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纳米金属氧化物的光化学性质使其成为新的催化剂和杀菌剂,而活性氧化物种(Reactive Oxygen Species,ROS)作为其具有催化杀菌性能的主要原因受到广泛关注.本研究通过电子顺磁共振(EPR)自旋捕捉和自旋标记技术,研究了5种纳米金属氧化物(n Al_2O_3、n CuO、n Ti O_2、n Fe_2O_3和n ZnO)在不同光照条件下形成光生电子、羟基自由基(·OH)、超氧阴离子(O_2~-·)和单线态氧(~1O_2)的能力.结果表明,在光照过程中,n Al_2O_3、n CuO、n Ti O_2和n ZnO能够生成·OH和~1O_2,n Fe_2O_3只生成了~1O_2.其中,n Ti O_2生成的光生电子和·OH最多,n CuO仅次于n Ti O_2,n Al_2O_3和n ZnO能够生成·OH,但生成量很少.本实验结果可为预测和评价纳米金属氧化物的光催化性能及环境风险提供一定的理论支持.
The photochemical properties of nano-sized metal oxides make them a new catalyst and bactericide, and Reactive Oxygen Species (ROS) as a major cause of their catalytic bactericidal activity has attracted much attention.In this study, the electron-paramagnetic resonance (EPR ) Spin trapping and spin labeling techniques were used to study the formation of photogenerated electrons under different light conditions for five kinds of nano metal oxides (n Al 2 O 3, n CuO, n Ti O 2, n Fe 2 O 3 and n ZnO) ), Superoxide anion (O_2 ~ -) and singlet oxygen (~ 1O_2) .The results show that nAl 2 O 3, n CuO, n Ti O 2 and n ZnO can generate · OH and ~ n Fe 2 O 3 formed only ~ 1 O 2. Among them, n Ti O 2 produced most photogenerated electrons and · OH, n CuO was second only to n Ti O 2, n Al 2 O 3 and n ZnO were able to generate · OH, It can provide theoretical support for the prediction and evaluation of the photocatalytic properties and environmental risks of nano-sized metal oxides.