Encapsulated Silver Nanoparticles Can Be Directly Converted to Silver Nanoshell in the Gas Phase

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• 作者：Peipei Yang ; Yong Xu ; Lei Chen ; Xuchun Wang ; Baohua Mao ; Zhongzhi Xie ; Sui-Dong Wang ; Feng Bao ; Qiao Zhang
• 刊名：Nano Letters
• 出版年：2015
• 出版时间：December 9, 2015
• 年：2015
• 卷：15
• 期：12
• 页码：8397-8401
• 全文大小：419K
• ISSN：1530-6992

文摘

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鈥?reagent, in which a soluble silver鈥揳mmonia complex was formed. Starting with Ag@resorcinol-formaldehyde (RF) resin core鈥搒hell 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.