Sol-gel synthesis of zinc oxide nanoparticle at three different temperatures and its characterization via XRD, IR and EPR

In this work, nanoparticles of zinc oxide were synthesized; they were formed using the sol-gel method (citrate route) at calcination temperatures (Tc) of 500, 550 and 600 °C. For all samples studied, IR spectroscopy showed the presence of the bands associated with water molecules present in the zinc...

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Autores:
Acosta Humánez, Manuel Fernando
Montes Vides, Luis Alfredo
Almanza-Montero, Ovidio Amado
Tipo de recurso:
Article of journal
Fecha de publicación:
2016
Institución:
Universidad Nacional de Colombia
Repositorio:
Universidad Nacional de Colombia
Idioma:
spa
OAI Identifier:
oai:repositorio.unal.edu.co:unal/60605
Acceso en línea:
https://repositorio.unal.edu.co/handle/unal/60605
http://bdigital.unal.edu.co/58937/
Palabra clave:
62 Ingeniería y operaciones afines / Engineering
X-Ray diffraction
IR spectroscopy
sol-gel method
electron paramagnetic resonance
zinc oxide.
Rights
openAccess
License
Atribución-NoComercial 4.0 Internacional
Description
Summary:In this work, nanoparticles of zinc oxide were synthesized; they were formed using the sol-gel method (citrate route) at calcination temperatures (Tc) of 500, 550 and 600 °C. For all samples studied, IR spectroscopy showed the presence of the bands associated with water molecules present in the zinc oxide and carbon dioxide adsorbed on its surface. The formation of zinc oxide phase was confirmed by XRD, which showed that from 500 ºC it had this type of Wurtzite structure. However, samples calcinated at 600 ºC have higher crystallinity. Crystallite size was calculated using the Scherrer equation. The Rietveld method was used to obtain lattice parameters a and c for Wurtzite cell types as well as cell volume and the ratio c/a of each sample. These parameters do not show significant changes when they are compared with values obtained from samples with different calcination temperatures. Electron paramagnetic resonance showed the presence of defects in the zinc oxide. Three signals with g values of 1.96, 2.00 and 2.04 were associated with oxygen and zinc vacancies. Defects in the structure disappear when the calcination temperature is increased. The sample that was highlighted with the highest concentration of vacancies has a mean crystallite size greater than 30 nm, and this may also be responsible for this feature.