Estudo da eletrodeposição da liga Fe-Mo a partir de soluções levemente alcalinas contendo NTA - Nitrilo Acetato de Sódio
Autor(a) principal: | |
---|---|
Data de Publicação: | 2012 |
Tipo de documento: | Dissertação |
Idioma: | por |
Título da fonte: | Repositório Institucional da UFSCAR |
Texto Completo: | https://repositorio.ufscar.br/handle/ufscar/6535 |
Resumo: | Fe-Mo alloys were electrochemically deposited on to a Pt substrate, from an alkaline solution containing FeCl3, Na2MoO4, trisodium nitrilotriacetic (NTA), in which Fe3+ ions were ddissolved to form [Fe(OH)(NTA)]-, [Fe(OH)2(NTA)]2- and [Fe(NTA)2]3- or [Fe2O(NTA)2]2- complexes, for NTA 0.110 mol L-1 or 0.055 mol L-1 in solution respectively. Voltammetric studies of Pt in the solution containing Fe and Mo salts and 0.110 mol L-1 NTA, led to suggest that [Fe(NTA)2]3- complex reduced to [Fe(NTA)2]4- and [Fe(OH)(NTA)]1- to [FeOH(NTA)]2- In addition it was proposed that the codeposition of Fe-Mo takes play only for more negative potentials than ~ -0,92V, im parallel to the hydrogen evolution reaction HER. However, in the presence of 0,055 mol L-1 NTA, only a cathodic peak c´ was seen, which corresponds to reduction of [Fe(OH)(NTA)]1- a [Fe(OH)(NTA)]2-. Also, it was proposed that only beyond this peak Fe and Mo codeposited in parallel to HER. However, only a cathodic peak was seen for the system Pt/Fe(III), Mo(IV), NTA 0.055 mol L-1 that corresponds to the reduction of [Fe(OH)(NTA)]- to [Fe(OH)(NTA)]2- and only beyond ~ -0,88 V, Fe and Mo codeposit simultaneously to HER. Voltammetric deposition of Fe and Mo at various rotating speeds of the Pt disk electrode showed that the reduction process was controlled by mass transport. Fe- Mo deposition potential (Ed) was varied and the morphology, chemical composition and phase composition of deposits were investigated. Scanning electron microscope (SEM) images of Fe-Mo deposits obtained at - Ed = - 2.10 V e -2.70 V, with Qd = 95.55 C cm-2 and both NTA concentrations, showed that, they were uniform and formed by coalesced globular crystallites. Moreover, for Ed = -2.10 V the globular crystallites were more refined. Also, for the latter with xii ABSTRACT NTA 0.110 mol L-1, the deposit was thinner that the other, due to more intense HER in this case. Energy dispersive spectroscopy (EDS) analysis of Fe-Mo deposit produced in the presence of NTA 0.110 mol L-1, with Qd = 95.55 C cm-2, showed that only in a more negative Ed than -1.30 V Fe and Mo codeposited. Nevertheless, in the presence of NTA 0.055 mol L-1, Fe and Mo codeposition occurred at Ed, more negative than -2.0 V. Furthermore, the presence of NTA 0.110 mol L-1, the codeposition occurs at Ed, more negative than -1.20 V. Thus, these results indicate that fe and Mo codeposition was inhibited in the presence of NTA 0.055 mol L-1, due to the presence of the ([Fe2O(NTA)2]2- complex in the bath. Oxygen incorporation in the electrodeposits occurred for both NTA concentrations, irrespective of the Ed, due to metallic hydroxide precipitation. X-ray diffraction spectroscopy (DRX) analyses of the Fe-Mo deposits produced at various Ed and with Qd = 95.55 C cm-2, irrespective of NTA concentrations, showed, in general, that they were formed of a phase mixture. Also, the deposit diffractograms obtained in the presence of NTA 0.055 mol L-1 showed broad diffraction peaks, which are characteristics of low crystalline structures. The presence of different phases, at each Ed, for both NTA concentrations, indicated that the nucleation process was dissimilar. |
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Barbano, Elton PatrickCarlos, Ivani Aparecidahttp://genos.cnpq.br:12010/dwlattes/owa/prc_imp_cv_int?f_cod=K4780131E6http://lattes.cnpq.br/38233419670731769a58c1d5-34e2-4ea4-84f5-b276c7431d112016-06-02T20:36:40Z2012-09-252016-06-02T20:36:40Z2012-02-29BARBANO, Elton Patrick. Estudo da eletrodeposição da liga Fe-Mo a partir de soluções levemente alcalinas contendo NTA - Nitrilo Acetato de Sódio. 2012. Dissertação (Mestrado em Química) – Universidade Federal de São Carlos, São Carlos, 2012. Disponível em: https://repositorio.ufscar.br/handle/ufscar/6535.https://repositorio.ufscar.br/handle/ufscar/6535Fe-Mo alloys were electrochemically deposited on to a Pt substrate, from an alkaline solution containing FeCl3, Na2MoO4, trisodium nitrilotriacetic (NTA), in which Fe3+ ions were ddissolved to form [Fe(OH)(NTA)]-, [Fe(OH)2(NTA)]2- and [Fe(NTA)2]3- or [Fe2O(NTA)2]2- complexes, for NTA 0.110 mol L-1 or 0.055 mol L-1 in solution respectively. Voltammetric studies of Pt in the solution containing Fe and Mo salts and 0.110 mol L-1 NTA, led to suggest that [Fe(NTA)2]3- complex reduced to [Fe(NTA)2]4- and [Fe(OH)(NTA)]1- to [FeOH(NTA)]2- In addition it was proposed that the codeposition of Fe-Mo takes play only for more negative potentials than ~ -0,92V, im parallel to the hydrogen evolution reaction HER. However, in the presence of 0,055 mol L-1 NTA, only a cathodic peak c´ was seen, which corresponds to reduction of [Fe(OH)(NTA)]1- a [Fe(OH)(NTA)]2-. Also, it was proposed that only beyond this peak Fe and Mo codeposited in parallel to HER. However, only a cathodic peak was seen for the system Pt/Fe(III), Mo(IV), NTA 0.055 mol L-1 that corresponds to the reduction of [Fe(OH)(NTA)]- to [Fe(OH)(NTA)]2- and only beyond ~ -0,88 V, Fe and Mo codeposit simultaneously to HER. Voltammetric deposition of Fe and Mo at various rotating speeds of the Pt disk electrode showed that the reduction process was controlled by mass transport. Fe- Mo deposition potential (Ed) was varied and the morphology, chemical composition and phase composition of deposits were investigated. Scanning electron microscope (SEM) images of Fe-Mo deposits obtained at - Ed = - 2.10 V e -2.70 V, with Qd = 95.55 C cm-2 and both NTA concentrations, showed that, they were uniform and formed by coalesced globular crystallites. Moreover, for Ed = -2.10 V the globular crystallites were more refined. Also, for the latter with xii ABSTRACT NTA 0.110 mol L-1, the deposit was thinner that the other, due to more intense HER in this case. Energy dispersive spectroscopy (EDS) analysis of Fe-Mo deposit produced in the presence of NTA 0.110 mol L-1, with Qd = 95.55 C cm-2, showed that only in a more negative Ed than -1.30 V Fe and Mo codeposited. Nevertheless, in the presence of NTA 0.055 mol L-1, Fe and Mo codeposition occurred at Ed, more negative than -2.0 V. Furthermore, the presence of NTA 0.110 mol L-1, the codeposition occurs at Ed, more negative than -1.20 V. Thus, these results indicate that fe and Mo codeposition was inhibited in the presence of NTA 0.055 mol L-1, due to the presence of the ([Fe2O(NTA)2]2- complex in the bath. Oxygen incorporation in the electrodeposits occurred for both NTA concentrations, irrespective of the Ed, due to metallic hydroxide precipitation. X-ray diffraction spectroscopy (DRX) analyses of the Fe-Mo deposits produced at various Ed and with Qd = 95.55 C cm-2, irrespective of NTA concentrations, showed, in general, that they were formed of a phase mixture. Also, the deposit diffractograms obtained in the presence of NTA 0.055 mol L-1 showed broad diffraction peaks, which are characteristics of low crystalline structures. The presence of different phases, at each Ed, for both NTA concentrations, indicated that the nucleation process was dissimilar.Ligas de Fe-Mo foram eletroquimicamente depositadas sobre substrato de Pt a partir de uma solução levemente alcalina (pH = 8,0) contendo FeCl3, Na2MoO4 e nitrilotriacetato de sódio (NTA). Os ions Fe3+ foram dissolvidos para formar os complexos [Fe(OH)(NTA)]-, [Fe(OH)2(NTA)]2-, [Fe(NTA)2]3- ou [Fe2O(NTA)2]2- para 0,110 mol L-1 e 0,055 mol L-1 de NTA em solução, respectivamente. Estudos voltamétricos das soluções para o sistema Pt/Fe(III), Mo(IV), NTA 0,110 mol L-1, sobre substrato de Pt, levaram a sugerir que o complexo [Fe(NTA)2]3- reduziu-se a [Fe(NTA)2]4-, e o [Fe(OH)(NTA)]1- a [FeOH(NTA)]2-. Também, foi proposto que codeposição de Fe-Mo ocorre somente para potenciais mais negativos que ~ -0,92 V, paralelamente à reação de desprendimento de hidrogênio (RDH). No entanto, para o sistema Pt/Fe(III), Mo(IV), NTA 0,055 mol L-1 apenas um pico catódico foi visto, correspondendo à redução de [Fe(OH)(NTA)]1- a [Fe(OH)(NTA)]2- e, somente além de ~ 0,88 V, Fe e Mo codepositam paralelamente a RDH. Deposição voltamétrica de Fe-Mo a diferentes velocidades de rotação (ω) do eletrodo de disco rotatório (EDR) mostrou que o processo de redução é controlado por transporte de massa. O potencial de deposição (Ed) de Fe-Mo foi variado e a morfologia, a composição química, e a composição de fase dos depósitos foram investigadas. Microscopia eletrônica de varredura (MEV) dos eletrodepósitos de Fe-Mo obtidos nos Ed de -2,10 V e de -2.70 V, com Qd = 95,55 C cm-2 e ambas concentrações de NTA, mostrou que os eleterodepósitos foram uniformes e formados por cristalitos globulares coalescidos, sendo que para Ed de -2,70 V os cristalitos globulares foram mais refinados. Também, para este Ed e 0,110 mol L-1 NTA, o depósito foi mais liso devido à intensa RDH neste caso. Análise por espectroscopia de dispersão de x LISTA DE FIGURAS raios X (EDX) dos eletrodepósitos de Fe-Mo obtidos na presença de NTA 0,110 mol L-1, com Qd = 95,55 C cm-2, mostrou que apenas para Ed mais negativos que - 1,30 V Fe e Mo codepositam. No entanto, na presença de NTA 0,055 mol L-1, codeposição de Fe e Mo ocorreu a Ed mais negativos que -2,00 V, sendo que na presença de NTA 0,110 mol L-1, codeposição já ocorre em Ed mais negativos que - 1,20 V. Então, estes resultados indicam que a codeposição de Fe e Mo foi inibida na presença de NTA 0,055 mol L-1, devido a presença do complexo [Fe2O(NTA)2]2- no banho. Incorporacão de oxigênio nos eletrodepósitos ocorreu para ambas às concentrações de NTA, independentemente do Ed, devido à precipitação de hidróxidos metálicos. Análise por espectroscopia de difração de raios X (DRX) dos eletrodepósitos de Fe-Mo obtidos em diferentes Ed e Qd = 95,55 C cm-2, independentemente da concentração de NTA, mostrou, de modo geral, que eles são formados de uma mistura de fases. Também, os difratogramas dos eletrodepósitos obtidos na presença de NTA 0,055 mol L-1, apresentaram picos de difração alargados, os quais são característicos de estrutura de baixa cristalinidade. A presença de diferentes fases, para cada Ed, para ambas as concentrações de NTA, indicou que o processo de nucleação não foi similar.Universidade Federal de Minas Geraisapplication/pdfporUniversidade Federal de São CarlosCâmpus São CarlosPrograma de Pós-Graduação em Química - PPGQUFSCarBREletrodeposiçãoQuímica de superfícieQuímica analíticaCIENCIAS EXATAS E DA TERRA::QUIMICAEstudo da eletrodeposição da liga Fe-Mo a partir de soluções levemente alcalinas contendo NTA - Nitrilo Acetato de SódioStudy of electrodeposition of Fe-Mo alloy from slightly alkaline solutions containing NTA - Nitrile Sodium Acetateinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesis-1-16ab22b71-dd06-4945-bc9e-1a23f05da42einfo:eu-repo/semantics/embargoedAccessreponame:Repositório Institucional da UFSCARinstname:Universidade Federal de São Carlos (UFSCAR)instacron:UFSCARORIGINALDissEPB.pdfDissEPB.pdfapplication/pdf2853969https://repositorio.ufscar.br/bitstream/ufscar/6535/1/DissEPB.pdf24476c22c7d203bd7003f48e29522b6fMD51TEXTDissEPB.pdf.txtDissEPB.pdf.txtExtracted texttext/plain127153https://repositorio.ufscar.br/bitstream/ufscar/6535/2/DissEPB.pdf.txt570b057c44218c213a5bb8d430ed4654MD52THUMBNAILDissEPB.pdf.jpgDissEPB.pdf.jpgIM Thumbnailimage/jpeg10271https://repositorio.ufscar.br/bitstream/ufscar/6535/3/DissEPB.pdf.jpg4787aeee31786c736e7858c01c92be0eMD53ufscar/65352023-09-18 18:32:40.163oai:repositorio.ufscar.br:ufscar/6535Repositório InstitucionalPUBhttps://repositorio.ufscar.br/oai/requestopendoar:43222023-09-18T18:32:40Repositório Institucional da UFSCAR - Universidade Federal de São Carlos (UFSCAR)false |
dc.title.por.fl_str_mv |
Estudo da eletrodeposição da liga Fe-Mo a partir de soluções levemente alcalinas contendo NTA - Nitrilo Acetato de Sódio |
dc.title.alternative.eng.fl_str_mv |
Study of electrodeposition of Fe-Mo alloy from slightly alkaline solutions containing NTA - Nitrile Sodium Acetate |
title |
Estudo da eletrodeposição da liga Fe-Mo a partir de soluções levemente alcalinas contendo NTA - Nitrilo Acetato de Sódio |
spellingShingle |
Estudo da eletrodeposição da liga Fe-Mo a partir de soluções levemente alcalinas contendo NTA - Nitrilo Acetato de Sódio Barbano, Elton Patrick Eletrodeposição Química de superfície Química analítica CIENCIAS EXATAS E DA TERRA::QUIMICA |
title_short |
Estudo da eletrodeposição da liga Fe-Mo a partir de soluções levemente alcalinas contendo NTA - Nitrilo Acetato de Sódio |
title_full |
Estudo da eletrodeposição da liga Fe-Mo a partir de soluções levemente alcalinas contendo NTA - Nitrilo Acetato de Sódio |
title_fullStr |
Estudo da eletrodeposição da liga Fe-Mo a partir de soluções levemente alcalinas contendo NTA - Nitrilo Acetato de Sódio |
title_full_unstemmed |
Estudo da eletrodeposição da liga Fe-Mo a partir de soluções levemente alcalinas contendo NTA - Nitrilo Acetato de Sódio |
title_sort |
Estudo da eletrodeposição da liga Fe-Mo a partir de soluções levemente alcalinas contendo NTA - Nitrilo Acetato de Sódio |
author |
Barbano, Elton Patrick |
author_facet |
Barbano, Elton Patrick |
author_role |
author |
dc.contributor.authorlattes.por.fl_str_mv |
http://lattes.cnpq.br/3823341967073176 |
dc.contributor.author.fl_str_mv |
Barbano, Elton Patrick |
dc.contributor.advisor1.fl_str_mv |
Carlos, Ivani Aparecida |
dc.contributor.advisor1Lattes.fl_str_mv |
http://genos.cnpq.br:12010/dwlattes/owa/prc_imp_cv_int?f_cod=K4780131E6 |
dc.contributor.authorID.fl_str_mv |
9a58c1d5-34e2-4ea4-84f5-b276c7431d11 |
contributor_str_mv |
Carlos, Ivani Aparecida |
dc.subject.por.fl_str_mv |
Eletrodeposição Química de superfície Química analítica |
topic |
Eletrodeposição Química de superfície Química analítica CIENCIAS EXATAS E DA TERRA::QUIMICA |
dc.subject.cnpq.fl_str_mv |
CIENCIAS EXATAS E DA TERRA::QUIMICA |
description |
Fe-Mo alloys were electrochemically deposited on to a Pt substrate, from an alkaline solution containing FeCl3, Na2MoO4, trisodium nitrilotriacetic (NTA), in which Fe3+ ions were ddissolved to form [Fe(OH)(NTA)]-, [Fe(OH)2(NTA)]2- and [Fe(NTA)2]3- or [Fe2O(NTA)2]2- complexes, for NTA 0.110 mol L-1 or 0.055 mol L-1 in solution respectively. Voltammetric studies of Pt in the solution containing Fe and Mo salts and 0.110 mol L-1 NTA, led to suggest that [Fe(NTA)2]3- complex reduced to [Fe(NTA)2]4- and [Fe(OH)(NTA)]1- to [FeOH(NTA)]2- In addition it was proposed that the codeposition of Fe-Mo takes play only for more negative potentials than ~ -0,92V, im parallel to the hydrogen evolution reaction HER. However, in the presence of 0,055 mol L-1 NTA, only a cathodic peak c´ was seen, which corresponds to reduction of [Fe(OH)(NTA)]1- a [Fe(OH)(NTA)]2-. Also, it was proposed that only beyond this peak Fe and Mo codeposited in parallel to HER. However, only a cathodic peak was seen for the system Pt/Fe(III), Mo(IV), NTA 0.055 mol L-1 that corresponds to the reduction of [Fe(OH)(NTA)]- to [Fe(OH)(NTA)]2- and only beyond ~ -0,88 V, Fe and Mo codeposit simultaneously to HER. Voltammetric deposition of Fe and Mo at various rotating speeds of the Pt disk electrode showed that the reduction process was controlled by mass transport. Fe- Mo deposition potential (Ed) was varied and the morphology, chemical composition and phase composition of deposits were investigated. Scanning electron microscope (SEM) images of Fe-Mo deposits obtained at - Ed = - 2.10 V e -2.70 V, with Qd = 95.55 C cm-2 and both NTA concentrations, showed that, they were uniform and formed by coalesced globular crystallites. Moreover, for Ed = -2.10 V the globular crystallites were more refined. Also, for the latter with xii ABSTRACT NTA 0.110 mol L-1, the deposit was thinner that the other, due to more intense HER in this case. Energy dispersive spectroscopy (EDS) analysis of Fe-Mo deposit produced in the presence of NTA 0.110 mol L-1, with Qd = 95.55 C cm-2, showed that only in a more negative Ed than -1.30 V Fe and Mo codeposited. Nevertheless, in the presence of NTA 0.055 mol L-1, Fe and Mo codeposition occurred at Ed, more negative than -2.0 V. Furthermore, the presence of NTA 0.110 mol L-1, the codeposition occurs at Ed, more negative than -1.20 V. Thus, these results indicate that fe and Mo codeposition was inhibited in the presence of NTA 0.055 mol L-1, due to the presence of the ([Fe2O(NTA)2]2- complex in the bath. Oxygen incorporation in the electrodeposits occurred for both NTA concentrations, irrespective of the Ed, due to metallic hydroxide precipitation. X-ray diffraction spectroscopy (DRX) analyses of the Fe-Mo deposits produced at various Ed and with Qd = 95.55 C cm-2, irrespective of NTA concentrations, showed, in general, that they were formed of a phase mixture. Also, the deposit diffractograms obtained in the presence of NTA 0.055 mol L-1 showed broad diffraction peaks, which are characteristics of low crystalline structures. The presence of different phases, at each Ed, for both NTA concentrations, indicated that the nucleation process was dissimilar. |
publishDate |
2012 |
dc.date.available.fl_str_mv |
2012-09-25 2016-06-02T20:36:40Z |
dc.date.issued.fl_str_mv |
2012-02-29 |
dc.date.accessioned.fl_str_mv |
2016-06-02T20:36:40Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/masterThesis |
format |
masterThesis |
status_str |
publishedVersion |
dc.identifier.citation.fl_str_mv |
BARBANO, Elton Patrick. Estudo da eletrodeposição da liga Fe-Mo a partir de soluções levemente alcalinas contendo NTA - Nitrilo Acetato de Sódio. 2012. Dissertação (Mestrado em Química) – Universidade Federal de São Carlos, São Carlos, 2012. Disponível em: https://repositorio.ufscar.br/handle/ufscar/6535. |
dc.identifier.uri.fl_str_mv |
https://repositorio.ufscar.br/handle/ufscar/6535 |
identifier_str_mv |
BARBANO, Elton Patrick. Estudo da eletrodeposição da liga Fe-Mo a partir de soluções levemente alcalinas contendo NTA - Nitrilo Acetato de Sódio. 2012. Dissertação (Mestrado em Química) – Universidade Federal de São Carlos, São Carlos, 2012. Disponível em: https://repositorio.ufscar.br/handle/ufscar/6535. |
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https://repositorio.ufscar.br/handle/ufscar/6535 |
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Universidade Federal de São Carlos Câmpus São Carlos |
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Programa de Pós-Graduação em Química - PPGQ |
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Universidade Federal de São Carlos Câmpus São Carlos |
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