title: [Adsorption of Cu on Core-shell Structured Magnetic Particles: Relationship Between Adsorption Performance and Surface Properties].
abstract: In order to reveal the relationship between the adsorption performance of adsorbents and their compositions, structure, and surface properties, the core-shell structured Fe₃O₄/MnO2 and Fe-Mn/Mn₂2 magnetic particles were systematically characterized using multiple techniques and their Cu adsorption behaviors as well as mechanism were also investigated in details. It was found that both Fe₃O4 and Fe-Mn had spinel structure and no obvious crystalline phase change was observed after coating with MnO₂. The introduction of Mn might improve the affinity between the core and the shell, and therefore enhanced the amount and distribution uniformity of the MnO₂ coated. Consequently, Fe-Mn/MnO₂ exhibited a higher BET specific surface area and a lower isoelectric point. The results of sorption experiments showed that Fe-Mn had a higher maximal Cu adsorption capacity of 33.7 mg · g⁻¹ at pH 5.5, compared with 17.5 mg · g⁻¹ of Fe₃O4. After coating, the maximal adsorption capacity of Fe-Mn/MnO₂ was increased to 58.2 mg · g⁻¹, which was 2.6 times as high as that of Fe₃O₄/MnO₂ and outperformed the majority of magnetic adsorbents reported in literature. In addition, a specific adsorption of Cu occurred at the surface of Fe₃O₄/MnO₂ or Fe-Mn/MnO₂ through the formation of inner-sphere complexes. In conclusion, the adsorption performance of the magnetic particles was positively related to their compositions, structure, and surface properties.
authors.forename: Qiu-mei
authors.initials: QM
authors.lastname: Li
authors.forename: Jing
authors.initials: J
authors.lastname: Chen
authors.forename: Hai-ning
authors.initials: HN
authors.lastname: Li
authors.forename: Xiao-lei
authors.initials: XL
authors.lastname: Zhang
authors.forename: Gao-sheng
authors.initials: GS
authors.lastname: Zhang
mesh_terms: D000327:Adsorption; D003300:Copper / Q000737:chemistry*; D052203:Ferrosoferric Oxide / Q000737:chemistry*; D008280:Magnetics; D013499:Surface Properties
chemical_list: D003300:Copper; D052203:Ferrosoferric Oxide