Application of the Stopped Flow Technique to the TiO 2 -Heterogeneous Photocatalysis of Hexavalent Chromium in Aqueous Suspensions: Comparison with O 2 and H 2 O 2 as Electron Acce...

Autores
Meichtry, Jorge Martin; Dillert, Ralf; Bahnemann, Detlef W.; Litter, Marta Irene
Año de publicación
2015
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
The dynamics of transfer of electrons stored in TiO2 nanoparticles to Cr(VI) in aqueous solution have been investigated using the stopped flow technique. TiO2 nanoparticles were previously irradiated under UV light in the presence of formic acid, and trapped electrons (eCBtrap−) were made to react with Cr(VI) as acceptor species; other common acceptor species such as O2 and H2O2 were also tested. The temporal evolution of the trapped electrons was followed by the decrease of the absorbance at 600 nm, and the kinetics of the electron transfer reaction was modeled. Additionally, the rate of formation of the surface complex between Cr(VI) and TiO2 was determined with the stopped flow technique by following the evolution of the absorbance at 400 nm of suspensions of non-irradiated TiO2 nanoparticles and Cr(VI) at different concentrations. An approximately quadratic relationship was observed between the maximum absorbance of the surface complex and the concentration of Cr(VI), suggesting that Cr(VI) adsorbs over the TiO2 as dichromate. The kinetic analyses indicate that the electron transfer from TiO2 to Cr(VI) does not require the previous formation of the Cr(VI)-TiO2 surface complex, at least the complex detected here through the stopped flow experiments. When previously irradiated nTiO2 was used to follow the evolution of the Cr(VI)-TiO2 complex, an inhibition of the formation of the complex was observed, which can be related with the TiO2 deactivation caused by Cr(III) deposition.
Fil: Meichtry, Jorge Martin. Comisión Nacional de Energía Atómica. Gerencia Química. CAC; Argentina. Universidad Nacional de San Martín; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
Fil: Dillert, Ralf. Leibniz Universitat Hannover; Alemania
Fil: Bahnemann, Detlef W.. Leibniz Universitat Hannover; Alemania
Fil: Litter, Marta Irene. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Gerencia Química. CAC; Argentina
Materia
Stopped-Flow Technique
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:11336/41598
Acceder
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oai_identifier_str oai:ri.conicet.gov.ar:11336/41598
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repository_id_str 3498
network_name_str CONICET Digital (CONICET)
spelling Application of the Stopped Flow Technique to the TiO 2 -Heterogeneous Photocatalysis of Hexavalent Chromium in Aqueous Suspensions: Comparison with O 2 and H 2 O 2 as Electron AcceptorsMeichtry, Jorge MartinDillert, RalfBahnemann, Detlef W.Litter, Marta IreneStopped-Flow Techniquehttps://purl.org/becyt/ford/1.4https://purl.org/becyt/ford/1The dynamics of transfer of electrons stored in TiO2 nanoparticles to Cr(VI) in aqueous solution have been investigated using the stopped flow technique. TiO2 nanoparticles were previously irradiated under UV light in the presence of formic acid, and trapped electrons (eCBtrap−) were made to react with Cr(VI) as acceptor species; other common acceptor species such as O2 and H2O2 were also tested. The temporal evolution of the trapped electrons was followed by the decrease of the absorbance at 600 nm, and the kinetics of the electron transfer reaction was modeled. Additionally, the rate of formation of the surface complex between Cr(VI) and TiO2 was determined with the stopped flow technique by following the evolution of the absorbance at 400 nm of suspensions of non-irradiated TiO2 nanoparticles and Cr(VI) at different concentrations. An approximately quadratic relationship was observed between the maximum absorbance of the surface complex and the concentration of Cr(VI), suggesting that Cr(VI) adsorbs over the TiO2 as dichromate. The kinetic analyses indicate that the electron transfer from TiO2 to Cr(VI) does not require the previous formation of the Cr(VI)-TiO2 surface complex, at least the complex detected here through the stopped flow experiments. When previously irradiated nTiO2 was used to follow the evolution of the Cr(VI)-TiO2 complex, an inhibition of the formation of the complex was observed, which can be related with the TiO2 deactivation caused by Cr(III) deposition.Fil: Meichtry, Jorge Martin. Comisión Nacional de Energía Atómica. Gerencia Química. CAC; Argentina. Universidad Nacional de San Martín; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Dillert, Ralf. Leibniz Universitat Hannover; AlemaniaFil: Bahnemann, Detlef W.. Leibniz Universitat Hannover; AlemaniaFil: Litter, Marta Irene. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Gerencia Química. CAC; ArgentinaAmerican Chemical Society2015-05info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/41598Meichtry, Jorge Martin; Dillert, Ralf; Bahnemann, Detlef W.; Litter, Marta Irene; Application of the Stopped Flow Technique to the TiO 2 -Heterogeneous Photocatalysis of Hexavalent Chromium in Aqueous Suspensions: Comparison with O 2 and H 2 O 2 as Electron Acceptors; American Chemical Society; Langmuir; 31; 22; 5-2015; 6229-62360743-7463CONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/url/https://pubs.acs.org/doi/abs/10.1021/acs.langmuir.5b00574info:eu-repo/semantics/altIdentifier/doi/10.1021/acs.langmuir.5b00574info:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-09-03T09:56:42Zoai:ri.conicet.gov.ar:11336/41598instacron: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 09:56:42.443CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv Application of the Stopped Flow Technique to the TiO 2 -Heterogeneous Photocatalysis of Hexavalent Chromium in Aqueous Suspensions: Comparison with O 2 and H 2 O 2 as Electron Acceptors
title Application of the Stopped Flow Technique to the TiO 2 -Heterogeneous Photocatalysis of Hexavalent Chromium in Aqueous Suspensions: Comparison with O 2 and H 2 O 2 as Electron Acceptors
spellingShingle Application of the Stopped Flow Technique to the TiO 2 -Heterogeneous Photocatalysis of Hexavalent Chromium in Aqueous Suspensions: Comparison with O 2 and H 2 O 2 as Electron Acceptors
Meichtry, Jorge Martin
Stopped-Flow Technique
title_short Application of the Stopped Flow Technique to the TiO 2 -Heterogeneous Photocatalysis of Hexavalent Chromium in Aqueous Suspensions: Comparison with O 2 and H 2 O 2 as Electron Acceptors
title_full Application of the Stopped Flow Technique to the TiO 2 -Heterogeneous Photocatalysis of Hexavalent Chromium in Aqueous Suspensions: Comparison with O 2 and H 2 O 2 as Electron Acceptors
title_fullStr Application of the Stopped Flow Technique to the TiO 2 -Heterogeneous Photocatalysis of Hexavalent Chromium in Aqueous Suspensions: Comparison with O 2 and H 2 O 2 as Electron Acceptors
title_full_unstemmed Application of the Stopped Flow Technique to the TiO 2 -Heterogeneous Photocatalysis of Hexavalent Chromium in Aqueous Suspensions: Comparison with O 2 and H 2 O 2 as Electron Acceptors
title_sort Application of the Stopped Flow Technique to the TiO 2 -Heterogeneous Photocatalysis of Hexavalent Chromium in Aqueous Suspensions: Comparison with O 2 and H 2 O 2 as Electron Acceptors
dc.creator.none.fl_str_mv Meichtry, Jorge Martin
Dillert, Ralf
Bahnemann, Detlef W.
Litter, Marta Irene
author Meichtry, Jorge Martin
author_facet Meichtry, Jorge Martin
Dillert, Ralf
Bahnemann, Detlef W.
Litter, Marta Irene
author_role author
author2 Dillert, Ralf
Bahnemann, Detlef W.
Litter, Marta Irene
author2_role author
author
author
dc.subject.none.fl_str_mv Stopped-Flow Technique
topic Stopped-Flow Technique
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 dynamics of transfer of electrons stored in TiO2 nanoparticles to Cr(VI) in aqueous solution have been investigated using the stopped flow technique. TiO2 nanoparticles were previously irradiated under UV light in the presence of formic acid, and trapped electrons (eCBtrap−) were made to react with Cr(VI) as acceptor species; other common acceptor species such as O2 and H2O2 were also tested. The temporal evolution of the trapped electrons was followed by the decrease of the absorbance at 600 nm, and the kinetics of the electron transfer reaction was modeled. Additionally, the rate of formation of the surface complex between Cr(VI) and TiO2 was determined with the stopped flow technique by following the evolution of the absorbance at 400 nm of suspensions of non-irradiated TiO2 nanoparticles and Cr(VI) at different concentrations. An approximately quadratic relationship was observed between the maximum absorbance of the surface complex and the concentration of Cr(VI), suggesting that Cr(VI) adsorbs over the TiO2 as dichromate. The kinetic analyses indicate that the electron transfer from TiO2 to Cr(VI) does not require the previous formation of the Cr(VI)-TiO2 surface complex, at least the complex detected here through the stopped flow experiments. When previously irradiated nTiO2 was used to follow the evolution of the Cr(VI)-TiO2 complex, an inhibition of the formation of the complex was observed, which can be related with the TiO2 deactivation caused by Cr(III) deposition.
Fil: Meichtry, Jorge Martin. Comisión Nacional de Energía Atómica. Gerencia Química. CAC; Argentina. Universidad Nacional de San Martín; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
Fil: Dillert, Ralf. Leibniz Universitat Hannover; Alemania
Fil: Bahnemann, Detlef W.. Leibniz Universitat Hannover; Alemania
Fil: Litter, Marta Irene. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Gerencia Química. CAC; Argentina
description The dynamics of transfer of electrons stored in TiO2 nanoparticles to Cr(VI) in aqueous solution have been investigated using the stopped flow technique. TiO2 nanoparticles were previously irradiated under UV light in the presence of formic acid, and trapped electrons (eCBtrap−) were made to react with Cr(VI) as acceptor species; other common acceptor species such as O2 and H2O2 were also tested. The temporal evolution of the trapped electrons was followed by the decrease of the absorbance at 600 nm, and the kinetics of the electron transfer reaction was modeled. Additionally, the rate of formation of the surface complex between Cr(VI) and TiO2 was determined with the stopped flow technique by following the evolution of the absorbance at 400 nm of suspensions of non-irradiated TiO2 nanoparticles and Cr(VI) at different concentrations. An approximately quadratic relationship was observed between the maximum absorbance of the surface complex and the concentration of Cr(VI), suggesting that Cr(VI) adsorbs over the TiO2 as dichromate. The kinetic analyses indicate that the electron transfer from TiO2 to Cr(VI) does not require the previous formation of the Cr(VI)-TiO2 surface complex, at least the complex detected here through the stopped flow experiments. When previously irradiated nTiO2 was used to follow the evolution of the Cr(VI)-TiO2 complex, an inhibition of the formation of the complex was observed, which can be related with the TiO2 deactivation caused by Cr(III) deposition.
publishDate 2015
dc.date.none.fl_str_mv 2015-05
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/11336/41598
Meichtry, Jorge Martin; Dillert, Ralf; Bahnemann, Detlef W.; Litter, Marta Irene; Application of the Stopped Flow Technique to the TiO 2 -Heterogeneous Photocatalysis of Hexavalent Chromium in Aqueous Suspensions: Comparison with O 2 and H 2 O 2 as Electron Acceptors; American Chemical Society; Langmuir; 31; 22; 5-2015; 6229-6236
0743-7463
CONICET Digital
CONICET
url http://hdl.handle.net/11336/41598
identifier_str_mv Meichtry, Jorge Martin; Dillert, Ralf; Bahnemann, Detlef W.; Litter, Marta Irene; Application of the Stopped Flow Technique to the TiO 2 -Heterogeneous Photocatalysis of Hexavalent Chromium in Aqueous Suspensions: Comparison with O 2 and H 2 O 2 as Electron Acceptors; American Chemical Society; Langmuir; 31; 22; 5-2015; 6229-6236
0743-7463
CONICET Digital
CONICET
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/url/https://pubs.acs.org/doi/abs/10.1021/acs.langmuir.5b00574
info:eu-repo/semantics/altIdentifier/doi/10.1021/acs.langmuir.5b00574
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
dc.publisher.none.fl_str_mv American Chemical Society
publisher.none.fl_str_mv American Chemical Society
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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