可见光/H2O2体系中的协同敏化

Co-sensitization in the Visible Light/H2O2 System

分析了可见光/H 2O 2体系中产生协同敏化效应的原因.通过分析苯酚红、甲基橙、天青Ⅰ及三者混合物的紫外-可见光谱发现,三者混合后拓宽了在可见光区的响应范围,提高了对可见光的利用率.采用邻菲罗啉法、二苯基卡巴肼法和磷钼酸铵分光光度法分别测试了上述有色物在可见光/H 2O 2体系中产生光生电子e、单线态氧和超氧阴离子自由基的量,结果表明,三者混合物在可见光下超氧阴离子自由基的产量明显比单独有色物的高,光生电子和单线态氧的产量相差不大,说明超氧阴离子自由基产量的提高是产生协同敏化的主要原因.测试结果还证实光生电子不能催化过氧化氢产生羟自由基.

The causes of co-sensitization in the visible light/H 2O 2 system was analyzed.Through the analysis of the UV-Vis spectra of the phenol red,methyl orange,azure I and the mixed solution which consisted of all the three solutions mentioned above,it was seen that the mixed solution broadened the response range in the visible light region so that the utilization rate of visible light was increased.The yields of photoinduced electron(hydrated electron),singlet oxygen and superoxide anion radical generated under visible light in these matters mentioned above were tested by 1,10-phenanthroline method,1,5-diphenylcarbazide method and ammonium molybdophosphate spectrophotometry.The result showed that the yields of superoxide anion radical in the mixed solution was significantly higher than that of the single chromophoric dissolved organic matters,more-over,the yields of photoinduced electron and singlet oxygen were not much different in each solution.Hence the increase of superoxide anion radical production is the main reason for the co-sensitization.In addition,experimental results confirmed that photoinduced electron could not catalyze hydrogen peroxide to generate hydroxyl radical.