Synthesis of High-Purity Silicon Carbide Nanowires by a Catalyst-Free Arc-Discharge Method

High-purity silicon carbide (SiC) nanowires were synthesized through a catalyst-free arc-discharge process using silicon dioxide powders as a filler in a graphite anode. The characterization of the as-synthesized SiC nanowires showed that the diameter of the single-crystalline SiC nanowires was about 3−15 nm and the length was up to several micrometers. To understand the formation mechanism of the SiC nanowires in the absence of a catalyst, we found that oxygen plays a key role in the growth process and suggest that the growth mechanism of SiC nanowires is a catalyst-free vapor−solid (VS) mechanism. Photoluminescence measurements of the SiC nanowires revealed that the material emits blue-green light with a peak wavelength of 472 nm (CIE coordinates: x = 0.19, y = 0.24).