Synthesis of High Quality Single-Walled Carbon Nanotubes by CVD and Effect of Catalyst’s Acidity-Basicity on Nanotubes Growth

High quality SWNTs are synthesized by catalytic decomposition of CH4/N2 at 1000 ℃ on the Fe-Mo/MgO catalyst prepared by a combustion method. The best combustion temperature is 550 ℃ for the catalyst. The fitting acidity-basicity can explain the high catalytic performance. The as-prepared SWNTs have been characterized by SEM, TEM, HRTEM, TGA and Raman spectroscopy. The results show that the synthesized SWNTs are usually bundles and they have a narrow diameter distribution with 0.85~1.22 nm. The best reaction atmosphere is 50/300 for the catalyst. Under this ratio of CH4/N2, the content of the prepared raw SWNTs is close to 40% weighting over the catalyst. After the raw SWNTs are treated by diluted HCl at room temperature, the sample can contain yield of SWNTs to over 75%.