Synthesis of Au@Ag core-shell nanocubes containing varying shaped cores, their localized surface plasmon resonances

摘要

We have synthesized Au@Ag core-shell nanocubes containing Au cores with varying shapes, sizes through modified seed-mediated methods. Bromide ions are found to be crucial in the epitaxial growth of Ag atoms onto Au cores, in the formation of the shell's cubic shape. The Au@Ag core-shell nanocubes exhibit very abundant, distinct localized surface plasmon resonance (LSPR) properties, which are core-shape, size-dependent. With the help of theoretical calculation, the physical origin, the resonance mode profile of each LSPR peak are identified, studied. The core-shell nanocrystals with varying shaped cores offer a new rich category for LSPR control through the plasmonic coupling effect between core, shell materials.