Study On The Degradation Of VOCs With Lower Concentration By Supported Nano-TiO₂ Photocatalyst Film

The deterioration of environment, especially the atmosphere pollution, resulting from the increasing and developing of industrialization, has become one of the city's environment problems, which is an absolutely urgent problem. Nano- TiO2 is the very novel green catalyst with its renewal ability and storability of energy and friendliness of environment. Now its relevant study becomes the focus of the field of photocatalysis, especially in exhaust gas treatment. In this paper, nano-TiO2 sol was prepared by sol-gel method and different carriers and supported method were investigated. Selected toluene as the target pollutant, through a set of DIY gas occurrence and photocatalysis reaction device, mensurated its take-off efficiency by the gas chromatography to appraises its photochemical catalysis activeness. Finally has researched the deactivated charcoal-loaded photocatalyst's regeneration method.Firstly, on the basis of the former research, we further studied the technical parameters of TiO2 sol preparation, it is found that to control the volume of Tetrabutyl Titanate,Anhydrous Alcohol,Water and Glacial Acetic Acid by the proportion of 5︰40︰2︰5, pH value is 4, stable sol system can be obtained. Sol forms a gel after laying for about 22 hours. Moreover, dopes the mole score of 1% transition metal Co2+in the sol can help further reduced the grain size of TiO2 crystal, thus enhancing its photochemical catalysis activeness.Aluminum sheet, stainless steel net and bamboo-made actived carbon are respectively selected as the TiO2 loaded carriers (the carriers which loads TiO2), and measured their performance by X-ray diffraction and FSEM techniques. Taking toluene as the target pollutant, using the photocatalysis reaction device, its take-off efficiency is mensurated, and the influence of the reactant initial concentration and the gas flow rate to toluene degradation efficiency are studied. The results showed that when taken the activated carbon is used as the carrier, the degradative efficiency of toluene can reach to 80%. The removal effect using the activated carbon is higher than the stainless steel, and that using aluminum sheet is the lowest. The take-off amounts of toluene is increased with the load increasing, but the uptrend gradually goes slow, the current capacity and the concentration change gradually lead to different removal; with the load further increasing, the take-off amounts of toluene come down.Finally, the regeneration method of the deactivated charcoal-loaded photocatalyst has been investigated. The reason why catalyst became deactivated has been analyzed by FT-IR technique. We found that the catalyst's activeness can be completely or partially restored with the method of passing clean air into the reactor under ultraviolet illumination, microwave irradiation and high-temperature treatment, realizing regeneration. However, from the point of running cost and time, the microwave irradiation is one of the most ideal method to realize catalysis's regeneration.