Synthesis of Gold and Silver Nanoparticles and Characterization of Structural, Optical, and Electronic Properties

Authors: Eric N Lee; Mark H Griep; Shashi P Karna; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD WEAPONS AND MATERIALS RESEARCH DIRECTORATE

Abstract:

Metallic nanoparticles, most notably gold and silver, portray multiple structural, optical, electronic, and photoelectric properties, all of which often vary with particle diameter. When synthesized as alloys, as compared to purely monometallic particles, changes in the synthesis procedure and conditions can yield entirely unique particles with variable absorbance levels, sizes, and emission intensities, and stronger characteristics much more suited for use in electronic applications. Through solution-phase synthesis and replacement-reaction synthesis, this experiment generated both single element nanoparticles within the quantum range (less than 15 nm in diameter) and alloy nanoparticles of gold and silver in aqueous solution. Through ultraviolet-visible spectroscopy and spectrofluoroscopy, the existence of an alloy metal was characterized through the presence of a single combined absorbance and emission peak. Particle size analysis through dynamic light scattering, atomic force microscopy, and transmission electron microscopy concluded that alloy nanoparticles synthesized through replacement reactions resulted in an even size distribution of particles. These characteristics combined with the ability to modify particle size and resulting characteristics make this method of synthesis much more useful in a wide array of applications.

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APPROVED FOR PUBLIC RELEASE