Theoretical Investigation on Single-Wall Carbon Nanotubes Doped with Nitrogen, Pyridine-Like Nitrogen Defects, and Transition Metal Atoms
Figure 1
Geometrically optimized structures, bond lengths (Å), and highest occupied molecular orbital (HOMO) of (a) pure zigzag (10, 0) nanotube; (b) direct substitution of two nitrogen atoms into the carbon framework wherein the two N substitution atoms in C118N2 are in the opposite positions; (c) N substitution into the carbon framework with the formation of pyridine-like vacancy: pyridine-like doping C112N6 wherein two vacancies are formed in opposite positions; (d) adsorption configuration of the transition metal on a nanotube with pyridine-like defect. Grey ball denotes C atom, blue ball denotes N atom, and white denotes TM (Sc). A fragment of the supercell was taken out to elucidate the bond lengths at the vicinity of the impurities.
