Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10624556 | Ceramics International | 2015 | 10 Pages |
Abstract
Mixed Ni,Fe oxides have been prepared by calcination of precursors with the hydrotalcite-type structure which had been prepared by the reverse micelle method using different surfactants. The solids have been characterized by several physicochemical techniques: Powder X-ray diffraction, nitrogen adsorption-desorption at â196 °C for specific surface area assessment, particle size distribution, UV-vis spectroscopy, and temperature-programmed reduction. The solids are formed by NiO and NiFe2O4 (spinel) and their properties depend on the experimental conditions used to prepare the hydrotalcite-type precursor. The crystallite size is larger for the spinel crystallites than for the NiO crystallites and in all cases depends on the surfactant used and the pH during the synthesis. The original, uncalcined samples, show intense mainly yellow color, but on calcination almost all of them change to dark brown or even almost black; only when using a cyclic surfactant the color is markedly different from that obtained when linear surfactants are used.
Related Topics
Physical Sciences and Engineering
Materials Science
Ceramics and Composites
Authors
Patricia H. Holgado, MarÃa J. Holgado, MarÃa S. San Román, Vicente Rives,