Novel synthesis and characterization of silicon carbide nanowires on graphite flakes

Silicon carbide nanowires were synthesized on the surface of graphite by partially reacting with silicon powders in NaF–NaCl based salt at 1150–1400°C in argon. The effects of temperature and time of heat treatment as well as Si/graphite ratio on synthesis of SiC nanowires were studied. The results showed that the formation of SiC nanowires started at about 1200°C, and the amounts of SiC nanowires increased in the resultant powders with increasing temperature. Their morphologies were characterized by scanning electron microscopy and high-resolution transmission electron microscopy. It was found that β-SiC nanowires with diameter of 10–50nm and various lengths grew along their preferred direction perpendicular to (111). The zeta potential of graphite was also increased after coating with silicon carbide nanowires. SiC nanowires that formed on the graphite surface acted as an anti-oxidant to a certain extent, and they protected the inner graphite from oxidation.