Silver/Gold Heterometallic Nanostructures and Their Surface Plasmon-Related Behaviors

Abstract

A combination of silver and gold is demonstrated in nanoscale objects. Silver and gold have similar but distinct chemical and physical properties. We employed three main chemistry related to silver and gold – underpotential deposition, epitaxial growth, and Galvanic replacement. Selective underpotential deposition of silver guided the growth direction of gold and generated gold octahedrons, cuboctahedrons, cubes, and rods. Epitaxial growth of silver on gold decahedral seeds formed silver-gold-silver heterometallic nanorods and wires. Galvanic replacement of silver for gold yielded asymmetric single hollow and symmetric double hollow structures. All silver/gold nanostructures exhibited characteristic optical features in the UV-vis- NIR ranges. Such structural variation and corresponding optical properties are useful for diverse applications in electronics, photonics, biology, and catalysis.