Abstract:
Wellaligned nontangled carbon nanotubes (CNTs) were grown in ethanol flames on a nanocrystalline Ni layer that was electrodeposited on a Cu alloy substrate using periodic reverse pulse plating. The morphologies and microstructures of the nanocrystalline layers and the CNTs were characterized by XRD, SEM, TEM, AFM and laser Raman spectroscopy. It was found that a large area of vertically aligned CNTs with uniform density could be produced with high repeatability by controlling the thickness of the Ni nanocrystalline layer and time in the flame. A low electrodeposition time was favorable for the formation of thin layer nanocrystalline Ni with high local roughness and high catalytic activity on which wellaligned CNTs were generated with overcrowded growth that prevented them from becoming tangled. A low aspect ratio of CNTs was needed to keep them from tangling, and this could be adjusted by controlling the pulse electrodeposition parameters to form the desired catalyst particles. The best CNTs can be produced by passing ethanol through a nanocrystalline Ni layer supported substrate at 600℃ for 1 min that had been electrodeposited at an output pulse frequency of 154Hz with duty cycle of 38.5% for 1min.