title: Catalytic properties of silica/silver nanocomposites.
abstract: The catalytic properties of silver nanoparticles supported on silica and the relation between catalytic activity of silver particles and the support (silica) size are investigated in the present article. The silver nanoparticles with 4 nm diameters were synthesized and were attached to silica spheres with sizes of 40, 78, 105 nm, respectively. The reduction of Rhodamine 6G (R6G) by NaBH4 was designed by using the SiO2/Ag core-shell nanocomposites as catalysts. The experimental results demonstrated that the catalytic activity of silica/silver nanoparticles depends on not only the concentration of catalysts (silver) but also the support silica size. Silver particles supported on small SiO2 spheres (approximately 40 nm) show high catalytic activity. Moreover, by making a comparison between the UV-vis spectra of the catalyst before and after the catalytic reaction, we found that the position of surface plasma resonance (SPR) peak of Ag nanoparticles changes little. The above results suggested that the size and morphology of silver particles were probably kept unchanged after the reduction of R6G and also implied that the catalytic activity of silver particles was hardly lost during the catalytic reaction.
authors.affiliation: Key Laboratory of Rare Earth Chemistry and Physics, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, P R China.
authors.forename: Hong-Ju
authors.initials: HJ
authors.lastname: Zhai
authors.forename: De-Wu
authors.initials: DW
authors.lastname: Sun
authors.forename: Hai-Shui
authors.initials: HS
authors.lastname: Wang
mesh_terms: D001894:Borohydrides / Q000737:chemistry*; D002384:Catalysis; D003460:Crystallization / Q000379:methods*; D046911:Macromolecular Substances; D008422:Materials Testing; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D036103:Nanotechnology / Q000379:methods; D010084:Oxidation-Reduction; D010316:Particle Size; D012235:Rhodamines / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D001894:Borohydrides; D046911:Macromolecular Substances; D012235:Rhodamines; C026188:rhodamine 6G; D012834:Silver; D012822:Silicon Dioxide; C025364:sodium borohydride