INVESTIGADORES
LEIVA Ezequiel Pedro M.
congresos y reuniones científicas
Título:
Underpotential Deposition at the Nanoscale
Autor/es:
E.P.M. LEIVA
Lugar:
Praga
Reunión:
Congreso; 63th Annual Meeting of the International Society of Electrochemistry; 2012
Institución organizadora:
International Socieyt of Electrochemistry
Resumen:
Underpotential
Deposition at the Nanoscale
O. A. Oviedo, O. A. Pintos, C. F. A. Negre, M. M.
Mariscal, C. G. Sánchez, E. P. M. Leiva
Departamento de
Matemática y Física, Facultad de Ciencias Química, INFIQC
Universidad Nacional
de Córdoba, Córdoba, Argentina.
eleiva@fcq.unc.edu.ar
Electrosorption
of metal ions on foreign substrates at potentials more positive than the
reversible Nernst deposition potential, known as underpotential deposition
(upd), allows surface control of metal coverage by straightforward application
of a potential difference. The possibility of using upd to control the shape of
Au-NPs has been explored by Personik et
al. [1] but recent experiments developed by Compton and co-workers [2] show that
remarkable size effects occur when nanoparticle size is reduced below 50 nm,
where the upd phenomenon seems to vanish. Such a curious transition from upd to
overpotential deposition has also been predicted by calculations [3,4].
In
the present work, we report on recent advances in the theoretical modelling of
upd on free NPs [5,6]. We discuss this problem in three different contexts: 1)
theoretical approach: from a nanothermodynamic formalism up to a statistical
mechanical model; 2) atomistic simulation: using different Monte Carlo simulation
techniques, from simple gas models up to continuum simulations in the grand
canonical ensemble; 3) experimental feasibility: by means of a state-of-the art
quantum mechanical atomistic model, we simulate the plasmon spectra of
nanoparticles in different conditions. We discuss the electrochemical
decoration of Au, Ag and Pd nanoparticles by different foreign metals. It is
found that depending on precursor nanoparticle size and shape, controlled
decoration may be achieved in undersaturation or oversaturation conditions.
Multilayer deposition is also considered, with the finding that this phenomenon
is also size dependent, in agreement with experimental measurements.
[1]
M.L. Personick, M.R. Langille, J. Zhang, and C.A. Mirkin, Nano Lett. 11 (2011)
3394.
[2]
F.W. Campbell, Y. Zhou and R.G. Compton, New Journal of Chemistry, 34, (2010),
187. F.W. Campbell and R.G. Compton, Int. J. Electrochem. Sci., 5 (2010) 407.
Y. Zhou, N.V. Rees, and R.G. Compton, ChemPhysChem, 12, (2011), 2085.
[3]
O. A. Oviedo, E. P. M. Leiva and M. M. Mariscal, Phys. Chem. Chem. Phys., 10
(2008) 3561.
[4]
O. A. Oviedo, M. M. Mariscal and E. P. M. Leiva. Phys. Chem. Chem. Phys. 12
(2010) 4580.
[5]
O.A. Oviedo, C.F.A. Negre, M.M. Mariscal, C.G. Sánchez, E.P.M. Leiva.
Electrochemistry Communications 16 (2012) 1-5.
[6]
Metal Clusters and Nanoalloys: From Modeling to Applications, Nanostructure
Science and Technology. Springer. ISBN 978-1-4614-3267-82012. In press.