CoFe_(2)O_(4)/MCM-41催化剂的制备及其光催化降解亚甲基蓝性能

Preparation of CoFe_(2)O_(4)/MCM-41 catalyst and photocatalytic degradation of methylene blue

采用水热法将纳米CoFe_(2)O_(4)与MCM-41介孔分子筛复合,制备了CoFe_(2)O_(4)/MCM-41光催化剂。通过TG-DTA,XRD,SEM,N2吸附-脱吸等方法对制备的催化剂进行表征,并以亚甲基蓝染料废水为研究对象,考察了催化剂光催化降解亚甲基蓝的性能。实验结果表明,CoFe_(2)O_(4)/MCM-41催化剂仍具有介孔材料的孔道结构,CoFe_(2)O_(4)纳米粒子在分子筛孔道或表面均匀分散,呈现尖晶石结构,使CoFe_(2)O_(4)/MCM-41复合催化剂具有良好的催化活性。CoFe_(2)O_(4)/MCM-41复合催化剂(Co与Si摩尔比为1∶1)在初始染料质量浓度为10 mg/L、溶液pH=7、可见光照射的条件下,2 h内对亚甲基蓝降解率达到98.3%,降解速率符合一级反应动力学。CoFe_(2)O_(4)/MCM-41重复使用5次后,亚甲基蓝的降解率仍可达到86.6%。

CoFe_(2)O_(4)/MCM-41 photocatalytic materials were prepared with nano CoFe_(2)O_(4)and MCM-41 mesoporous molecular sieve by hydrothermal method.The catalysts were characterized by TG-DTA,XRD,SEM and N2 adsorption-desorption.Using methylene blue dye wastewater as the research object,the photocatalytic capability of the catalyst for methylene blue degradation was investigated.The experimental results show that CoFe_(2)O_(4)/MCM-41 catalysts still have the pore structure of mesoporous material,and CoFe_(2)O_(4)nanoparticles are uniformly dispersed in the pore or on the surface of molecular sieve,showing spinel structure,thus the CoFe_(2)O_(4)/MCM-41 composite catalyst has good catalytic activity.When the mole ratio of Co to Si of the catalyst CoFe_(2)O_(4)/MCM-41 is 1∶1,the initial mass concentration of dye is 10 mg/L,the solution pH is 7 and irradiation under visible light for 2 h,the degradation rate of methylene blue reaches 98.3%,and the degradation speed is consistent with the first-order kinetics.After 5 times of reuse,the degradation rate of methylene blue by CoFe_(2)O_(4)/MCM-41 still reaches 86.6%.