Large scale synthesis of single-wall carbon nanotubes by arc-discharge method

Using a graphite rod with a hole filled with the powder of a mixture of Y-N i alloy and graphite or calcium carbide and nickel as anode, single-wall ca rbon nanotubes (SWCNTs) with high yield were produced in quantity of tens o f grams a day under the are conditions of 40 similar to 60 A d.c. and heliu m pressure of 500 or 700 torr. The yield of SWCNTs can be quantitatively de termined by thermogravimetric analysis (TGA) method. The morphology and str ucture of SWCNTs were observed by SEM, HREM and Raman spectroscopy. The res ults showed that the helium atmosphere strongly affects the yield of SWCNTs and the diameter distributions of SWCNTs are different when different cata lyst was used, proving that the diameter of SWCNTs is dependent on the prop erties of the metal catalysts. Our results suggested a formation mechanism of SWCNTs and the roles played by nickel and yttrium or calcium atoms. (C) 2000 Elsevier Science Ltd. All rights reserved.