PORPHYRIN-LIKE MOLECULES INTO THE LATTICE OF CARBON NANOTUBES AND GRAPHENE: ELECTRONIC, ADSORPTION, AND TRANSPORT AND PROPERTIES.

摘要

The combination of topological defects and chemical doping in single walled carbon nanotubes (SWCNTs) is an attractive issue due to the unexpected surface reactivity [1]. The doping of carbon materials modifies their electronic properties. In this work, we will focus on nitrogen-doped defected single walled carbon nanotubes. In particular, the Stone-Thrower-Wales (STW) transformation, wich is a 90° rotation of a C-C bond in a honeycomb-hexagonal lattice (see figure 1 a). STW transformation gives rise to two opposed pentagonal and two opposed heptagonal rings (see figure 1 b). Thus, more complex topological defects can be created when several bond rotations are performed generating non hexagonal carbon rings. If two STW transformations are performed on two adjacent bonds along the axis of a zigzag nanotube pentagonal, heptagonal and octagonal carbon rings are emerge (see figure 1 c). When the pentagonal rings are doped with nitrogen atoms, in particular that found in sites type C and D, the doping defect has much similarity with porphyrin molecule. Topological defects in conjunction with chemical doping are believed to have a pivotal role in tailoring the physical and chemical properties of graphene and carbon nanotubes [3-4]. In this study, we investigate the electronic properties of nitrogen-doped DSTW defects in a zigzag (10,0) SWCNT. First-principles spin-polarized DFT calculations are performed. The electronic and magnetic properties can also be modified through chemical functionalization of transition metals (TMs) [5j. In the following, the method of calculations and results on nitrogen-doped carbon nanotubes are analyzed and discussed in detail.