活性炭孔径和比表面积对TiO_2/AC光催化性能的影响  

Influence of Pore Size and Surface Area of Activated Carbon on the Performance of TiO_2/AC Photocatalyst

作　　者：陈玉娟[1] 胡中华[1] 王晓静[1] 赵国华[1] 刘亚菲[1] 刘巍[1] 

机构地区：[1]同济大学化学系,上海200092

出　　处：《物理化学学报》2008年第9期1589-1596,共8页Acta Physico-Chimica Sinica

基　　金：国家863基金(2008AA06Z329)资助项目

摘　　要：采用"同步物理-化学活化法"二次活化商品活性炭,制备不同孔径和比表面积的系列活性炭(AC)载体,以偏钛酸为钛源,利用均匀沉淀法制备TiO2负载型光催化剂(TiO2/AC),用氮吸附、XRD、SEM等方法表征,研究活性炭的孔径和比表面积对TiO2/AC性能的影响;并通过降解水溶液中的亚甲基蓝(MB)研究TiO2/AC光催化氧化特性,考察催化剂投加量、不同MB浓度等因素对光催化氧化的影响.结果表明,负载的TiO2粒子粒径为12-20nm,活性炭的比表面积大、平均孔径大有利于TiO2的均匀分散,阻止TiO2晶粒生长,有利于充分发挥TiO2小尺度效应;另外,活性炭吸附和TiO2光解的协同效应使TiO2/AC光催化剂对MB降解的效率显著提高.动力学研究表明,TiO2/AC光催化降解MB反应符合表观一级动力学特征.Commercial activated carbon （AC） was post-activated by means of simultaneous physical-chemical activation in order to produce porous carbon supports with different pore sizes and surface areas. Photocatalysts of AC-supported TiO2 were prepared by well-dispersed deposition using inorganic species of H2TiO3 as Ti source. Nitrogen adsorption, XRD, and SEM were used to characterize ACs and TiO2/ACs and to investigate the influence of AC surface area and pore size on the resultant catalysts. The photocatalytic performance of TiO2/AC catalysts was studied by degradation of methylene blue （MB） in aqueous solution. The influence of catalyst dosage and MB concentration on the degradation was investigated. The results showed that nano-TiO2 deposit was formed in the particle size of 12-20 nm. The larger the AC surface area and average pore size, the smaller the TiO2 particle formed on the carbon surface. It was found that TiO2/AC catalysts had a synergetic effect of AC adsorption and TiO2 photocatalysis on the degradation of MB, so that the efficiency increased significantly. The kinetics of MB degradation by TiO2/AC was of apparent first order reaction mechanism.

关 键 词：负载型TIO2 活性炭载体 孔径 光催化剂 亚甲基蓝 

分 类 号：O643.36[理学—物理化学]