Surface chemistry determines electron storage capabilities in alcoholic sols of titanium dioxide nanoparticles. A combined FTIR and room temperature EPR investigation

Electron accumulation in TiO 2 ethanolic sols prepared by the HCl hydrolysis of a titanium alkoxide has been scrutinized by UV-vis and EPR spectroscopy. Unexpectedly, Ti(III) centers, g = 1.9551, formed after controlled monochromatic irradiation of the sols could be detected at room temperature by E...

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Autores principales: Iorio, Y.D., Aguirre, M.E., Brusa, M.A., Grela, M.A.
Formato: JOUR
Lenguaje:English
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Acceso en línea:http://hdl.handle.net/20.500.12110/paper_19327447_v116_n17_p9646_Iorio
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spelling todo:paper_19327447_v116_n17_p9646_Iorio2023-10-03T16:35:53Z Surface chemistry determines electron storage capabilities in alcoholic sols of titanium dioxide nanoparticles. A combined FTIR and room temperature EPR investigation Iorio, Y.D. Aguirre, M.E. Brusa, M.A. Grela, M.A. Chloride ions Electron accumulation Electron storage EPR spectroscopy Ethoxides FTIR Hydroxylic groups Molar ratio Monochromatic irradiation Paramagnetic signals Production efficiency Reducing species Room temperature Room temperature detection TiO Titanium alkoxides Titanium dioxide nanoparticles Titanium dioxide surfaces Chlorine compounds Oxides Paramagnetic resonance Paramagnetism Sols Surface chemistry Titanium Titration Titanium dioxide Electron accumulation in TiO 2 ethanolic sols prepared by the HCl hydrolysis of a titanium alkoxide has been scrutinized by UV-vis and EPR spectroscopy. Unexpectedly, Ti(III) centers, g = 1.9551, formed after controlled monochromatic irradiation of the sols could be detected at room temperature by EPR spectroscopy. The yield of the paramagnetic signal and the number of accumulated reducing species, detected in dark titration experiments, increase as the water to titanium molar ratio, h, used in the synthesis diminishes. A 3.8% Ti(III) production efficiency was estimated for h = 6.5. Bidentate ethoxide coordination to the titanium dioxide surface and the replacement of surface hydroxylic groups by chloride ions is directly inferred by FTIR and EPR spectroscopies. Both findings are proposed to account for the room temperature detection of the Ti(III) species, and the higher electron storage capacity of the colloids prepared with lower h values. © 2012 American Chemical Society. JOUR English info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_19327447_v116_n17_p9646_Iorio
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
language English
orig_language_str_mv English
topic Chloride ions
Electron accumulation
Electron storage
EPR spectroscopy
Ethoxides
FTIR
Hydroxylic groups
Molar ratio
Monochromatic irradiation
Paramagnetic signals
Production efficiency
Reducing species
Room temperature
Room temperature detection
TiO
Titanium alkoxides
Titanium dioxide nanoparticles
Titanium dioxide surfaces
Chlorine compounds
Oxides
Paramagnetic resonance
Paramagnetism
Sols
Surface chemistry
Titanium
Titration
Titanium dioxide
spellingShingle Chloride ions
Electron accumulation
Electron storage
EPR spectroscopy
Ethoxides
FTIR
Hydroxylic groups
Molar ratio
Monochromatic irradiation
Paramagnetic signals
Production efficiency
Reducing species
Room temperature
Room temperature detection
TiO
Titanium alkoxides
Titanium dioxide nanoparticles
Titanium dioxide surfaces
Chlorine compounds
Oxides
Paramagnetic resonance
Paramagnetism
Sols
Surface chemistry
Titanium
Titration
Titanium dioxide
Iorio, Y.D.
Aguirre, M.E.
Brusa, M.A.
Grela, M.A.
Surface chemistry determines electron storage capabilities in alcoholic sols of titanium dioxide nanoparticles. A combined FTIR and room temperature EPR investigation
topic_facet Chloride ions
Electron accumulation
Electron storage
EPR spectroscopy
Ethoxides
FTIR
Hydroxylic groups
Molar ratio
Monochromatic irradiation
Paramagnetic signals
Production efficiency
Reducing species
Room temperature
Room temperature detection
TiO
Titanium alkoxides
Titanium dioxide nanoparticles
Titanium dioxide surfaces
Chlorine compounds
Oxides
Paramagnetic resonance
Paramagnetism
Sols
Surface chemistry
Titanium
Titration
Titanium dioxide
description Electron accumulation in TiO 2 ethanolic sols prepared by the HCl hydrolysis of a titanium alkoxide has been scrutinized by UV-vis and EPR spectroscopy. Unexpectedly, Ti(III) centers, g = 1.9551, formed after controlled monochromatic irradiation of the sols could be detected at room temperature by EPR spectroscopy. The yield of the paramagnetic signal and the number of accumulated reducing species, detected in dark titration experiments, increase as the water to titanium molar ratio, h, used in the synthesis diminishes. A 3.8% Ti(III) production efficiency was estimated for h = 6.5. Bidentate ethoxide coordination to the titanium dioxide surface and the replacement of surface hydroxylic groups by chloride ions is directly inferred by FTIR and EPR spectroscopies. Both findings are proposed to account for the room temperature detection of the Ti(III) species, and the higher electron storage capacity of the colloids prepared with lower h values. © 2012 American Chemical Society.
format JOUR
author Iorio, Y.D.
Aguirre, M.E.
Brusa, M.A.
Grela, M.A.
author_facet Iorio, Y.D.
Aguirre, M.E.
Brusa, M.A.
Grela, M.A.
author_sort Iorio, Y.D.
title Surface chemistry determines electron storage capabilities in alcoholic sols of titanium dioxide nanoparticles. A combined FTIR and room temperature EPR investigation
title_short Surface chemistry determines electron storage capabilities in alcoholic sols of titanium dioxide nanoparticles. A combined FTIR and room temperature EPR investigation
title_full Surface chemistry determines electron storage capabilities in alcoholic sols of titanium dioxide nanoparticles. A combined FTIR and room temperature EPR investigation
title_fullStr Surface chemistry determines electron storage capabilities in alcoholic sols of titanium dioxide nanoparticles. A combined FTIR and room temperature EPR investigation
title_full_unstemmed Surface chemistry determines electron storage capabilities in alcoholic sols of titanium dioxide nanoparticles. A combined FTIR and room temperature EPR investigation
title_sort surface chemistry determines electron storage capabilities in alcoholic sols of titanium dioxide nanoparticles. a combined ftir and room temperature epr investigation
url http://hdl.handle.net/20.500.12110/paper_19327447_v116_n17_p9646_Iorio
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AT aguirreme surfacechemistrydetermineselectronstoragecapabilitiesinalcoholicsolsoftitaniumdioxidenanoparticlesacombinedftirandroomtemperatureeprinvestigation
AT brusama surfacechemistrydetermineselectronstoragecapabilitiesinalcoholicsolsoftitaniumdioxidenanoparticlesacombinedftirandroomtemperatureeprinvestigation
AT grelama surfacechemistrydetermineselectronstoragecapabilitiesinalcoholicsolsoftitaniumdioxidenanoparticlesacombinedftirandroomtemperatureeprinvestigation
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