Effects of crystallinity and grain size on photocatalytic activity of titania films

The crystalline structure and grain size of the plasma-nitrided titania films annealed with various temperatures were examined. In the plasma-nitrided titania films, transition temperature from anatase to rutile rises and grain growth is suppressed compared with non-doped titania film. The photocatalytic activity between anatase and rutile films is compared without the effect of surface area. It is shown that the photocatalytic activity of rutile film is lower than that of anatase film. Therefore, it is concluded that the photocatalytic activity of the anatase film is essentially higher than that of rutile film.