核壳结构Fe_(3)O_(4)@SiO_(2)@介孔TiO_(2)的合成及其光电催化降解水中有机污染物

Synthesis of core-shell Fe_(3)O_(4)@SiO_(2)@mesoporous TiO_(2) and its photoelectrocatalysis degradation of organic pollutants in water

为了实现太阳能光催化和光电催化降解污染物实用化,需要研发高效、稳定、易分离的催化剂。采用溶胶-凝胶法和水热法制备了Fe_(3)O_(4)@SiO_(2)@介孔TiO_(2)(FST)复合光电催化剂。通过表征分析证实了纳米FST成功合成,Fe_(3)O_(4),SiO_(2)和TiO_(2)纳米颗粒层层包裹,具有独特的核壳结构。在外加磁场的作用下,FST催化剂可以很容易地从悬浮液中分离出来。FST的表面光电流响应和阻抗测试结果显示其活性显著增强。利用制备的FST对其他有机污染物在可见光下的光电催化降解进行了研究,对亚甲基蓝、罗丹明B、甲基橙、阿莫西林光电催化90 min,降解率分别为98%,95%,92%,90%。主要活性物种捕获实验表明,FST通过光电耦合作用产生大量h^(+)和·OH从而使污染物降解为CO_(2),H_(2)O和无机离子。

To realize the practical application of solar photocatalysis and photoelectrocatalysis degradation of pollutants,the efficient,stable,and easily separable catalysts should be studied.Fe_(3)O_(4)@SiO_(2)@mesoporous TiO_(2)(FST)composite photoelectrocatalysts were prepared by sol-gel and hydrothermal methods.The successful synthesis of nano FST was confirmed by characterization analysis.Fe_(3)O_(4),SiO_(2),and TiO_(2) nanoparticles were coated layer by layer with a unique core-shell structure.The FST catalyst can be easily separated from the suspension under the applied magnetic field.The surface photocurrent response and impedance test results of FST show that its activity is significantly enhanced.The photoelectrocatalysis degradation of other organic pollutants under visible light is investigated using the synthesized FST,the 90 min photoelectrocatalysis degradation rates of methylene blue,rhodamine B,methyl orange,and amoxicillin are 98%,95%,92%,and 90%,respectively.The main active species capture experiments show that FST produces a large amount of h+and·OH through photoelectrocatalysis coupling,which degrades pollutants into CO_(2),H_(2)O,and inorganic ions.