Preparation Of TiO₂ Thin Films Photocatalyst And Photocatalytic Degradation Stugy Of Indoor Air Volatile Organic Compounds

With the development of realty and decoration, indoor air quality (IAQ) hasbecome major public concem. However, the detailed study has not done much,especially in the air decontaminated equipment. Volatile organic compounds can bedegraded to H₂O and CO₂, and do not produce other by-products. So it will be a goodsolution to improve indoor air quality by using TiO₂ photocatalyst.Focusing on the situation of indoor air contaminatment, the preparation of TiO₂ thinfilms coated on novel glass spring is studied. And also, a simulating gas photocatalyticreactor is designed, by which simulated VOCs are degraded.TiO₂ catalyst,Ce-TiO₂ catalyst and Ag-TiO₂ catalyst were prepared by thedip-coating method. Photocatalytic degradation of indoor air pollutants taking theseparation of acetone, toluene and p-xylene as the typical VOCs was investigated inself-made reactor as a function of gas flux, doping and mix.The main study and production in this paper:1. The storage stability of the TiO₂ sol-gel is perfect. TiO₂ sol-gel can be used toprepare coated TiO₂ films. The TiO₂ thin films are lubricous, uniform and transparentand there is no desquamation substance. Depending on the analysis of DSC-TG,UV-VIS and SEM, the best sintered temperature was determined on 510℃and the bestfilm layer was five.2. Metal doping study has done for improving photocatalysis of TiO₂, it was foundthat the maximal absorbency wavelength of Ce-TiO₂ catalyst was higher than the TiO₂catalyst, while it was opposite for Ag-TiO₂ catalyst; The gas degradation studyindicated that the best catalyst was Ce-TiO₂ catalyst, the worst catalyst was Ag-TiO₂catalyst.3. Benzene and formaldehyde were photocatalysed by the TiO₂ thin film catalystcoated on novel glass spring in the self-made simulating gas photocatalytic reactor,good degradation effect was gained.4. Ce-TiO₂ catalyst and Ag-TiO₂ catalyst were used for photocatalysing benzene andformaldehyde, and the gas flux was considered. It was found during the experiment:the influence of gas flux under lower bound was distincter for benzene thanformaldehyde; there was no reaction heat produced during the process, so the temperature did not changed much; the relative humidity changed differently becauseof gas flux, absorbency and water vapor produced during experiment.5. The photocatalytic degradation of acetone, toluene and p-xylene was studied, itwas indicated in the experiment that the flow rate influenced the degradationsignificantly and there were the optimal values, the optimal flow rate of acetonetoluene and p-xylene were 3L/min, 5 L/min and 7 L/min respectively. The degradationrates of acetone and p-xylene in VOCs were much lower than the singles under thesame condition, while the degradation rate of toluene in VOCs was higher than thesingle toluene.