Carbon nanotube formation in situ during carbonization in shaped bulk solid cobalt nanoparticle compositions

Abstract

Carbon nanotubes are formed in bulk compositions from thermal decomposition of a cobalt-containing organometallic compound in the presence of an excess amount of a multi(ethynyl)aromatic compound. The novel method described here permits the large-scale production of carbon nanotubes in a shaped, solid configuration. 1,2,4,5-Tetrakis(phenylethynyl)benzene was reacted with varying amounts of cobalt octacarbonyl to produce the cobalt carbonyl complex. Heat treatment of various compositions, formulated from the cobalt complex and an excess amount of 1,2,4,5-tetrakis(phenylethynyl)benzene, to temperatures up to 1400 °C resulted in the decomposition of the complex and the formation of cobalt nanoparticles in the polymeric-to-carbon nanoparticle-to-carbon nanotube compositions. The cobalt nanoparticles are the key to the formation of the carbon nanotubes. X-ray diffraction, Raman spectroscopy, high resolution scanning electron microscopy (HRSEM), and transmission electron microscopy (TEM) studies show the formation of carbon nanotubes in the developing carbon composition above 600 °C.