Low-Temperature Transformation of C/SiO2 Nanocomposites to β-SiC with High Surface Area

Abstract

Mesoporous silicon carbide (SiC) nanostructures were synthesized by magnesiothermic reduction of carbon–silica (C/SiO2) nanocomposites at a low temperature of 700 °C by using furfuryl alcohol as the carbon source. The phase, morphology, and structure of the samples were characterized by a combination of X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectra, X-ray photoelectron spectroscopy, thermogravimetric analysis, and N2 adsorption. The starting C/SiO2 composites exhibited an interpenetrating network and the resulting SiC preserved the mesoporous properties of the original templates. The SiC products were of β-SiC phase and showed a high surface area of 786 m2/g. The reaction mechanism and role of intermediate species (Mg2Si) were explored in detail. Furthermore, the resulting β-SiC exhibits remarkable electromagnetic wave absorption performance with a minimum reflection loss of −17.2 dB and reflection loss bandwidth less than −10 dB of 3...