氨基功能化纳米Fe_3O_4复合材料的一步法合成及其对五氯酚的吸附与降解性能

采用溶剂热一步法制备氨基功能化纳米Fe_3O_4磁性复合材料(NH_2-nFe_3O_4)。通过EA、XRD、FTIR、TEM、VSM等手段对NH_2-nFe_3O_4进行组成、结构、形貌、磁性等表征,并研究其吸附和降解水中五氯酚(PCP)污染物的性能。结果表明:NH_2-nFe_3O_4平均粒径约为20nm,饱和磁化强度为56.8emu/g;对PCP的等温吸附线符合Freundlich模型,当PCP的初始浓度为1 000mg/L时,吸附容量(q)可达899.2mg/g。吸附动力学研究表明,吸附过程可在5min内达到平衡,符合准二级动力学模型;将吸附PCP后的NH2-nFe_3O_4加入Fe~(3+)-H_2O_2体系,采用类Fenton反应可以实现PCP在可见光下原位降解。在pH值为3.0~8.0、5 min内对固载量为6.25~120.0mg/g的PCP实现近100%降解,较普通Fenton反应体系有更宽的pH适用范围。且NH_2-nFe_3O_4可循环使用,是具有优异潜力的水中PCP绿色吸附与降解材料。

One-pot preparation of amino-functionalized nano-Fe3O4 magnetic composite and its adsorption-degradation of pentachlorophenol

An amino-functionalized nano-Fe3O4 magnetic composite material (NH2-nFe3O4) was synthesized by one-pot solvothermal method.The NH2-nFe3O4 was characterized by EA, XRD, FTIR, TEM and VSM.Its application for adsorption and degradation of pentachlorophenol (PCP) was investigated.The results show that the NH2-nFe3O4 has an average size of about 20 nm, with the saturation magnetization intensity of 56.8 emu/g.The adsorption capacities were investigated by adsorbing the PCP from aqueous solutions.Thermodynamic studies suggest that the adsorption processes fit the Freundlich isotherms well.The adsorption capacity of NH2-nFe3O4 is found to be 899.2 mg/g when the initial concentration of PCP at 1000 mg/L.The adsorption kinetic studies show that the adsorption processes reach the equilibrium within 5 min and the kinetic data are well fitted to the pseudo-second-order model.The post-adsorbed material was added to Fe3+-H2O2 system.In situ degradation of PCP via Fenton-like reaction under visible light can be realized.The results indicate that at pH 3.0-8.0, the degradation of PCP with loading concentration at 6.25-120.0 mg/g can be reached to almost 100% within 5 min.NH2-nFe3O4 can be reused after regeneration.It is a potential effective and reusable material for adsorption and degradation of PCP.