Electrochemical formation of palladium islands on HOPG: Kinetics, morphology, and growth mechanisms

Autores
Gimeno, Y.; Hernández Creus, A.; Carro, P.; González, S.; Salvarezza, Roberto Carlos; Arvia, Alejandro Jorge
Año de publicación
2002
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
Scanning tunneling microscopy (STM) and conventional electrochemical techniques were utilized to investigate the growth kinetics and mechanism of palladium island electroformation on highly oriented pyrolitic graphite (HOPG) from aqueous acid palladium chloride solutions at 298 K. Initially, the electrodeposition reaction at low cathodic overpotentials involves an activation process in which a PdCl2 surface intermediate is formed. At intermediate overpotentials, the growth of palladium islands involves a progressive nucleation and growth model under diffusion control, whereas at high overpotentials, the bulk discharge of soluble palladium species undergoes a free convective-diffusion process. As the cathodic overpotential is shifted negatively, the aspect ratio of the islands, defined as the ratio of the maximum height of the island to the island radius, and the island size decrease, whereas the island density increases. As the cathodic overpotential becomes a few millivolts more positive than the threshold potential of the hydrogen evolution reaction, the island shape changes from a compact disk to a quasi-2D dense radial Pd(111) island. The formation of a dense radial morphology and its small departure from a perfect 2D pattern indicates the presence of weak step-edge energy barriers, as expected from theoretical calculations for Pd(111). These results stress the key role of step-edge energy barriers in determining growth patterns during metal electrodeposition.
Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas
Facultad de Ciencias Exactas
Materia
Ciencias Exactas
Química
scanning tunneling microscopy
Electroquímica
Paladio
Cinética química
electroformation
Técnicas Electroquímicas
Nivel de accesibilidad
acceso abierto
Condiciones de uso
http://creativecommons.org/licenses/by-nc-sa/4.0/
Repositorio
SEDICI (UNLP)
Institución
Universidad Nacional de La Plata
OAI Identificador
oai:sedici.unlp.edu.ar:10915/83728

id SEDICI_b37eb233449ff84955dda7607fa88738
oai_identifier_str oai:sedici.unlp.edu.ar:10915/83728
network_acronym_str SEDICI
repository_id_str 1329
network_name_str SEDICI (UNLP)
spelling Electrochemical formation of palladium islands on HOPG: Kinetics, morphology, and growth mechanismsGimeno, Y.Hernández Creus, A.Carro, P.González, S.Salvarezza, Roberto CarlosArvia, Alejandro JorgeCiencias ExactasQuímicascanning tunneling microscopyElectroquímicaPaladioCinética químicaelectroformationTécnicas ElectroquímicasScanning tunneling microscopy (STM) and conventional electrochemical techniques were utilized to investigate the growth kinetics and mechanism of palladium island electroformation on highly oriented pyrolitic graphite (HOPG) from aqueous acid palladium chloride solutions at 298 K. Initially, the electrodeposition reaction at low cathodic overpotentials involves an activation process in which a PdCl<sub>2</sub> surface intermediate is formed. At intermediate overpotentials, the growth of palladium islands involves a progressive nucleation and growth model under diffusion control, whereas at high overpotentials, the bulk discharge of soluble palladium species undergoes a free convective-diffusion process. As the cathodic overpotential is shifted negatively, the aspect ratio of the islands, defined as the ratio of the maximum height of the island to the island radius, and the island size decrease, whereas the island density increases. As the cathodic overpotential becomes a few millivolts more positive than the threshold potential of the hydrogen evolution reaction, the island shape changes from a compact disk to a quasi-2D dense radial Pd(111) island. The formation of a dense radial morphology and its small departure from a perfect 2D pattern indicates the presence of weak step-edge energy barriers, as expected from theoretical calculations for Pd(111). These results stress the key role of step-edge energy barriers in determining growth patterns during metal electrodeposition.Instituto de Investigaciones Fisicoquímicas Teóricas y AplicadasFacultad de Ciencias Exactas2002-04-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionArticulohttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdf4232-4244http://sedici.unlp.edu.ar/handle/10915/83728enginfo:eu-repo/semantics/altIdentifier/issn/1520-6106info:eu-repo/semantics/altIdentifier/doi/10.1021/jp014176einfo:eu-repo/semantics/openAccesshttp://creativecommons.org/licenses/by-nc-sa/4.0/Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)reponame:SEDICI (UNLP)instname:Universidad Nacional de La Platainstacron:UNLP2025-09-29T11:15:55Zoai:sedici.unlp.edu.ar:10915/83728Institucionalhttp://sedici.unlp.edu.ar/Universidad públicaNo correspondehttp://sedici.unlp.edu.ar/oai/snrdalira@sedici.unlp.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:13292025-09-29 11:15:55.724SEDICI (UNLP) - Universidad Nacional de La Platafalse
dc.title.none.fl_str_mv Electrochemical formation of palladium islands on HOPG: Kinetics, morphology, and growth mechanisms
title Electrochemical formation of palladium islands on HOPG: Kinetics, morphology, and growth mechanisms
spellingShingle Electrochemical formation of palladium islands on HOPG: Kinetics, morphology, and growth mechanisms
Gimeno, Y.
Ciencias Exactas
Química
scanning tunneling microscopy
Electroquímica
Paladio
Cinética química
electroformation
Técnicas Electroquímicas
title_short Electrochemical formation of palladium islands on HOPG: Kinetics, morphology, and growth mechanisms
title_full Electrochemical formation of palladium islands on HOPG: Kinetics, morphology, and growth mechanisms
title_fullStr Electrochemical formation of palladium islands on HOPG: Kinetics, morphology, and growth mechanisms
title_full_unstemmed Electrochemical formation of palladium islands on HOPG: Kinetics, morphology, and growth mechanisms
title_sort Electrochemical formation of palladium islands on HOPG: Kinetics, morphology, and growth mechanisms
dc.creator.none.fl_str_mv Gimeno, Y.
Hernández Creus, A.
Carro, P.
González, S.
Salvarezza, Roberto Carlos
Arvia, Alejandro Jorge
author Gimeno, Y.
author_facet Gimeno, Y.
Hernández Creus, A.
Carro, P.
González, S.
Salvarezza, Roberto Carlos
Arvia, Alejandro Jorge
author_role author
author2 Hernández Creus, A.
Carro, P.
González, S.
Salvarezza, Roberto Carlos
Arvia, Alejandro Jorge
author2_role author
author
author
author
author
dc.subject.none.fl_str_mv Ciencias Exactas
Química
scanning tunneling microscopy
Electroquímica
Paladio
Cinética química
electroformation
Técnicas Electroquímicas
topic Ciencias Exactas
Química
scanning tunneling microscopy
Electroquímica
Paladio
Cinética química
electroformation
Técnicas Electroquímicas
dc.description.none.fl_txt_mv Scanning tunneling microscopy (STM) and conventional electrochemical techniques were utilized to investigate the growth kinetics and mechanism of palladium island electroformation on highly oriented pyrolitic graphite (HOPG) from aqueous acid palladium chloride solutions at 298 K. Initially, the electrodeposition reaction at low cathodic overpotentials involves an activation process in which a PdCl<sub>2</sub> surface intermediate is formed. At intermediate overpotentials, the growth of palladium islands involves a progressive nucleation and growth model under diffusion control, whereas at high overpotentials, the bulk discharge of soluble palladium species undergoes a free convective-diffusion process. As the cathodic overpotential is shifted negatively, the aspect ratio of the islands, defined as the ratio of the maximum height of the island to the island radius, and the island size decrease, whereas the island density increases. As the cathodic overpotential becomes a few millivolts more positive than the threshold potential of the hydrogen evolution reaction, the island shape changes from a compact disk to a quasi-2D dense radial Pd(111) island. The formation of a dense radial morphology and its small departure from a perfect 2D pattern indicates the presence of weak step-edge energy barriers, as expected from theoretical calculations for Pd(111). These results stress the key role of step-edge energy barriers in determining growth patterns during metal electrodeposition.
Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas
Facultad de Ciencias Exactas
description Scanning tunneling microscopy (STM) and conventional electrochemical techniques were utilized to investigate the growth kinetics and mechanism of palladium island electroformation on highly oriented pyrolitic graphite (HOPG) from aqueous acid palladium chloride solutions at 298 K. Initially, the electrodeposition reaction at low cathodic overpotentials involves an activation process in which a PdCl<sub>2</sub> surface intermediate is formed. At intermediate overpotentials, the growth of palladium islands involves a progressive nucleation and growth model under diffusion control, whereas at high overpotentials, the bulk discharge of soluble palladium species undergoes a free convective-diffusion process. As the cathodic overpotential is shifted negatively, the aspect ratio of the islands, defined as the ratio of the maximum height of the island to the island radius, and the island size decrease, whereas the island density increases. As the cathodic overpotential becomes a few millivolts more positive than the threshold potential of the hydrogen evolution reaction, the island shape changes from a compact disk to a quasi-2D dense radial Pd(111) island. The formation of a dense radial morphology and its small departure from a perfect 2D pattern indicates the presence of weak step-edge energy barriers, as expected from theoretical calculations for Pd(111). These results stress the key role of step-edge energy barriers in determining growth patterns during metal electrodeposition.
publishDate 2002
dc.date.none.fl_str_mv 2002-04-01
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
Articulo
http://purl.org/coar/resource_type/c_6501
info:ar-repo/semantics/articulo
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://sedici.unlp.edu.ar/handle/10915/83728
url http://sedici.unlp.edu.ar/handle/10915/83728
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/issn/1520-6106
info:eu-repo/semantics/altIdentifier/doi/10.1021/jp014176e
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
http://creativecommons.org/licenses/by-nc-sa/4.0/
Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)
eu_rights_str_mv openAccess
rights_invalid_str_mv http://creativecommons.org/licenses/by-nc-sa/4.0/
Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)
dc.format.none.fl_str_mv application/pdf
4232-4244
dc.source.none.fl_str_mv reponame:SEDICI (UNLP)
instname:Universidad Nacional de La Plata
instacron:UNLP
reponame_str SEDICI (UNLP)
collection SEDICI (UNLP)
instname_str Universidad Nacional de La Plata
instacron_str UNLP
institution UNLP
repository.name.fl_str_mv SEDICI (UNLP) - Universidad Nacional de La Plata
repository.mail.fl_str_mv alira@sedici.unlp.edu.ar
_version_ 1844616031410061312
score 13.070432