Molten salt corrosion of graphite as a possible way to make carbon nanostructures

Abstract

The structural and microstructural changes in graphite occurring by heating a mixture of synthetic polycrystalline graphite and lithium chloride to 1250°C are studied by thermal analysis, X-ray diffraction, Raman scattering and microscopy. The average crystallite size of the graphite was found to increase significantly after the heat treatment. Although the oxidation of graphite was largely inhibited, different forms of corrosion attack on the graphite were observed. Consequently, these led to the formation of different microstructures comprising exfoliated carbon sheets and nanosheets, pitted particles and carbon nanorods. The possible mechanisms related to the microstructural changes are discussed. The effect of heating rate on the oxidation in air of graphite powder is also investigated.