摘要
用溶胶-凝胶法制备了不同载体、不同层数的锐钛矿纳米TiO2薄膜.利用TiO2薄膜作催化剂,光催化降解甲基橙溶液.研究了载体、光源、镀膜层数、pH值、初始浓度等对光催化降解脱色率的影响,从中获得了最佳镀膜及最佳光催化条件.结果表明:以太阳光为光源,以铝合金为载体,在500℃条件下镀3层膜,且在pH<8.00时光催化脱色效果最好;且该反应为表观一级反应,该光催化反应的极限速率常数为0.40 mg/(L.min),吸附平衡常数为2.65 L/mg;表面反应而非吸附是这个光催化反应的速度决定步骤,即该反应符合Langmuir-Hinshewood(L-H)机理.
Using Sol-Gel method, with different layers of anatase TiO2 films, were prepared on the substrates of glass, aluminum, steel and aluminum alloy, and the influences of the film thickness and substrates on the degradation efficiency were evaluated by decoloration rate of methyl orange. Other parameters influencing the degradation efficiency, such as light source, pH value and initial concentration, were investigated. The results indicate, under direct sunlight and the pH smaller than 8.0, the TiO2 film with three layers on aluminum alloy shows the highest pbotocatalytic activity. According to the relationship between methyl orange concentration and illumination time, a pseudo first-order kinetic model of the degradation with the limiting rate constant of 0.40 mg/（ L · min） and equilibrium adsorption constant 2.65 L/mg was evidenced. Furthermore, the Langmuir-Hinshewood （L H） model can be employed to describe the degradation reaction, which suggests that the surface reaction rather than adsorption is the rate-determining step in this photo-catalytic degradation.
出处
《大连交通大学学报》
CAS
2007年第2期74-79,共6页
Journal of Dalian Jiaotong University
基金
辽宁省教育厅科学研究计划资助项目(20040078)
