| How to remove nitrogen oxides effectively is important and difficult points in the filed of protecting air pollution, catalytic reduction and catalytic decompose have attracted extensive attentions, but all of these technologies have some defects about large investment and high operation cost and high energy consumed. The research found out that nano-titanium dioxide is an important inorganic material, it has some advantages about innocuity, cheapness and high photocatalytic performance, it can remove nitrogen oxides with ultraviolet radiation. Photocatalytic which be used with nano-titanium dioxide has been becoming a major research project. It will be a far-reaching meaning to resolve nitrogen oxides pollution and improve the survival environmental of human race in the future.In this paper, the method of preparing TiO2 and Zn2+/TiO2 nano-film coated on the glass-plate and their photocatalytic performance are investigated. Using Ti(OC4H9)4 or Ti(OC4H9)4 and Zn(NO3)2 as precursor, TiO2 and Zn2+/TiO2 sol are prepared by sol-gel method. Then uniform transparent glass-plate thin film was prepared by dip-coating method.According to the air-solid photocatalytic, we designed a photocatalytic reaction set. In this set, it can be touched enough between NO and photocatalysts, and ultraviolet can also irradiate into the set very well, so that the photocatalysts will react with NO adequately with ultraviolet irradiation.TiO2 film photocatalysts were prepared in different calcine temperature, and were used to reacte with NO, the result showed that different temperature were able to influence TiO2 film's activity. TiO2 had a good activity when the temperature was 500℃, and the NO removal rate was 43.2%, after 500℃, NO removal rate was decreased with increasing the calcine temperature. XRD was used to analysis the difference within crystal structure.For sake of improve TiO2 photocatalytic reactivity, Zn(NO3)2 was added as Zn2+'s precursor, and we prepared Zn2+/TiO2 photocatalysts which have different doping concentration of Zn2+ in 500℃(2%, 4%, 6%), and we researched the influence to the photocatalytic reactivity with different doping concentration of Zn2+, the result showed that addition of Zn2+ was able to improve TiO2 photocatalytic reactivity and there was a best NO removal rate (89%) when the dope concentration was 4%. SEM and XRD were used to analysis these reason, we found that from the analysis result, addition of Zn2+ had a good disperse ability, so it could improve the reunite phenomenon among TiO2 granules to minish the crystal size of TiO2.We also considered the influence of coating cycles (1 cycle - 6 cycles) and content of O2 to the photocatalytic activity, so that we can optimize the experimental condition. From the results, we found that there was a good NO removal rate of 89% when the coating time was 4 times, and when feed quantity of O2 was 80ml/min, there also revealed a good removal rate of 82.8%.
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