Unified Synthetic Approach to Silver Nanostructures by Galvanic Displacement Reaction on Copper: From Nanobelts to Nanoshells

We report a unified nontemplate approach to a variety of silver nanostructures, including nanobelts, dendrites, nanodisks, and nanoshells. The growth of these silver nanostructures occurs by galvanic displacement initiated by short-circuited nanobatteries formed between the copper nano/microparticles and protruding silver "seeds" on their surface. The silver nanostructures share analogous structural features because they develop from very similar silver seed crystals during their early growth stage. Transmission electron microcopy (TEM) studies reveal essentially identical electron diffraction patterns and crystal structures through the different growth stages. The formation of different silver nanostructures can be systematically controlled, for example, by varying the size of the copper particle as well as the identity and concentration of the starting silver(I) species.