• carbon nanotubes;
  • graphite thin films;
  • chemical vapor deposition;
  • sol–gel processing;
  • hydrogen


Layered carbon-nanotube (CNT) films were prepared using a thermal chemical vapor deposition method by introducing hydrogen gas for a period of time during the growth. Scanning electron microscopy indicates that the films are made up of two vertically oriented CNT layers separated by continuous graphite layers. Energy-dispersive spectrometry confirms that the two layers of CNT arrays have different growth modes: the tip growth mode for the bottom layer and the base growth mode for the top layer. Raman spectra were used to characterize the quality of the two layers of CNT arrays. A possible growth model for the layered CNT separated by graphite layers was proposed.