cm050355n_si_001.pdf (451.96 kB)

Hydrocarbon and Carbon Nanostructures Produced by Sonochemical Reactions of Organic Solvents on Hydrogen-Passivated Silicon Nanowires under Ambient Conditions

Download (451.96 kB)
journal contribution
posted on 15.11.2005 by C. P. Li, Boon K. Teo, X. H. Sun, N. B. Wong, S. T. Lee
A simple sonochemical solution method using silicon nanowires (SiNWs) as templates has been developed to synthesize a wide variety of carbon nanostructures under ambient conditions (room temperature and atmosphere pressure). In addition to the conventional carbon nanotubes (CNTs) and nano-onions (CNOs), with interlayer spacings of 3.4 Å, a new class of hydrocarbon nanostructures, characterized as hydrocarbon nanotubes (HCNTs) and nano-onions (HCNOs), which exhibit variable interlayer spacings greater than 3.4 Å, has been discovered. A wide variety of morphologies of these hydrocarbon nanostructures were observed, including, but not limited to, tubes (both solid and hollow tubes); onions (both solid and hollow onions); tubular networks; open, closed, or connected loops or other networks; and twisted tubes or loops. Strong evidence for the templating effect of the SiNWs, including the molding and the demolding (extrusion) processes, were provided by direct transmission electron microscopic observations. The structure and bonding characteristics of this class of hydrocarbon nanomaterials were probed by single-nanowire electron-energy-loss spectroscopy and Raman spectroscopy. The distinctive properties of the hydrocarbon nanotubes and nano-onions, which are different from those of the conventional carbon nanotubes and nano-onions, are also discussed. Based on these experimental observations, mechanistic pathways for the formation of these nanostructures are proposed.