title: One-pot fabrication of noble-metal nanoparticles that are encapsulated in hollow silica nanospheres: dual roles of poly(acrylic acid).
abstract: An efficient and facile one-pot method was developed to fabricate noble-metal nanoparticles (NMNs; Au, Pt, PdO and Ag) that were encapsulated within hollow silica nanospheres (HSNs; NMNs@HSNs) with a size of about 100 nm. NMNs@HSNs were afforded in very high yields between 85-95 %. Poly(acrylic acid) (PAA) polyelectrolyte played a dual role in the fabrication process, both as a core template of the HSNs and as a captor of the NMNs through coordination interactions between the COO(-) groups on the ammonium polyacrylate (APA) polyanionic chains and the empty orbital of the Au atom. The amount of Au loading in Au@HSNs was easily regulated by varying the volume of the HAuCl(4) solution added. In addition, these rattle-type particles were successfully applied in the catalytic reduction of 2-nitroaniline (2-NA) as a model reaction, thus indicating that the micropores in the silica shell could achieve the transport of small species--with a size smaller than that of the micropores--into the cavity. Thus, these fabricated NMNs@HSNs have promising applications in catalysis.
authors.affiliation: Functional Nanomaterials Laboratory, Technical Institute of Physics and Chemistry (TIPC), Chinese Academy of Sciences, Zhongguancun Donglu 29, Haidianqu, Beijing 100190, PR China.
authors.forename: Xin
authors.initials: X
authors.lastname: Du
authors.forename: Lin
authors.initials: L
authors.lastname: Yao
authors.forename: Junhui
authors.initials: J
authors.lastname: He
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D006046:Gold / Q000737:chemistry; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D054118:Nanospheres / Q000737:chemistry* / Q000648:ultrastructure; D012822:Silicon Dioxide / Q000737:chemistry*
chemical_list: D000180:Acrylic Resins; C006903:carbopol 940; D006046:Gold; D012822:Silicon Dioxide