BROAD BUNDLES OF SINGLE-WALLED CARBON NANOTUBE SYNTHESIZED OVER Fe2O3-Mg O VIA CHEMICAL VAPOR DEPOSITION OF METHANE (original) (raw)

Production of Multi-walled Carbon Nanotubes via Catalytic Decomposition of Methane in the Chemical Vapor Decomposition process

International journal of materials, 2015

In this paper, carbon nanotubes (CNTs) were synthesized via vapor deposition of methane as a carbon source in the presence of Ni/MgO catalyst. The catalyst crystallinity and morphology was examined by XRD and SEM and its superior size distribution and crystallinity was confirmed. The catalytic methane decomposition was conducted in a chemical vapor deposition reactor at 900 °C. Methane, with the flow rate of 600 ml/min, was used as a carbonous gas and hydrogen and nitrogen were used at the flow rate of 500 ml/min. The obtained carbon was characterized by transmission electron microscopy (TEM) and recognized to be multi-walled carbon nanotubes with an average diameter of ~8.6 nm. The Raman spectrum confirmed a high graphitization degree of the obtained CNTs with an I D /I G ratio of 2.05, indicative of high crystallinity with few structural defects. Moreover, the thermal analysis showed the high oxidation stability of the multi-walled carbon nanotubes. It was concluded that Ni/MgO catalyst can be used as an active catalyst in the production of multi-walled carbon nanotubes (MWCNTs) in the vapor phase deposition process.