| Nanosized TiO2 in photocatalytic technology of degradation environmental contaminant is a new promising catalyst. The preparation and catalysis of nanosized titanium dioxide, sol and the film of titanium dioxide,potocatalytic coating and midified potocatalytic coating were main study in this paper.nanosized titanium dioxide of 10-30nm was prepared by sol-gel techniques. The effective factors of reaction temperature,catalyst,gelatinization time and baking condition during the preparation process were studied. Aqueous transparent anatase TiO2 films were prepared and studied in degradating DBS solution with initial concentration of 200mg/L, and the degradation rate was 89.7% after 40 minutes.TiO2/SnO2 coupled photocatalyst was synthesised by uniform precipitation techniques and Fe3+/TiO2 was synthesised by sol-gel techniques. They were characterized by means of SEM,EDS,XPS and UVï¼Vis diffuse reflectance spectroscopy etc. The experiments showed that the oxidation state of Ti heighten and modified particles'absorption wavelength all red shift apparently.The degradation rate of SnO2/TiO2 rose relativly 40% compared with pure TiO2 and those of Fe3+/TiO2 with 30%.Photocatalytic coatings cured in room temperature were prepared by TiO2/SnO2 as photocatalyst,acryl-modified silicone resin as adhisive, polyurethane as curing catalyst. HPLC analytic method of fluorobenzene and 4-fluorobenzoic acid was established.The photocatalytic active of the two coatings were studied with self-made reactor, including the effect of pH, light intensity and reaction kinetics. The results showed that the degrdation rate of fluorobenzene by TiO2/SnO2 coating rosed from 71.9% to 90.1% compared with pure TiO2 coating. The apparent rate constant k of the photocatalytic degradation is related to the initial concentration of fluorobenzene and the reaction order is zero. The corresponding degradation rate of aldehyde with the concentration of 100ppm rosed from 69.2% to 91.4% and the reaction order is one. |
