NIT-Ph-p-BEN氮氧自由基的制备及其催化降解性能

Preparation and catalytic degradability of NIT-Ph-p-BEN nitroxide radical

对醛基苯甲酸与2,3-二甲基-2,3-二羟胺基丁烷进行缩合,再经Na IO_(4)氧化最终制得了4-(4,4,5,5-四甲基-1,3-二氧化物)咪唑基-1-苯甲酸(NIT-Ph-p-BEN氮氧自由基)。采用FTIR、UV-Vis、EPR(电子顺磁共振波谱)和元素分析对其结构进行表征;通过催化降解废水中有机染料甲基橙、甲基蓝和罗丹明B对其催化活性进行了评估。结果表明,当甲基橙、甲基蓝和罗丹明B质量浓度为15 mg/L、NIT-Ph-p-BEN氮氧自由基质量浓度为0.15 g/L、H_(2)O_(2)浓度为30 mmol/L时,NIT-Ph-p-BEN氮氧自由基对甲基橙有更好的催化降解性,仅在1 h内甲基橙的降解率达到94.26%。此外,反应机理表明,H_(2)O_(2)有助于实现NIT-Ph-p-BEN氮氧自由基的再生和循环利用。

4-(4,4,5,5-Tetramethyl-1,3-dioxide)imidazolyl-1-benzoic acid(NIT-Ph-p-BEN nitroxide radical)was synthesized by condensation between 4-formylbenzoic acid and 2,3-dimethyl-2,3-bischydyoxyl aminobutane and then oxidation by Na IO_(4).The structure of product was characterized by FTIR,UV-Vis,EPR and elemental analysis.The catalytic degradation activities of NIT-Ph-p-BEN nitroxide radical for organic dyes,such as methyl orange,methyl blue and rhodamine B in wastewater were investigated.The results showed that when the mass concentrations of methyl orange,methyl blue and rhodamine B were15 mg/L,mass concentration of NIT-Ph-p-BEN nitroxide radical was 0.15 g/L,and H_(2)O_(2) concentration was30 mmol/L,respectively,NIT-Ph-p-BEN nitroxide radical exhibited the best degradation activity for methyl orange.The degradation rate of methyl orange reached 94.26%only within 1 h.The catalytic mechanism demonstrated that H_(2)O_(2) was helpful for the regeneration and recycling of NIT-Ph-p-BEN nitroxide radical.