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利用激光闪光光解技术研究了水相中四氯化碳光分解和光氧化的微观机制,并且指证了水相中四氯化碳受光激发所产生的瞬态光谱中的一些瞬态物种的特征吸收峰.并对这些瞬态物种的行为和归宿进行了研究.研究表明在248nm激光作用下,四氯化碳受光激发将分解为CCl_3自由基和Cl自由基.CCl_3自由基在无氧/有氧条件下的反应途径是不同的:在无氧条件下CCl_3自由基将进行偶合反应生成更难于降解的C_2Cl_6;而在有氧条件下CCl_3自由基则与O_2反应生成CCl_3O_2自由基,而CCl_3O_2自由基最终转变为COCl_2,这意味着光氧化能够有效地降解CCl_4.Cl自由基基本上不受氧气存在的影响,其归宿是与水分子发生电荷转移反应.
The microscopic mechanism of photolysis and photooxidation of carbon tetrachloride in aqueous phase was studied by laser flash photolysis and the characteristic absorption of some transient species in the transient spectrum produced by carbon tetrachloride excitation in the aqueous phase was demonstrated And the behavior and fate of these transient species were studied.The results show that under the action of 248nm laser, carbon tetrachloride will be decomposed into CCl_3 radical and Cl radical by light excitation.CCl_3 radical in oxygen-free / aerobic Under the anaerobic conditions, the reaction of CCl_3 will lead to C_ (2_) ___6 which is more difficult to be degraded. Under aerobic conditions, CCl_3 reacts with O_2 to generate CCl_3O_2 free radical while CCl_3O_2 free radical Eventually converted to COCl_2, which means that photooxidation can effectively degrade CCl_4.Cl radical is not affected by the presence of oxygen, and its fate is charge transfer reaction with water molecules.