摘要
利用酸催化的溶胶-凝胶法成功地合成了一系列不同Cr3+掺杂量(x=0.01%~10%)的TiO2复合光催化剂(Cr3+/TiO2)。在太阳光条件下,以亚甲基蓝溶液的光催化降解对复合材料的光催化性能进行了表征,并考察了催化剂投加量、Cr3+掺杂量和溶液pH值等因素对光催化降解反应的影响。结果表明,亚甲基蓝溶液在复合微粒上的光催化降解反应遵循Langmuir-Hinshelwood动力学模型,在催化剂投加量为1g/L、Cr3+掺入量为0.3%和pH=7时,Cr3+/TiO2复合微粒光催化活性达最佳,测得表观反应速率常数K为7.27×10-3mg(L.min)-1,t1/2为95min,反应4h后亚甲基蓝的降解率可达79%,与纯的TiO2相比较,反应速率提高了2倍,降解率提高了20%。中性或碱性条件下有利于亚甲基蓝溶液的光催化降解。
The Cr^3＋ doped TiO2 composite particles with different doping amount （x=0. 01-10%） were successfully prepared by acid-catalyzed sol-gel method. Under the irradiation of sunlight, the photocatalytic activities of catalysts were studied by measuring the photodegradation rate of MB aqueous solution. The effects of catalyst dosage, doping amounts and pH value on photodegradation efficiency were also discussed. The results showed that the degradation of MB on the composite catalyst followed the Langmuir-Hinshelwood first-order reaction model; with the concentration of catalyst of 1 g/L, Cr^3＋ doping level of 0. 3% and pH= 7, the optimal photocatalytic activity of composite particles was realized, and the determined kinetic parameters K and t1/2 were 7.27 × 10^-3 mg（L· min） 1 and 95min, respectively. The photodegradation efficiency of MB reached 79% after 4h. Comparing with pure TiO2, the apparent reaction rate constant improved about 2 times and the photodegradation efficiency improved about 20%. The natural and alkaline condition had beneficial effect on the photodegradation of MB.
出处
《化工新型材料》
CAS
CSCD
北大核心
2009年第2期61-64,共4页
New Chemical Materials
基金
西部资源环境化学重点实验室基金资助项目(XZ0706)
