INVESTIGADORES
BENITEZ Guillermo Alfredo
artículos
Título:
Electrochemical and X-ray Photoelectron Spectroscopy Characterization of Alkanethiols Adsorbed on Palladium Surfaces
Autor/es:
G. CORTHEY; A.A. RUBERT; G. BENITEZ; M. FONTICELLI; R.C. SALVAREZZA
Revista:
JOURNAL OF PHYSICAL CHEMISTRY C
Editorial:
American Chemical Society
Referencias:
Año: 2009 vol. 113 p. 6735 - 6742
ISSN:
1932-7447
Resumen:
The self-assembly of alkanethiolate monolayers on palladium substrates and their stability in aqueous solutions
have been studied by electrochemical techniques and X-ray photoelectron spectroscopy (XPS). Alkanethiols
adsorb on Pd from ethanolic solutions forming a complex interface which consists of thiolates onto a diluted
palladium sulfide interphase, with surface coverages θSulfide ≈ 0.4 and θthiolate ≈ 0.30, respectively. These
complex adlayers exhibit hydrocarbon chain-length dependent barrier properties like those formed on Au and
Ag substrates. For short chain alkanethiols, thiolates are more stable against reductive desorption than selfassembled
monolayers (SAMs) on Au, Ag, and Ni. The increased stability of the organic species seems to be
related to the presence of the diluted sulfide layer that also explains the chain length independence of the
stability potential range. The stability of these monolayers in aqueous solutions indicates that Pd is a suitable
platform for thiolate-based devices such as sensors and biosensors. These results also suggest that
electrochemical cleaning should be a simple way to prepare metallic nanoparticles from thiol-capped Pd
nanoparticles adsorbed on conducting substrates.