Preparation and characterization of SiC@CNT coaxial nanocables using CNTs as a template

Abstract

Novel one-dimensional SiC@carbon nanotube (CNT) coaxial nanocables have been successfully fabricated on a large scale by using a carbothermal chemical vapor deposition method. Sol–gel-derived silica xerogels containing commercial multi-wall carbon nanotubes (MWCNT) were used as silicon and carbon sources. The obtained product was characterized by SEM, HRTEM, Raman spectroscopy and XRD. The coaxial nanocables have been found to be composed of a 40–100 nm diameter carbon nanotube as the core, surrounded by a thick SiC outlayer. The inner nanotube corresponded to the multi-walls of the carbon nanotube with a lattice spacing of 0.34 nm. The PL spectrum revealed that the SiC@CNT nanocables have two broad emission bands centered at 461 nm and 573 nm which can be attributed to the quantum confinement effect and the morphology effects. The morphology of the product was tuned by simply altering the reaction temperature. In the formation of SiC@carbon nanotube coaxial nanocables, it was proposed that CNTs acted as a template to confine the reaction, which resulted in the continuous SiC outlayer growth on the CNT surface to form SiC@CNT coaxial nanocables.