title: Fabrication of Fe3O4/SiO2 core/shell nanoparticles attached to graphene oxide and its use as an adsorbent.
abstract: Amino-functionalized Fe(3)O(4)/SiO(2) core/shell nanoparticles were synthesized by reacting Fe(3)O(4) nanoparticles with tetraethyl orthosilicate and (3-aminopropyl) triethoxysilane to introduce amino groups on the surface. The amino groups on the Fe(3)O(4)/SiO(2) were reacted with the carboxylic groups of graphene oxide (GO) with the aid of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinnimide to form Fe(3)O(4)/SiO(2)GO nanoparticles. The structural, surface, and magnetic characteristics of the material were investigated by scanning and transmission electron microscopy, energy-dispersive X-ray spectrometry, powder X-ray diffraction, Fourier transform infrared spectroscopy, and thermogravimetric analysis. Adsorption equilibrium and kinetics of methylene blue on the Fe(3)O(4)/SiO(2)GO were studied in a batch system. The maximum adsorption capacities were found to be 97.0, 102.6, and 111.1 mg g(-1) at 25, 45, and 60°C, respectively. A second-order kinetic equation could best describe the sorption kinetics. Thermodynamic parameters indicated that the adsorption of methylene blue onto the material was thermodynamically feasible and could occur spontaneously.
authors.affiliation: School of Chemical Engineering, Hefei University of Technology, Hefei 230009, China. yaoyunjin@gmail.com
authors.forename: Yunjin
authors.initials: Y
authors.lastname: Yao
authors.forename: Shiding
authors.initials: S
authors.lastname: Miao
authors.forename: Shaoming
authors.initials: S
authors.lastname: Yu
authors.forename: Li Ping
authors.initials: LP
authors.lastname: Ma
authors.forename: Hongqi
authors.initials: H
authors.lastname: Sun
authors.forename: Shaobin
authors.initials: S
authors.lastname: Wang
mesh_terms: D000327:Adsorption; D006108:Graphite / Q000737:chemistry*; D007700:Kinetics; D058185:Magnetite Nanoparticles / Q000737:chemistry*; D008751:Methylene Blue / Q000737:chemistry; D010087:Oxides / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*; D013499:Surface Properties; D013816:Thermodynamics
chemical_list: D058185:Magnetite Nanoparticles; D010087:Oxides; D012822:Silicon Dioxide; D006108:Graphite; D008751:Methylene Blue