The catalytic growth of single walled carbon nanotubes
Barron, Andrew R.
Doctor of Philosophy
Single walled carbon nanotubes were synthesized using a variety of transition metal catalyst nanoparticles under a variety of reaction conditions. The degree of control for the growth procedure was qualitatively and quantitatively assessed using a variety of characterization techniques including resonance Raman spectroscopy, scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis, and atomic force microscopy. It was found that doping the catalysts with a second metal, also from the first row transition series, would alter both the rate of growth, and the diameters of the nanotubes that were produced. Further to this, work conducted using a bimetallic FeCo catalyst was found to exhibit two distinct growth stages, where each stage required careful selection of reaction conditions to maximize product output. By this method the design of a ‘catalyst activity map’ is proposed such that optimal conditions for nucleation and growth are determined. As a corollary to this work the synthesis of multi walled nanotubes was also carried out and it was found that the affect of the reaction conditions also greatly influenced the product outcome. Whereby products ranged from long thin multi walled nanotubes, to making carbon nano fibers instead. In this manner a ‘process map’ was developed according to the carbon nanomaterials that were created, as a function of the reaction conditions that were employed.
Nanotubes; Catalysis; Nanoparticles; Education; Chemistry