Fast Rate Growth of Organized Carbon Nanotubes by CVD Using Iron Pentacarbonyl as Gas-Phase Catalyst
✍ Scribed by D.-H. Kuo; M.-Y. Su; W.-R. Chen
- Publisher
- John Wiley and Sons
- Year
- 2006
- Tongue
- English
- Weight
- 737 KB
- Volume
- 12
- Category
- Article
- ISSN
- 0948-1907
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✦ Synopsis
Abstract
Organized carbon nanotubes (CNTs) have been grown at a fast rate by a gas‐phase, catalytic CVD technique at 600–750 °C for 15 min with the iron pentacarbonyl/acetylene/hydrogen system. The CNT growth at various temperatures and flow rates of iron pentacarbonyl, acetylene, and hydrogen, has been quantitatively analyzed by its length. The CNT growth accelerates with growth temperatures up to 700 °C, but depends upon growth conditions at 750 °C. Acetylene at a higher input deactivates catalysts owing to its supersaturated carbon content, approaching that of Fe~3~C. The deactivation of catalysts can be overcome by the addition of hydrogen via a hydrocarbon reaction to refresh the poisoned catalysts or by the high input of iron pentacarbonyl to provide fresh catalysts for the continuous CNT growth. CNTs with a longest tube length of 845±28 μm and a fastest growth rate of 56±1.9 μm min^–1^ were obtained. A mixed‐mode growth mechanism combining the tip‐ and base‐growth modes was suggested.