Síntese, caracterização e avaliação da atividade fotoeletrocatalítica de filmes finos de Sb2S3

Detalhes bibliográficos
Autor(a) principal: Araújo, Moisés Albuquerque de
Data de Publicação: 2020
Tipo de documento: Tese
Idioma: por
Título da fonte: Repositório Institucional da UFSCAR
Texto Completo: https://repositorio.ufscar.br/handle/ufscar/14033
Resumo: Photoelectrochemical cells (PECs) have been shown to be a promising system for H2 generation from photoelectrolysis of water. Among the semiconductors materials that have been studied for PECs, Sb2S3 stands out due to its superlative photoelectrocatalytic properties, and for having abundant and low toxicity elements. In the light of this, herein we proposed the synthesis and characterisation of the bare and modified Sb2S3 thin films for the hydrogen evolution reaction (HER) via photoelectrolysis of water. The modifications of this material consisted of obtaining the SnS/Sb2S3 heterostructure, treating the Sb2S3 films under nitrogen plasma, and depositing molybdenum sulphide (MoSx) upon the Sb2S3 films. Initially we studied the SnS/Sb2S3, the synthesis of this system involved obtaining the SbSn films by electrodeposition at different potentials on glass-coated FTO substrate. Subsequently, the films were sulphurised under sublimated sulphur atmosphere and characterised in terms of their physical, chemical, and optical properties. Regarding the photoelectrochemical assessment, we achieved a photocurrent density (jphoto) of −0.12 ± 0.01 mA cm−2 at −0.32 V for the sulphurised SnS/Sb2S3 films which were obtained at −1.14 V. This jphoto value was 40 and 12 times higher than the pure SnS and Sb2S3 films, respectively. Additional studies based on band diagrams of the SnS and Sb2S3 films indicated the formation of the type II heterostructure, which favoured transportation of the photogenerated electron and holes. Aiming to obtain higher values of jphoto, we evaluated the effect of treating the Sb2S3 films under nitrogen plasma at different span times. The Sb2S3 films treated under nitrogen plasma for only 10 s had a jphoto of −0.48 ± 0.04 mA cm−2 at −0.32 V; this corresponded to a 24-fold increase compared to the untreated film. This photoresponse enhancement may be linked to the increased degree of wettability as the contact angle measurements indicated a superhydrophobic behaviour for the untreated film and hydrophilic once treated. Based on the XPS analysis, we also found that the hydrophilicity behaviour is probably due to the formation of the S-N polar group on the surface of the Sb2S3 films. Intending to further improve the photoelectroactivity of the Sb2S3 films, we studied the effect of the presence of MoSx on the plasma-treated Sb2S3 films. The jphoto for the Sb2S3/MoSx film was −0.89 ± 0.16 mA cm−2 at −0.20 V and that corresponded to a 2.2-fold increase. The jphoto gain is due to the reduction of the Rct as observed from the impedance experiments. The presence of the MoSx also resulted in a shift of ca. 100 and 280 mV towards less negative values of the Eonset and the Efb, respectively. This suggested that the MoSx behaved as a cocatalyst for the HER. At last, we achieved an even more substantial jphoto of −2.15 mA cm−2 at −0.20 V for the Sb2S3/MoSx film having a delimited geometrical area by placing a teflon mask.
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spelling Araújo, Moisés Albuquerque deMascaro, Lucia Helenahttp://lattes.cnpq.br/9130022476352844http://lattes.cnpq.br/1921841936471127600665ed-b54b-42cb-ae49-780c5bf8d2402021-03-26T15:01:20Z2021-03-26T15:01:20Z2020-08-27ARAÚJO, Moisés Albuquerque de. Síntese, caracterização e avaliação da atividade fotoeletrocatalítica de filmes finos de Sb2S3. 2020. Tese (Doutorado em Química) – Universidade Federal de São Carlos, São Carlos, 2020. Disponível em: https://repositorio.ufscar.br/handle/ufscar/14033.https://repositorio.ufscar.br/handle/ufscar/14033Photoelectrochemical cells (PECs) have been shown to be a promising system for H2 generation from photoelectrolysis of water. Among the semiconductors materials that have been studied for PECs, Sb2S3 stands out due to its superlative photoelectrocatalytic properties, and for having abundant and low toxicity elements. In the light of this, herein we proposed the synthesis and characterisation of the bare and modified Sb2S3 thin films for the hydrogen evolution reaction (HER) via photoelectrolysis of water. The modifications of this material consisted of obtaining the SnS/Sb2S3 heterostructure, treating the Sb2S3 films under nitrogen plasma, and depositing molybdenum sulphide (MoSx) upon the Sb2S3 films. Initially we studied the SnS/Sb2S3, the synthesis of this system involved obtaining the SbSn films by electrodeposition at different potentials on glass-coated FTO substrate. Subsequently, the films were sulphurised under sublimated sulphur atmosphere and characterised in terms of their physical, chemical, and optical properties. Regarding the photoelectrochemical assessment, we achieved a photocurrent density (jphoto) of −0.12 ± 0.01 mA cm−2 at −0.32 V for the sulphurised SnS/Sb2S3 films which were obtained at −1.14 V. This jphoto value was 40 and 12 times higher than the pure SnS and Sb2S3 films, respectively. Additional studies based on band diagrams of the SnS and Sb2S3 films indicated the formation of the type II heterostructure, which favoured transportation of the photogenerated electron and holes. Aiming to obtain higher values of jphoto, we evaluated the effect of treating the Sb2S3 films under nitrogen plasma at different span times. The Sb2S3 films treated under nitrogen plasma for only 10 s had a jphoto of −0.48 ± 0.04 mA cm−2 at −0.32 V; this corresponded to a 24-fold increase compared to the untreated film. This photoresponse enhancement may be linked to the increased degree of wettability as the contact angle measurements indicated a superhydrophobic behaviour for the untreated film and hydrophilic once treated. Based on the XPS analysis, we also found that the hydrophilicity behaviour is probably due to the formation of the S-N polar group on the surface of the Sb2S3 films. Intending to further improve the photoelectroactivity of the Sb2S3 films, we studied the effect of the presence of MoSx on the plasma-treated Sb2S3 films. The jphoto for the Sb2S3/MoSx film was −0.89 ± 0.16 mA cm−2 at −0.20 V and that corresponded to a 2.2-fold increase. The jphoto gain is due to the reduction of the Rct as observed from the impedance experiments. The presence of the MoSx also resulted in a shift of ca. 100 and 280 mV towards less negative values of the Eonset and the Efb, respectively. This suggested that the MoSx behaved as a cocatalyst for the HER. At last, we achieved an even more substantial jphoto of −2.15 mA cm−2 at −0.20 V for the Sb2S3/MoSx film having a delimited geometrical area by placing a teflon mask.As células fotoeletroquímicas (CFEs) têm se mostrado como um sistema promissor para geração de H2 a partir da fotoeletrólise da água. Dentre os materiais semicondutores estudados para CFEs, o Sb2S3 se destaca por apresentar excelentes propriedades fotoeletrocatalíticas e conter elementos abundantes e de baixa toxicidade. Perante o exposto, este trabalho teve como objetivo a síntese e caracterização de filmes finos de Sb2S3 puros e modificados para a reação de desprendimento de hidrogênio (RDH) via fotoeletrólise da água. As modificações desse material consistiram na obtenção da heteroestrutura SnS/Sb2S3, tratamento dos filmes de Sb2S3 com plasma de nitrogênio e a deposição do sulfeto de molibdênio (MoSx) sobre os filmes de Sb2S3. Inicialmente foi estudado o SnS/Sb2S3, a síntese desse sistema consistiu em obter filmes de SbSn por eletrodeposição em diferentes potenciais sobre substrato de vidro contendo FTO. Posteriormente esses filmes foram sulfurizados em atmosfera de enxofre sublimado e caracterizados quanto às suas propriedades física, química e óptica. Sobre os ensaios fotoeletroquímicos, obteve-se uma densidade de fotocorrente (jfoto) de –0,12 ± 0,01 mA cm−2 em −0,32 V para os filmes sulfurizados de SnS/Sb2S3 obtidos em −1,14 V. Esse valor de jfoto foi 40 e 12 vezes superior em relação aos filmes puros de SnS e Sb2S3, respectivamente. Estudos adicionais baseados em diagramas de bandas dos filmes de SnS e Sb2S3 indicaram a formação de uma heteroestrutura do tipo II, o que favoreceu o transporte de elétrons e buracos fotogerados. Visando obter valores de jfoto maiores, avaliamos o efeito do tempo de tratamento dos filmes de Sb2S3 em plasma de nitrogênio. Os filmes de Sb2S3 tratados em plasma de nitrogênio por apenas 10 s apresentaram uma jfoto de −0,48 ± 0,04 mA cm−2 em −0,32 V, isso correspondeu um aumento de 24 vezes em relação ao filme não tratado. Essa melhora da fotoresposta pode estar relacionada com o aumento do grau de molhabilidade, pois medidas de ângulo de contato indicaram comportamento super-hidrofóbico para o filme não tratado e hidrofílico uma vez tratado. Com base nas análises de XPS, constatamos ainda que a hidrofilicidade se deve provavelmente à formação do grupamento polar S-N na superfície do filme de Sb2S3. Visando melhorar ainda mais a fotoeletroatividade do Sb2S3, estudamos o efeito da presença do MoSx sobre o filme de Sb2S3 tratado. O filme de Sb2S3/MoSx apresentou jfoto igual a −0,89 ± 0,16 mA cm−2 em −0,20 V, isso correspondeu um aumento de 2,2 vezes. Conforme observado nos ensaios de impedância, esse ganho de jfoto está relacionado com a diminuição da Rtc. A presença do MoSx resultou também no deslocamento do Eonset e Ebp em ca. 100 e 280 mV, respectivamente, para valores menos negativos, o que indicou comportamento cocatalítico desse material para a RDH. Por fim, obtivemos valor de jfoto ainda mais expressivo igual a −2,15 mA cm−2 em −0,20 V ao delimitar a área geométrica do filme de Sb2S3/MoSx com uma máscara de teflon.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP: 2016/12681-0porUniversidade Federal de São CarlosCâmpus São CarlosPrograma de Pós-Graduação em Química - PPGQUFSCarAttribution-NonCommercial-NoDerivs 3.0 Brazilhttp://creativecommons.org/licenses/by-nc-nd/3.0/br/info:eu-repo/semantics/openAccessSulfeto de antimônio(III)Modificações superficiaisCélulas fotoeletroquímicasFotoeletrólise da águaGás hidrogênioAntimony(III) sulphideSuperficial modificationsPhotoelectrochemical cellsPhotoelectrochemical water splittingHydrogen gasCIENCIAS EXATAS E DA TERRA::QUIMICA::FISICO-QUIMICA::ELETROQUIMICACIENCIAS EXATAS E DA TERRA::QUIMICA::FISICO-QUIMICASíntese, caracterização e avaliação da atividade fotoeletrocatalítica de filmes finos de Sb2S3Synthesis, characterisation, and assessment of the photoelectrocatalytic activity of the Sb2S3 thin filmsinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/doctoralThesis60060048af9879-81a8-4651-b821-5243ab976eb2reponame:Repositório Institucional da UFSCARinstname:Universidade Federal de São Carlos (UFSCAR)instacron:UFSCARORIGINAL2020_de ARAÚJO, M.A._Tese.pdf2020_de ARAÚJO, M.A._Tese.pdf2020_de ARAÚJO, M.A._Teseapplication/pdf3600144https://repositorio.ufscar.br/bitstream/ufscar/14033/6/2020_de%20ARA%c3%9aJO%2c%20M.A._Tese.pdf1a75cdbbb25563a4d2d2eda35fdcbdf4MD56Carta comprovante_Orientadora.pdfCarta comprovante_Orientadora.pdfCarta Comprovante_Orientadoraapplication/pdf368763https://repositorio.ufscar.br/bitstream/ufscar/14033/7/Carta%20comprovante_Orientadora.pdf2d61541c08cb0326662abf0e78e4c29bMD57CC-LICENSElicense_rdflicense_rdfapplication/rdf+xml; charset=utf-8811https://repositorio.ufscar.br/bitstream/ufscar/14033/8/license_rdfe39d27027a6cc9cb039ad269a5db8e34MD58TEXT2020_de ARAÚJO, M.A._Tese.pdf.txt2020_de ARAÚJO, M.A._Tese.pdf.txtExtracted texttext/plain245499https://repositorio.ufscar.br/bitstream/ufscar/14033/9/2020_de%20ARA%c3%9aJO%2c%20M.A._Tese.pdf.txt0ed945517bd772097f550a23cbee3396MD59Carta comprovante_Orientadora.pdf.txtCarta comprovante_Orientadora.pdf.txtExtracted texttext/plain1393https://repositorio.ufscar.br/bitstream/ufscar/14033/11/Carta%20comprovante_Orientadora.pdf.txte9d001e5ed142356c88539c25977149bMD511THUMBNAIL2020_de ARAÚJO, M.A._Tese.pdf.jpg2020_de ARAÚJO, M.A._Tese.pdf.jpgIM Thumbnailimage/jpeg9065https://repositorio.ufscar.br/bitstream/ufscar/14033/10/2020_de%20ARA%c3%9aJO%2c%20M.A._Tese.pdf.jpg8096305a86739d40a4ef14faa6356471MD510Carta comprovante_Orientadora.pdf.jpgCarta comprovante_Orientadora.pdf.jpgIM Thumbnailimage/jpeg12258https://repositorio.ufscar.br/bitstream/ufscar/14033/12/Carta%20comprovante_Orientadora.pdf.jpg67274ee067a910f4a77ce836a4136562MD512ufscar/140332023-09-18 18:32:08.48oai:repositorio.ufscar.br:ufscar/14033Repositório InstitucionalPUBhttps://repositorio.ufscar.br/oai/requestopendoar:43222023-09-18T18:32:08Repositório Institucional da UFSCAR - Universidade Federal de São Carlos (UFSCAR)false
dc.title.por.fl_str_mv Síntese, caracterização e avaliação da atividade fotoeletrocatalítica de filmes finos de Sb2S3
dc.title.alternative.eng.fl_str_mv Synthesis, characterisation, and assessment of the photoelectrocatalytic activity of the Sb2S3 thin films
title Síntese, caracterização e avaliação da atividade fotoeletrocatalítica de filmes finos de Sb2S3
spellingShingle Síntese, caracterização e avaliação da atividade fotoeletrocatalítica de filmes finos de Sb2S3
Araújo, Moisés Albuquerque de
Sulfeto de antimônio(III)
Modificações superficiais
Células fotoeletroquímicas
Fotoeletrólise da água
Gás hidrogênio
Antimony(III) sulphide
Superficial modifications
Photoelectrochemical cells
Photoelectrochemical water splitting
Hydrogen gas
CIENCIAS EXATAS E DA TERRA::QUIMICA::FISICO-QUIMICA::ELETROQUIMICA
CIENCIAS EXATAS E DA TERRA::QUIMICA::FISICO-QUIMICA
title_short Síntese, caracterização e avaliação da atividade fotoeletrocatalítica de filmes finos de Sb2S3
title_full Síntese, caracterização e avaliação da atividade fotoeletrocatalítica de filmes finos de Sb2S3
title_fullStr Síntese, caracterização e avaliação da atividade fotoeletrocatalítica de filmes finos de Sb2S3
title_full_unstemmed Síntese, caracterização e avaliação da atividade fotoeletrocatalítica de filmes finos de Sb2S3
title_sort Síntese, caracterização e avaliação da atividade fotoeletrocatalítica de filmes finos de Sb2S3
author Araújo, Moisés Albuquerque de
author_facet Araújo, Moisés Albuquerque de
author_role author
dc.contributor.authorlattes.por.fl_str_mv http://lattes.cnpq.br/1921841936471127
dc.contributor.author.fl_str_mv Araújo, Moisés Albuquerque de
dc.contributor.advisor1.fl_str_mv Mascaro, Lucia Helena
dc.contributor.advisor1Lattes.fl_str_mv http://lattes.cnpq.br/9130022476352844
dc.contributor.authorID.fl_str_mv 600665ed-b54b-42cb-ae49-780c5bf8d240
contributor_str_mv Mascaro, Lucia Helena
dc.subject.por.fl_str_mv Sulfeto de antimônio(III)
Modificações superficiais
Células fotoeletroquímicas
Fotoeletrólise da água
Gás hidrogênio
topic Sulfeto de antimônio(III)
Modificações superficiais
Células fotoeletroquímicas
Fotoeletrólise da água
Gás hidrogênio
Antimony(III) sulphide
Superficial modifications
Photoelectrochemical cells
Photoelectrochemical water splitting
Hydrogen gas
CIENCIAS EXATAS E DA TERRA::QUIMICA::FISICO-QUIMICA::ELETROQUIMICA
CIENCIAS EXATAS E DA TERRA::QUIMICA::FISICO-QUIMICA
dc.subject.eng.fl_str_mv Antimony(III) sulphide
Superficial modifications
Photoelectrochemical cells
Photoelectrochemical water splitting
Hydrogen gas
dc.subject.cnpq.fl_str_mv CIENCIAS EXATAS E DA TERRA::QUIMICA::FISICO-QUIMICA::ELETROQUIMICA
CIENCIAS EXATAS E DA TERRA::QUIMICA::FISICO-QUIMICA
description Photoelectrochemical cells (PECs) have been shown to be a promising system for H2 generation from photoelectrolysis of water. Among the semiconductors materials that have been studied for PECs, Sb2S3 stands out due to its superlative photoelectrocatalytic properties, and for having abundant and low toxicity elements. In the light of this, herein we proposed the synthesis and characterisation of the bare and modified Sb2S3 thin films for the hydrogen evolution reaction (HER) via photoelectrolysis of water. The modifications of this material consisted of obtaining the SnS/Sb2S3 heterostructure, treating the Sb2S3 films under nitrogen plasma, and depositing molybdenum sulphide (MoSx) upon the Sb2S3 films. Initially we studied the SnS/Sb2S3, the synthesis of this system involved obtaining the SbSn films by electrodeposition at different potentials on glass-coated FTO substrate. Subsequently, the films were sulphurised under sublimated sulphur atmosphere and characterised in terms of their physical, chemical, and optical properties. Regarding the photoelectrochemical assessment, we achieved a photocurrent density (jphoto) of −0.12 ± 0.01 mA cm−2 at −0.32 V for the sulphurised SnS/Sb2S3 films which were obtained at −1.14 V. This jphoto value was 40 and 12 times higher than the pure SnS and Sb2S3 films, respectively. Additional studies based on band diagrams of the SnS and Sb2S3 films indicated the formation of the type II heterostructure, which favoured transportation of the photogenerated electron and holes. Aiming to obtain higher values of jphoto, we evaluated the effect of treating the Sb2S3 films under nitrogen plasma at different span times. The Sb2S3 films treated under nitrogen plasma for only 10 s had a jphoto of −0.48 ± 0.04 mA cm−2 at −0.32 V; this corresponded to a 24-fold increase compared to the untreated film. This photoresponse enhancement may be linked to the increased degree of wettability as the contact angle measurements indicated a superhydrophobic behaviour for the untreated film and hydrophilic once treated. Based on the XPS analysis, we also found that the hydrophilicity behaviour is probably due to the formation of the S-N polar group on the surface of the Sb2S3 films. Intending to further improve the photoelectroactivity of the Sb2S3 films, we studied the effect of the presence of MoSx on the plasma-treated Sb2S3 films. The jphoto for the Sb2S3/MoSx film was −0.89 ± 0.16 mA cm−2 at −0.20 V and that corresponded to a 2.2-fold increase. The jphoto gain is due to the reduction of the Rct as observed from the impedance experiments. The presence of the MoSx also resulted in a shift of ca. 100 and 280 mV towards less negative values of the Eonset and the Efb, respectively. This suggested that the MoSx behaved as a cocatalyst for the HER. At last, we achieved an even more substantial jphoto of −2.15 mA cm−2 at −0.20 V for the Sb2S3/MoSx film having a delimited geometrical area by placing a teflon mask.
publishDate 2020
dc.date.issued.fl_str_mv 2020-08-27
dc.date.accessioned.fl_str_mv 2021-03-26T15:01:20Z
dc.date.available.fl_str_mv 2021-03-26T15:01:20Z
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dc.identifier.citation.fl_str_mv ARAÚJO, Moisés Albuquerque de. Síntese, caracterização e avaliação da atividade fotoeletrocatalítica de filmes finos de Sb2S3. 2020. Tese (Doutorado em Química) – Universidade Federal de São Carlos, São Carlos, 2020. Disponível em: https://repositorio.ufscar.br/handle/ufscar/14033.
dc.identifier.uri.fl_str_mv https://repositorio.ufscar.br/handle/ufscar/14033
identifier_str_mv ARAÚJO, Moisés Albuquerque de. Síntese, caracterização e avaliação da atividade fotoeletrocatalítica de filmes finos de Sb2S3. 2020. Tese (Doutorado em Química) – Universidade Federal de São Carlos, São Carlos, 2020. Disponível em: https://repositorio.ufscar.br/handle/ufscar/14033.
url https://repositorio.ufscar.br/handle/ufscar/14033
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http://creativecommons.org/licenses/by-nc-nd/3.0/br/
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rights_invalid_str_mv Attribution-NonCommercial-NoDerivs 3.0 Brazil
http://creativecommons.org/licenses/by-nc-nd/3.0/br/
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dc.publisher.none.fl_str_mv Universidade Federal de São Carlos
Câmpus São Carlos
dc.publisher.program.fl_str_mv Programa de Pós-Graduação em Química - PPGQ
dc.publisher.initials.fl_str_mv UFSCar
publisher.none.fl_str_mv Universidade Federal de São Carlos
Câmpus São Carlos
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