| AVS 54th International Symposium | |
| Applied Surface Science | Thursday Sessions |
| Session AS-ThP |
| Session: | Aspects of Applied Surface Science II Poster Session |
| Presenter: | A. Majumder, University of Toyama, Japan |
| Authors: | A. Majumder, University of Toyama, Japan S. Biswas, University of Toyama, Japan M.F. Hossain, University of Toyama, Japan T. Takahashi, University of Toyama, Japan Y. Kubota, University of Yokohama City, Japan A. Fujishima, Kanagawa Academy of Science and Technology, Japan |
| Correspondent: | Click to Email |
Semiconductor photocatalysts, particularly titanium oxide (TiO2) with high photocatalytic activity, offers convenient route of purification of air and water and a provision of ‘self-maintaining’ clean surface. Several physical and chemical techniques have been used to prepare titanium dioxide thin film. Among the various techniques, the relatively simple sol-gel method is the most widely used because of its ability to obtain films with tailored properties on large, curved substrates. However, generally post-deposition annealing at high temperature is required for achieving crystalline phase. Crystallinity is one of the key factors behind the photocatalytic activity of TiO2, therefore achievement of better crystallinity at relatively low temperature is an important issue. In our present study, the titanium dioxide porous films were deposited on glass slides by sol–gel technique; where, an alcoholic solution of tetra-buthylorthotitane was hydrolysed in a water/alcohol/acetic acid mixture. The solution thus prepared was deposited on glass substrates. These films were transparent and crack free. All the films were annealed at different annealing temperatures, ranging from 350° C to 500°C. Sufficiently good crystalline sample was obtained by annealing at 350° C. For this present investigation; annealing temperature and number of coating layers were varied. The sol was initially characterized by DTA-TGA. The structure and optical characterizations of these films were made by X-ray diffraction and UV-Vis spectroscopy, respectively. XRD patterns of all the titanium dioxide films confirmed the anatase structure. The surface morphology of the films was observed by atomic force microscope (AFM) and scanning electron microscope (SEM). The morphology of porous titanium dioxide thin films strongly depends on annealing temperatures and number of coatings. The photocatalytic activity of the TiO2 thin films was evaluated by the decomposition of methanol with the help of FTIR spectroscopy. It has been observed that the photocatalytic activity of the TiO2 thin films increases with the optimization of annealing temperature as well as with the increase of the numbers of layers. The variation of photocatalytic activity with different annealing temperatures and different number of layers is interpreted in terms of different crystallinity, porosity and surface morphology.