Simple synthesis of ultrafine amorphous silicon carbide nanoparticles by atmospheric plasmas

Abstract

An atmospheric non-thermal arc plasma source based on magnetically stabilized gliding arc discharge was developed for the continuous preparation of ultrafine amorphous silicon carbide (a-SiC) nanoparticles via hexamethyldisilane decomposition. Results showed that the as-synthesized products were a mix of a-SiC nanoparticles and free carbon excess. The average particle size of nanoparticles was about 9 nm, and there were abundant functional groups and oxidized overlayers on the surface of the nanoparticles. Photoluminescence properties revealed the a-SiC nanoparticles had strong blue-green light emission under the excitation of 340–420 nm, which was possibly related to the surface functional groups, oxidized overlayers and quantum confinement effect due to ultrafine size. Correlations between the arc current and the crystal structure of the product indicated that the low input energy favored the synthesis of a-SiC nanoparticles, while the high input energy promotedthetransition from amorphous structure to β-SiC.