Synthesis of multi-wall carbon nanotubes by Ni-substituted (loading) MCM-41 mesoporous molecular sieve catalyzed pyrolysis of ethanol

Ni-loading MCM-41 mesoporous molecular sieve (Ni/MCM-41) and Ni-substituted MCM-41 mesoporous molecular sieve (Ni-MCM-41) were synthesized by wet impregnation method and hydrothermal method, respectively. Their mesoporous structures were evaluated by X-ray diffraction (XRD) and N-2 physical adsorption technique. Chemical vapor deposition (CVD) was employed to catalytically synthesize carbon nanotubes (CNTs) using Ni-MCM-41 or Ni/MCM-41 as catalyst via pyrolysis of ethanol at atmospheric pressure and 700 degrees C. The resulting carbon nanotubes were characterized by means of transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM) and Raman spectroscopy, respectively. The results show that the multi-wall carbon nanotubes (MWCNTs) were successfully obtained at 700 degrees C utilizing NiMCM-41 (or Ni/MCM-41) as a catalytic template by the pyrolysis of ethanol. MWCNTs obtained over Ni-MCM-41 catalyst have uniform diameter and high quality. On the other hand, the technique has great advantages such as low cost and easy operation for the preparation of carbon nanotubes. (C) 2011 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.