Air-assisted growth of ultra-long carbon nanotube bundles

We report an air-assisted chemical vapor deposition (CVD) method for the synthesis of super-long carbon nanotube (CNT) bundles. By mixing a small amount of air in the vapor phase catalyst CVD process, the catalyst lifetime can be dramatically increased, and extremely long dense and aligned CNT bundles up to 1.5?cm can be achieved. Electron microscopy characterization shows that the injection of air does not damage the CNT structures. Further, we have estimated that individual ultra-long CNTs can carry moderate current densities ～10(5)?A?cm(-2), indicating their possible use in nanoelectronic devices.