Indoor air pollution seriously threats the life and health of human beings. The improvement of indoor air quality has become a focus that people pay more and more attentions to. The photocatalytic of pollutants based on TiO2 is a promising air purification technology. In order to overcome the disadvantages of nanometer powder TiO2 catalyst and to enhance the photocatalytic activity of TiO2, series of glass plates covered with doped-TiO2 were prepared and the photocatalysis them were studied.
The glass plates covered with TiO2 which was doped in advance with N, F, or/and Fe were prepared by a sol-gel method. The doping content of N, F, Fe and heat treatment temperature were determined using the orthogonal array of the Taguchi quality design. The prepared gel was coated on the glass by spin-coating method. The effects of doping level of N, F and Fe and heat treatment temperature on the photocatalytic capabilities were investigated. The photocatalytic capabilities of prepared glass plates were investigated by degrading the solution of methylene blue (MB,C16H18ClN3S). The results show that appropriate addition of N, F and Fe and temperaturae are effective for improving the photocatalytic activities of TiO2 under visible light. The optimal TiO2 was prepared under the condition that the doping amount of F element was 9at %, that of N is 7at %, and none of Fe under 400 °C calcination temperature. The degradation rate of the sample for methylene blue solution reaches 23.49% under visible light irradiation for 5 hours. The influence order of the factors was the calcination temperature > F > N > Fe.