| Summary: | 碩士 === 國防大學中正理工學院 === 兵器系統工程研究所 === 93 === The thesis aimed on reducing the growth temperature for the synthesis of carbon nanotubes(CNT) using Ni-P alloy catalysts or Ni-Pd-P co-catalysts, deposited using isothermal/non-isothermal(NITD) electroless techniques, by thermal chemical vaper deposition(CVD) of acetylene gas, down to 400~500°C. The influence of deposition time on the size, density and morphology of the Ni-P alloy catalysts was investigated. The chemical composition of the deposited Ni-Pd-P co-catalysts was evaluated qualitatively and quantitatively by ESCA and EPMA techniques respectively. The effects of catalysts and growth temperature on the growth, morphology and structure of the synthesized CNTs were also evaluated.
The result indicated that the size and density of the Ni-P alloy catalysts were increased with the increasing of deposition time. The morphologies (density and diameter) of the grown CNTs were shown to be strongly dependent upon the catalyst deposition time and growth temperature. The optimum growth temperature for the synthesis of CNTs using Ni-P alloy catalysts was observed to be at around 700°C. It is shown that there was no carbon by-products (CNTs, carbon nanofibers – CNFs, carbon nanocoils - CNCs) to be produced on Ni-P alloy catalytic substrates while the growth temperatures controlled under 500°C. The density and length of CNTs synthesized on Ni-Pd-P catalyzed substrates were observed to be denser and longer than those synthesized on Ni-P catalyzed substrates while the growth temperatures set ranged from 600 - 900°. It is noted that the Ni-Pd-P co-catalysts had the effect on reducing the growth temperature for the synthesis of CNTs, down to 400°, resulting in the production of a group of carbon by-products - CNTs, CNFs, and CNCs. The bamboo like-shaped CNTs with the diameter of 80nm were proved to be grown under the top growth mechanism using high resolution transmission electron microscopy technique. The distribution uniformity and morphology of Pd and P on Ni catalysts were also shown to play an important role in forming the curled CNCs.
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