Controlled growth of single-walled carbon nanotubes at atmospheric pressure by catalytic decomposition of ethanol and an efficient purification method

By using an originally designed chemical vapor deposition chamber, high-quality single-walled carbon nanotubes (SWNTs) have been synthesized over Fe - Co/MgO catalyst by catalytic decomposition of ethanol at atmospheric pressure. The as-synthesized carbon material primarily consists of the SWNTs bundle with few defects and a certain amount of amorphous carbon. By adjusting the concentration of ethanol solution, we can control diameter distribution of the SWNTs. We suggest that both addition of water and the designed setup play important roles for the controlled growth of SWNTs. After the efficient purification combining hydrochloric acid treatment, reflux of nitric acid and air oxidation, 98% purity of the SWNTs is obtained.