改性光催化剂的制备与表征及其在光芬顿中的应用

摘要

针对目前高浓度有机废水难以高效降解的问题,本文以三聚氰胺和均苯四甲酸酐为原料制备改性光催化剂聚酰亚胺(PI).通过电子扫描(SEM)、电子透射(TEM)、X射线衍射光谱(XRD)、傅里叶变化红外光谱(FTIR)、热重分析(TG)等其进行表征,结果表明聚酰亚胺反应已完成,这可以有效降低光生电子—空穴对的复合率.将PI 引入以降解罗丹明 B 为污染物的光芬顿系统中,结果表明当三聚氰胺和均苯四甲酸酐(PMDA)配比为 1 :2 ,p H=3 时系统达到最高降解效率,高于传统光催化剂g-C3N4作用时30.9%.通过在系统内添加捕获剂叔丁醇(TBA),对苯醌(BNQ)和乙二酸四乙酸二钠(EDTA-2Na),来研究PI 作光催化剂时的光芬顿系统降解机理.%Modified photocatalyst PI was prepared with melamine and pyromellitic anhydride,and then was characterized through scanning electron (SEM),electron transmission (TEM),X ray diffraction (XRD),Fourier transform infrared spectroscopy (FTIR)and thermogravimetric analysis (TG).The results showed that the polyimide reaction was complete, which could effectively reduce the recombination rate of the photogenerated electron hole pair.PI was added to the electro-Fenton (EF) system to degrade the organic dye Rhodamine B.It was found that when the ratio of melamine to pyromellitic anhydride(PMDA)was 1:2 and pH was 3,the EF system achieved the highest degradation efficiency,30.9% higher than the traditional photocatalyst g-C3N4is used.The mechanism of UV - EF system with PI used as photocatalyst was studied by adding butyl alcohol (TBA),p-Benzoquinone (BNQ)and EDTA-2Na into the system.