"Our method is a simple and effective one for producing ordered arrays of metal-filled carbon nanotubes and can be applied to other metals and alloys," Zheng Xu of Nanjing University told nanotechweb.org. "In particular, the wall thickness of the carbon nanotubes and the length, diameter and structure of the metal nanowires inside the nanotubes can be controlled via changing the synthesis conditions."
First, the scientists deposited an array of aligned carbon nanotubes in a porous alumina membrane by catalytic pyrolysis of acetylene. Then they used electrodeposition to fill the tubes with nickel. The resulting nickel nanowires completely filled the carbon nanotubes and were up to about 50 μm in length. What's more, the team says that its technique produces a high yield of metal-filled carbon nanotubes.
"We will continue to develop other concentric composite nanostructures and will study their properties and microstructure, including under high temperature and high pressure," added Xu.
The scientists reported their work in Applied Physics Letters.