title: Multifunctional Fe₃O₄@nSiO₂@mSiO₂-Fe core-shell microspheres for highly efficient removal of 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (DDT) from aqueous media.
abstract: A novel multifunctional microsphere with an iron oxide-improved mesoporous silica shell and a Fe3O4@SiO2 core has been successfully prepared by a hydrothermal method and impregnation process. The resulting Fe3O4@nSiO2@mSiO2-Fe core-shell microspheres are utilized as a catalyst for the removal of 1,1,1-trichloro-2,2-bis(4-chlorophenyl) ethane (DDT) and its derivatives, i.e., 1,1-dichloro-2,2-bis(4-chlorophenyl) ethane (DDD) and 1,1-dichloro-2,2-bis(4-chlorophenyl) ethylene (DDE). The results indicated that the iron oxide nanoparticles were well dispersed on the mesoporous silica shell of Fe3O4@nSiO2@mSiO2. DDT, DDD and DDE could be quickly and effectively removed from aqueous media in 60 min, and completely dechlorinated at 350°C by Fe3O4@nSiO2@mSiO2-Fe. More importantly, the Fe3O4@nSiO2@mSiO2-Fe microspheres were superparamagnetic and could be separated and collected easily and rapidly using a magnet.
authors.affiliation: Functional Nanomaterials Laboratory and Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences (CAS), Beijing 100190, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Tian
authors.affiliation: Functional Nanomaterials Laboratory and Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences (CAS), Beijing 100190, China; School of Chemical & Environmental Engineering, China University of Mining & Technology, Beijing 100083, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Liu
authors.affiliation: Functional Nanomaterials Laboratory and Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences (CAS), Beijing 100190, China. Electronic address: jhhe@mail.ipc.ac.cn.
authors.forename: Junhui
authors.initials: J
authors.lastname: He
keywords: Catalytic dechlorination; Core–shell structure; DDT; Magnetic separation; Mesoporous silica