TiO_2/AC复合催化剂的制备及其对六氯苯的光催化降解性能研究

以颗粒活性炭（AC）和钛酸丁酯为原料,采用微波辐射法制备TiO2/AC复合光催化剂,并对制备的催化剂进行了表征;采用该催化剂对六氯苯进行光催化降解,确定了六氯苯降解的最佳工艺条件,并就几种外加试剂对TiO2/AC光催化降解六氯苯的强化作用进行了探讨。结果表明,制备的催化剂中TiO2均匀分布在活性炭表面、呈单一的锐钛矿晶型,晶粒生长完善。该催化剂催化降解六氯苯的最佳工艺条件为：pH值为5、TiO2负载量为18.2%、TiO2/AC投加量为0.4 g/L、反应时间为60 min。在此条件下,六氯苯降解效率达90.3%。添加适量的H2O2、AgNO3、K2S2O8、KIO4和KMnO4均能提高TiO2/活性炭对六氯苯的光催化降解效率。5种外加试剂的适宜添加量分别为0.3%、1.0、1.0、0.1和0.1 mmol/L,对TiO2/AC光催化效率的强化作用大小顺序为：H2O2〉AgNO3〉K2S2O8〉KMnO4〉KIO4。

Study on preparation of composite catalyst TiO_2/AC and photocatalytic performance for degradation of HCB

Granular activated carbon and tetrabutyltitanate were used as materials to prepare TiO2/AC composite photocatalyst by microwave irradiation.TiO2/AC catalyst was characterized and used to degrade hexachlorobenzene（HCB）.The optimal conditions of the degradation of HCB were determined.Enhancement of degradation of HCB by addition of five kinds of chemical reagents were also discussed.The results showed that the particles of TiO2 deposited on the surface of activated carbon were uniform and exist as anatase entirely.The crystal style of TiO2 was perfect.The optimal conditions of degradation of HCB were as follows： pH was 5.0,dosage of TiO2/AC was 0.4 g/L,loading amount of TiO2 was 18.2% and reaction time was 60 min.Under these conditions,degradation efficiency of HCB could reach up to 90.3%.Addition of chemical reagents such as H2O2,AgNO3,K2S2O8,KIO4 and KMnO4 could enhance degradation of HCB.The optimal dosage of H2O2,AgNO3,K2S2O8,KIO4 and KMnO4 was 0.3%,1.0,1.0, 0.1 and 0.1 mmol/L,respectively.The sequence of effect on degradation of HCB was H2O2AgNO3K2S2O8KMnO4KIO4.