Preparation Of Silicon Carbide Hollow Spheres By A Template Method

Hollow silicon carbide (SiC) spheres have been synthesized by a microwave heating and carbothermal reduction method with carbon spheres as template and fly ash (a solid waste from coal-fired power plant) as silica source. X-ray diffraction and scanning electron microscope were employed to characterize the morphology, structure of the products. The results show that hollow spheres prepared at 1300 degrees C under argon atmosphere have a hollow core and SiC shell structure. The shell of a hollow SiC sphere is composed of a lot of irregular SiC nanowires with 5-20 mu m in length and 50-500 nm in diameter which belongs to the beta-SiC. Moreover, the formation mechanism of the hollow SiC spheres is also discussed.