【作者】 刘建华；

【导师】 廖莉玲；

【作者基本信息】 贵州师范大学 ， 环境科学， 2005， 硕士

【摘要】 本文用溶胶-凝胶法制备了 TiO₂、SO^2-₄ /Fe₂O₃-TiO₂复合物光催化剂。并对制备的光催化剂的结构进行表征,透射电镜显示所制备的光催化剂的粒径达到纳米级;X-衍射结果表明所制备的光催化剂在不同的温度下锐钛矿型和金红石型的比例也不同。TiO2前驱体在 510℃以后重量几乎不再变化,失重率为 24.98%左右。SO^2-₄ /Fe₂O₃-TiO₂ 复合物前驱体在 500℃以后重量几乎不再变化,失重率为 20.7%左右。本文首次用 SO₄ /Fe₂O3-TiO₂ 作光催化剂对西素绿、刚果红、结晶紫进行了降解研究,并与 TiO2作比较。结果表明,TiO2粉体在 550℃下煅烧对上述染料的降解效果较好;溶胶-凝胶法制备的 SO^2-₄ /Fe₂O₃-TiO₂复合物在 500℃下煅烧对上述染料降解效果较好。SO^2-₄ /Fe₂O₃-TiO₂复合物中,n（Ti）:n（Fe）为 6:1 时对上述染料的降解效果最好。但总的来说 SO₄ /Fe₂O₃-TiO₂复合物对上述染料降解效果优于纯的 TiO₂。 本文考察了溶液 PH 值、反应温度、光催化剂投加量、光源和H₂O₂ 浓度等几个因素对光催化氧化降解刚果红、西素绿和结晶紫速率的影响。其结果是 TiO₂ 作光催化剂时,弱碱性条件有利于上述染料的光催化降解;SO^2-₄ /Fe₂O₃-TiO₂作光催化剂时,酸性条件有利于染料的光催化降解。对于西素绿而言, TiO2光催化剂用量小于 1.5g/L 的时候,光催化降解效果随光催化剂的用量增加而增加. 大于 1.5g/L 时光催化效果反而降低.对于刚果红和结晶紫而言, TiO2 光催化剂用量小于 2.0g/L 的时候,光催化降解效果随光催化剂的用量增加而增加。更多还原

【Abstract】 In this paper, the TiO2 powder and SO^2-₄ /Fe₂O₃-TiO₂ composite wereprepared by the sol-gel method using ethanol as the solvent. Thestructures of TiO₂ powder and SO^2-₄ /Fe₂O₃-TiO₂ composite were analyzedby thermograrimetric analysis, transmission electron microscopy, X-raydiffraction. The results show that the diameter of the powder is nanometer;the temperature and time of annealing affected the proportion of theanatase and the rutile; the weight of the pioneer of TiO2 is invariableexceed 510℃, the loss of the weight is 24.98%; the weight of the pioneerof SO^2-₄ /Fe₂O₃-TiO₂ is invariable exceed 500℃,the loss of the weigh ofthe pioneer is 20.7%. It was found that the photocatalytic activity of TiO₂is the highest calcined at 550℃ for 2h。While the SO^2-₄ /Fe₂O₃-TiO₂ hashighest photocatalytic activity calcined at 500℃ for 2h.Thephotocatalytic reactivity of SO₄ /Fe₂O₃-TiO₂ is higher than that of TiO2,and the best amount of n（Ti）:n（Fe） is 6:1. TiO₂/UV and SO^2-₄ /Fe₂O₃-TiO₂/UV photocatalytic degradation ofcongo red, alizarine green, crystal violet, had been investigated. Theinfluence of initial pH, the reaction temperature, the amount of catalystand the reaction time had been investigated. Using TiO₂ as thepotocatalyst, the conditions as follow: the initial dye solution wasalkalescent, the catalyst 1.5-2.0g/L, the concentration of H₂O₂ 4-6mmol/L;the results indicated that the decolorizing rates of these three dyes wereall over 90% ,degraded for 2.0h. Using SO^2-₄ /Fe₂O₃-TiO₂ as thepotocatalyst, the conditions as follow: the initial dye solution was acidic,the catalyst 2.0g/L, the concentration of H₂O₂ 3-4mmol/L; the resultsindicated that the decolorizing rates of these three dyes were all over95% ,degraded for 1.5h. The pH and the NO^-₃ as well as NH⁺₄ were detected in the reaction.During the degradation process, the pH fell and then rose gain. From theaspect of transformation of nitrogen atoms, It was found that thosenitrogen atoms in azo bone were more stable and hardly transformed toNO^-₃ and NH4 ionic, the nitrogen of the azo transformed into molecule ofthe nitrogen; While those nitrogen atoms in other forms could generatedthese ionic species. The relation ship among the NO^-₃ and NH⁺₄ was alsoclarified.更多还原