Time evolution of surface speciation during heterogeneous photocatalysis: Gallic acid on titanium dioxide

Autores
Araujo, Paula Zulema; Morando, Pedro Juan; Martínez, Eduardo David; Blesa, Miguel Angel
Año de publicación
2012
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
Gallic acid adsorbs onto TiO2 films deposited onto an ATR crystal in two steps, both described by the kinetic Langmuir equation, as shown by measuring the spectral changes due to adsorbed species. Both pathways lead to species with the same spectral signature. Upon irradiation for preset times, integrated spectral absorbance profiles (log(A/A0) vs time) for the adsorbate peaks coincides with the analogous profile of remnant concentration in solution (log(C/C0) vs time). In our experiments, initially there are similar amounts of adsorbed and dissolved gallic acid. Hence, the rate of destruction of surface complexed gallic acid is approximately twice as large as the net rate of ligand uptake from solution. Upon irradiation, ligand surface concentration falls below equilibrium values, as also shown by plotting spectral signal intensity as a function of solution concentration. Under intermittent irradiation, the original rates were the same, but at larger radiation doses, the overall conversion was higher. This result demonstrates that during the intervening dark periods thermal reactions contribute to the overall rate. These thermal reactions may include desorption of intermediates, dark oxidation of intermediates, and re-equilibration of the surface with increasing gallic acid surface concentration. A description of photocatalysis based in the concept of oxidation length is provided.
Fil: Araujo, Paula Zulema. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; Argentina
Fil: Morando, Pedro Juan. Comisión Nacional de Energía Atómica. Gerencia del Área de Seguridad Nuclear y Ambiente. Gerencia de Química (CAC); Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de San Martín. Instituto Sabato; Argentina
Fil: Martínez, Eduardo David. Comisión Nacional de Energía Atómica. Gerencia del Área de Seguridad Nuclear y Ambiente. Gerencia de Química (CAC); Argentina. Universidad Nacional de San Martín. Instituto de Investigación e Ingeniería Ambiental. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e Ingeniería Ambiental; Argentina
Fil: Blesa, Miguel Angel. Universidad Nacional de San Martín. Instituto de Investigación e Ingeniería Ambiental. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e Ingeniería Ambiental; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Seguridad Nuclear y Ambiente. Gerencia de Química (CAC); Argentina
Materia
GALLIC ACID ADSORPTION KINETICS
INTERMITTENT IRRADIATION
PHOTOCATALYSIS
SURFACE SPECIATION
TITANIUM DIOXIDE
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:11336/197044
Acceder
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oai_identifier_str oai:ri.conicet.gov.ar:11336/197044
network_acronym_str CONICETDig
repository_id_str 3498
network_name_str CONICET Digital (CONICET)
spelling Time evolution of surface speciation during heterogeneous photocatalysis: Gallic acid on titanium dioxideAraujo, Paula ZulemaMorando, Pedro JuanMartínez, Eduardo DavidBlesa, Miguel AngelGALLIC ACID ADSORPTION KINETICSINTERMITTENT IRRADIATIONPHOTOCATALYSISSURFACE SPECIATIONTITANIUM DIOXIDEhttps://purl.org/becyt/ford/1.4https://purl.org/becyt/ford/1Gallic acid adsorbs onto TiO2 films deposited onto an ATR crystal in two steps, both described by the kinetic Langmuir equation, as shown by measuring the spectral changes due to adsorbed species. Both pathways lead to species with the same spectral signature. Upon irradiation for preset times, integrated spectral absorbance profiles (log(A/A0) vs time) for the adsorbate peaks coincides with the analogous profile of remnant concentration in solution (log(C/C0) vs time). In our experiments, initially there are similar amounts of adsorbed and dissolved gallic acid. Hence, the rate of destruction of surface complexed gallic acid is approximately twice as large as the net rate of ligand uptake from solution. Upon irradiation, ligand surface concentration falls below equilibrium values, as also shown by plotting spectral signal intensity as a function of solution concentration. Under intermittent irradiation, the original rates were the same, but at larger radiation doses, the overall conversion was higher. This result demonstrates that during the intervening dark periods thermal reactions contribute to the overall rate. These thermal reactions may include desorption of intermediates, dark oxidation of intermediates, and re-equilibration of the surface with increasing gallic acid surface concentration. A description of photocatalysis based in the concept of oxidation length is provided.Fil: Araujo, Paula Zulema. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; ArgentinaFil: Morando, Pedro Juan. Comisión Nacional de Energía Atómica. Gerencia del Área de Seguridad Nuclear y Ambiente. Gerencia de Química (CAC); Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de San Martín. Instituto Sabato; ArgentinaFil: Martínez, Eduardo David. Comisión Nacional de Energía Atómica. Gerencia del Área de Seguridad Nuclear y Ambiente. Gerencia de Química (CAC); Argentina. Universidad Nacional de San Martín. Instituto de Investigación e Ingeniería Ambiental. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e Ingeniería Ambiental; ArgentinaFil: Blesa, Miguel Angel. Universidad Nacional de San Martín. Instituto de Investigación e Ingeniería Ambiental. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e Ingeniería Ambiental; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Seguridad Nuclear y Ambiente. Gerencia de Química (CAC); ArgentinaElsevier Science2012-08info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/197044Araujo, Paula Zulema; Morando, Pedro Juan; Martínez, Eduardo David; Blesa, Miguel Angel; Time evolution of surface speciation during heterogeneous photocatalysis: Gallic acid on titanium dioxide; Elsevier Science; Applied Catalysis B: Environmental; 125; 8-2012; 215-2210926-3373CONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/url/http://www.sciencedirect.com/science/article/pii/S092633731200238Xinfo:eu-repo/semantics/altIdentifier/doi/10.1016/j.apcatb.2012.05.035info:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-09-03T09:44:57Zoai:ri.conicet.gov.ar:11336/197044instacron: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 09:44:58.154CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv Time evolution of surface speciation during heterogeneous photocatalysis: Gallic acid on titanium dioxide
title Time evolution of surface speciation during heterogeneous photocatalysis: Gallic acid on titanium dioxide
spellingShingle Time evolution of surface speciation during heterogeneous photocatalysis: Gallic acid on titanium dioxide
Araujo, Paula Zulema
GALLIC ACID ADSORPTION KINETICS
INTERMITTENT IRRADIATION
PHOTOCATALYSIS
SURFACE SPECIATION
TITANIUM DIOXIDE
title_short Time evolution of surface speciation during heterogeneous photocatalysis: Gallic acid on titanium dioxide
title_full Time evolution of surface speciation during heterogeneous photocatalysis: Gallic acid on titanium dioxide
title_fullStr Time evolution of surface speciation during heterogeneous photocatalysis: Gallic acid on titanium dioxide
title_full_unstemmed Time evolution of surface speciation during heterogeneous photocatalysis: Gallic acid on titanium dioxide
title_sort Time evolution of surface speciation during heterogeneous photocatalysis: Gallic acid on titanium dioxide
dc.creator.none.fl_str_mv Araujo, Paula Zulema
Morando, Pedro Juan
Martínez, Eduardo David
Blesa, Miguel Angel
author Araujo, Paula Zulema
author_facet Araujo, Paula Zulema
Morando, Pedro Juan
Martínez, Eduardo David
Blesa, Miguel Angel
author_role author
author2 Morando, Pedro Juan
Martínez, Eduardo David
Blesa, Miguel Angel
author2_role author
author
author
dc.subject.none.fl_str_mv GALLIC ACID ADSORPTION KINETICS
INTERMITTENT IRRADIATION
PHOTOCATALYSIS
SURFACE SPECIATION
TITANIUM DIOXIDE
topic GALLIC ACID ADSORPTION KINETICS
INTERMITTENT IRRADIATION
PHOTOCATALYSIS
SURFACE SPECIATION
TITANIUM DIOXIDE
purl_subject.fl_str_mv https://purl.org/becyt/ford/1.4
https://purl.org/becyt/ford/1
dc.description.none.fl_txt_mv Gallic acid adsorbs onto TiO2 films deposited onto an ATR crystal in two steps, both described by the kinetic Langmuir equation, as shown by measuring the spectral changes due to adsorbed species. Both pathways lead to species with the same spectral signature. Upon irradiation for preset times, integrated spectral absorbance profiles (log(A/A0) vs time) for the adsorbate peaks coincides with the analogous profile of remnant concentration in solution (log(C/C0) vs time). In our experiments, initially there are similar amounts of adsorbed and dissolved gallic acid. Hence, the rate of destruction of surface complexed gallic acid is approximately twice as large as the net rate of ligand uptake from solution. Upon irradiation, ligand surface concentration falls below equilibrium values, as also shown by plotting spectral signal intensity as a function of solution concentration. Under intermittent irradiation, the original rates were the same, but at larger radiation doses, the overall conversion was higher. This result demonstrates that during the intervening dark periods thermal reactions contribute to the overall rate. These thermal reactions may include desorption of intermediates, dark oxidation of intermediates, and re-equilibration of the surface with increasing gallic acid surface concentration. A description of photocatalysis based in the concept of oxidation length is provided.
Fil: Araujo, Paula Zulema. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; Argentina
Fil: Morando, Pedro Juan. Comisión Nacional de Energía Atómica. Gerencia del Área de Seguridad Nuclear y Ambiente. Gerencia de Química (CAC); Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de San Martín. Instituto Sabato; Argentina
Fil: Martínez, Eduardo David. Comisión Nacional de Energía Atómica. Gerencia del Área de Seguridad Nuclear y Ambiente. Gerencia de Química (CAC); Argentina. Universidad Nacional de San Martín. Instituto de Investigación e Ingeniería Ambiental. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e Ingeniería Ambiental; Argentina
Fil: Blesa, Miguel Angel. Universidad Nacional de San Martín. Instituto de Investigación e Ingeniería Ambiental. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e Ingeniería Ambiental; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Seguridad Nuclear y Ambiente. Gerencia de Química (CAC); Argentina
description Gallic acid adsorbs onto TiO2 films deposited onto an ATR crystal in two steps, both described by the kinetic Langmuir equation, as shown by measuring the spectral changes due to adsorbed species. Both pathways lead to species with the same spectral signature. Upon irradiation for preset times, integrated spectral absorbance profiles (log(A/A0) vs time) for the adsorbate peaks coincides with the analogous profile of remnant concentration in solution (log(C/C0) vs time). In our experiments, initially there are similar amounts of adsorbed and dissolved gallic acid. Hence, the rate of destruction of surface complexed gallic acid is approximately twice as large as the net rate of ligand uptake from solution. Upon irradiation, ligand surface concentration falls below equilibrium values, as also shown by plotting spectral signal intensity as a function of solution concentration. Under intermittent irradiation, the original rates were the same, but at larger radiation doses, the overall conversion was higher. This result demonstrates that during the intervening dark periods thermal reactions contribute to the overall rate. These thermal reactions may include desorption of intermediates, dark oxidation of intermediates, and re-equilibration of the surface with increasing gallic acid surface concentration. A description of photocatalysis based in the concept of oxidation length is provided.
publishDate 2012
dc.date.none.fl_str_mv 2012-08
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/11336/197044
Araujo, Paula Zulema; Morando, Pedro Juan; Martínez, Eduardo David; Blesa, Miguel Angel; Time evolution of surface speciation during heterogeneous photocatalysis: Gallic acid on titanium dioxide; Elsevier Science; Applied Catalysis B: Environmental; 125; 8-2012; 215-221
0926-3373
CONICET Digital
CONICET
url http://hdl.handle.net/11336/197044
identifier_str_mv Araujo, Paula Zulema; Morando, Pedro Juan; Martínez, Eduardo David; Blesa, Miguel Angel; Time evolution of surface speciation during heterogeneous photocatalysis: Gallic acid on titanium dioxide; Elsevier Science; Applied Catalysis B: Environmental; 125; 8-2012; 215-221
0926-3373
CONICET Digital
CONICET
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/url/http://www.sciencedirect.com/science/article/pii/S092633731200238X
info:eu-repo/semantics/altIdentifier/doi/10.1016/j.apcatb.2012.05.035
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
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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