磁性纳米CeO_2/Fe_3O_4非均相Fenton反应催化降解氧氟沙星

Heterogeneous Fenton Reaction for Degradation of Ofloxacin with Magnetic CeO_2/Fe_3O_4

为了提高Fe_3O_4的催化活性,制备了磁性CeO_2/Fe_3O_4复合纳米粒子,构成非均相Fenton反应体系,催化降解水环境中的氧氟沙星抗生素。研究了CeO_2含量、H_2O_2浓度、pH等因素对CeO_2/Fe_3O_4非均相催化活性的影响,并通过溶出铁离子测定、动力学拟合等方式对反应机理进行探究。结果表明,CeO_2/Fe_3O_4较Fe_3O_4具有更强的催化活性,氧氟沙星的降解率随CeO_2含量、H_2O_2浓度和溶液酸度的增加而提高,当H_2O_2浓度为100 mmol/L以及pH为3时,CeO_2/Fe_3O_4(摩尔比=0.780)-H_2O_2体系催化降解氧氟沙星的效果最佳。CeO_2/Fe_3O_4体系催化降解氧氟沙星反应遵循一级反应动力学方程,反应机理主要为催化剂表面的催化反应,同时CeO_2产生氧空位的电子转移对Fe_3O_4的催化反应起到协同强化的作用。

CeO2/Fe3O4 magnetic nanoparticles were prepared for promoting the catalytic activity of Fe3O4, which is applied as the catalyst of heterogeneous Fenton reaction system for the degradation of ofloxacin. Several factors that affected the degradation efficiency of the system such as CeO2 content, H2O2 concentration and pH were investigated. The mechanism of catalytic degradation was also explored via the measurement of iron ion and kinetics fitting. The results show that the catalytic activity of CeO2/Fe3O4 is better than that of Fe3O4. The degradation efficiency of ofloxacin increases with the addition of CeO2 content, H2O2 concentration or solution acidity increase. The degradation effect of ofloxacin is the best for CeO2/Fe3O4（molar roction=0.780）-H2O2 catalytic system when H2O2 concentration is 100 mmol/L and pH is 3, which accords first order kinetics model. The catalytic ability of CeO2/Fe3O4 is strengthened through surface catalytic reaction and electronic transfer of oxygen vacancies of CeO2 during catalytic reaction.