J. Mater. Sci. Technol. ›› 2015, Vol. 31 ›› Issue (8): 834-839.DOI: 10.1016/j.jmst.2015.06.006

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Separation of Silver Nanocrystals for Surface-enhanced Raman Scattering Using Density Gradient Centrifugation

Qijin Huang1, Wenfeng Shen1, *, Ruiqin Tan2, Wei Xu1, Weijie Song1   

  1. 1 Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China; 2 Faculty of Information Science and Engineering, Ningbo University, Ningbo 315211, China
  • Received:2014-11-11 Online:2015-08-20
  • Contact: * Corresponding authors. Prof., Ph.D.; Tel./Fax: t86 574 86686792.E-mail addresses: wfshen@nimte.ac.cn (W. Shen), xuwei@nimte.ac.cn (W. Xu).
  • Supported by:
    This work was supported by the National Natural Science Foundation of China (Nos. 21205127, 21203226 and 21377063).

Abstract: One-dimensional silver nanocrystals (AgNCs) have been prepared by a polyol process using sodium hydroxide and nitric acid at a constant silver source concentration. Results indicate that the acidity-basicity plays an important role in silver-nanocrystal formation. Different morphologies of AgNCs were synthesized by changing the NaOH or HNO3 amount. We demonstrate that nearly monodisperse silver nanocrystals can be separated from polydisperse samples using density gradient centrifugation separation (DGCS). We also demonstrate that the separated AgNCs can be used as substrates for surface-enhanced Raman scattering (SERS) spectroscopy. The separation approach provides a method of improving the nanocrystal quality produced by large-scale synthetic methods.

Key words: Silver, Raman scattering, Nanomaterials, Separation efficiency