紫外和可见光照射下金属离子对TiO_2/膨润土光催化降解罗丹明B的影响  

Effect of Metal Ions on the Photocatalytic Degradation of RhB over TiO_2/bentonite Catalysts under UV and Visible Light Irradiation

作　　者：李静谊[1] 斯琴高娃[1] 刘丽娜[1] 马俊华[1] 

机构地区：[1]内蒙古大学化学化工学院,呼和浩特010021

出　　处：《内蒙古大学学报（自然科学版）》2008年第1期24-29,共6页Journal of Inner Mongolia University：Natural Science Edition

基　　金：国家自然科学基金(NSFC;Nos.20567002);内蒙古大学科研启动基金;内蒙古教育厅项目(NJ04093);教育部春晖计划(Z2004-2-15030);内蒙古大学"513人才计划"资助

摘　　要：采用溶胶-凝胶(Sol-Gel)法将TiO2负载到膨润土上,制备了TiO2/膨润土催化剂.在紫外光和可见光的照射下,以TiO2/膨润土及P25为催化剂,分别在溶液中加入金属离子Cu2+、Zn2+、Al3+、Mg2+,以罗丹明B的降解率及COD去除率评价反应降解活性,以电子顺磁共振方法捕获自由基.实验结果表明:紫外光照射下,用TiO2/膨润土做催化剂,金属离子加入均阻碍了光降解过程,并且均阻碍.OH和O-2.的生成.可见光照射下,TiO2/膨润土催化剂降解率和COD去除率均大于P25,且TiO2/膨润土催化剂更易于沉降,说明它是一个在可见光下效果较好的光催化剂.而且加入金属离子对这两种催化剂降解活性影响都不大.TiO2/bentonite catalysts are prepared by using the sol-gel method. Under UV and visible light irradiation,Cu^2＋ ,Zn^2＋ ,Al^3＋ and Mg2＋ are added into RhB solution using TiO2/bentonite and P25 as catalysts. The photodegradation reactivity is appraised by the degradation rate and COD removing rate,and free radicals are captured by the EPR method. The experiment results show that the addition of metal ions counteract the photodegradation course and block the production of ^·OH and O2^-· free radical under the UV light irradiation. The degradation rate and COD removing rate on TiO2/bentonite catalysts are bigger than that of P25 under the visible light irradiation and TiO2/bentonite catalysts are easier to sediment. This phenomenon shows that it is a better photocatalyst under visible light irradiation. And the addition of metal ions has no effect on these catalysts.

关 键 词：紫外光 可见光 金属离子 TiO2/膨润土催化剂 

分 类 号：O643[理学—物理化学]