Synthesis of single- and double-walled carbon nanotube forests on conducting metal foils

Here, we report a highly efficient growth of single-walled carbon nanotubes (SWNTs) and double-walled carbon nanotubes (DWNTs) on conducting metal foils. We found that foils made of Ni-based alloys with Cr or Fe serve as excellent substrates for SWNT (DWNT) synthesis. In significant contrast, a CNT grown on Ni, Fe foils contains a significant ratio of MWNTs. This result opens up an economical route for the mass production of SWNT (DWNT) forests and also enables the straightforward integration of CNTs into nanoelectronic devices, such as field emission displays.