Electron microscopy Archives – Institute of Nano Electronic Engineering

Effect of FeOx loaded on CoOx/Al2O3 catalyst for the formation of thin-walled carbon nanotubes

February 17, 2014 By Editor

Abstract – Effects of FeOx loaded on CoOx/Al2O3 catalyst on the yield and morphology of the produced carbon nanotubes were studied. The findings showed that the addition of a small amount of FeOx on the CoOx/Al2O3 catalyst provoked the formation of carbon nanotubes with a thin wall structure. The results also revealed that an increase in FeOx content decreased the yield of carbon nanotubes. An optimized weight ratio of CoOx to FeOx was found to be 8:2 (w/w) whereby the catalyst of this composition grew carbon nanotubes with a thin wall structure and not of diminutive carbon yield.

Keywords – carbon nanotubes, catalyst, electron microscopy, methane decomposition

Corresponding Author: Liu Wei Wen
Corresponding Author’s Email: wwliu@unimap.edu.my

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Synthesis of single-walled carbon nanotubes by chemical vapor deposition using sodium chloride support

September 4, 2013 By Editor

Abstract – Bundled single-walled carbon nanotubes (SWCNTs) together with multi-walled carbon nanotubes (MWCNTs) were directly grown on a water-soluble support catalyst that was prepared via sublimation of ferrocene on sodium chloride. The synthesis of nanotubes was carried out at a growth temperature of 700 °C in a combined methane and nitrogen environment of 1:1 volumetric ratio at a total flowrate of 80 ml/min for 1 h in a vertical reactor. Characterization techniques such as scanning electron microscope, transmission electron microscope, thermogravimetric analysis, and Raman spectroscopy were employed to study the carbon deposits. Transmission electron microscope shows the presence of SWCNTs with an average diameter of ca. 1.18 nm on the catalyst. The radial breathing mode (RBM) of Raman for shifts below 350 ^-1cm further confirmed the presence of SWCNTs and the diameters were calculated to be 0.93, 1.36, 1.5 and 1.85nm.

Keywords – Single-walled carbon nanotubes, Multi-walled carbon nanotubes, Electron microscopy, Raman spectroscopy

Corresponding Author: Liu Wei Wen
Corresponding Author’s Email: wwliu@unimap.edu.my

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Preparation of iron oxide nanoparticles supported on magnesium oxide for producing high-quality single-walled carbon nanotubes

November 22, 2012 By Editor

Abstract – Fe3O4 nanoparticles with a narrow diameter distribution having an average diameter of 10.33 nm ± 2.99 nm (average diameter ± standard deviation) were prepared by a precipitation method. The Fe3O4 nanoparticles were supported on MgO by mixing the MgO nanopowder with the required amount of Fe3O4 nanoparticles in water under extensive sonication. Single-walled carbon nanotubes (SWCNTs) were synthesized by the chemical vapor deposition (CVD) of methane over the Fe3O4/MgO catalyst. Transmission electron microscopy showed that a large number of SWCNT bundles of nearly uniform diameter were produced by the CVD method. The average diameter of the produced SWCNTs was ca. 1.22 nm. Thermogravimetric analysis showed that the weight loss was approximately 19% by oxidation of carbon in the temperature range of 400-680 oC. The ratio of the intensity of the D-band to the G-band was 0.03, indicating that the SWCNTs were well-graphitized.

Keywords – Single-walled carbon nanotubes, Chemical vapor deposition, Electron microscopy, Raman spectroscopy

Corresponding Author: Liu Wei Wen
Corresponding Author’s Email: wwliu@unimap.edu.my

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