Study On The Loading Of Nano-TiO₂ And Application For Photocatalytic Degradation Of Gas Pollutants

Nano-TiO₂ photocatalysis technique is a kind of “green” and “environmental friendly” technology which can degrade gas pollutants effectively. Being characterized by the advantages of high processing ability, simple equipment and operating condition, it exhibits favorable prospect in the field of gas pollutants purification. In the work, upon utilizing mixed crystal nano-TiO₂ powder as raw material, ethanol as solvent with surfactant and thickening agent, nano-TiO₂ slurry was prepared. On the basis, porous ceramic honeycomb and honeycomb aluminum were introduced as the carrier to obtain loaded nano-TiO₂ photocatalytic materials via dip coating method. To conduct the research, inclosed gas photocatalytic experiment, flow gas photocatalytic experiment and photochemical/photocatalytic waste gas treatment devices were designed respectively. The removal efficiencies of ammonia and formaldehyde gas pollutants by the above equipments were measured.Firstly, the best light source was UV254nm+ 185 nm lamp which was determined by inclosed gas photocatalytic experiment; the prepared formula ratio of TiO₂ slurry was optimized: TiO₂, anhydrous ethanol, ethyl cellulose, terpineol, surfactant A was 6.0 g, 20 mL, 1.0 g, 10 mL and 5 mL, respectively.Secondly, by analyzing the ammonia photocatalytic degradation results given by flow dynamic gas photocatalytic experiment device, it was revealed that ammonia could be effectively decomposed, the degradation rate achieved about 50.0% when initial concentration of ammonia was 8.00 mg/m3.Thirdly, combining the photochemical with photocatalytic method, photochemical/photocatalytic waste gas treatment device was manufactured to deal with ammonia and formaldehyde gas pollutants. It was found that the removal efficiency could be 60.0% for the original ammonia concentration of 15.00 mg/m3, while formaldehyde of 3.10 mg/m3 was tested, degradation efficeiency was about 80.0%.