Synthesis of Au@Ag Core–Shell\nNanocubes Containing\nVarying Shaped Cores and Their Localized Surface Plasmon Resonances

Abstract

We have synthesized Au@Ag core–shell nanocubes\ncontaining\nAu cores with varying shapes and sizes through modified seed-mediated\nmethods. Bromide ions are found to be crucial in the epitaxial growth\nof Ag atoms onto Au cores and in the formation of the shell’s\ncubic shape. The Au@Ag core–shell nanocubes exhibit very abundant\nand distinct localized surface plasmon resonance (LSPR) properties,\nwhich are core-shape and size-dependent. With the help of theoretical\ncalculation, the physical origin and the resonance mode profile of\neach LSPR peak are identified and studied. The core–shell nanocrystals\nwith varying shaped cores offer a new rich category for LSPR control\nthrough the plasmonic coupling effect between core and shell materials.