活性炭负载钴铁氧体催化PMS降解水中罗丹明B

Degradation of rhodamine B in aqueous solution by PMS activated with activated carbon loaded with Co-Fe ferrite

采用化学共沉淀法制备了磁性活性炭负载钴铁氧体(CoFe_2O_4@AC),用于催化过硫酸氢钾(PMS)产生SO_4^-·自由基降解水中罗丹明B(RhB)。采用SEM、HR-TEM、XRD、FTIR、XPS等测试手段对CoFe_2O_4@AC的表面物理化学特性进行了表征,考察了PMS投加量、RhB浓度、pH、温度对降解RhB的影响。实验结果表明:与AC/PMS、CoFe_2O_4/PMS相比,CoFe_2O_4@AC/PMS催化体系对RhB具有更高的降解效率,且适用于较宽的pH范围(pH=5.0~9.0);CoFe_2O_4@AC/PMS体系对RhB的降解随温度的升高而显著加快,其降解活化能为67.46kJ·mol^(-1)。降解机理研究结果表明,复合材料中的AC和Co(Ⅱ)协同参与了催化PMS产生·OH和SO_4^-·的过程。总之,磁性CoFe_2O_4@AC不仅具有高效的催化效果而且易于从水中分离,对有机染料废水的处理有着良好的前景。

A magnetic activated carbon coating Co-Fe ferrite（CoFe2O4@AC） was synthesized through coprecipitation method and used to activate peroxymonosulfate（PMS） to generate sulfate radicals（SO4^-·） for the degradation of rhodamine B（Rh B）. The physico-chemical properties of the composite was characterized using SEM, HR-TEM, XRD, FTIR, XPS analyses. Effects of PMS dosage, Rh B concentration, initial pH and temperature on Rh B degradation were discussed systematically. Experiments results showed that CoFe2O4@AC/PMS system exhibited a higher degradation efficiency for Rh B than AC/PMS and CoFe2O4/PMS systems, and adapted to a wide solution p H range from 5.0 to 9.0. The degradation rate of RhB increased rapidly with increasing temperature, and the activation energy was calculated to be 67.46 k J·mol^（-1）.Mechanism study indicated that both the AC and Co（Ⅱ） in the composite participated in activating PMS to produce ·OH and SO4^-· radicals. In a word, the novel catalyst have a bright prospects in dyes treatment not only because of its efficient catalytic effect but also the characteristic of easily separated from water.