Au Nanorice Assemble Electrolytically into Mesostars

Abstract

Star-shaped mesotructures are formed when an aqueous suspension of Au nanorice particles, which consist of prolate hematite cores and a thin Au shell, is subjected to an electric current. The nanorice particles assemble to form hyperbranched micrometer-scale mesostars. To our knowledge, this is the first reported observation of nanoparticle assembly into larger ordered structures under the influence of an electrochemical process (H2O electrolysis). The assembly is accompanied by significant modifications in the morphology, dimensions, chemical composition, crystallographic structure, and optical properties of the constituent nanoparticles