Synthesis of vertically aligned carbon nanotube films on macroporous alumina substrates

This communication reports experimental efforts to grow vertically aligned carbon nanotube (CNT) films on macroporous α-Al₂O₃ disks of 20 mm in diameter. Vertically aligned CNT films could not be obtained by the methods of preloading catalyst. About 10 μm thick vertically aligned CNT films were obtained on the macroporous alumina disks by chemical vapor deposition with the alumina substrates exposed first to a flow of ferrocene in NH₃ then to a flow of acetylene and NH₃ for about 10 min at substrate temperature of 800 °C. The CNTs are about 100 nm in diameter and have a bamboo-type structure, with pore openings of about 4.2 nm in diameter. Possible formation mechanism of vertical aligned CNTs on the disk was also discussed in this communication.