Scavenging activity of Magnéli phases as a function of Ti(4+)/Ti(3+) ratios
Autor(a) principal: | |
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Data de Publicação: | 2017 |
Outros Autores: | , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | https://hdl.handle.net/10216/121099 |
Resumo: | TiO2 is able to scavenge reactive oxygen and nitrogen species (ROS and RNS) in the absence of light. The scavenging mechanism has been related to the chemistry of defects (oxygen vacancy reduced oxidation states of Ti) but it is still unknown. This study describes the ROS scavenging activity of different titanium oxide phases and relates their scavenging activities with the Ti4+/Ti3+ molar ratio as well as the band gap value. The Ti5O9 phase, with a mixture of both oxidation states, presented a substantially higher percentage of 2,2-diphenyl-1-picrylhydracyl radicals (DPPH) eliminated per m2 of specific surface area in comparison to phases with predominant oxidation states Ti4+ or Ti3+ such as TiO2 and Ti2O3, respectively. The obtained results indicate that the DPPH scavenging mechanism corresponds to a catalytic process on the Ti5O9 surface which is facilitated by the presence of charges that can easily move through the material. The mobility of charges and electrons in the semiconductor surface, related to the presence of oxidation states Ti4+ and Ti3+ and a small band gap, could create an attractive surface for radical species such as DPPH. This puts forward Ti5O9 as a promising candidate coating for implantable biomedical devices, as an electrode, since it can cushion inflammatory processes which could lead to device encapsulation and, consequently, failure. |
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Scavenging activity of Magnéli phases as a function of Ti(4+)/Ti(3+) ratiosTiO2 is able to scavenge reactive oxygen and nitrogen species (ROS and RNS) in the absence of light. The scavenging mechanism has been related to the chemistry of defects (oxygen vacancy reduced oxidation states of Ti) but it is still unknown. This study describes the ROS scavenging activity of different titanium oxide phases and relates their scavenging activities with the Ti4+/Ti3+ molar ratio as well as the band gap value. The Ti5O9 phase, with a mixture of both oxidation states, presented a substantially higher percentage of 2,2-diphenyl-1-picrylhydracyl radicals (DPPH) eliminated per m2 of specific surface area in comparison to phases with predominant oxidation states Ti4+ or Ti3+ such as TiO2 and Ti2O3, respectively. The obtained results indicate that the DPPH scavenging mechanism corresponds to a catalytic process on the Ti5O9 surface which is facilitated by the presence of charges that can easily move through the material. The mobility of charges and electrons in the semiconductor surface, related to the presence of oxidation states Ti4+ and Ti3+ and a small band gap, could create an attractive surface for radical species such as DPPH. This puts forward Ti5O9 as a promising candidate coating for implantable biomedical devices, as an electrode, since it can cushion inflammatory processes which could lead to device encapsulation and, consequently, failure.Royal Society of Chemistry20172017-01-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfhttps://hdl.handle.net/10216/121099eng1359-734510.1039/c7cc05862dCanillas, MChinarro, EPêgo, APMoreno, Binfo:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2023-11-29T14:18:21Zoai:repositorio-aberto.up.pt:10216/121099Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T23:58:28.341342Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse |
dc.title.none.fl_str_mv |
Scavenging activity of Magnéli phases as a function of Ti(4+)/Ti(3+) ratios |
title |
Scavenging activity of Magnéli phases as a function of Ti(4+)/Ti(3+) ratios |
spellingShingle |
Scavenging activity of Magnéli phases as a function of Ti(4+)/Ti(3+) ratios Canillas, M |
title_short |
Scavenging activity of Magnéli phases as a function of Ti(4+)/Ti(3+) ratios |
title_full |
Scavenging activity of Magnéli phases as a function of Ti(4+)/Ti(3+) ratios |
title_fullStr |
Scavenging activity of Magnéli phases as a function of Ti(4+)/Ti(3+) ratios |
title_full_unstemmed |
Scavenging activity of Magnéli phases as a function of Ti(4+)/Ti(3+) ratios |
title_sort |
Scavenging activity of Magnéli phases as a function of Ti(4+)/Ti(3+) ratios |
author |
Canillas, M |
author_facet |
Canillas, M Chinarro, E Pêgo, AP Moreno, B |
author_role |
author |
author2 |
Chinarro, E Pêgo, AP Moreno, B |
author2_role |
author author author |
dc.contributor.author.fl_str_mv |
Canillas, M Chinarro, E Pêgo, AP Moreno, B |
description |
TiO2 is able to scavenge reactive oxygen and nitrogen species (ROS and RNS) in the absence of light. The scavenging mechanism has been related to the chemistry of defects (oxygen vacancy reduced oxidation states of Ti) but it is still unknown. This study describes the ROS scavenging activity of different titanium oxide phases and relates their scavenging activities with the Ti4+/Ti3+ molar ratio as well as the band gap value. The Ti5O9 phase, with a mixture of both oxidation states, presented a substantially higher percentage of 2,2-diphenyl-1-picrylhydracyl radicals (DPPH) eliminated per m2 of specific surface area in comparison to phases with predominant oxidation states Ti4+ or Ti3+ such as TiO2 and Ti2O3, respectively. The obtained results indicate that the DPPH scavenging mechanism corresponds to a catalytic process on the Ti5O9 surface which is facilitated by the presence of charges that can easily move through the material. The mobility of charges and electrons in the semiconductor surface, related to the presence of oxidation states Ti4+ and Ti3+ and a small band gap, could create an attractive surface for radical species such as DPPH. This puts forward Ti5O9 as a promising candidate coating for implantable biomedical devices, as an electrode, since it can cushion inflammatory processes which could lead to device encapsulation and, consequently, failure. |
publishDate |
2017 |
dc.date.none.fl_str_mv |
2017 2017-01-01T00:00:00Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
https://hdl.handle.net/10216/121099 |
url |
https://hdl.handle.net/10216/121099 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
1359-7345 10.1039/c7cc05862d |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.publisher.none.fl_str_mv |
Royal Society of Chemistry |
publisher.none.fl_str_mv |
Royal Society of Chemistry |
dc.source.none.fl_str_mv |
reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação instacron:RCAAP |
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Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
instacron_str |
RCAAP |
institution |
RCAAP |
reponame_str |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
repository.name.fl_str_mv |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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1799135906962079744 |