臭氧提高纳米TiO_2光催化活性的ESR分析  

ESR Analysis on the Ozone Enhanced Photocatalytic Activity of Aqueous Nanosized Titanium Dioxide Suspensions

作　　者：叶苗苗[1] 陈忠林[1] 沈吉敏[1] 贲岳[1] 刘小为[1] 

机构地区：[1]哈尔滨工业大学城市水资源与水环境国家重点实验室,黑龙江哈尔滨150090

出　　处：《影像科学与光化学》2008年第6期460-467,共8页Imaging Science and Photochemistry

基　　金：863计划专题课题(2007AA06Z339);国家自然科学基金资助项目(50578052)

摘　　要：以5,5-二甲基-1-吡咯啉-N-氧化物(DMPO)为自由基捕获剂,分别以去离子水和二甲基亚砜(DMSO)为溶剂,利用电子自旋共振(ESR)方法对UV、O_3、TiO_2/O_3、TiO_2/UV/O_2、UV/O_3和TiO_2/UV/O_3这6种体系中形成的羟基自由基(·OH)和超氧阴离子自由基(·O_2^-)进行了检测,同时考察了反应时间、催化剂投量以及体系溶解氧对TiO_2/UV/O_3体系形成·OH和·O_2^-的影响.结果显示,在纳米TiO_2光催化体系中加入臭氧,能显著增加反应体系中·OH和·O_2^-自由基的生成量,6种体系中DMPO-·OH和DMPO-·O_2^-加合物的ESR波谱峰信号强度分别为:TiO_2/UV/O_3>TiO_2/UV/O_2>UV/O_3>UV>TiO_2/ O_3>O_3和TiO_2/UV/O_3≈TiO_2/UV/O_2>TiO_2/O_3>UV>UV/O_3>O_3,在TiO_2/UV/O_3体系中成功监测到·O_3^-自由基的存在.Abstract： The reaction activities of UV、O3、TiO2/O3、TiO2/UV/O2、UV/P3 and TiO2/UV/O3 six different processes were tested in aqueous or dimethylsulfoxide （DMSO） suspensions using electron spin resonance （ESR） technique with 5, 5-dimethyl-l-pyrroline N-oxide （DMPO） spin trap, in the meantime, the effect of different reaction time, amount of catalyst used and dissolved oxygen on the formation of ·OH and O2^- in TiO2/UV/O3 process were discussed. Result showed that the concentration of · OH and · O2^- increased obviously by adding ozone. The relative intensity of DM- PD-·OH and DMPO-·O2^- in six different conditions was TiO2/UV/O3〉TiO2/LiO2/O2〉UV/03〉UV〉TiO2/O3 and TiO2/UV/O3≈TiO2/UV/O2〉TiO2/O3〉UV〉UV/O3〉O3, respectively. At last, the DMPO-·O3^- was successfully detected in TiO2/UV/O3 process.

关 键 词：二氧化钛 光催化 臭氧 电子自旋共振 自由基 

分 类 号：O643.36[理学—物理化学]