摘要
以商用TiO2P25为催化剂,分别在TiO2/UV/O2和TiO2/UV/N2两种体系下进行降解对氯硝基苯(pCNB)试验.采用ESR对两种体系下光催化反应形成的.OH进行测定,利用LC-MS对两种体系下反应形成的中间产物进行了定性和定量分析,最后对pCNB降解过程中氯和硝基的存在形式进行了研究.结果表明:TiO2/UV/O2体系的催化降解效果要明显优于TiO2/UV/N2体系;两种反应体系都有.OH产生,并且TiO2/UV/O2体系产生的.OH的量多于TiO2/UV/N2体系产生的.OH的量;TiO2/UV/O2体系形成的中间产物的种类要多于TiO2/UV/N2体系形成的,苯环上的氢、氯、硝基均可被.OH取代形成对硝基酚(pNP)、5-氯-2-硝基酚(5-C-2-PN)等酚类物质;两种体系下均有Cl-和NO2-存在,其中Cl-生成势与pCNB的去除势一致,只有TiO2/UV/O2体系中存在NO3-.
The photocatalytic degradation of p-nitrochlorobenzene（pCNB） was studied using two different catalytic system TiO2/UV/O2 and TiO2/UV/N2. The main intermediate products in the two systems were identified and quantified by means of HPLC-MS, the modality of chlorine and nitryl on pCNB was studied during the photocatalytic degradation reaction, at last, the hydroxyl radicals in these two different catalytic systems were detected. Results showed that the efficiency of the degradation of pCNB in TiO2/UV/O2 system is much better than that of TiO2/UV/N2 system; the hydroxyl radicals was formed in both of the two systems, but the quantity of the hydroxyl radicals is much more than that of TiO2/UV/N2 system; the main intermediate products in TiO2/UV/ O2 system is much more than that of TiO2/UV/N2 system, and p-nitrophenol（pNP）, p-chlorophenol（pCP）, 5-chlor-2-nitrophenol（5-C-2-PN） were the same intermediate products in both of these two systems; Cl^- and NO2 were detected in both of these two reaction systems, and NO2 was detected only in the TiO2/UV/O2 system.
出处
《感光科学与光化学》
CSCD
2007年第4期296-305,共10页
Photographic Science and Photochemistry
基金
国家自然科学基金项目(50008004)
关键词
二氧化钛
对氯硝基苯
光催化
羟基自由基
ESR
titanium oxide
p-nitrochlorobenzene
photocatalysis
hydroxyl radicals
ESR
