Synthesis of SiC/SiO2 nanochains by carbonthermal reduction process and its optimization

Abstract

SiC/SiO2 nanochains have been successfully synthesized by carbonthermal reduction process with economical Silicon sources and Carbon sources in crucible furnace, which can largely promote the industrialization of the SiC synthesis process. The important effect of Si/SiO2 ratio, catalysts, gas atmosphere, Carbon source, reduction temperature on growth and morphology of the nanochains has been analyzed to optimize the synthesizing conditions, and so on. The characterization and performance of nanochains have been studied by IR, XRD, SEM, and TEM. The results indicate that the evenly dispersed SiC/SiO2 nanochains with uniform surface morphology and better crystallization can be obtained by calcination at 1500°C in N2 with activated carbon as Carbon sources, Si/SiO2=4 and Fe2O3 as catalyst. The synthesis mechanism of the nanochains has also been studied by TG and TEM, which verifies that the growth process obeys the VLS mechanism. The SiC nanochains are grown out from the Si–Fe–O systems and SiO vapors play an important role in the development of the reduction process.