PW/MCM-41光催化降解亚甲基蓝的动力学研究

Kinetics Study of the Photocatalytic Degradation of Methylene Blue on PW/MCM-41

采用浸渍法制备了负载型光催化剂PW/MCM-41,并将其用于亚甲基蓝的光催化降解过程,研究其动力学规律.结果表明,PW/MCM-41光催化降解亚甲基蓝是拟一级反应,其表观反应速率常数k′与初始浓度c0的关系为k′=0.067 5 c-0.506 7.该反应符合Langmuir-Hinshelwood(L-H)动力学模型,其反应速率常数k=0.923 5min-1,表观吸附速率常数K=0.018 1 L.mg-1.随着光照强度的增大,表观反应速率常数不断增大.

PW/MCM-41 is prepared by loaded method. In order to investigate the kinetic rules on the photocatalytic deg- radation of methylene blue, PW/MCM-41 is used. Results of kinetic study show that the degradation reaction could be ex- pressed by the first-order reaction kinetic model, ＇and the relationship between apparent reaction rate constant and initial concen- tration of methylene blue is k＇=0. 067 5 co^-0.5067. The reaction accords with Langmuir-Hinshelwood （L-H） model, The reac- tion rate constant k and adsorption equilibrium constant K are k=0. 923 5 min-1 and K：0. 018 1 L · mg^-1. The apparent reac- tion rate constant accelerate with increasing the light intensity.