Investigation of Fe/MgO Catalyst Support Precursors for the Chemical Vapour Deposition Growth of Carbon Nanotubes

Abstract

Carbon nanotubes have been grown by the catalytic chemical vapour deposition (CCVD) method using an Fe catalyst supported on MgO. The influence of using either pure MgO or Mg(NO3)2 x 6H2O as the source of the MgO catalyst support as well as the effects of varying the Fe metal loading on the support has been investigated. The catalyst was prepared at room temperature by the wet impregnation method from a mixture of Fe2(SO4)3 x xH2O and either MgO or Mg(NO3)2 x 6H2O in aqueous solution; the weight percent of Fe/MgO was varied between 5, 10, and 15. Preparation of CNTs was carried out in a horizontal furnace at 900 degrees C under methane gas with flow rate of 6 litres/min. The supported catalysts and carbon nanotubes (CNTs) were investigated by Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), X-ray Diffraction pattern (XRD) and Fourier Transform (FT)-Raman spectroscopy. Results revealed that the number of nanotubes was maximised by using MgO as a support precursor instead of Mg(NO3)2 x 6H2O and also by increasing the amount of Fe.

Methods for carbon nanotubes synthesis—review

“…with Au. 80 Concerning the carbon source, the most preferred in CVD are hydrocarbons such as methane, 81 ethane, 82 ethylene, 83 acetylene, 84 xylene, 85,86 eventually their mixture, 87 isobutane 88 or ethanol. 89,90 In the case of gaseous carbon source, the CNTs growth efficiency strongly depends on the reactivity and concentration of gas phase intermediates produced together with reactive species and free radicals as a result of hydrocarbon decomposition.…”

Magnesium oxide as a heterogeneous catalyst support

“…The chemical reaction mechanism contains two stages, including adsorption of CH 4 molecules on the surface of the carbon particles, followed by the decomposition of adsorbed CH 4 into H 2 and carbon. Therefore, it was Brought to you by | Rutgers University Authenticated Download Date | 10/5/15 11:26 AM concluded that the use of MgO increased the yield of synthesized nanocarbon compared to other support materials, including Al 2 O 3 and SiO 2 (Palizdar et al 2011, Su et al 2011, Jin et al 2012, Wang et al 2012a.…”

Direct growth of vertically aligned carbon nanotubes on silicon substrate by spray pyrolysis of Glycine max oil

“…Ferrocene has been shown to be a good precursor of iron nanoparticles suitable to catalyze CNT growth [16][17]. Conventionally hydrocarbons such as methane, ethane, ethylene, acetylene, xylene and ethanol were used as a carbon source for the synthesis of CNTs [18][19][20][21][22][23]. The number of studies utilizing low-cost carbon sources for the synthesis of CNTs such as botanical hydrocarbon is very limited [24][25][26][27][28].…”