Research On The Preparation Of TiO₂ Film On The Ceramic Surface And Its Photocatalytic Activity

Semiconductor photocatalysis as a method for destroying pollutants has been extensively researched. The importance of photocatalysis lies in the fact that it can provide a potentially inexpensive and convenient method to treat organic and inorganic contaminants and eventually degrade these compounds to water, carbon dioxide and harmless inorganic matters etc.TiO2 is a metal oxide semiconductor that has been investigated most extensively. It has advantages of being harmless to the environment, stable in aqueous environments as well as relatively inexpensive, but the difficultly of TiO2 power being separating is still a problem. In the thesis, TiO2 films material on the ceramic surface has been prepared. The preparation parameters and TiO2 crystallite and structure have been studied. The photocatalytic activity have been also explored.The TiO2 films materials have been prepared on the surface of ceramic using sol-gel method in the paper. The research have studied some parameters , such as rising temperature speed, dry time, temperature retention time,calcinations temperature, coating number, deliquescence time and deliquescence way, which have impacted on photocatalytic activity. The results of experiments indicate TiO2 film on the ceramic surface has the best photocatalytic activity when rising temperature speed is 4.8 C /min, 100 C temperature retention time 90 min, 40 C temperature retention time 90min,Calcination temperature 540 C, dry time 5min, the number of films five, deliquescence time 1 min and deliquescence way is perpendicular.Using X-ray diffraction, energy spectrum analysis and scanning electron microscope, TiO2 crystallite, shape and size on ceramic surface are tested. The results indicate that the main type of crystallite for TiO2 is anatase and the average crystallite size of TiO2 is 20 nm-50nm. The surface shape is smooth and transparent, the thickness of 5 films is 109nm, TiO2 quality is probably 0. 00425 g.Isobutyl sodium xanthate widely used in flotation and methyl orange used in dyestuffs industry are degraded by TiO2 films. The research indicates that the degradation rate of isobutyl sodium xanthate by 0.00425g five-film TiO2 is equivalent to that of 0.1g A.R TiO2 power :62.7% and 61.1% respectively. The degradation rates of methylorange by 0.00425g five-film TiO2 catalyst and 0.4g TiO2 A.R power are 47.9% and 31.5% respectively. The experiment of solution thickness shows that the correlation between the degradation rates of isobutyl sodium xanthate and methyl orange and solution thickness accord with the exponential equation. The photocatalytic degradation of isobutyl sodium xanthate follows the second order dynamics, but the photocatalytic degradation of the methyl orange by the TiO2 films material follows the first order dynamics. After 5 min irradiation of 300W UV light, The degradation rate of isobutyl sodium xanthate is 98%, and the degradation rate of methyl orange is 98% after 5 min. Under the sunlight conditions, TiO2 films can effectively degrade isobutyl sodium xanthate and methyl orange . The results mentioned above demonstrate that TiO2 films on the ceramic surface have high photocatalytic activity...