Abstract
Arc discharge was generally used to synthesize high quality single-walled carbon nanotubes (SWNTs) with low voltage (20 ~ 40 V) and high current (50 ~ 100 A), respectively. Meanwhile, reaction time is controlled to 15 ~ 120 minutes and 50 % total yields is estimated. In our study, it is the first time to produce SWNTs via high voltage (200 V) and low current (20A), and finally, a high efficient condition (100 torr He, 200 V, composition of C：Y：Ni＝2.5：0.1953 ：0.5415 and 3 minutes reaction time) was proposed to synthesize SWNTs. When the anode was consumed 5cm in length and 1cm in diameter, 2g raw soot will be obtained and its purity is about 20%. Heat-oxidized and hydrochloric acid-pickling treatments are used to purify our raw soot and then the yield percentage is rise to more than 60%. Furthermore, compared to pristine SWNTs, purified SWNTs perform a higher capacitance and electrical conductance which are confirmed by a 2 port measurement.