Síntese e caracterização do core-shell ZrO2:Y3+@TiO2
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Data
2016-03-21
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Universidade Federal de Goiás
Resumo
Since the early 90's researchers have investigated the
combination of nanocomposites comprised of multilayers, which have better efficiency than their corresponding individual particles, may present in certain cases, new properties. The resulting structure is called a core-shell. In this study, were synthesized
ZrO2:Y 3+ coated with TiO2, obtaining nanocomposites ZrO2:Y 3+ @TiO2 with a thickness of
10, 20 and 50% shell. The photoluminescent property (FL) of the nanocomposites was studied. Such interest is due to the fact that the order/disorder structural at the interface of the core-shell type systems may be possible recombination processes responsible for the photoluminescence emission of these materials. Nanoparticles of the core and the shell were obtained by the Method of Polymeric Precursors. The samples were characterized by X-ray diffraction (XRD) to identify the formation of the nanocomposite and evaluate the structural order in the synthesized materials. The core was obtained with tetragonal structure and the shell with anatase structure. From the diffractograms have been carried out calculations of the crystallite size and lattice parameters. The characterization by Transmission Electron Microscopy (TEM), it was not possible to differentiate the core of the shell by the images, since both are structurally ordered, requiring analysis by Energy Dispersive X-ray (EDX), which was verified the presence of Zr and Ti elements that
comprise the core-shell nanocomposite. The FL emission results were explained as a function of the shell thickness, as well as the effect of calcination temperature on the order-disorder structural material. To evaluate the performance of the FL issuing nanocomposites were calculated chromaticity coordinates, based on the FL emission spectra.
Descrição
Palavras-chave
Core-shell, Método dos precursores poliméricos, Emissão fotoluminescente, Core-shell, Method of polymeric precursors, Photoluminescent emission
Citação
SILVA, P. D. G. Síntese e caracterização do core-shell ZrO2:Y3+@TiO2. 2016. 80 f. Dissertação (Mestrado em Química) - Universidade Federal de Goiás, Catalão, 2016.