Estudo sistemático de nanopartículas de óxido de cobalto através da espectroscopia Raman
Raman spectroscopy applied to the nanostructured metal oxides is quite efficient, since the active Raman modes evidenced in the spectra of these materials are directly related to the symmetry of their crystalline structure, which provides accurate information of the solids. However, in the literatur...
| Autor principal: | VIEIRA, Emerson Patrick dos Santos |
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| Grau: | Trabalho de Conclusão de Curso - Graduação |
| Idioma: | por |
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2019
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https://bdm.ufpa.br/jspui/handle/prefix/2531 |
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oai:https:--bdm.ufpa.br:8443:prefix-25312021-07-29T18:49:00Z Estudo sistemático de nanopartículas de óxido de cobalto através da espectroscopia Raman VIEIRA, Emerson Patrick dos Santos COSTA, Cleidilane Sena http://lattes.cnpq.br/4274598374126989 PASCA, Gabriel Adolfo Cabrera http://lattes.cnpq.br/5642784995274060 Espectroscopia de Raman Óxido de cobalto Nanopartículas Raman spectroscopy Cobalt oxides Nanoparticles CNPQ::CIENCIAS EXATAS E DA TERRA::FISICA Raman spectroscopy applied to the nanostructured metal oxides is quite efficient, since the active Raman modes evidenced in the spectra of these materials are directly related to the symmetry of their crystalline structure, which provides accurate information of the solids. However, in the literature there is a divergence on the positions of the peaks of the Raman spectrum referring to the phases: CoO-fcc, CoO-hcp and Co3O4. Thus, this study presents the characterization and analysis of the Raman spectra of cobalt oxide nanoparticles synthesized using the thermal decomposition method used oleylamine, bacaba oil and oleic acid in different proportions. In addition, a bulk sample of Co3O4, synthesized by the sol-gel method, was characterized as reference. Measurements Raman spectrums were performed at room temperature using the Jobin Yvon T64000 Raman spectrometer, laser power of 1.2 to 12 mW and objective lens of 20 mm. The bands were adjusted by the addition and peak decomposition method in Lorentzian functions and the displacement and the symmetry of the spectra were evaluated in relation to the Co3O4 sample. With the results, it was verified that the bulk sample had 5 Bands corresponding to the vibrational modes Eg, A1g and 3F2g predicted theoretically for Co3O4, also presented a Band indicated as contribution of CoO-fcc in the bulk scale. With this, samples synthesized with 10% with 10 washes and 5% of bacaba oil have bands at positions close to Co3O4. However, samples with 10% bacaba oil with 5 washes showed the contribution of the CoOOH and CoO-fcc phases. The samples with 10, 4 and 1% of oleic acid presented the spectrum profile similar to Co3O4, however, the Raman detachment of the Bands occurs according to the concentration of oleic acid in the solution, where two hypotheses were suggested for this effect. Moreover, the sample with 4% presented the contribution of CoO-fcc. For samples with 100% oleylamine, their bands presented values close to those of Co3O4. However, it was verified for Band 5 of higher intensity (active mode A1g) that a Lorentzian function did not compensate the experimental data. Band 5 was decomposed into three lorentzianas where the contribution of the CoO-fcc and CoO-hcp phases in their formation was confirmed. Therefore, Raman spectroscopy can evaluate the influence of the different methods used in the synthesis of bulk material and nanostructured oxides. A espectroscopia Raman aplicada aos óxidos metálicos nanoestruturados é bastante eficiente, visto que, os modos Raman ativos evidenciados nos espectros destes materiais são diretamente relacionados com à simetria da estrutura cristalina deles, o que fornece informações precisas dos sólidos. No entanto, na literatura há uma divergência sobre as posições das Bandas dos espectros Raman referentes as fases: CoO-fcc, CoO-hcp e o Co3O4. Assim, este estudo apresenta a caracterização e análise dos espectros Raman de nanopartículas de óxido de cobalto sintetizadas através do método de decomposição térmica utilizado oleilamina, óleo de bacaba e ácido oleico em diferentes proporções. Além disso, caracterizou-se uma amostra bulk de Co3O4, sintetizada pelo método de sol-gel, como referência. Realizou-se medidas dos espectros Raman, em temperatura ambiente, com o espectrômetro Raman modelo T64000 da Jobin Yvon, laser na potência de 1.2 a 12 mW e lente objetiva de 20 mm. Efetuou-se ajustes nas Bandas através do método de soma e decomposição de picos em funções lorentzianas e avaliou-se o deslocamento Raman e a simetria dos espectros em relação a amostra de Co3O4. Com os resultados, constatou-se que a amostra bulk teve 5 Bandas correspondem aos modos vibracionais Eg, A1g e 3F2g prevista teoricamente para o Co3O4, apresentou também uma Banda indicada como contribuição do CoO-fcc na escala bulk. Com isto, amostras sintetizadas com 10% com 10 lavagens e 5% de óleo de bacaba possuem bandas nas posições próximas ao Co3O4. No entanto, amostras com 10% de óleo de bacaba e 5 lavagens apresentou a contribuição das fases CoOOH e CoO-fcc. As amostras com 10, 4 e 1% de ácido oleico apresentaram o perfil do espectro semelhante ao Co3O4, contudo, o descolamento Raman das Bandas ocorre conforme a concentração de ácido oleico na solução, onde duas hipóteses foram sugeridas para este efeito. Além do mais, a amostra com 4% apresentou a contribuição do CoO-fcc. Para as amostras com 100% oleilamina, suas bandas apresentaram valores próximos as do Co3O4. Porém, foi verificada para a Banda 5 de maior intensidade (modo ativo A1g) que uma função lorentziana não compensava os dados experimentais. A Banda 5 foi decomposta em três lorentzianas onde se comprovou a contribuição das fases CoO-fcc e CoO-hcp na sua formação. Portanto, através da espectroscopia Raman pode-se avaliar a influência dos diferentes métodos utilizados na síntese de material bulk e óxidos nanoestruturados. 2019-11-12T16:21:21Z 2019-11-12T16:21:21Z 2019-07-04 Trabalho de Conclusão de Curso - Graduação VIEIRA, Emerson Patrick dos Santos. Estudo sistemático de nanopartículas de óxido de cobalto através da espectroscopia Raman. Orientadora: Cleidilane Sena Costa, Coorientador; Coorientador: Gabriel Adolfo Cabrera Pasca. 2019. 67 f. Trabalho de Conclusão de Curso (Licenciatura em Física) – Faculdade de Ciências Exatas e Tecnologia, Campus Universitário de Abaetetuba, Universidade Federal do Pará, Abaetetuba, 2019. Disponível em: https://bdm.ufpa.br/jspui/handle/prefix/2531. Acesso em:. https://bdm.ufpa.br/jspui/handle/prefix/2531 por Acesso Aberto 1 CD-ROM |
| institution |
Biblioteca Digital de Monografias - UFPA |
| collection |
MonografiaUFPA |
| language |
por |
| topic |
Espectroscopia de Raman Óxido de cobalto Nanopartículas Raman spectroscopy Cobalt oxides Nanoparticles CNPQ::CIENCIAS EXATAS E DA TERRA::FISICA |
| spellingShingle |
Espectroscopia de Raman Óxido de cobalto Nanopartículas Raman spectroscopy Cobalt oxides Nanoparticles CNPQ::CIENCIAS EXATAS E DA TERRA::FISICA VIEIRA, Emerson Patrick dos Santos Estudo sistemático de nanopartículas de óxido de cobalto através da espectroscopia Raman |
| topic_facet |
Espectroscopia de Raman Óxido de cobalto Nanopartículas Raman spectroscopy Cobalt oxides Nanoparticles CNPQ::CIENCIAS EXATAS E DA TERRA::FISICA |
| description |
Raman spectroscopy applied to the nanostructured metal oxides is quite efficient, since the active Raman modes evidenced in the spectra of these materials are directly related to the symmetry of their crystalline structure, which provides accurate information of the solids. However, in the literature there is a divergence on the positions of the peaks of the Raman spectrum referring to the phases: CoO-fcc, CoO-hcp and Co3O4. Thus, this study presents the characterization and analysis of the Raman spectra of cobalt oxide nanoparticles synthesized using the thermal decomposition method used oleylamine, bacaba oil and oleic acid in different proportions. In addition, a bulk sample of Co3O4, synthesized by the sol-gel method, was characterized as reference. Measurements Raman spectrums were performed at room temperature using the Jobin Yvon T64000 Raman spectrometer, laser power of 1.2 to 12 mW and objective lens of 20 mm. The bands were adjusted by the addition and peak decomposition method in Lorentzian functions and the displacement and the symmetry of the spectra were evaluated in relation to the Co3O4 sample. With the results, it was verified that the bulk sample had 5 Bands corresponding to the vibrational modes Eg, A1g and 3F2g predicted theoretically for Co3O4, also presented a Band indicated as contribution of CoO-fcc in the bulk scale. With this, samples synthesized with 10% with 10 washes and 5% of bacaba oil have bands at positions close to Co3O4. However, samples with 10% bacaba oil with 5 washes showed the contribution of the CoOOH and CoO-fcc phases. The samples with 10, 4 and 1% of oleic acid presented the spectrum profile similar to Co3O4, however, the Raman detachment of the Bands occurs according to the concentration of oleic acid in the solution, where two hypotheses were suggested for this effect. Moreover, the sample with 4% presented the contribution of CoO-fcc. For samples with 100% oleylamine, their bands presented values close to those of Co3O4. However, it was verified for Band 5 of higher intensity (active mode A1g) that a Lorentzian function did not compensate the experimental data. Band 5 was decomposed into three lorentzianas where the contribution of the CoO-fcc and CoO-hcp phases in their formation was confirmed. Therefore, Raman spectroscopy can evaluate the influence of the different methods used in the synthesis of bulk material and nanostructured oxides. |
| author_additional |
COSTA, Cleidilane Sena |
| author_additionalStr |
COSTA, Cleidilane Sena |
| format |
Trabalho de Conclusão de Curso - Graduação |
| author |
VIEIRA, Emerson Patrick dos Santos |
| title |
Estudo sistemático de nanopartículas de óxido de cobalto através da espectroscopia Raman |
| title_short |
Estudo sistemático de nanopartículas de óxido de cobalto através da espectroscopia Raman |
| title_full |
Estudo sistemático de nanopartículas de óxido de cobalto através da espectroscopia Raman |
| title_fullStr |
Estudo sistemático de nanopartículas de óxido de cobalto através da espectroscopia Raman |
| title_full_unstemmed |
Estudo sistemático de nanopartículas de óxido de cobalto através da espectroscopia Raman |
| title_sort |
estudo sistemático de nanopartículas de óxido de cobalto através da espectroscopia raman |
| publishDate |
2019 |
| url |
https://bdm.ufpa.br/jspui/handle/prefix/2531 |
| _version_ |
1787154882329837568 |
| score |
11.753896 |