Synthesis of "a β-SiC nanorod within a SiO₂ nanorod" one dimensional composite nanostructures

"A β-SiC nanorod within a SiO₂ nanorod" one dimensional composite nanostructures were synthesized by the combination of a low temperature (1650°C) carbothermal reduction and a high temperature (1800°C) heating of sol-gel derived silica xerogels containing carbon nanoparticles. The composite nanostructures are more than 20 μm in length. The diameters of the center thinner β-SiC nanorods are typically in the range 10-30 nm, while the outside diameters of the corresponding thicker amorphous SiO₂ nanorods are between 20 and 70 nm. Large quantities of SiC rod nuclei and the nanometer-sized nucleus sites on carbon nanoparticles are both favorable to the formation of much thinner β-SiC nanorods. The formation of the outer coaxial thicker amorphous SiO₂ nanorods is from the combination reaction of decomposed SiO vapor and O₂ during cooling.