Gold nanorod-seeded growth of silver nanostructures: from homogeneous coating to anisotropic coating

Langmuir. 2008 Apr 1;24(7):3465-70. doi: 10.1021/la702999c. Epub 2008 Feb 23.

Abstract

Single crystalline gold nanorods (Au NRs) dominated by {110} side facets were employed as seeds to tailor the deposition of Ag. Apart from homogeneous coating, anisotropic coating of Ag was observed and resulted in an orange slice-like shape for the Au@Ag nanocrystal. Different growth rates for the {110} side facets were responsible for this shape: among the four {110} facets, two of the neighboring {110} facets grew more quickly and another two grew more slowly, thus inducing the anisotropic deposition of Ag around the Au NR. This growth behavior is believed to be a consequence of competition between the strong stabilization of cetyltrimethylammomium bromide (CTAB) molecules to the {110} facets of Ag and minimization of the overall surface energy. Although the reason for the anisotropic coating remains to be clarified, our results lead to one important conclusion: The interaction of CTAB and metal can be utilized to tune the shapes of bimetallic structures.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cetrimonium
  • Cetrimonium Compounds
  • Crystallization / methods*
  • Gold
  • Metal Nanoparticles / chemistry
  • Nanostructures / chemistry*
  • Nanotubes
  • Silver*

Substances

  • Cetrimonium Compounds
  • Silver
  • Gold
  • Cetrimonium