INFIQC   05475
INSTITUTO DE INVESTIGACIONES EN FISICO- QUIMICA DE CORDOBA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Change in the properties of the graphene sheet modified with different functional groups: a DFT study
Autor/es:
GUILLERMINA LETICIA LUQUE; MARIANA ISABEL ROJAS; EZEQUIEL PEDRO MARCOS LEIVA
Lugar:
Cancún, México
Reunión:
Congreso; International Materials Research Congress (IMRC XIX); 2010
Institución organizadora:
International Materials Research
Resumen:
CHANGE IN THE PROPERTIES OF THE GRAPHENE SHEET MODIFIED
WITH DIFFERENT FUNCIONAL GROUPS: A DFT STUDY
G.L. Luque, M.I. Rojas, E.P.M. Leiva
Departamento de Matemática y
Física, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, 5000
Córdoba, Argentina. E-mail: mrojas@fcq.unc.edu.ar
Graphene has attracted considerable attention from both the experimental
and theoretical scientific communities since it was discovered
and successfully isolated from bulk graphite just a few years ago [1]. Its unique properties such as high surface area,
fast electron transfer rate, high thermal conductivity, excellent mechanical
stiffness, good biocompatibility [2] and low fabrication procedure cost, makes it a
perfect alternative to carbon nanotubes in the construction of electrochemical
(bio)sensors.
In the present work, using Density Functional Theory (DFT) calculations, we
investigate the functionalization of the graphene layer with carboxyl [3],
amino, and thiol groups considering perfect and defective layers. In the last
case we take into account
Stone-Wales (SW) defects which are common defects on graphene.
The chemical
functionalization of these surfaces with electron donor or acceptor groups modified
the physical (electric properties) and chemical properties of the layer. Thus, it
is of technological importance to understand where this functionalization takes
place and how the properties change.
We compare the adsorption energies of the hydrogen peroxide on the
different functionalized layers and also how the functionalization modified the
catalytic properties of the layer.
The
local minima where found through the conjugate gradient (CG) technique,
employing DFT calculations with spin polarization (sp) as implemented in SIESTA [4]
and the minimum energy path for the reaction and determine the energy barriers we performed state-of-the-art
calculation methods using the nudged elastic band method (NEB) [5].
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Novoselov, A.K. Geim, S.V. Morozov, D. Jiang, Y. Zhang, S. V. Dubonos, Science
306 (2004) 666.
[2]
H. Chen, M.B. Müller, K.J. Gilmore, G.G. Wallace, D. Li, Adv. Mater.
20 (2008) 3557.
[3] G.L. Luque,
M.I. Rojas, G.A. Rivas, E.P.M. Leiva, submitted to Electrochimica Acta.
[4] J. M. Soler, E. Artacho, J. D.
Gale, A. García, J. Junquera, P. Ordejón, D. Sánchez-Portal, J. Phys.: Condens.
Matter 14 2745 (2002).
[5] G. Henkelman,
B.P. Uberuaga, H. Jonsson, J. Chem. Phys. 113 (2000) 9901-04.
G. Henkelman, H.
Jonsson, J. Chem. Phys. 113
(2000) 9978-85.