An additive-free electrochemical route to rapid synthesis of large-area copper nano-octahedra on gold film substrates

We report the first fabrication of large-area Cu nano-octahedra with well-defined shape, good monodispersity and uniform distribution on a gold film substrate (GFS) by a very simple, rapid and cost-effective low-potential electrodeposition (LPED) technique. Different from general surfactant-assisted electrochemical approaches, LPED is an additive-free strategy that exploits the subtle surface energy differences among various crystallographic planes of metals themselves. The size of the octahedra depends on deposition time and is adjustable over a wide range. The shape evolution is found to be remarkably different from that of octahedral particles formed in solution. A formation mechanism is proposed for the unique evolution of Cu octahedra as resulting from the anisotropic growth under appropriate applied potentials.