摘要
采用酸催化的溶胶-凝胶法制备了一系列Fe3+掺杂TiO2/凹凸棒(Fe3+-TiO2/ATP)复合光催化剂材料。在可见光条件下,以亚甲基蓝(MB)溶液的光催化降解反应,评价了样品的光催化性能,研究了TiO2负载量、Fe3+掺杂量和焙烧温度对复合材料光催化性能的影响。在单因素实验的基础上,采用正交实验设计(L25(53))优化了催化剂的制备条件。光催化实验结果表明,MB在复合材料上的光催化降解反应遵循Langmuir-Hinshelwood(L-H)动力学模型。正交实验结果表明,当TiO2负载量为15%、Fe3+掺杂量为0.5%和焙烧温度为550℃时,得到的复合材料对MB的光催化降解效率最佳,测得表观反应速率常数kapp为6.09×10-3min-1,反应4 h后MB的降解率(Dt)可达75.88%,相同实验条件下与P25(1.51×10-3min-1)相比较,反应速率提高了4.03倍,降解率提高了45.05%。另外,复合材料的沉降性能优于P25,易于分离,是一类有应用前景的复合光催化剂。
A series of Fe^3＋ doped TiO2/attapulgite composite photocatalyst（Fe^3＋-TiO2/ATP） were synthesized by acid-catalyzed sol-gel process.Their photocatalytic activity was evaluated by degrading methylene blue（MB） in aqueous solution under visible light irradiation.The influences of TiO2 loading amounts,Fe^3＋ doping amounts and calcination temperature were studied.Based on the above results,the preparation condition of composite photocatalyst was optimized by the orthogonal experiments（L25（53））.The results of photocatalytic experiments showed that the degradation of MB on the composite catalysts followed the Langmuir-Hinshelwood（L-H） first-order reaction model.The optimal photocatalytic activity of composite particles was realized when the TiO2 loading amounts was 15%,Fe^3＋ doping amounts was 0.5% and calcination temperature was 550℃,and the determined kinetic parameters kapp and degradation efficiency（Dt）were 6.09×10^-3min^-1 and 75.88% after 4 h of visible light irradiation,respectively.Comparing with P25（1.51×10^-3min^-1）,the apparent reaction rate constant increased about 4.03 times and the photodegradation efficiency increased about 45.05%.Furthermore,the Fe^3＋-TiO2/ATP composite photocatalyst exhibited easy separation property comparing with P25.The advantages of composite photocatalyst revealed its great practical potential in wastewater treatment.
出处
《环境工程学报》
CAS
CSCD
北大核心
2010年第2期458-464,共7页
Chinese Journal of Environmental Engineering
基金
河西学院西部资源环境化学重点实验室面上项目基金资助(XZ0706)
