- Mesoporous, highly structured silicon carbide (beta-SiC) was synthesised from renewable plant materials (two Equisetaceae species) in a one-step carbothermal process at remarkably low temperatures down to 1200 degrees C. The SiC precursor is a silicon-carbon mixture with finely dispersed carbon prepared by pyrolysis of the organic plant matrix. Yields are 3 to 100% (omega(Si/Si) related to the silicon deposited in the plant material), depending on reaction temperature and time. IR spectroscopy, X-ray diffraction, and nitrogen sorption prove the formation of high-purity beta-SiC with minor inorganic impurities after purification and a high specific surface area of up to 660 m(2) g(-1). Scanning electron microscopy shows that the plant morphology is maintained in the final SiC. Sedimentation analysis finds a mean particle size (diameters d(50)) of 20 mu m.
