Synthesis of single-wall carbon nanohorns by arc-discharge in air and their formation mechanism

Single-wall carbon nanohorns (SWCNHs) with different morphologies were generated by direct current arc-discharge between pure graphite rods in different atmospheres, including air, CO2 and CO. In the arc-discharge process, the O2 in the air reacted with carbon atoms and transformed into CO so that the formation of SWCNHs was a result of a combination of CO and N2. The effect of different volume ratios of CO/N2 on the formation of SWCNHs was examined and a mechanism for the formation of SWCNHs is proposed.