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利用溶胶-凝胶法制备掺钒纳米TiO_2,研究其在可见光条件下对SO2气体的催化氧化效果。采用烟气分析仪和碘量法测定SO2的浓度。利用XRD、BET、TEM、SEM、XPS、UV对掺钒TiO_2进行表征;研究焙烧温度、时间以及掺杂量等制备条件,对TiO_2脱除SO2的影响效果,探讨光催化氧化SO2的机理。结果表明:有O2条件下,在焙烧温度为700℃,时间为3 h,掺钒量物质的量含量为1.0%时,制备的TiO_2光催化氧化性能最好,SO2的脱除效率大于97%,氧化产物为SO3;光照和催化剂是SO2氧化的必要条件;光氧化效率随初始浓度的增大而增大,光催化反应符合一级反应动力学,且包括吸附和表面反应两部分,其中吸附为速控步骤;钒的掺杂使TiO_2产生红移,增强可见光催化活性,提高SO2气体的氧化效率。
The vanadium-doped nano-TiO 2 was prepared by sol-gel method and its catalytic oxidation effect on SO 2 gas under visible light condition was studied. Determination of SO2 concentration by flue gas analyzer and iodometric method. The vanadium-doped TiO_2 was characterized by XRD, BET, TEM, SEM, XPS and UV. The effects of the preparation conditions such as calcination temperature, time and doping amount on the removal of SO2 from TiO_2 were investigated and the mechanism of photocatalytic oxidation of SO_2 was discussed. The results show that under the condition of O2, the prepared TiO2 has the best photocatalytic oxidation performance and the removal efficiency of SO2 is more than 97% when the calcination temperature is 700 ℃, the time is 3 h and the content of vanadium content is 1.0% , And the oxidation product is SO3. The light and catalyst are the necessary conditions for the oxidation of SO2. The photo-oxidation efficiency increases with the increase of the initial concentration. The photocatalytic reaction conforms to the first-order reaction kinetics and includes two parts: adsorption and surface reaction, For the speed control step; doping of vanadium red shift TiO 2, enhance visible light catalytic activity, improve the oxidation efficiency of SO 2 gas.