First-principles study of transition metal adsorbed on porphyrin-like motifs in pyrrolic nitrogen-doped carbon nanostructures

• Published in: Carbon (New York) 2017-05, Vol.116, p.381-390
• Main Authors: Jiménez-Ramírez, Luis E., Camacho-Mojica, Dulce C., Muñoz-Sandoval, Emilio, López-Urías, Florentino
• Format: Article
• Language: English
• Subjects: Band structure of solids; Binding energy; Carbon; Carbon nanotubes; Catalysis; Chemical bonds; Chromium; Cobalt; Copper; Defects; Density functional theory; Density of states; Doping; Electron spin; Energy of formation; First-principles; Half-metallicity; Iron; Magnetic properties; Mathematical analysis; Metallicity; Nanotubes; Nickel; Nitrogen; Porphyrin; Transition metals; Wave functions
• ISSN: 0008-6223; 1873-3891
• DOI: 10.1016/j.carbon.2017.02.018

First-principles density functional theory calculations were performed on a porphyrin-like motif into the lattice of carbon nanotubes and graphene. The porphyrin-like motif was generated by applying the Stone-Thrower-Wales (STW) transformation twice on two consecutive carbon bonds in a semiconducting (10 0) single-walled carbon nanotube (SWCNT) and graphene, resulting in a porphyrin-like motif that contained an octagon surrounded by four pentagons, two hexagons, and two heptagons. When one carbon atom of each pentagon is substituted by nitrogen (N-pyrrolic doping), the motif mimics the skeleton of a porphyrin molecule (DSTW-N4-porphyrin-like motif). Transition metals (TMs) (Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn) are incorporated to the double Stone-Thrower-Wales (DSTW)-N4-porphyrin motif. The band-structure, electronic density of states, binding energy, formation energy, and wave functions were calculated. The binding and formation energy calculations demonstrated that the proposed TM-DSTW-N4 defects are stable and energetically competitive with other types of defects. The calculated systems exhibit spin-dependent semiconducting band gap and half-metallicity. Our investigations offered insights into how TM atoms are adsorbed by sp2 carbon materials doped with N-pyrrolic. The interplay between the type of nitrogen doping (pyridine, substitutional, and pyrrolic) and structural defects in sp2 carbon materials are crucial for tailoring the electronic, magnetic, and catalytic properties. Porphyrin-like motifs into the lattice of carbon nanotubes and graphene are studied using DFT-calculations. The porphyrin-like motif contains an octagon surrounded by four pentagons, two hexagons, and two heptagons. When one carbon atom of each pentagon is substituted by nitrogen (N-pyrrolic doping), the motif mimics the skeleton of a porphyrin molecule. We investigated the ability to adsorb 3d-transition metals (Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn) by this porhyrin-like defect. [Display omitted]