Hubert Valencia - Trends in the Adsorption of 3d Transition Metal Atoms onto Graphene and Nanotube Surfaces: A DFT Study and Molecular Orbital Analysis

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      Publication Details (including relevant citation   information):

      Hubert Valencia, Adria Gil, and Gilles   Frapper, J. Phys. Chem. C  114 (33),   pp 14141–14153 (2010).


      The functionalization of graphene and (8,0) single-walled carbon   nanotubes (SWCNTs) with individual 3d transition metal (TM) atoms   was modeled using density functional theory (DFT) calculations.   The structural geometry, magnetism, and binding energies were   analyzed in terms of the density of states (DOS), Bader charges,   and organometallic M(η6-C6H6)   orbital molecular models. Trends in the binding energies were   explained by a model, which included several contributions from   the chemisorbed atoms: Coulomb interaction,   3dn4sx →   3dn+x electronic promotion energy   (EPE), and occupation of the 1e2(δ),   2e1(π), and 2a1(σ) metal orbitals. 4s   occupation, which causes Pauli repulsion, explained the   physisorption trends of Cr, Mn, and Cu. The model was   successfully extrapolated to a convex surface, such as that of   (8,0) SWCNTs. The potential energy surfaces for the adatoms   adsorbed on graphene were determined to evaluate the diffusion   energy barriers. We found that Sc, Ti, Fe, and Co metals could be   isolated on the graphene surface, whereas all other 3d TM atoms   diffused (with possible aggregate formation).

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