Preparation Of Nanosized TiO₂ Film On Glass Surface And Study On Its Photocatalytic Activity

Aiming at the actuality of disadvantages of TiO2 powder, difficult to separate, low using rate of light and easy to deposit and agglomerate, which hold back the transformation of photocatalytic technology into utility, preparation process of nanosized TiOi powder and film were studied, and the fixation of TiO2 was solved and firm TiO2/glass thin films with nano-crystalline have been prepared by the sol-gel processing using tetrabutyl titanate as a precursor in this paper. On this basis, using ultraviolet germicidal lamp with main wavelength of 253.7nm or sunlight as light source, the contaminants removal effect in water, including oily waste water and simulated dye wastewater, was studied under the treatment of suspended nanosized TiO2 photocatalytic reactor and fixed nanosized TiO2 photocatalytic reactor. Factors influencing the treatment efficiency of reactor in its preparation process were discussed, consequently the optimized process parameters were obtained. By the examine of performance of fixed nanosized TiO2 photocatalytic reactor and the environmental factors influencing its performance, the research of photocatalytic reactor design was carried out from utility point of view of photocatalytic technology. The kinetics law of fixe d photocatalytic reactordealing with the simulated dye wastewater of Rhodamine B was discussed, and the kinetics model of Rhodamine B was put forwardThe main results showed that TiO2 semiconductor with nano-crystalline have been prepared by the sol-gel processing using tetrabutyl titanate as a precursor. The reaction condition was easy to control and the process was stable, thus the distribution uniformity can reach molecule level, and highly quality sol and gel can be acquired, and further obtained the nanosized particles, micro-analytic results of AFM, XRD, TEM, SEM and thickness analysis showed that crystal type, granularity and particle size distribution of TiO2 can be controlled by optimizing reaction conditions. TiO2 prepared in this experiment was anatase, in which the average size of TiO2 powder was 10~30nm and that of TiO2 particles in the thin film was 3~4nm, and the thickness of single layer was in namo-meter class. Distributions of granularity were narrow in both processes. The suspended nanosized TiO2 photocatlytic reactor was highly effective in degrading the oily wastewater, and its degradation rate preceded that of general biochemical method, and phtotcatalytic technology was feasible using sunlight as light source. In fixed photocatalytic reactor, nanosized TiO2/glass film was high in adsorption, the fastness of film was ideal and it had the ability resisting the attach of medium that influence the lifetime of film under bad environment. The film lifetime was long. Between fixed photocatalytic reactors, efficiency of the filled type was distinctively higherthan that of the none-filled type. The hypothesis that the degradation process of Rhodamine B was irreversible reaction with two steps was put forward, and proved the correctness of this hypothesis by theory deducing and phenomena in experiment.