Fluorination of Arc-Produced Carbon Material Containing Multiwall Nanotubes

Abstract

The fluorination of arc-produced carbon material, which contained multiwall carbon nanotubes, was performed at room temperature by using a gaseous mixture of BrF3 and Br2. The elemental composition of the sample was determined by X-ray photoelectron spectroscopy to be CF0.3Br0.02, while graphite is fluorinated up to a C2F stoichiometry under the same reaction conditions. The fluorinated carbon material and graphite fluoride were comparatively analyzed by means of X-ray diffraction, infrared spectroscopy, and thermogravimetry. Transmission electron microscopy indicated that only the outer shells of carbon nanotubes and polyhedral particles were fluorinated whereas the inner shells remained intact. We suggest that some of the arc-produced multiwall carbon nanotubes are composed of concentric cylindrical shells surrounded by nestled scrolls.