Formation of spherical nanocrystalline silicon carbide via carbothermal reduction of water glass and sugar

Abstract

A simple method was developed to synthesise spherical nanocrystalline silicon carbide via carbothermal reduction of water glass and sugar. The overall process is composed of three steps: the preparation of spray dried precursors, carbonisation of the precursors and carbothermal reduction. The precursors and products were characterised by XRD, infrared, Brunauer–Emmett–Teller, SEM and TEM. The results show that carbothermal reduction of the precursors could be completed at 1500°C for 2 h. The as prepared product is spherical nanocrystalline β-SiC powders with the diameter about 13·6 nm and the BET specific areas of 17 m² g^–1. In addition, the powder is of high purity, because sodium oxide in the precursor could be eliminated by the escape of sodium at high temperature.