Tailoring Surface Plasmons through the Morphology and Assembly of Metal Nanoparticles

TLDR

Metal nanoparticles serve as building blocks for nanostructured materials, and their optical properties—primarily governed by surface plasmon resonance—depend on metal type, particle size and shape, surface capping, and surrounding dielectric environment, enabling diverse design approaches. The article surveys the optical properties of gold, silver, and their combinations prepared by colloid chemical methods. The review examines recent findings on how particle size, shape, surface capping, and surrounding medium influence optical properties. The review demonstrates that colloid chemical synthesis affords high control over the optical properties of noble metal nanoparticles.

Abstract

Metal nanoparticles can be used as building blocks for the formation of nanostructured materials. For the design of materials with specific (optical) properties, several approaches can be followed, even when starting from the very same basic units. In this article, a survey is provided of the optical properties of noble metal nanoparticles, specifically gold, silver, and their combinations, prepared in solution through colloid chemical methods. The optical properties are shown to be mainly influenced by the surface plasmon resonance of conduction electrons, the frequency of which is not only determined by the nature of the metal but also by a number of other parameters, such as particle size and shape, the presence of a capping shell on the particle surface, or the dielectric properties of the surrounding medium. Recent results showing how these various parameters affect the optical properties are reviewed. The results highlight the high degree of control that can now be achieved through colloid chemical synthesis.