Optical and electronic properties of TiO2/GOQDs composites: A combined experimental and first-principles calculations study
Autor(a) principal: | |
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Data de Publicação: | 2021 |
Outros Autores: | , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Institucional da UNESP |
Texto Completo: | http://dx.doi.org/10.1016/j.commatsci.2021.110503 http://hdl.handle.net/11449/207932 |
Resumo: | In this work, the optical and electronic properties of a TiO2/graphene oxide quantum dots (GOQDs) composite were studied by experimental and computational methods. The experimental procedures were made on TiO2 and GOQDs nanoparticles synthesized by a sol-gel method and one-pot electrochemical carbonization, respectively. The characterization of these materials and the TiO2/GOQDs composite was made using field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), X-ray photoelectron microscopy (XPS), FT-IR spectroscopy, and dynamic light scattering (DLS). The experimental measurements of the optical properties of these materials by UV–Vis absorption spectroscopy indicate that the addition of GOQDs promotes the expansion of the radiation absorption of TiO2 towards the visible range. Similarly, photoelectrochemical tests performed to determine the electronic properties show that GOQDs improve the separation of the photogenerated electron-hole pairs, increasing the photocatalytic activity of the TiO2. These results were further contrasted with a computational study based on first-principles DFT-D3 calculations, using the projector augmented wave (PAW) method on TiO2, pristine GQDs, GOQDs, TiO2/GQDs, and TiO2/GOQDs clusters. The computational results showed that GOQDs exhibit properties of a p-type semiconductor due to the presence of oxygenated groups. Therefore, when used as TiO2/GOQDs composite, these form a type II heterojunction, increasing the photocatalytic activity of the material. |
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Optical and electronic properties of TiO2/GOQDs composites: A combined experimental and first-principles calculations studyDFT-D3Graphene oxide quantum dotsHeterojunctionPhotocatalytic activityTiO2In this work, the optical and electronic properties of a TiO2/graphene oxide quantum dots (GOQDs) composite were studied by experimental and computational methods. The experimental procedures were made on TiO2 and GOQDs nanoparticles synthesized by a sol-gel method and one-pot electrochemical carbonization, respectively. The characterization of these materials and the TiO2/GOQDs composite was made using field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), X-ray photoelectron microscopy (XPS), FT-IR spectroscopy, and dynamic light scattering (DLS). The experimental measurements of the optical properties of these materials by UV–Vis absorption spectroscopy indicate that the addition of GOQDs promotes the expansion of the radiation absorption of TiO2 towards the visible range. Similarly, photoelectrochemical tests performed to determine the electronic properties show that GOQDs improve the separation of the photogenerated electron-hole pairs, increasing the photocatalytic activity of the TiO2. These results were further contrasted with a computational study based on first-principles DFT-D3 calculations, using the projector augmented wave (PAW) method on TiO2, pristine GQDs, GOQDs, TiO2/GQDs, and TiO2/GOQDs clusters. The computational results showed that GOQDs exhibit properties of a p-type semiconductor due to the presence of oxygenated groups. Therefore, when used as TiO2/GOQDs composite, these form a type II heterojunction, increasing the photocatalytic activity of the material.Laboratorio de Investigación de Electroquímica Aplicada Facultad de Ciencias Universidad Nacional de Ingeniería, Av. Túpac Amaru 210, RímacCenter for the Development of Advanced Materials and Nanotechnology – CEMAT – UNIInstitute of Chemistry Department of Engineering Physics and Mathematics São Paulo State University (UNESP)Institute of Chemistry Department of Engineering Physics and Mathematics São Paulo State University (UNESP)Universidad Nacional de IngenieríaCenter for the Development of Advanced Materials and Nanotechnology – CEMAT – UNIUniversidade Estadual Paulista (Unesp)Jauja-Ccana, V. R.Córdova Huamán, Allison V.Feliciano, Gustavo T. [UNESP]La Rosa-Toro Gómez, Adolfo2021-06-25T11:03:26Z2021-06-25T11:03:26Z2021-07-01info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articlehttp://dx.doi.org/10.1016/j.commatsci.2021.110503Computational Materials Science, v. 195.0927-0256http://hdl.handle.net/11449/20793210.1016/j.commatsci.2021.1105032-s2.0-85104408584Scopusreponame:Repositório Institucional da UNESPinstname:Universidade Estadual Paulista (UNESP)instacron:UNESPengComputational Materials Scienceinfo:eu-repo/semantics/openAccess2021-10-23T17:51:55Zoai:repositorio.unesp.br:11449/207932Repositório InstitucionalPUBhttp://repositorio.unesp.br/oai/requestopendoar:29462021-10-23T17:51:55Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP)false |
dc.title.none.fl_str_mv |
Optical and electronic properties of TiO2/GOQDs composites: A combined experimental and first-principles calculations study |
title |
Optical and electronic properties of TiO2/GOQDs composites: A combined experimental and first-principles calculations study |
spellingShingle |
Optical and electronic properties of TiO2/GOQDs composites: A combined experimental and first-principles calculations study Jauja-Ccana, V. R. DFT-D3 Graphene oxide quantum dots Heterojunction Photocatalytic activity TiO2 |
title_short |
Optical and electronic properties of TiO2/GOQDs composites: A combined experimental and first-principles calculations study |
title_full |
Optical and electronic properties of TiO2/GOQDs composites: A combined experimental and first-principles calculations study |
title_fullStr |
Optical and electronic properties of TiO2/GOQDs composites: A combined experimental and first-principles calculations study |
title_full_unstemmed |
Optical and electronic properties of TiO2/GOQDs composites: A combined experimental and first-principles calculations study |
title_sort |
Optical and electronic properties of TiO2/GOQDs composites: A combined experimental and first-principles calculations study |
author |
Jauja-Ccana, V. R. |
author_facet |
Jauja-Ccana, V. R. Córdova Huamán, Allison V. Feliciano, Gustavo T. [UNESP] La Rosa-Toro Gómez, Adolfo |
author_role |
author |
author2 |
Córdova Huamán, Allison V. Feliciano, Gustavo T. [UNESP] La Rosa-Toro Gómez, Adolfo |
author2_role |
author author author |
dc.contributor.none.fl_str_mv |
Universidad Nacional de Ingeniería Center for the Development of Advanced Materials and Nanotechnology – CEMAT – UNI Universidade Estadual Paulista (Unesp) |
dc.contributor.author.fl_str_mv |
Jauja-Ccana, V. R. Córdova Huamán, Allison V. Feliciano, Gustavo T. [UNESP] La Rosa-Toro Gómez, Adolfo |
dc.subject.por.fl_str_mv |
DFT-D3 Graphene oxide quantum dots Heterojunction Photocatalytic activity TiO2 |
topic |
DFT-D3 Graphene oxide quantum dots Heterojunction Photocatalytic activity TiO2 |
description |
In this work, the optical and electronic properties of a TiO2/graphene oxide quantum dots (GOQDs) composite were studied by experimental and computational methods. The experimental procedures were made on TiO2 and GOQDs nanoparticles synthesized by a sol-gel method and one-pot electrochemical carbonization, respectively. The characterization of these materials and the TiO2/GOQDs composite was made using field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), X-ray photoelectron microscopy (XPS), FT-IR spectroscopy, and dynamic light scattering (DLS). The experimental measurements of the optical properties of these materials by UV–Vis absorption spectroscopy indicate that the addition of GOQDs promotes the expansion of the radiation absorption of TiO2 towards the visible range. Similarly, photoelectrochemical tests performed to determine the electronic properties show that GOQDs improve the separation of the photogenerated electron-hole pairs, increasing the photocatalytic activity of the TiO2. These results were further contrasted with a computational study based on first-principles DFT-D3 calculations, using the projector augmented wave (PAW) method on TiO2, pristine GQDs, GOQDs, TiO2/GQDs, and TiO2/GOQDs clusters. The computational results showed that GOQDs exhibit properties of a p-type semiconductor due to the presence of oxygenated groups. Therefore, when used as TiO2/GOQDs composite, these form a type II heterojunction, increasing the photocatalytic activity of the material. |
publishDate |
2021 |
dc.date.none.fl_str_mv |
2021-06-25T11:03:26Z 2021-06-25T11:03:26Z 2021-07-01 |
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 |
http://dx.doi.org/10.1016/j.commatsci.2021.110503 Computational Materials Science, v. 195. 0927-0256 http://hdl.handle.net/11449/207932 10.1016/j.commatsci.2021.110503 2-s2.0-85104408584 |
url |
http://dx.doi.org/10.1016/j.commatsci.2021.110503 http://hdl.handle.net/11449/207932 |
identifier_str_mv |
Computational Materials Science, v. 195. 0927-0256 10.1016/j.commatsci.2021.110503 2-s2.0-85104408584 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
Computational Materials Science |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.source.none.fl_str_mv |
Scopus reponame:Repositório Institucional da UNESP instname:Universidade Estadual Paulista (UNESP) instacron:UNESP |
instname_str |
Universidade Estadual Paulista (UNESP) |
instacron_str |
UNESP |
institution |
UNESP |
reponame_str |
Repositório Institucional da UNESP |
collection |
Repositório Institucional da UNESP |
repository.name.fl_str_mv |
Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP) |
repository.mail.fl_str_mv |
|
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1797790316415156224 |