Bottom-up synthesis of gold octahedra with tailorable hollow features.

Gold octahedra with hollow features have been synthesized in high yield via the controlled overgrowth of preformed concave cube seeds. This Ag(+)-assisted, seed-mediated synthesis allows for the average edge length of the octahedra and the size of the hollow features to be independently controlled. We propose that a high concentration of Ag(+) stabilizes the {111} facets of the octahedra through underpotential deposition while the rate of Au(+) reduction controls the dimensions of the hollow features. This synthesis represents a highly controllable bottom-up approach for the preparation of hollow gold nanostructures.