Synthesis of Nano-Sized SiC Powders by Carbothermal Reduction

Abstract

Nano sized SiC powder was successfully synthesized by the carbothermal reduction in SiO2. Precursor for SiC was prepared by using phenolic resin as a carbon source and ethylsilicate as a silicon source. After mixing, hydrolysis, drying and pyrolysis at 1000°C, SiC precursor consisted of C and SiO2 was obtained. The precursor was heat treated at 1500-1800°C in Ar to synthesize SiC by the carbothermal reduction. The carbothermal redction reaction was almost completed at 1700°C and then SiC particle with suitable size was obtained at this temperature. Nano-sized SiC particles could be achieved at 1600 °C, and unreacted SiO2 and C remained in the sample. Pure SiC particles were obtained by oxidation and acid treatment. Nano-sized SiC powder had the diameter of 10-20 nm and BET surface area of 156 m²/g.