In this work, we demonstrated a simple and efficacious two-step method for the synthesis of Ag@Au core–shell nanoparticles(Ag@Au NPs) and the Ag/Au hollow nanocages(Ag/Au NCs) with Ag nanoparticles(Ag NPs) as seeds b...In this work, we demonstrated a simple and efficacious two-step method for the synthesis of Ag@Au core–shell nanoparticles(Ag@Au NPs) and the Ag/Au hollow nanocages(Ag/Au NCs) with Ag nanoparticles(Ag NPs) as seeds by adjusting p H, and the preparation of hybrid Ag@Au NPs- or Ag/Au NCs-graphene oxide nanocomposites(Ag@Au NPs-GO or Ag/Au NCs-GO)based on the self-assembly. It was noticed from the electrostatic assembly experiment that the loading amount of Ag/Au NCs on GO nanosheet was more than that of Ag@Au NPs. The as-synthesized hybrid materials were characterized by transmission electron microscopy, atomic force microscopy, f-potential, high-angle annular darkfield scanning transmission electron microscopy, thermogravimetric analyzer and X-ray diffraction. Catalytic activities of Ag@Au NPs, Ag/Au NCs and Ag/Au NCs-GO nanostructures were investigated in the reduction of 4-, 3-or 2-nitrophenol to 4-, 3- or 2-aminophenol, and on the basis of comparative kinetic studies the following trend was obtained for the related catalytic activity: Ag/Au NCsGO [ Ag/Au NCs [ Ag@Au NPs. These observations were attributed to the simultaneous effects of surface area available for catalytic reaction and composition of the hybrid nanostructures.展开更多
基金supported by the National Natural Science Foundation of China(21105042)the Science Foundation of China Postdoctor(2014M560572)+2 种基金the Natural Science Foundation of Shandong Province(ZR2015BM024)Tai-Shan Scholar Research Fund of Shandong Provincesupported by grant NIH 1R01DA037838 to Drs.Li and Nair
文摘In this work, we demonstrated a simple and efficacious two-step method for the synthesis of Ag@Au core–shell nanoparticles(Ag@Au NPs) and the Ag/Au hollow nanocages(Ag/Au NCs) with Ag nanoparticles(Ag NPs) as seeds by adjusting p H, and the preparation of hybrid Ag@Au NPs- or Ag/Au NCs-graphene oxide nanocomposites(Ag@Au NPs-GO or Ag/Au NCs-GO)based on the self-assembly. It was noticed from the electrostatic assembly experiment that the loading amount of Ag/Au NCs on GO nanosheet was more than that of Ag@Au NPs. The as-synthesized hybrid materials were characterized by transmission electron microscopy, atomic force microscopy, f-potential, high-angle annular darkfield scanning transmission electron microscopy, thermogravimetric analyzer and X-ray diffraction. Catalytic activities of Ag@Au NPs, Ag/Au NCs and Ag/Au NCs-GO nanostructures were investigated in the reduction of 4-, 3-or 2-nitrophenol to 4-, 3- or 2-aminophenol, and on the basis of comparative kinetic studies the following trend was obtained for the related catalytic activity: Ag/Au NCsGO [ Ag/Au NCs [ Ag@Au NPs. These observations were attributed to the simultaneous effects of surface area available for catalytic reaction and composition of the hybrid nanostructures.
