M.Sc., Faculty of Science, University of the Witwatersrand, 2011 / In this dissertation, the synthesis of nitrogen doped carbon nanotubes (N-CNTs) was
performed successfully, using a floating catalyst chemical vapour deposition (CVD)
method. Fe(CO)5 was utilized as the catalyst and acetonitrile and toluene as nitrogen
and carbon sources respectively. Two different procedures were used to add reagents
to the reactor: an injection method and a bubbling method. The effect of nitrogen
concentration and physical parameters such as reaction temperature, gas flow rate on
the morphology, crystallinity and thermal stability of the tubes was studied. The
synthesized materials were characterized by means of Raman spectroscopy, TGA and
TEM analyses. The presence of nitrogen was confirmed by the presence of the
bamboo formations in the tubes by TEM. A comparison of the data from the
numerous reactions revealed that N-CNTs can be made from Fe(CO)5 and
acetonitrile. Further the main conclusions achieved using the injection method were:
i) the maximum number of tubes with bamboo structure were made using on
acetonitrile concentration of 15%, ii) The best growth temperature to make N-CNTs
was 850 oC, iii) An increase in acetonitrile concentration decreased the yield of NCNTs
and iv) Tubes with the narrowest outer diameters were made using an
acetonitrile concentration of 15%.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:wits/oai:wiredspace.wits.ac.za:10539/11348 |
| Date | 24 February 2012 |
| Creators | Ghadimi, Nafise |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | application/pdf |
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