO₂ phases have increased with the current density. Degradation of Rhodamine B dye was used to test the photo-catalytic activity of the films. The relatively better degradation efficiency compared with Rhodamine B mineralization was obtained with the sample produced with a current density of 10 A/dm². This behavior of the films is ascribed to the larger specific surface area and the higher crystallinity of anatase TiO₂.