Study Of TiO₂ Catalyst Used In Photocatalytic Degradation Of Xylene

In this paper,using tetrabutyl titanate as titanium source,TiO₂ particles were prepared by microwave-assisted sol-gel method,and then were used for the degradation of methylene blue dye under UV irradiation.The catalytic activities of the undoped,B doped,N doped and B-N co-doped TiO₂ were investigated,and their microstructures were characterized by scanning electron microscopy.Kinetics fitting was carried by Langmuir-Hinshelwood model.The catalysts were analysed by electrochemistry method.And then,the catalyst was improved by the innovation idea that TiO₂ was loaded on the silkworm cocoon.The new catalysts were used in a self-made differential optical catalytic system for the internal catalytic system couldn't show the instantaneous effect of the catalyst.The kinetic analysis was carried out.The xylene gases were photocatlytic degradated and the initial concentration,oxygen concentration was studied by a real-time differential analysis method.The results showed that B-N co-doped TiO₂ possessed the best catalytic activity,and more uniform surface morphology than undoped TiO₂.TiO₂ catalyst had good catalytic activity due to the p-n junction effect at the microscopic level,which co-doping of B and N produced.When the concentration of B-N co-doped TiO₂ was 2 g/L and the initial concentration of methylene blue was 10 mg/L,the degradation rate of methylene blue reached 91.6% at room temperature under UV irradiation for 4 h.The experiment of photocatalytic degradation of gasous xylene indicated that the degradation efficiency of the B-N co-doped TiO₂ was significantly higher than that of undoped TiO₂.The result coincided with the experiment of photocatlytic degradation of methylene blue.Kinetic studies showed that there was an optimum value of the initial concentration of xylene and the concentration of oxygen.The optimum concentration was 11mg/L and 20%,respectively.