The photochemical generation of hydroxyl radicals in the UV-vis/ferrioxalate/H2O2 system

被引：170

作者：

Hislop, KA ^{[1
]}

Bolton, JR ^{[1
]}

机构：

[1] Univ Western Ontario, Dept Chem, Photochem Unit, London, ON N6A 5B7, Canada

来源：

ENVIRONMENTAL SCIENCE & TECHNOLOGY | 1999年 / 33卷 / 18期

关键词：

D O I：

10.1021/es9810134

中图分类号：

X [环境科学、安全科学];

学科分类号：

08 ; 0830 ;

摘要：

A reaction mechanism has been validated for the photochemical generation of hydroxyl radicals by ultraviolet or visible irradiation of oxalato iron(III) complexes (ferrioxalate) in the presence of hydrogen peroxide and 2-propanol as a model substrate. A kinetic simulation program incorporating the set of reactions was written to predict the behavior of this photochemical system. The program calculates the quantum yield of oxidation of 2-propanol used as a hydroxyl radical scavenger. The scavenger's oxidation product, 2-propanone, was analyzed by gas chromatography after controlled exposure of the solution to a calibrated light source. The theoretical quantum yields of 2-propanol oxidation, Phi(RH), agreed reasonably well with experimentally determined Phi(RH) values under a variety of initial reaction conditions. The value of Phi(RH), which under appropriate conditions is directly proportional to the quantum yield for the generation of hydroxyl radicals, Phi(OH), was considerably greater than unity in most cases (often Phi(RH) = 3.0-4.0), indicative of a chain mechanism involving iron cycling between the II and III oxidation states.

引用

页码：3119 / 3126

页数：8

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