Síntese e caracterização de nanoestruturas de óxido de estanho (IV)

• Autor(a) principal: Romano, Camila Naressi [UNESP]
• Data de Publicação: 2018
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/203590; http://www.athena.biblioteca.unesp.br/exlibris/bd/capelo/2019-06-25/000915938.pdf
• topic: Microscopia eletrônica de varredura; Nanoestrutura; Espectroscopia Raman; Nanotecnologia; Compostos de estanho

The main objective of this monograph research was to obtain nanostructures of tin oxide (IV) through the association of growth mechanisms by vapor phase (Vapor-Liquid-Solid, VLS, self catalytic and Vapor-Solid, VS) and carbothermal reduction that requires the presence of a carbon source to reduce the precursors oxidation state, allowing their evaporation at lower temperatures. In order to do the structural characterization of these nanostructures, experimental techniques such as Scanning Electron Microscopy (SEM), X-ray Diffractometry (XRD) and Raman Spectroscopy were used. With the images obtained by SEM it was possible to observe a mixed growth of nanostructures: SnO nanowires grew by the VLS mechanism and SnO2 nanobelts grew by VS mechanism. Through the XRD analysis it was possible to affirm that the SnO nanowires have tetragonal crystalline structure and the SnO2 crystallizes in the rutile phase. As the VLS process is self catalytic, we expected that the catalytic drop observed at the end of the nanowires were Sn metallic and it was confirmed through the analysis of experimental data obtained from XRD and Energy Dispersion X-ray Spectroscopy (EDS). SnO nanobelts, in turn, presented growth with tape morphology with thicknesses from 9 to 50 nm as revealed by scanning electron microscopy performed on their samples. With the Raman spectroscopy of these samples, it was possible to confirm, through the predicted active Raman modes, that the samples are actually SnO and SnO2 with effects of nanostruction