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 N2 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 °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 °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.