1. International Center for Materials Nanoarchitectonics (MANA‐WPI) and Biomaterials Center, National Institute for Materials Science, 1‐1 Namiki, Tsukuba, Ibaraki 305‐0044 (Japan), Fax: (+81)?29‐860‐4714;2. Materials Analysis Station, National Institute for Materials Science, 1‐2‐1 Sengen, Tsukuba, Ibaraki 305‐0047 (Japan)
Abstract:
It′s what′s on the inside that counts : In some cases, the metallic impurities within residual catalyst metallic nanoparticle impurities, which remain in carbon nanotubes even after their purification, are responsible for the “electrocatalytic” properties of carbon nanotubes. This is demonstrated by using double‐walled carbon nanotubes (DWCNTs) containing cobalt residual catalyst nanoparticle impurities, which themselves contain iron‐based impurities.
