The appearance of a total of 1 wt.% of the catalysts (Co, Ni) used to synthesize single shell nanotubes remaining in purified samples even after prolonged sample treatments in boiling HNO3 was analyzed. NMR observations show that nonmetallic Co as well as the Co-Ni alloy are still present in the purified samples, although very few particle of impurities are seen by HRTEM. It is proposed that the remaining metals could be evenly dispersed in the form of isolated atoms or extremely small clusters between nanotubes inside the bundles or even within the structure of the nanotubes.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Materials Chemistry