Controllable template synthesis of Ni/Cu nanocable and Ni nanotube arrays: a one-step coelectrodeposition and electrochemical etching method.

We describe a new synthetic approach to fabricate Ni/Cu nanocable arrays by co-depositing nickel and copper atoms into the pores of anodic alumina membranes and to fabricate Ni nanotube arrays by selectively etching the Cu cores from the Ni/Cu nanocable arrays. The formation of the Ni-shelled Ni/Cu nanocables is attributed to the Ni ions adsorbed on the pore walls by a chemical complexation through hydroxyl groups. By varying electrodepositon parameters in this technique, we can control the lengths of nanocables and nanotubes, the shell thickness of the nanocables, and the wall thickness and surface morphology of the nanotubes.