Electrochemical and photocatalytic reactions of polycyclic aromatic hydrocarbons investigated by raman spectroscopy
Autor(a) principal: | |
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Data de Publicação: | 2009 |
Outros Autores: | |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Journal of the Brazilian Chemical Society (Online) |
Texto Completo: | http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532009000100014 |
Resumo: | This paper presents the study of photochemical behavior of polycyclic aromatic hydrocarbons (PAHs), potential pollutants in secondary reactions in aerosols, through Raman spectroscopy compared with its electrochemical behavior. The PAHs studied include pyrene, anthracene, phenanthrene and fluorene. These were adsorbed onto TiO2 and irradiated with ultraviolet light (254 nm). Their electrochemical oxidation was studied by in situ Surface-enhanced Raman Scattering (SERS) and led to the formation of carbonyl-containing products. Oxidized intermediates bearing the C=O group were also formed during photodegradation. The joint analysis of the photodegradation data with those produced by electrochemical means - using spectroscopic techniques for the identification and characterization of the products - revealed the formation of identical products for anthracene, but not for pyrene. A reasonable explanation for this difference in results is that photochemical and electrochemical oxidation reactions proceed via different mechanisms. While photocatalytic degradation over TiO2 is initiated by hydroxyl radicals, electrochemical oxidation is initiated by the direct electron transfer from adsorbed PAH to the electrode, generating PAH cation radicals that undergo subsequent reactions. |
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Electrochemical and photocatalytic reactions of polycyclic aromatic hydrocarbons investigated by raman spectroscopyadvanced oxidative processesphotocatalysisTiO2spectroelectrochemistrySERSThis paper presents the study of photochemical behavior of polycyclic aromatic hydrocarbons (PAHs), potential pollutants in secondary reactions in aerosols, through Raman spectroscopy compared with its electrochemical behavior. The PAHs studied include pyrene, anthracene, phenanthrene and fluorene. These were adsorbed onto TiO2 and irradiated with ultraviolet light (254 nm). Their electrochemical oxidation was studied by in situ Surface-enhanced Raman Scattering (SERS) and led to the formation of carbonyl-containing products. Oxidized intermediates bearing the C=O group were also formed during photodegradation. The joint analysis of the photodegradation data with those produced by electrochemical means - using spectroscopic techniques for the identification and characterization of the products - revealed the formation of identical products for anthracene, but not for pyrene. A reasonable explanation for this difference in results is that photochemical and electrochemical oxidation reactions proceed via different mechanisms. While photocatalytic degradation over TiO2 is initiated by hydroxyl radicals, electrochemical oxidation is initiated by the direct electron transfer from adsorbed PAH to the electrode, generating PAH cation radicals that undergo subsequent reactions.Sociedade Brasileira de Química2009-01-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersiontext/htmlhttp://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532009000100014Journal of the Brazilian Chemical Society v.20 n.1 2009reponame:Journal of the Brazilian Chemical Society (Online)instname:Sociedade Brasileira de Química (SBQ)instacron:SBQ10.1590/S0103-50532009000100014info:eu-repo/semantics/openAccessCordeiro,Denise S.Corio,Paolaeng2009-01-23T00:00:00Zoai:scielo:S0103-50532009000100014Revistahttp://jbcs.sbq.org.brONGhttps://old.scielo.br/oai/scielo-oai.php||office@jbcs.sbq.org.br1678-47900103-5053opendoar:2009-01-23T00:00Journal of the Brazilian Chemical Society (Online) - Sociedade Brasileira de Química (SBQ)false |
dc.title.none.fl_str_mv |
Electrochemical and photocatalytic reactions of polycyclic aromatic hydrocarbons investigated by raman spectroscopy |
title |
Electrochemical and photocatalytic reactions of polycyclic aromatic hydrocarbons investigated by raman spectroscopy |
spellingShingle |
Electrochemical and photocatalytic reactions of polycyclic aromatic hydrocarbons investigated by raman spectroscopy Cordeiro,Denise S. advanced oxidative processes photocatalysis TiO2 spectroelectrochemistry SERS |
title_short |
Electrochemical and photocatalytic reactions of polycyclic aromatic hydrocarbons investigated by raman spectroscopy |
title_full |
Electrochemical and photocatalytic reactions of polycyclic aromatic hydrocarbons investigated by raman spectroscopy |
title_fullStr |
Electrochemical and photocatalytic reactions of polycyclic aromatic hydrocarbons investigated by raman spectroscopy |
title_full_unstemmed |
Electrochemical and photocatalytic reactions of polycyclic aromatic hydrocarbons investigated by raman spectroscopy |
title_sort |
Electrochemical and photocatalytic reactions of polycyclic aromatic hydrocarbons investigated by raman spectroscopy |
author |
Cordeiro,Denise S. |
author_facet |
Cordeiro,Denise S. Corio,Paola |
author_role |
author |
author2 |
Corio,Paola |
author2_role |
author |
dc.contributor.author.fl_str_mv |
Cordeiro,Denise S. Corio,Paola |
dc.subject.por.fl_str_mv |
advanced oxidative processes photocatalysis TiO2 spectroelectrochemistry SERS |
topic |
advanced oxidative processes photocatalysis TiO2 spectroelectrochemistry SERS |
description |
This paper presents the study of photochemical behavior of polycyclic aromatic hydrocarbons (PAHs), potential pollutants in secondary reactions in aerosols, through Raman spectroscopy compared with its electrochemical behavior. The PAHs studied include pyrene, anthracene, phenanthrene and fluorene. These were adsorbed onto TiO2 and irradiated with ultraviolet light (254 nm). Their electrochemical oxidation was studied by in situ Surface-enhanced Raman Scattering (SERS) and led to the formation of carbonyl-containing products. Oxidized intermediates bearing the C=O group were also formed during photodegradation. The joint analysis of the photodegradation data with those produced by electrochemical means - using spectroscopic techniques for the identification and characterization of the products - revealed the formation of identical products for anthracene, but not for pyrene. A reasonable explanation for this difference in results is that photochemical and electrochemical oxidation reactions proceed via different mechanisms. While photocatalytic degradation over TiO2 is initiated by hydroxyl radicals, electrochemical oxidation is initiated by the direct electron transfer from adsorbed PAH to the electrode, generating PAH cation radicals that undergo subsequent reactions. |
publishDate |
2009 |
dc.date.none.fl_str_mv |
2009-01-01 |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532009000100014 |
url |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532009000100014 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
10.1590/S0103-50532009000100014 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
text/html |
dc.publisher.none.fl_str_mv |
Sociedade Brasileira de Química |
publisher.none.fl_str_mv |
Sociedade Brasileira de Química |
dc.source.none.fl_str_mv |
Journal of the Brazilian Chemical Society v.20 n.1 2009 reponame:Journal of the Brazilian Chemical Society (Online) instname:Sociedade Brasileira de Química (SBQ) instacron:SBQ |
instname_str |
Sociedade Brasileira de Química (SBQ) |
instacron_str |
SBQ |
institution |
SBQ |
reponame_str |
Journal of the Brazilian Chemical Society (Online) |
collection |
Journal of the Brazilian Chemical Society (Online) |
repository.name.fl_str_mv |
Journal of the Brazilian Chemical Society (Online) - Sociedade Brasileira de Química (SBQ) |
repository.mail.fl_str_mv |
||office@jbcs.sbq.org.br |
_version_ |
1750318169436717056 |