METHOD FOR PRODUCING HOLLOW NANOFIBER

摘要

PROBLEM TO BE SOLVED: To obtain carbon nanotubes controlled in the number of layers and in the diameter and being less defective in the graphite layer. SOLUTION: A catalyst (1) is prepared by impregnating a support with cobalt microparticles in which the bonding energy of a cobalt2P3/2 electron is 779.3 to 781.0 eV as measured by X-ray photoelectron spectroscopy. A catalyst (2) is prepared by impregnating a support with cobalt microparticles in which the atomic ratio of cobalt on the surface of the support is 0.1 to 1.5% as measured by X-ray photoelectron spectroscopy under conditions of 10 kV and 18 mA. A catalyst (3) is prepared by impregnating a support containing titanium with cobalt microparticles in which the cobalt/titanium atomic ratio on the surface of the support is 0.3 to 2.0 as measured by X-ray photoelectron spectroscopy under conditions of 10 kV and 18 mA. Or a catalyst (4) is prepared by impregnating a support with cobalt microparticles in which the weight ratio of cobalt to the second metal component (the weight of cobalt)/(the weight of the second metal component) on the surface of the support is 2.5 or larger. A hollow nanofiber is formed by bringing any one of the above catalysts into contact with a carbon-containing compound at 500 to 1,200°C. COPYRIGHT: (C)2004,JPO