ASPECTS OF SYNTHESIS BY PREFERENTIAL REDUCTION AND CHARACTERIZATION OF CO-ZNO NANOCOMPOSITE. / ASPECTOS DA SÍNTESE POR REDUÇÃO PREFERENCIAL E CARACTERIZAÇÃO DO NANOCOMPÓSITO CO-ZNO

AUTOR(ES)
DATA DE PUBLICAÇÃO

2005

RESUMO

This work covers the Co-ZnO nano-composite synthesis by hydrogen preferential reduction of these metals oxides which, in turn, were obtained by simultaneous dissociation of their nitrates. Initially it has been developed a thermodynamic evaluation of the main process reactions such as the zinc and cobalt nitra tes pyrolises and the respective oxides reduction by hydrogen. The experimental work was carried out in order to study the effect of the most important variables on the reduction reaction kinetics of the cobalt oxide as well as to investigate some experimental conditions for the formation of the Co-ZnO nanocomposite. It can be said that cobalt oxide is completely and preferentially reduced in 20 minutes at 690K, then allowing the composite formation at this temperature. The materials involved in the process were characterized by X-R diffraction (oxides and co-obtained oxides) and electronic microscopy (SEM/EDS, TEM), being possible to identify a Co-ZnO homogeneous and containing particles in the nano range scale.

ASSUNTO(S)

nano-composites characterization caracterizacao reduction with hydrogen nano-composito reducao com hidrogenio

ACESSO AO ARTIGO

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