title: Encapsulated Silver Nanoparticles Can Be Directly Converted to Silver Nanoshell in the Gas Phase.
abstract: We report, for the first time, that an encapsulated silver nanoparticle can be directly converted to a silver nanoshell through a nanoscale localized oxidation and reduction process in the gas phase. Silver can be etched when exposed to a mixture of NH3/O2 gases through a mechanism analogous to the formation of aqueous Tollens' reagent, in which a soluble silver-ammonia complex was formed. Starting with Ag@resorcinol-formaldehyde (RF) resin core-shell nanoparticles, we demonstrate that RF-core@Ag-shell nanoparticles can be prepared successfully when the etching rate and RF thickness were well controlled. Due to the strong surface plasmon resonance (SPR) coupling effect among neighboring silver nanoparticles, the RF@Ag nanoparticle showed great SPR and SERS performance. This process provides a general route to the conversion of Ag-core to Ag-shell nanostructures and might be extended to other systems.
authors.affiliation: Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano and Soft Materials (FUNSOM), and Collaborative Innovation Centre of Suzhou Nano Science and Technology, SWC for Synchrotron Radiation Research, Soochow University , Suzhou 215123, P. R. China.
authors.forename: Peipei
authors.initials: P
authors.lastname: Yang
authors.affiliation: Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano and Soft Materials (FUNSOM), and Collaborative Innovation Centre of Suzhou Nano Science and Technology, SWC for Synchrotron Radiation Research, Soochow University , Suzhou 215123, P. R. China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano and Soft Materials (FUNSOM), and Collaborative Innovation Centre of Suzhou Nano Science and Technology, SWC for Synchrotron Radiation Research, Soochow University , Suzhou 215123, P. R. China.
authors.forename: Lei
authors.initials: L
authors.lastname: Chen
authors.affiliation: Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano and Soft Materials (FUNSOM), and Collaborative Innovation Centre of Suzhou Nano Science and Technology, SWC for Synchrotron Radiation Research, Soochow University , Suzhou 215123, P. R. China.
authors.forename: Xuchun
authors.initials: X
authors.lastname: Wang
authors.affiliation: Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano and Soft Materials (FUNSOM), and Collaborative Innovation Centre of Suzhou Nano Science and Technology, SWC for Synchrotron Radiation Research, Soochow University , Suzhou 215123, P. R. China.
authors.forename: Baohua
authors.initials: B
authors.lastname: Mao
authors.affiliation: Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano and Soft Materials (FUNSOM), and Collaborative Innovation Centre of Suzhou Nano Science and Technology, SWC for Synchrotron Radiation Research, Soochow University , Suzhou 215123, P. R. China.
authors.forename: Zhongzhi
authors.initials: Z
authors.lastname: Xie
authors.affiliation: Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano and Soft Materials (FUNSOM), and Collaborative Innovation Centre of Suzhou Nano Science and Technology, SWC for Synchrotron Radiation Research, Soochow University , Suzhou 215123, P. R. China.
authors.forename: Sui-Dong
authors.initials: SD
authors.lastname: Wang
authors.affiliation: Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano and Soft Materials (FUNSOM), and Collaborative Innovation Centre of Suzhou Nano Science and Technology, SWC for Synchrotron Radiation Research, Soochow University , Suzhou 215123, P. R. China.
authors.forename: Feng
authors.initials: F
authors.lastname: Bao
authors.affiliation: Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano and Soft Materials (FUNSOM), and Collaborative Innovation Centre of Suzhou Nano Science and Technology, SWC for Synchrotron Radiation Research, Soochow University , Suzhou 215123, P. R. China.
authors.forename: Qiao
authors.initials: Q
authors.lastname: Zhang
keywords: SERS; Silver nanoshell; Tollens’ reagent; core−shell nanostructure; surface plasmon resonance