Synthesis of conducting fibers, nanotubes, and thin films of carbon from commercial kerosene

Abstract

Commercial kerosene, commonly used as a cheap fuel for cooking or lighting in underdeveloped areas, has for the first time been found capable of producing conducting fibers, nanotubes, and thin films of carbon. The process of synthesis involves simple pyrolysis of kerosene vapor at 1000°C in argon atmosphere. Various kinds of conducting fibers were obtained, viz., 6–7-cm-long straight fibers (70–75 μm φ), flexible hair-like fibers (2 μm φ), soft wool-like fibers (60–250 nm φ), tiny earthworm-like fibers (50 nm φ), rough bitter-gourd-like fibers (3 μm φ), and uniform hollow fibers (nanotubes of inner and outer diameters of 30 and 80 nm, respectively). Formation of these kerosene-pyrolyzed products and their interrelation are discussed on the basis of scanning electron microscopy (SEM) and transmission electron microscopy (TEM) studies. X-ray diffraction (XRD) analyses of these nanocarbon materials suggest that they have a novel structure, not matching that of known forms of carbon. This conclusion is supported by FTIR and laser-Raman analyses. Thin film of conducting carbon was found to possess an electrochemical potential window as wide as 2.91 V and was effectively used to electrolyze 30% brine solution at a current density of 300 mA cm −2 at 3 V. It is suggested that the kerosene-pyrolyzed carbon electrodes can be used in the chloro-alkali industry.