title: Multifunctional nanocomposites constructed from Fe3O4-Au nanoparticle cores and a porous silica shell in the solution phase.
abstract: This work is directed towards the synthesis of multifunctional nanoparticles composed of Fe(3)O(4)-Au nanocomposite cores and a porous silica shell (Fe(3)O(4)-Au/pSiO(2)), aimed at ensuring the stability, magnetic, and optical properties of magnetic-gold nanocomposite simultaneously. The prepared Fe(3)O(4)-Au/pSiO(2) core/shell nanoparticles are characterized by means of TEM, N(2) adsorption-desorption isotherms, FTIR, XRD, UV-vis, and VSM. Meanwhile, as an example of the applications, catalytic activity of the porous silica shell-encapsulated Fe(3)O(4)-Au nanoparticles is investigated by choosing a model reaction, reduction of o-nitroaniline to benzenediamine by NaBH(4). Due to the existence of porous silica shells, the reaction with Fe(3)O(4)-Au/pSiO(2) core/shell nanoparticles as a catalyst follows second-order kinetics with the rate constant (k) of about 0.0165 l mol(-1) s(-1), remarkably different from the first-order kinetics with the k of about 0.002 s(-1) for the reduction reaction with the core Fe(3)O(4)-Au nanoparticles as a catalyst.
authors.affiliation: School of Material and Chemical Engineering, Zhengzhou University of Light Industry, 5 Dongfeng Road, Zhengzhou, 450002, P. R. China. cfh_ciac@yahoo.com.cn
authors.forename: Fenghua
authors.initials: F
authors.lastname: Chen
authors.forename: Qingtao
authors.initials: Q
authors.lastname: Chen
authors.forename: Shaoming
authors.initials: S
authors.lastname: Fang
authors.forename: Yu'an
authors.initials: Y
authors.lastname: Sun
authors.forename: Zhijun
authors.initials: Z
authors.lastname: Chen
authors.forename: Gang
authors.initials: G
authors.lastname: Xie
authors.forename: Yaping
authors.initials: Y
authors.lastname: Du
mesh_terms: D000814:Aniline Compounds / Q000737:chemistry; D002384:Catalysis; D052203:Ferrosoferric Oxide / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D007700:Kinetics; D058185:Magnetite Nanoparticles / Q000737:chemistry*; D053761:Nanocomposites / Q000737:chemistry*; D057145:Nanoshells / Q000737:chemistry*; D010084:Oxidation-Reduction; D016062:Porosity; D012822:Silicon Dioxide / Q000737:chemistry*
chemical_list: D000814:Aniline Compounds; D058185:Magnetite Nanoparticles; C008625:nitroaniline; D006046:Gold; D012822:Silicon Dioxide; D052203:Ferrosoferric Oxide