Facet-dependent surface plasmon resonance properties of Au-Cu2 o core-shell nanocubes, octahedra, and rhombic dodecahedra

Au-Cu2 O core-shell nanocubes, octahedra, and rhombic dodecahedra display facet-dependent optical properties. Furthermore, different-sized Au-Cu2 O octahedra with 58, 65, 68, and 73 nm octahedral gold cores clearly show a transition from the shell thickness-independent gold surface plasmon resonance band for octahedra with smaller gold cores to progressive red-shifts of the band with increasing shell thickness in octahedra with larger gold cores.