Matchstick-like carbon nanotube synthesis and structure

Matchstick-like carbon nanotubes (CNTs) have been synthesized by catalytic pyrolysis of thiophene, using a mixture of cobalt nitrate and calcium nitrate as a catalyst. The nanotubes thus grown are aligned, straight, and short, and have spherical heads at their tips. High resolution transmission electron microscopy, selected area electron diffraction, and energy dispersive X-ray spectroscopy results indicate that the spherical heads of the matchstick-like CNTs are crystalline Co₉S₈ nanoparticles and the CNTs have herringbone-type graphite structure. The effect of temperature on the formation of the matchstick-like CNTs has been investigated. A simple growth model is proposed to describe the growth process of the matchstick-like CNTs. PACS 81.05.Uw; 61.46 Fg; 81.15.Gh; 68.37.Hk; 68.37.Lp