FT-IR-ATR as a tool to probe photocatalytic interfaces

Autores
Araujo, Paula Zulema; Mendive, Cecilia Beatriz; García Rodenas, Luis Alberto; Morando, Pedro Juan; Regazzoni, Alberto Ernesto; Blesa, Miguel Angel; Bahnemann, Detlef
Año de publicación
2005
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
The catalytic photo-oxidation on TiO2 (Degussa P-25) of oxalic acid at pH 3.7 and of catechol at pH 6.2 has been studied by in situ ATR-FT-IR. In the case of catechol, both FT-IR and HPLC demonstrate the formation of an intermediate, the accumulation of carbonate, and the depletion of the ligand on the illuminated surface. Ligand depletion is also demonstrated by the spectral evolution of adsorbed oxalate; the data in the case also suggest that different surface complexes may inter-convert directly on the surface. These findings illustrate the potentiality of in situ ATR-FT-IR to follow the evolution of the catalytic surface. It is also clearly demonstrated that under our experimental conditions, the photolytic oxidation of the adsorbed ligands is fast as compared with the rate of exchange with the bulk. In terms of simple mechanistic considerations, the systems behave as expected for low degrees of coverage, determined by fast surface reactions, k2{h+} ≫ k -1, where k-1 is the rate constant for hole trapping by the adsorbed ligand, k-1 the rate constant for ligand desorption, and {h+} is the effective hole concentration, determined by the intensity of light. The rate law then turns out to be R = k1N S[HL], where R is the reaction rate, k1 the adsorption rate constant, NS the surface site density, and [HL] is the bulk ligand concentration.
.
Fil: Araujo, Paula Zulema. Comisión Nacional de Energía Atómica. Gerencia Química. CAC; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
Fil: Mendive, Cecilia Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Gerencia Química. CAC; Argentina. Hannover Universitat. Institut fur Technische Chemie; Alemania
Fil: García Rodenas, Luis Alberto. Comisión Nacional de Energía Atómica. Gerencia Química. CAC; Argentina
Fil: Morando, Pedro Juan. Comisión Nacional de Energía Atómica. Gerencia Química. CAC; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de San Martín; Argentina
Fil: Regazzoni, Alberto Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Gerencia Química. CAC; Argentina. Universidad Nacional de San Martín; Argentina
Fil: Blesa, Miguel Angel. Universidad Nacional de San Martín; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Gerencia Química. CAC; Argentina
Fil: Bahnemann, Detlef. Hannover Universitat. Institut fur Technische Chemie; Alemania
Materia
Catechol
Ft-Ir/Atr
Gallic Acid
Intermediates
Photocatalysis
Surface Complexes
Nivel de accesibilidad
acceso abierto
Condiciones de uso
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
Repositorio
CONICET Digital (CONICET)
Institución
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identificador
oai:ri.conicet.gov.ar:11336/57279
Acceder
id CONICETDig_f9dc1bf14d0a0645471321e76c202236
oai_identifier_str oai:ri.conicet.gov.ar:11336/57279
network_acronym_str CONICETDig
repository_id_str 3498
network_name_str CONICET Digital (CONICET)
spelling FT-IR-ATR as a tool to probe photocatalytic interfacesAraujo, Paula ZulemaMendive, Cecilia BeatrizGarcía Rodenas, Luis AlbertoMorando, Pedro JuanRegazzoni, Alberto ErnestoBlesa, Miguel AngelBahnemann, DetlefCatecholFt-Ir/AtrGallic AcidIntermediatesPhotocatalysisSurface Complexeshttps://purl.org/becyt/ford/1.4https://purl.org/becyt/ford/1The catalytic photo-oxidation on TiO2 (Degussa P-25) of oxalic acid at pH 3.7 and of catechol at pH 6.2 has been studied by in situ ATR-FT-IR. In the case of catechol, both FT-IR and HPLC demonstrate the formation of an intermediate, the accumulation of carbonate, and the depletion of the ligand on the illuminated surface. Ligand depletion is also demonstrated by the spectral evolution of adsorbed oxalate; the data in the case also suggest that different surface complexes may inter-convert directly on the surface. These findings illustrate the potentiality of in situ ATR-FT-IR to follow the evolution of the catalytic surface. It is also clearly demonstrated that under our experimental conditions, the photolytic oxidation of the adsorbed ligands is fast as compared with the rate of exchange with the bulk. In terms of simple mechanistic considerations, the systems behave as expected for low degrees of coverage, determined by fast surface reactions, k2{h+} ≫ k -1, where k-1 is the rate constant for hole trapping by the adsorbed ligand, k-1 the rate constant for ligand desorption, and {h+} is the effective hole concentration, determined by the intensity of light. The rate law then turns out to be R = k1N S[HL], where R is the reaction rate, k1 the adsorption rate constant, NS the surface site density, and [HL] is the bulk ligand concentration..Fil: Araujo, Paula Zulema. Comisión Nacional de Energía Atómica. Gerencia Química. CAC; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mendive, Cecilia Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Gerencia Química. CAC; Argentina. Hannover Universitat. Institut fur Technische Chemie; AlemaniaFil: García Rodenas, Luis Alberto. Comisión Nacional de Energía Atómica. Gerencia Química. CAC; ArgentinaFil: Morando, Pedro Juan. Comisión Nacional de Energía Atómica. Gerencia Química. CAC; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de San Martín; ArgentinaFil: Regazzoni, Alberto Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Gerencia Química. CAC; Argentina. Universidad Nacional de San Martín; ArgentinaFil: Blesa, Miguel Angel. Universidad Nacional de San Martín; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Gerencia Química. CAC; ArgentinaFil: Bahnemann, Detlef. Hannover Universitat. Institut fur Technische Chemie; AlemaniaElsevier Science2005-09-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/57279Araujo, Paula Zulema; Mendive, Cecilia Beatriz; García Rodenas, Luis Alberto; Morando, Pedro Juan; Regazzoni, Alberto Ernesto; et al.; FT-IR-ATR as a tool to probe photocatalytic interfaces; Elsevier Science; Colloids and Surfaces A: Physicochemical and Engineering Aspects; 265; 1-3; 1-9-2005; 73-800927-7757CONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/doi/10.1016/j.colsurfa.2004.10.137info:eu-repo/semantics/altIdentifier/url/https://www.sciencedirect.com/science/article/pii/S0927775705002633info:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-09-03T09:53:40Zoai:ri.conicet.gov.ar:11336/57279instacron:CONICETInstitucionalhttp://ri.conicet.gov.ar/Organismo científico-tecnológicoNo correspondehttp://ri.conicet.gov.ar/oai/requestdasensio@conicet.gov.ar; lcarlino@conicet.gov.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:34982025-09-03 09:53:41.006CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv FT-IR-ATR as a tool to probe photocatalytic interfaces
title FT-IR-ATR as a tool to probe photocatalytic interfaces
spellingShingle FT-IR-ATR as a tool to probe photocatalytic interfaces
Araujo, Paula Zulema
Catechol
Ft-Ir/Atr
Gallic Acid
Intermediates
Photocatalysis
Surface Complexes
title_short FT-IR-ATR as a tool to probe photocatalytic interfaces
title_full FT-IR-ATR as a tool to probe photocatalytic interfaces
title_fullStr FT-IR-ATR as a tool to probe photocatalytic interfaces
title_full_unstemmed FT-IR-ATR as a tool to probe photocatalytic interfaces
title_sort FT-IR-ATR as a tool to probe photocatalytic interfaces
dc.creator.none.fl_str_mv Araujo, Paula Zulema
Mendive, Cecilia Beatriz
García Rodenas, Luis Alberto
Morando, Pedro Juan
Regazzoni, Alberto Ernesto
Blesa, Miguel Angel
Bahnemann, Detlef
author Araujo, Paula Zulema
author_facet Araujo, Paula Zulema
Mendive, Cecilia Beatriz
García Rodenas, Luis Alberto
Morando, Pedro Juan
Regazzoni, Alberto Ernesto
Blesa, Miguel Angel
Bahnemann, Detlef
author_role author
author2 Mendive, Cecilia Beatriz
García Rodenas, Luis Alberto
Morando, Pedro Juan
Regazzoni, Alberto Ernesto
Blesa, Miguel Angel
Bahnemann, Detlef
author2_role author
author
author
author
author
author
dc.subject.none.fl_str_mv Catechol
Ft-Ir/Atr
Gallic Acid
Intermediates
Photocatalysis
Surface Complexes
topic Catechol
Ft-Ir/Atr
Gallic Acid
Intermediates
Photocatalysis
Surface Complexes
purl_subject.fl_str_mv https://purl.org/becyt/ford/1.4
https://purl.org/becyt/ford/1
dc.description.none.fl_txt_mv The catalytic photo-oxidation on TiO2 (Degussa P-25) of oxalic acid at pH 3.7 and of catechol at pH 6.2 has been studied by in situ ATR-FT-IR. In the case of catechol, both FT-IR and HPLC demonstrate the formation of an intermediate, the accumulation of carbonate, and the depletion of the ligand on the illuminated surface. Ligand depletion is also demonstrated by the spectral evolution of adsorbed oxalate; the data in the case also suggest that different surface complexes may inter-convert directly on the surface. These findings illustrate the potentiality of in situ ATR-FT-IR to follow the evolution of the catalytic surface. It is also clearly demonstrated that under our experimental conditions, the photolytic oxidation of the adsorbed ligands is fast as compared with the rate of exchange with the bulk. In terms of simple mechanistic considerations, the systems behave as expected for low degrees of coverage, determined by fast surface reactions, k2{h+} ≫ k -1, where k-1 is the rate constant for hole trapping by the adsorbed ligand, k-1 the rate constant for ligand desorption, and {h+} is the effective hole concentration, determined by the intensity of light. The rate law then turns out to be R = k1N S[HL], where R is the reaction rate, k1 the adsorption rate constant, NS the surface site density, and [HL] is the bulk ligand concentration.
.
Fil: Araujo, Paula Zulema. Comisión Nacional de Energía Atómica. Gerencia Química. CAC; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
Fil: Mendive, Cecilia Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Gerencia Química. CAC; Argentina. Hannover Universitat. Institut fur Technische Chemie; Alemania
Fil: García Rodenas, Luis Alberto. Comisión Nacional de Energía Atómica. Gerencia Química. CAC; Argentina
Fil: Morando, Pedro Juan. Comisión Nacional de Energía Atómica. Gerencia Química. CAC; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de San Martín; Argentina
Fil: Regazzoni, Alberto Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Gerencia Química. CAC; Argentina. Universidad Nacional de San Martín; Argentina
Fil: Blesa, Miguel Angel. Universidad Nacional de San Martín; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Gerencia Química. CAC; Argentina
Fil: Bahnemann, Detlef. Hannover Universitat. Institut fur Technische Chemie; Alemania
description The catalytic photo-oxidation on TiO2 (Degussa P-25) of oxalic acid at pH 3.7 and of catechol at pH 6.2 has been studied by in situ ATR-FT-IR. In the case of catechol, both FT-IR and HPLC demonstrate the formation of an intermediate, the accumulation of carbonate, and the depletion of the ligand on the illuminated surface. Ligand depletion is also demonstrated by the spectral evolution of adsorbed oxalate; the data in the case also suggest that different surface complexes may inter-convert directly on the surface. These findings illustrate the potentiality of in situ ATR-FT-IR to follow the evolution of the catalytic surface. It is also clearly demonstrated that under our experimental conditions, the photolytic oxidation of the adsorbed ligands is fast as compared with the rate of exchange with the bulk. In terms of simple mechanistic considerations, the systems behave as expected for low degrees of coverage, determined by fast surface reactions, k2{h+} ≫ k -1, where k-1 is the rate constant for hole trapping by the adsorbed ligand, k-1 the rate constant for ligand desorption, and {h+} is the effective hole concentration, determined by the intensity of light. The rate law then turns out to be R = k1N S[HL], where R is the reaction rate, k1 the adsorption rate constant, NS the surface site density, and [HL] is the bulk ligand concentration.
publishDate 2005
dc.date.none.fl_str_mv 2005-09-01
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
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://hdl.handle.net/11336/57279
Araujo, Paula Zulema; Mendive, Cecilia Beatriz; García Rodenas, Luis Alberto; Morando, Pedro Juan; Regazzoni, Alberto Ernesto; et al.; FT-IR-ATR as a tool to probe photocatalytic interfaces; Elsevier Science; Colloids and Surfaces A: Physicochemical and Engineering Aspects; 265; 1-3; 1-9-2005; 73-80
0927-7757
CONICET Digital
CONICET
url http://hdl.handle.net/11336/57279
identifier_str_mv Araujo, Paula Zulema; Mendive, Cecilia Beatriz; García Rodenas, Luis Alberto; Morando, Pedro Juan; Regazzoni, Alberto Ernesto; et al.; FT-IR-ATR as a tool to probe photocatalytic interfaces; Elsevier Science; Colloids and Surfaces A: Physicochemical and Engineering Aspects; 265; 1-3; 1-9-2005; 73-80
0927-7757
CONICET Digital
CONICET
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/doi/10.1016/j.colsurfa.2004.10.137
info:eu-repo/semantics/altIdentifier/url/https://www.sciencedirect.com/science/article/pii/S0927775705002633
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
eu_rights_str_mv openAccess
rights_invalid_str_mv https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
dc.format.none.fl_str_mv application/pdf
application/pdf
application/pdf
application/pdf
application/pdf
application/pdf
application/pdf
dc.publisher.none.fl_str_mv Elsevier Science
publisher.none.fl_str_mv Elsevier Science
dc.source.none.fl_str_mv reponame:CONICET Digital (CONICET)
instname:Consejo Nacional de Investigaciones Científicas y Técnicas
reponame_str CONICET Digital (CONICET)
collection CONICET Digital (CONICET)
instname_str Consejo Nacional de Investigaciones Científicas y Técnicas
repository.name.fl_str_mv CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicas
repository.mail.fl_str_mv dasensio@conicet.gov.ar; lcarlino@conicet.gov.ar
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score 13.13397

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