Controlled growth of single-walled carbon nanotubes from an ordered mesoporous silica template

We have grown carbon nanotubes (CNTs) with controlled orientation and diameter (1-4 nm) from thermally stable, highly ordered mesoporous SiO2 thin films by methane chemical vapor deposition (CVD). Controlled incorporation of an Fe precursor into one-dimensional (1D) and three-dimensional (3D) pore channels of mesoporous SiO2 results in a nanostructure catalytically active for CNT growth and stable to typical CVD temperatures. Growth of CNTs starts within the mesoporous SiO2, whose pore direction and. pore dimension play an important role in controlling the orientation and diameter of the CNTs at the early stage of the growth. Lateral growth across micropatterned trenches results in oriented CNT assemblies with controlled tube dimension. The flexibility of constructing parallel nanotube assemblies and nanotube junctions by this simple method suggests its high potential for fabricating future integrated molecular electronic nanodevices.