Evidence for seed-mediated nucleation in the chemical reduction of gold salts to gold nanoparticles

N. R. Jana, L. Gearheart, C. J. Murphy

Research output: Contribution to journalArticle

Abstract

Central to the concept of seed-mediated growth of nanoparticles is that small nanoparticle seeds serve as nucleation centers to grow nanoparticles to a desired size. We have examined this common assumption in a model system, the wet chemical synthesis of gold nanoparticles via reduction of a gold salt, by transmission electron microscopy and electronic absorption spectroscopy. We find that changing the seed concentration does affect the size of the product nanoparticles, but the method of reagent addition drastically affects the outcome even more. For fast addition of reducing agent, the presence of seeds appears to promote the formation of more seeds instead of growth. The observed nucleations are drastically enhanced (99%) compared to particle growth. For slow addition of reducing agent, the seeds do grow, but the product nanoparticle's degree of homogeneity in shape is compromised. For higher concentrations of seeds, nanoparticle growth is better controlled for slow addition of reducing agent compared to fast addition of reducing agent. We propose a mechanistic step to explain the commonly observed size distribution.

Original languageEnglish (US)
Pages (from-to)2313-2322
Number of pages10
JournalChemistry of Materials
Volume13
Issue number7
DOIs
StatePublished - Sep 21 2001
Externally publishedYes

ASJC Scopus subject areas

  • Chemistry(all)
  • Chemical Engineering(all)
  • Materials Chemistry

Fingerprint Dive into the research topics of 'Evidence for seed-mediated nucleation in the chemical reduction of gold salts to gold nanoparticles'. Together they form a unique fingerprint.

  • Cite this