苯醌类与苯醌亚胺类在日光/Fenton体系中的光敏性

基于苯酚降解中间产物（苯醌）、酸性甲基橙的目标化合物，研究了苯醌类与苯醌亚胺类在光/Fenton体系中的降解特性，分析了苯醌及酸性甲基橙的光敏特性，测定了光敏剂存在的情况下日光/Fenton和UV/Fenton体系中·OH的产量.结果表明，苯醌类光解，由于其光敏性好，能促进日光体系产生更多的·OH，日光/Fenton法好于UV/Fenton法.苯醌亚胺类降解，浓度较低时，UV/Fenton法好，浓度较高时，日光/Fenton法好，造成这种现象的主要原因是苯醌亚胺类光敏性一般，浓度低时日光体系中·OH的产量少于紫外体系，但苯醌亚胺类降解过程中有苯醌类生成，苯醌类的光敏性比苯醌亚胺类好，苯醌亚胺类浓度越高，其降解产物中苯醌类越多，进而导致日光体系中¹O₂、O₂^-·和·OH的产量多于紫外体系.

Photosensitivity of benzoquinones and benzoquinoneimines in the sunlight/fenton system

Based on the model compounds of benzoquinone and acid methyl orange, the degradation characters of benzoquinones and benzoquinoneimines in the light/Fenton system were investigated. The photosensitivity of benzoquinone and acid methyl orange was analyzed by measuring the yield of ·OH in the sunlight/Fenton and UV/Fenton system, respectively. The results demonstrated that sunlight/Fenton method was better than the UV/Fenton method for the degradation of benzoquinones, due to its higher photosesitity, more ·OH produced in the sunlight system. For benzoquinoneimines, UV/Fenton was better than sunlight/Fenton at lower concentration, but sunlight/Fenton was better at higher concentration. The reason was that benzoquinoneimines was not a good photosensitizer with a lower yield of ·OH in the sunlight system, so UV system was better with lower concentration of benzoquinoneimines. Nevertheless, benzoquinones could be generated during the degradation of benzoquinoneimines, which was a better photosensitizer that could generate ¹O₂、O₂^-· and ·OH in sunlight system, thereby more benzoquinones generated with higher concentration of benzoquinoneinines resulting fast degradation in sunlight system.