流动方式和消光系数对TiO_2光催化性能的影响

Effects of Flow Pattern and Extinction Coefficient on Photocatalytic Degradation of Organic Compounds with TiO_2 Thin Film

利用溶胶-凝胶法在陶瓷管内壁负载了TiO2薄膜，研究了流动方式和消光系数对光催化降解有机物的影响。结果表明，易直接被紫外线光解的苯酚适于采用溢流的方式进行降解，其反应速率常数约为降膜式的2倍；不易直接光解的亚甲基蓝则适于采用降膜的方式，所得速率常数约为溢流式反应的2～3倍；消光系数是影响光催化降解效果的一个重要因素，反应速率常数随消光系数的减小而增大，当消光系数固定时，存在最佳管径和速率常数的最大值。

The effects of flow patterns and extinction coefficient on the photodegradation of organic compounds with TiO2 film immobilized on the inner surface of glazed ceramic tube were investigated. Results indicate that overflow is appropriate for photodegradation of phenol, which can be easily directly degraded easily by UV lights. The constant of reaction rate is about 2 - 3 times of that with overflow. In addition, extinction coefficient is an important influencing factor on the photodegradation. The rate constant will increase with the decrease of extinction coefficient, and an optimal tube radius and the maximum value of constant of reaction rate can be found while extinction coefficient is fixed.