Growth of SiC whiskers by carbothermal reduction of mesoporous silica-carbon composites infiltrated with SiC nuclei

Mesoporous C-SiO₂ nanocomposite with a low C/SiO₂ molar ratio was infiltrated with polycarbosilane (PCS) which is a preceramic precursor for silicon carbide. Different silicon carbide nanostructures were synthesized by carbothermal reduction of mesoporous C-SiO₂ nanocomposites via different heat treatments. X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and nitrogen adsorption-desorption analysis were used to characterize C-SiO₂ nanocomposites and SiC products. SiC was not formed in the mesoporous C-SiO ₂ nanocomposites without PCS at 1450°C. However, when it was infiltrated with PCS to allow a conversion of PCS into SiC nuclei in the mesopores during the heat treatment, highly crystalline SiC nanofibers and nanoparticles were produced.