Synthesis of Silver:Silicon Dioxide:Silver core:spacer:shell nanoparticles via the hydrogen reduction method and the characterization of their optical properties.

摘要

Plasmonic nanostructures are of considerable interest due to their unique mechanism for light interaction and the considerable number of applications that result from, or are enhanced by, these interactions. Extensive work has been reported on the synthesis, modeling, and utilization of various morphologies of plasmonic structures. As such, there is an increasing need to better define the optical properties of these materials to better understand and refine current theories in order to adapt to future applications. Herein the synthesis of Ag:SiO2:Ag core:spacer:shell (CSS) nanoparticles of varying geometries is reported. CSS synthesis utilizes an adaptation of the hydrogen reduction method and results in highly crystalline particles free of surface-modifying groups. This is advantageous as any molecule on the surface of the particle will influence the plasmonic properties. Extinction efficiencies of the composite CSS particles as well as the effect of varying shell and spacer thicknesses on the relative ratio of the scattering and absorptive plasmon relaxation modes are reported. Likewise, the relationship between CSS particle geometry and surface enhanced Raman spectroscopy (SERS) enhancement factor is explored.