纳米TiO2薄膜对活性深蓝ST-2GLN染料的光催化降解研究

摘要

采用溶胶-凝胶(Sol-Gel)法,以钛酸正丁酯为前驱体,以不锈钢表面为基底,用提拉法镀膜,在400℃下高温煅烧2h,制备出纳米TiO2薄膜光催化剂.在以波长为254 nm、8W的紫外灯为光源、光源到溶液的距离为2 cm的条件下,对活性深蓝ST-2GLN模拟染料废水进行光催化降解试验.探讨了光照时间、初始质量浓度、TiO2提拉层数、初始pH值和H2O2的投加量等因素对脱色率的影响.结果表明:初始质量浓度为80 mg/L、TiO2提拉层数为4层、pH值为7.0的条件下,H2O2(30％)的投加量为3.0 mL,经2h的光照,脱色率达到87％.光催化降解活性深蓝ST-2GLN染料的动力学研究表明,其降解过程是一个一级反应过程,反应速率常数为0.0132 min-1.%Using Ti (0Bu)4 as precursor, stainless as substrate, nano —sized TiO2 film photocatalyst was prepared by sol-gel dip-coating method with 2 hours of calcinations at 400 ℃. Using the UV lamp with 254 nm of wave length and 8W of intensity as the light source, when the distance from the lamp to the solution was 2 cm, a test on the said photocatalyst degrading simulant dyeing wastewater containing reactive dark bule ST-2GLN was carried out. The influences of irradiation time, initial mass concentration, layers of nano—sized TiO2 film, initial pH value, H2O2 dosage and some other factors on the decolorization rate were discussed. The results showed that: under the condition that, the initial mass concentration of the solution was 80 mg/L, the layers of nano-sized TiO2 film was 4, the pH value was 7.0, the H2O2 (30%) dosage was 3.0 mL, the irradiation time was 2 h, the decolorization rate reached 87%. The research on the kinetics of photodegradation of reactive dark blue ST-2GLN showed that, the degradation was a first order reaction and the reaction rate constant was 0.0132 min-1.