Novel synthesis of silicon carbide nanotubes by microwave heating of blended silicon dioxide and multi-walled carbon nanotubes: The effect of the heating temperature

Silicon carbide nanomaterials, especially silicon carbide nanotubes (SiCNTs), are known as excellent materials for high-power and high-temperature harsh environment electronics applications because of the unique properties of SiCNTs, such as a high thermal stability, good chemical inertness and excellent electronic properties. In this article, we presented a novel synthesis of SiCNTs by microwave heating a blend of silicon dioxide (SiO2) and multi-walled carbon nanotubes (MWCNTs) at a ratio of 1:3 at temperatures of 1350 degrees C, 1400 degrees C and 1450 degrees C. The effects of different heating temperatures on the synthesis of SiCNTs were studied. X-ray diffraction revealed the presence of single phase beta-SiC for syntheses conducted at 1400 degrees C and 1450 degrees C. Meanwhile, field-emission scanning electron microscopy images showed that no residual silicon dioxide or MWCNTs was observed with syntheses conducted at 1400 degrees C and 1450 degrees C. High-magnification transmission electron microscopy revealed that the tubular structure of the MWCNTs was preserved and that SiCNTs had a lattice fringe spacing of 0.261 nm corresponding to the (111) plane of beta-SiC. Photoluminescence spectroscopy showed the presence of a beta-SiC peak at a wavelength of 465 nm, and the band gap energy of SiCNTs was 2.67 eV. Fourier transform infrared spectroscopy analysis revealed that the absorption band of the Si-C bond was detected at 803 cm(-1). The purity of SiCNTs synthesized at 1400 degrees C and 1450 degrees C is high, as indicated by the low weight loss in thermo-gravimetric analysis. (C) 2016 Elsevier Ltd and Techna Group S.r.l. All rights reserved.