title: Adsorption of heavy metal ions by hierarchically structured magnetite-carbonaceous spheres.
abstract: Magnetically driven separation technology has received considerable attention in recent decade for its great potential application. In this work, hierarchically structured magnetite-carbonaceous microspheres (Fe(3)O(4)-C MSs) have been synthesized for the adsorption of heavy metal ions from aqueous solution. Each sphere contains numerous unique rattle-type structured magnetic particles, realizing the integration of rattle-type building unit into microspheres. The as-prepared composites with high BET surface area, hierarchical as well as mesoporous structures, exhibit an excellent adsorption capacity for heavy metal ions and a convenient separation procedure with the help of an external magnet. It was found that the maximum adsorption capacity of the composite toward Pb(2+) was ∼126mgg(-1), displaying a high efficiency for the removal of heavy metal ions. The Freundlich adsorption isotherm was applicable to describe the removal processes. Kinetics of the Pb(2+) removal was found to follow pseudo-second-order rate equation. The as-prepared composite of Fe(3)O(4)-C MSs as well as Pb(2+)-adsorbed composite were carefully examined by scanning electron microscopy (SEM), Zeta potential measurements, Fourier transform infrared spectroscopy (FT-IR), nitrogen sorption measurements, and X-ray photoelectron spectroscopy (XPS). Based on the characterization results, a possible mechanism of Pb(2+) removal with the composite of Fe(3)O(4)-C MSs was proposed.
authors.affiliation: Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079, PR China. jmgong@mail.ccnu.edu.cn
authors.forename: Jingming
authors.initials: J
authors.lastname: Gong
authors.forename: Xiaoqing
authors.initials: X
authors.lastname: Wang
authors.forename: Xiulan
authors.initials: X
authors.lastname: Shao
authors.forename: Shuang
authors.initials: S
authors.lastname: Yuan
authors.forename: Chenlin
authors.initials: C
authors.lastname: Yang
authors.forename: Xianluo
authors.initials: X
authors.lastname: Hu
mesh_terms: D000327:Adsorption; D002244:Carbon / Q000737:chemistry*; D052203:Ferrosoferric Oxide / Q000737:chemistry*; D007700:Kinetics; D019216:Metals, Heavy / Q000737:chemistry* / Q000302:isolation & purification; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D014874:Water Pollutants, Chemical / Q000737:chemistry* / Q000302:isolation & purification; D014961:X-Ray Diffraction
chemical_list: D019216:Metals, Heavy; D014874:Water Pollutants, Chemical; D002244:Carbon; D052203:Ferrosoferric Oxide