Growing pillars of densely packed carbon nanotubes on Ni-coated silica Original Research Article

We report the growth of pillar-like cylindrical structures consisting of densely packed and vertically aligned multiwalled carbon nanotubes by exposing Ni-coated oxidized-Si (001) substrates to a xylene–ferrocene mixture. The nanotube pillars have a diameter between 10 and 100 μm, and lengths of several tens of micrometres. Formation of circular microcracks in the film allows ferrocene and xylene molecules to reach the underlying SiO2 layer where pillars nucleate and grow out of the plane of the film surface. The nanotube pillars are attractive for applications such as energy storage, electrodes, and composite reinforcements.