Research Output
Microwave synthesis of silicon carbide nanowhiskers: Effect of molar ratio
The effect of graphite type on the synthesis of SiC nanomaterials by microwave-assisted synthesis
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Publication
Silicon carbide (SiC) is an attractive material for its excellent properties such as wide band gap, high chemical stability and thermal conductivity. The conventional methods for the preparation of SiC are time and energy consuming. In this paper, SiC nanowhiskers were synthesized by utilizing microwave heating. Mixture of graphite and silica of various ratio was heated to 1400 °C for 30 min at a heating rate of 20 °C/min. It was found that almost complete conversion of graphite and silica to silicon carbide nanowhiskers was observed for sample of mixture in the ratio of 1:3. Vapor-solid mechanism was suggested to explain the formation of SiC nanowhiskers.
Publication
SiC nanomaterial (SiCNM) is known for its excellent properties and has great potential for a wide range of applications. In this article, preparation of SiCNMs from different types of graphite was performed by microwave-assisted synthesis. Different types of graphite which are graphite flake (GF) and expanded graphite (EG) were used to react with silica for the synthesis of SiCNMs in laboratory microwave furnace at 1400 °C. It was found that SiC nanowhiskers (SiCNWs) were formed when EG was used, while irregular shaped SiC nanoparticles (SiCNPs) were formed when GF was used. β-SiC appeared as the only phase in the XRD patterns for both SiCNMs formed using GF and EG. SiCNWs and SiCNPs have interplanar spacing of around 0.25 nm which is the axial direction of [111]. The difference of formation mechanism is believed to be the origin of different morphology of SiCNMs synthesized from different types of graphite.