Low-temperature catalytic synthesis of SiC nanopowder from liquid phenolic resin and diatomite

Abstract

3C–SiC nanopowder was catalytically synthesised at 1400°C for 3 h in argon using industrial diatomite powder and phenolic resin as raw materials, and cobalt nitrate as a catalyst precursor. Phase composition and microstructure of product samples were characterised using X-ray diffraction analysis, scanning electronic microscopy and transmission electronic microscopy. The effects of temperature, catalyst content and reaction time on the formation of SiC were examined. The results indicated that (1) phase pure 3C–SiC can be synthesised at 1400°C for 3 h using 1.0 wt-% Co catalyst; (2) if no catalyst was used, only little 3C–SiC was formed under the identical firing condition; (3) as-prepared 3C–SiC nanoparticles had irregular shapes with overall sizes of 30–300 nm. Density functional theory calculations further reveal that the Co catalyst assisted Si–O bond breaking and thus the SiC formation.