Formação e crescimento do óxido de zinco e óxido de zinco dopado com cobre
Autor(a) principal: | |
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Data de Publicação: | 2015 |
Tipo de documento: | Tese |
Idioma: | por |
Título da fonte: | Repositório Institucional da UNESP |
Texto Completo: | http://hdl.handle.net/11449/124521 |
Resumo: | Zinc oxide (ZnO) nanoparticles were prepared by a sol-gel method, adapted from a synthesis route already well established. The kinetics of the ZnO synthesis was monitored by in situ UV-visible absorbance spectroscopy, pH measurements and small angle X-ray scattering (SAXS). Results allowed proposing a new mechanism of ZnO formation and growth. The second step of this work was to establish a new route of synthesis to obtain copper doped ZnO from two different sources: copper (II) acetate and copper (II) nitrate, at predetermined Zn/Cu ratio (0,1%; 0,25%, 0,5%; 0,75% e 1,0%). These syntheses were also monitored by UV-visible and SAXS spectroscopy. The powders prepared from colloidal suspensions precipitation were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM-EDS). Results show that the synthesis method is suitable for obtaining copper doped ZnO nanoparticles. The wurtzite crystalline structure, characteristic from bulk ZnO, was kept in doped samples. In fact, both the acetate and the nitrate anions inhibit the particles formation and growth, but induce to distinct growth mechanisms: reaction limited cluster-cluster aggregation (RLCA) and diffusion limited cluster-cluster aggregation (DLCA), respectively. Otherwise, the final size of doped particles was kept irrespective of the doping nature and quantity. Qualitative tests of samples response to visible irradiation show photochromic effects, which intensity and time of duration are influenced by the amount of dopant in the sample. |
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Formação e crescimento do óxido de zinco e óxido de zinco dopado com cobreNucleaçãoÓxido de zincoCrescimentoSemicondutores - DopagemEspectroscopia de raio XZinc oxide (ZnO) nanoparticles were prepared by a sol-gel method, adapted from a synthesis route already well established. The kinetics of the ZnO synthesis was monitored by in situ UV-visible absorbance spectroscopy, pH measurements and small angle X-ray scattering (SAXS). Results allowed proposing a new mechanism of ZnO formation and growth. The second step of this work was to establish a new route of synthesis to obtain copper doped ZnO from two different sources: copper (II) acetate and copper (II) nitrate, at predetermined Zn/Cu ratio (0,1%; 0,25%, 0,5%; 0,75% e 1,0%). These syntheses were also monitored by UV-visible and SAXS spectroscopy. The powders prepared from colloidal suspensions precipitation were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM-EDS). Results show that the synthesis method is suitable for obtaining copper doped ZnO nanoparticles. The wurtzite crystalline structure, characteristic from bulk ZnO, was kept in doped samples. In fact, both the acetate and the nitrate anions inhibit the particles formation and growth, but induce to distinct growth mechanisms: reaction limited cluster-cluster aggregation (RLCA) and diffusion limited cluster-cluster aggregation (DLCA), respectively. Otherwise, the final size of doped particles was kept irrespective of the doping nature and quantity. Qualitative tests of samples response to visible irradiation show photochromic effects, which intensity and time of duration are influenced by the amount of dopant in the sample.Universidade Estadual Paulista (Unesp)Pulcinelli, Sandra Helena [UNESP]Universidade Estadual Paulista (Unesp)Silva, Marlon Nunes da [UNESP]2015-07-13T12:10:29Z2015-07-13T12:10:29Z2015-04-28info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/doctoralThesis147 f. : il.application/pdfSILVA, Marlon Nunes da. Formação e crescimento do óxido de zinco e óxido de zinco dopado com cobre. 2015. 147 f. Tese (Doutorado) - Universidade Estadual Paulista Júlio de Mesquita Filho, Instituto de Química, 2015.http://hdl.handle.net/11449/124521000837239000837239.pdf33004030072P89971202585286967Alephreponame:Repositório Institucional da UNESPinstname:Universidade Estadual Paulista (UNESP)instacron:UNESPporinfo:eu-repo/semantics/openAccess2023-10-10T06:05:15Zoai:repositorio.unesp.br:11449/124521Repositório InstitucionalPUBhttp://repositorio.unesp.br/oai/requestopendoar:29462024-08-05T14:31:14.712118Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP)false |
dc.title.none.fl_str_mv |
Formação e crescimento do óxido de zinco e óxido de zinco dopado com cobre |
title |
Formação e crescimento do óxido de zinco e óxido de zinco dopado com cobre |
spellingShingle |
Formação e crescimento do óxido de zinco e óxido de zinco dopado com cobre Silva, Marlon Nunes da [UNESP] Nucleação Óxido de zinco Crescimento Semicondutores - Dopagem Espectroscopia de raio X |
title_short |
Formação e crescimento do óxido de zinco e óxido de zinco dopado com cobre |
title_full |
Formação e crescimento do óxido de zinco e óxido de zinco dopado com cobre |
title_fullStr |
Formação e crescimento do óxido de zinco e óxido de zinco dopado com cobre |
title_full_unstemmed |
Formação e crescimento do óxido de zinco e óxido de zinco dopado com cobre |
title_sort |
Formação e crescimento do óxido de zinco e óxido de zinco dopado com cobre |
author |
Silva, Marlon Nunes da [UNESP] |
author_facet |
Silva, Marlon Nunes da [UNESP] |
author_role |
author |
dc.contributor.none.fl_str_mv |
Pulcinelli, Sandra Helena [UNESP] Universidade Estadual Paulista (Unesp) |
dc.contributor.author.fl_str_mv |
Silva, Marlon Nunes da [UNESP] |
dc.subject.por.fl_str_mv |
Nucleação Óxido de zinco Crescimento Semicondutores - Dopagem Espectroscopia de raio X |
topic |
Nucleação Óxido de zinco Crescimento Semicondutores - Dopagem Espectroscopia de raio X |
description |
Zinc oxide (ZnO) nanoparticles were prepared by a sol-gel method, adapted from a synthesis route already well established. The kinetics of the ZnO synthesis was monitored by in situ UV-visible absorbance spectroscopy, pH measurements and small angle X-ray scattering (SAXS). Results allowed proposing a new mechanism of ZnO formation and growth. The second step of this work was to establish a new route of synthesis to obtain copper doped ZnO from two different sources: copper (II) acetate and copper (II) nitrate, at predetermined Zn/Cu ratio (0,1%; 0,25%, 0,5%; 0,75% e 1,0%). These syntheses were also monitored by UV-visible and SAXS spectroscopy. The powders prepared from colloidal suspensions precipitation were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM-EDS). Results show that the synthesis method is suitable for obtaining copper doped ZnO nanoparticles. The wurtzite crystalline structure, characteristic from bulk ZnO, was kept in doped samples. In fact, both the acetate and the nitrate anions inhibit the particles formation and growth, but induce to distinct growth mechanisms: reaction limited cluster-cluster aggregation (RLCA) and diffusion limited cluster-cluster aggregation (DLCA), respectively. Otherwise, the final size of doped particles was kept irrespective of the doping nature and quantity. Qualitative tests of samples response to visible irradiation show photochromic effects, which intensity and time of duration are influenced by the amount of dopant in the sample. |
publishDate |
2015 |
dc.date.none.fl_str_mv |
2015-07-13T12:10:29Z 2015-07-13T12:10:29Z 2015-04-28 |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/doctoralThesis |
format |
doctoralThesis |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
SILVA, Marlon Nunes da. Formação e crescimento do óxido de zinco e óxido de zinco dopado com cobre. 2015. 147 f. Tese (Doutorado) - Universidade Estadual Paulista Júlio de Mesquita Filho, Instituto de Química, 2015. http://hdl.handle.net/11449/124521 000837239 000837239.pdf 33004030072P8 9971202585286967 |
identifier_str_mv |
SILVA, Marlon Nunes da. Formação e crescimento do óxido de zinco e óxido de zinco dopado com cobre. 2015. 147 f. Tese (Doutorado) - Universidade Estadual Paulista Júlio de Mesquita Filho, Instituto de Química, 2015. 000837239 000837239.pdf 33004030072P8 9971202585286967 |
url |
http://hdl.handle.net/11449/124521 |
dc.language.iso.fl_str_mv |
por |
language |
por |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
147 f. : il. application/pdf |
dc.publisher.none.fl_str_mv |
Universidade Estadual Paulista (Unesp) |
publisher.none.fl_str_mv |
Universidade Estadual Paulista (Unesp) |
dc.source.none.fl_str_mv |
Aleph 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 |
|
_version_ |
1808128372962754560 |