engleski

Precipitation of alfa-Fe2O3 particles by forced hydrolysis of Fe3+ ions

Forced hydrolysis of Fe(III)-salt solutions is a simple method to produce various iron oxides. In spite of the simplicity of the method, it is not always easy to characterize the hydrolysis products. The time and temperature of hydrothermal treatment, the concentration of Fe(III)-salt, the presence of various anions or the surface active agent, all this can significantly influence the phase composition, morphology and size of the particles. In the present work, the influence of Fe(ClO4)3, FeCl3 or Fe(NO3)3 salt and its concentration, as well as the presence of the surface active agent in the precipitation of alfa- Fe2O3 by forced hydrolysis will be shown. XRD, 57Fe Mössbauer and FT-IR spectroscopies plus FE- SEM + EDS were used as experimental techniques. In dependence on experimental conditions, a unique microstructure of alfa-Fe2O3 particles was obtained. In the formation of alfa-Fe2O3 the aggregation mechanism played a very important role, i.e., they were formed by the aggregation of nanosize alfa-Fe2O3 subparticles. In specific cases some other iron oxide phases could be detected.

iron oxide; precipitation; hydrolysis

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