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-Ni alloy and graphite or calcium carbide and nickel as anode, single-wall carbon nanotubes (SWCNTs) with high yield were produced in quantity of tens of grams a day under the are conditions of 40 similar to 60 A d.c. and helium pressure of 500 or 700 torr. The yield of SWCNTs can be quantitatively determined by thermogravimetric analysis (TGA) method. The morphology and structure of SWCNTs were observed by SEM, HREM and Raman spectroscopy. The results showed that the helium atmosphere strongly affects the yield of SWCNTs and the diameter distributions of SWCNTs are different when different catalyst was used, proving that the diameter of SWCNTs is dependent on the properties 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.