Document Type : Research Paper


1 Reseach institute of petroleum industry, RIPI

2 Research Institute of Petroleum Industry (RIPI)


Multi-walled carbon nanotubes (MWNT’s) were synthesized using chemical vapor deposition (CVD) method in a fluidized bed reactor under the flow of methane and hydrogen gases. A Cobalt-molybdenum/magnesium oxide (Co-Mo/MgO) nanocatalyst was used as the catalyst of the process. The samples were analyzed using scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses. The effects of different combinations of purification methods, including oxidation, HCl treatment, and HNO3 treatment and the sequence of performing these methods on the quality of the carbon nanotubes are discussed. Raman spectroscopy with a laser excitation of 532 nm was utilized as the measurement tool. The results provide the best purification methods of synthesized carbon nanotubes. The IG/ID ratio for the optimum sample is equal to 1.28. Moreover, as another application of Raman analysis results, the apparent Young’s modulus of MWNT’s was calculated by the use of intensity ratio ID/IG. As expected, the optimum sample had the highest apparent Young’s modulus of 40459.85 MPa.


      [1]     Iijima S., “Helical Microtubules of Graphitic Carbon,” Nature, 1991,354, 56-58.
      [2]     Bethune D. S., Klang C. H., Vries M. S., Gorman G., et al., “Cobalt-catalyzed Growth of Carbon Nanotubes with Single-atomic-layer Walls,” Nature, 1993, 363, 605-607.
      [3]     Iijima S. and Ichihashi T., “Single-shell Carbon Nanotubes of 1-nm Diameter,” Nature, 1993, 363, 603-605.
      [4]     Vairavapandian D., Vichchulada P., and Lay M. D., “Electrodeposition on SWNT’s: Review of Recent Advances and Applications in Catalysis and Sensing,” Anal. Chim. Acta., 2008, 626, 119-129.
      [5]     Ebbesen T. W. and Ajayan P. M., “Large-scale Synthesis of Carbon Nanotubes,” Nature, 1992, 358, 220-221.
      [6]     Shi Z., Lian Y., Zhou X., Gu Z., et al., “Mass Production of Single-walled Carbon Nano-tubes by Arc Discharge Method,” Carbon, 1999, 37, 1449-1453.
      [7]     Liu C., Cong H., and Li F., “Semi-continuous Synthesis of Single-walled Carbon Nanotubes by a Hydrogen Arc Discharge Method,” Carbon, 1999, 37, 1865-1868.
      [8]     Guo T., Nikolaev P., and Thess A., “Catalytic Growth of Single-walled Nanotubes by Laser Vaporization,” Chem. Phys. Lett., 1995, 243, 49-54.
      [9]     Thess A., Lee R., Nikolaev P., Dai H., et al., “Crystalline Ropes of Metallic Carbon Nanotubes,” Science, 1996, 273, 483-487.
    [10]    Hernadi K., Fonseca A., Nagy J., Bernaerts D., et al., “Fe-catalyzed Carbon Nanotubes Formation,” Carbon, 1996, 34, 1249-1257.
    [11]    Hernadi K., Fonseca A., Nagy J. B., Siska A., et al., “Production of Nanotubes by the Catalytic Decomposition of Different Carbon-containing Compounds,” Appl. Catal. A, 2000, 199, 245-255.
    [12]    Ren Z. F., Huang Z. P., Xu J. W., Wang J. H., et al., “Synthesis of Large Arrays of Well-aligned Carbon Nanotubes on Glass,” Science, 1998, 282, 1105-1107.
    [13]    Li Y., Chen J., Qin Y., and Chang L., “Simultaneous Production of Hydrogen and Nanocarbon from Decomposition of Methane of a Nickel-based Catalyst,” Energy Fuels, 2000, 14, 1188-1194.
    [14]    Shin D. K., Ju W. K., Ji S. I., Young H. K., et al., “A Comparative Study on Properties of Multi-walled Carbon Nanotubes (MWCNT’s) Modified with Acids and Oxyfluorination,” J. Fluorine. Chem., 2007, 128, 60-64.
    [15]    Musumeci A. W., Waclawik E. R., and Ray F. L., “A Comparative Study of Single-walled Carbon Nanotube Purification Techniques Using Raman Spectroscopy,” Spectrochim. Acta Part A, 2008, 71, 140-142.
    [16]    Lafi L., Cossement D., and Chahine R., “Raman Spectroscopy and Nitrogen Vapor Adsorption for the Study of Structural Changes During Purification of Single-walled Carbon Nanotubes,” Carbon, 2005, 43, 1347-1357.
    [17]    MacKenzie K., Dunens O., and Harris A. T., “A Review of Carbon Nanotube Purifica-tion by Microwave Assisted Acid Diges-tion,” Separation and Purification Technol-ogy, 2009, 66, 209-222.
    [18]    Liu X., Spencer J. L., Kaiser A. B., and Arnold W. M., “Selective Purification of Multi-walled Carbon Nanotubes by Dielectrophoresis within a Large Array,” Current Applied Physics, 2006, 6, 427-431.
    [19]    Stobinski L., Lesiak B., Kövér L., Tóth J., et al., “Multi-walled Carbon Nanotubes Purification and Oxidation by Nitric Acid Studied by the FTIR and Electron Spectroscopy Methods,” Journal of Alloys and Compounds, 2010, 501, 77-84.
    [20]    Ciambelli P., Sannino D., Sarno M., and Leone C., “Wide Characterization to Compare Conventional and Highly Effective Microwave Purification and Functionalization of Multi-walled Carbon Nanotubes,” Thin Solid Films, 2011, 519, 2121-2131.
    [21]    Xinlong L., Yizhe W., Liming Z., and Su X., “The Effect of Different Order of Purification Treatments on the Purity of Multi-walled Carbon Nanotubes,” Applied Surface Science, 2013, 276, 159-166.
    [22]    Sainz R., Small W. R., Young N. A., Valle´s C., et al., “Synthesis and Characterization of Optically Active Polyaniline Carbon Nanotube Composites,” Macromolecules, 2006, 39, 7324.
    [23]    Rashidi A. M., Akbarnejad M. M., Khodadadi A. A., Mortazavi Y., et al., “Single-walled Carbon Nanotubes Synthesized Using Organic Additives to Co -Mo Catalysts Supported on Nanoporous MgO,” J. Nanotechnol., 2007, 18, 315605.
    [24]    Pak T. J., Banerjee S., Benny T. H., and Wong S. S., “Purification Strategies and Purity Visualization Techniques for Single-
walled Carbon Nanotubes,” J. Mater. Chem., 2006, 16, 141-154.
    [25]    Ouyang Y., Cong L. M., Chen L., Liu Q. X., et al., “Raman Study on Single-walled Carbon Nanotubes and Multi-walled Car-bon Nanotubes with Different Laser Excitation Energies,” Physica E., 2008, 40, 2386-238.
    [26]    Enomoto K., Kitakata S., Yasuhara T., Ohtake N., et al., “Measurement of Young’s Modulus of Carbon Nanotubes by Nanoprobe Manipulation in a Trans-mission Electron Microscope,” Appl. Phys. Lett., 2006, 88, 153115.