微波水热合成花球状BiOCl光催化降解甲硝唑

以五水硝酸铋，氯化钾，乙二醇和P123为原料，用微波水热合成法制备出具有花球状的BiOCl.通过优化微波功率，温度和微波保持时间3种因素，发现微波功率为600W，温度为120℃，保持时间为30min时制备的BiOCl在模拟太阳光下对甲硝唑的降解效果最为显著.利用XRD和SEM对制备的BiOCl进行表征，考察了BiOCl的晶体结构和表面特征.同时研究了BiOCl投加量，甲硝唑浓度及pH值对甲硝唑降解的影响.结果表明，当BiOCl的投加量为2g/L，甲硝唑的初始浓度为5mg/L，体系初始pH值为3时，BiOCl对甲硝唑的降解效果达到98.3%.通过自由基捕获剂实验，发现光催化降解甲硝唑反应中的主要活性物种为空穴（h⁺）和过氧自由基（·O₂^-）.

Photocatalytic degradation of metronidazole using flower-like BiOCl prepared by microwave hydrothermal method

In this paper, BiOCl was prepared by microwave-assisted hydrothermal synthesis method using bismuth nitrate pentahydrate, potassium chloride, ethylene glycol and P123 as raw materials. Microwave power, temperature and microwave holding time were changed to determine the conditions of the BiOCl preparation for the best photocatalytic degradation of metronidazole. The optimal synthetic condition of BiOCl was determined to be 600W, 120℃ and 30 min, under which the synthetic product showed the best degradation on metronidazole under simulated sunlight. The prepared materials were characterized by XRD and SEM to investigate crystal structure and surface characteristics of BiOCl. Besides, the effect of reaction conditions such as catalyst dosage, metronidazole initial concentration and pH on the degradation of metronidazole were also investigated. At the condition of catalyst dosage 2.5g/L, metronidazole concentration 5mg/L and pH 3, the degradation efficiency of metronidazole reached to 98.3%. The capture experiment indicated the main active species wereholes (h⁺) and superoxide radical (·O₂^-) in the degradation of metronidazole.