Synthesis of SiC from kenyaite-carbon nanocomposite using cobalt catalyst

Abstract

SiC phases were synthesized by carbothermal conversion of kenyaite/pyrolyzed fuel oil (PFO) nanocomposite (KPN) for a duration of 3–48 h at the temperature range 1100–1350 °C. During the conversion, graphitic layered carbon was formed below 1100 °C and SiC was formed above 1200 °C. Well-crystallized SiC was obtained by reacting for 3 h at 1300–1350 °C and for 48 h at 1200 °C. The crystallinity of the SiC phase was largely improved by increasing sintering time and temperature. Notably, using a cobalt catalyst lowered the temperature required for SiC formation by 100 °C. SiC particles exhibited a fiber-type (without cobalt) and a spherical-type (with cobalt) morphology. The specific surface areas of the graphitic layered carbon and SiC were ~265 m2/g and 8.8–90.5 m2/g, respectively. These results indicated that nano-mixing by sandwiching of carbon between silicate layers and using cobalt catalyst influenced the formation of graphitic layered carbon and SiC.