Fabrication and Corrosion Resistance of SiC-coated Multi-walled Carbon Nanotubes

Multi-walled carbon nanotubes (MWNTs) were coated with nanometer sized SiC layer by magnetron sputtering, and their corrosion resistances in oxygen and gaseous silicon were studied, respectively. X-ray diffraction (XRD) reveals that the as-coated MWNTs are comprised of the amorphous SiC and the phase could transfer from amorphous to polycrystalline SiC by annealing at 1360 °C. Scanning electron microscopy (SEM) observation indicates that SiC nanoparticles are uniformly coated on the MWNTs, forming a continuous SiC coating. Thermogravimetric analysis (TGA) confirms that the onset temperature of oxidation increases from 540 to 700 °C with the SiC coating. The morphologies of non-coated and SiC-coated MWNTs after corrosion by oxygen and gaseous silicon were also characterized by SEM. The results revealed that SiC coating could protect MWNTs from the corrosion with gaseous silicon effectively.