Photochemical Strategies\nfor the Seed-Mediated Growth\nof Gold and Gold–Silver Nanoparticles

Abstract

Gold nanoparticles (AuNP) can be used as seeds for the\nsynthesis\nof larger AuNP of controllable size with narrow size distribution\nby photochemical reduction of additional Au­(III) using water-soluble\nbenzoins or H₂O₂ as sources of reducing radicals.\nFurther, beyond simply enlarging the AuNP, it is possible to add a\nshell of another metal, such as silver, leading to Au/Ag core–shell\nstructures with controllable dimensions for both core and shell. This\nstrategy illustrates the fine spatial and temporal control achievable\nusing clean photochemical techniques without the addition of hard\nsurface ligands often necessary to control the size and structure\nof gold–silver nanostructures. The mild nature of the surface\ncoverage makes these nanomaterials ideal for further surface modification.