Time-Resolved Small-Angle X-ray Scattering Study on the Growth Behavior of Silver Nanoparticles

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• 作者：Shi Yan ; Zhonghua Wu ; Hongying Yu ; Yu Gong ; Yuanyuan Tan ; Rong Du ; Wen Chen ; Xueqing Xing ; Guang Mo ; Zhongjun Chen ; Quan Cai ; Dongbai Sun
• 刊名：Journal of Physical Chemistry C
• 出版年：2014
• 出版时间：May 29, 2014
• 年：2014
• 卷：118
• 期：21
• 页码：11454-11463
• 全文大小：484K
• 年卷期：v.118,no.21(May 29, 2014)
• ISSN：1932-7455

文摘

Silver nanoparticles were prepared with a chemical reduction method in the presence of polyvinylpyrrolidone (PVP) used as a stabilizing agent. During the synthesis of Ag nanoparticles, aqueous silver nitrate solutions were used as the precursors and sodium borohydride was used as the reducing agent. Four Ag-nanoparticle suspensions were prepared with the initial Ag⁺ concentrations of 2, 4, 6, and 8 mM in the corresponding precursors. The in-situ time-resolved small-angle X-ray-scattering (SAXS) technique was used to monitor the nucleation and growth processes of Ag nanoparticles. The particle-size change with time was obtained by analyzing the SAXS data with a tangent-by-tangent method. The SAXS results demonstrate that the Ag nanoparticle growth behaves as a linear relation in the initial growth stage (<1 s), which was used to evaluate the critical particle size. The growth of Ag nanoparticles experienced a fast stage and then a slow stage in their whole formation process. A diffusion鈥揷oalescence model has been proposed to describe the growth behavior. The particle size change with growth time can be fitted well by this model. The effect of initial Ag⁺ concentration on the final particle size and the growth mechanism of Ag nanoparticles are discussed in this paper.