4-一溴联苯醚的紫外光降解反应研究

Photodegradation of 4-Bromodiphenyl Ether by UV Irradiation

以汞灯为光源研究了4-一溴联苯醚在有机溶剂中的光化学反应特性,探讨了初始浓度、紫外光源和溶剂介质对其光解速率的影响。结果表明,4-一溴联苯醚在有机溶剂中的紫外光降解均符合准一级动力学规律;300 W汞灯下,4-一溴联苯醚在不同有机溶剂中的光解速率存在明显差异,其在正己烷中的降解速率与甲醇接近,分别为1.22 min-1和1.20 min-1,而在丙酮中光解速率显著降低,仅为0.0082 min-1;光源强度越高,4-一溴联苯醚降解速率越快;因竞争吸光作用,溶液初始浓度也对4-一溴联苯醚的光解反应有影响,初始浓度增高其降解速率减慢。

Photochemical degradation of 4-bromodiphenyl ether was investigated under UV irradiation. The effects of light intensity, initial concentration of 4-bromodiphenyl ether and solvent media on the photochemical degradation rate was discussed. Results showed that all photodegradation reactions in organic solvents under UV light followed the pseudo-first-order kinetics. And remarkably different rate constants were viewed during the degradation of 4-bromodiphenyl ether in different solvents. The degradation rate of 4-bromodiphenyl ether in hexane is 1.22 min-1, which is close to the obtained one of 1.20 min-1 in methanol. While, the degradation rate in acetone is only 0.0082 min-1. The degradation rate constant （k） increased with the increasing intensity of light source. However, the rise of the initial concentration suppressed the photodegradation due to the enhanced competitive adsorption of light.