Ultra-rapid, sustainable and selective synthesis of silicon carbide powders and nanomaterials via microwave heating

Abstract

Silicon carbide has been synthesised from silicon or silica combined with activated carbon or graphitevia microwave heating over timescales from minutes to seconds without the need for inert atmospheres or subsequent purification. The carbide morphology and phase purity can be controlled by the microwave cavity used and the power applied and hence by the heating rate. Short irradiation times (ca. 5 minutes) in a multimode cavity using activated carbon produce single phase β-SiC nanofibres as small as 5 nm in diameter while large crystallites of α- and β-SiC can obtained in ≪1 minute using high power, single mode cavity microwave techniques.