Lithium-doped endohedral single-walled carbon nanotubes can arise during tube growth

This Letter shows that it is possible to dope single-walled carbon nanotubes (SWCNT) with lithium during SWCNT growth in an arc reactor. Depending on the oxygen and lithium concentrations in the reactor, one can obtain endohedral Li@SWCNT after rinsing the product in water. Oxygen plays a decisive role in Li insertion during SWCNT growth and in the diameter distribution of the samples. Doping the tubes with Li produces end-closed SWCNT bundles that afford more stable dispersion in water as compared with non-doped tubes.