Hybridized plasmon resonances in core/half-shell silver/cuprous oxide nanoparticles

Abstract

Core/shell nanoparticles are of interest due to their attractive optical, electronic, and catalytic properties. By combining these core/shell features with physical anisotropy of the shell – by selectively capping only a portion of the core – nanostructures with unique properties can be formed. This work presents the synthesis and investigates the plasmonic properties of silver nanocube (AgNC)/cuprous oxide core/half-shell nanoparticles. The developed partial shell growth technique is suitable for any room temperature two-step core/shell synthesis. Using this technique AgNC/Cu₂O core/shell nanoparticles were formed with a distinct half-shell morphology, either pyramidal or cubic, where the geometry of the half-shell can be precisely controlled by selecting specific synthesis conditions. Furthermore, the cuprous oxide half-shells induced hybridization of the plasmon modes in the silver core and thus enabled spatial and spectral manipulation of plasmon resonances for nanoparticles in suspension. The proposed core/half-shell morphology will be particularly advantageous for directed assembly, formation of dimers for SERS sensing, or as individual particles for catalysis.