Development of porous α-Fe2O3 microstructure by forced hydrolysis of FeCl3 solutions in the presence of AOT

The effect of AOT (sodium di-2-ethylhexyl sulfosuccinate) on the formation and microstructure of α-Fe2O3 by the forced hydrolysis of FeCl3 solutions was investigated. The precipitates formed were characterized by XRD, 57Fe Mössbauer, FT-IR and optical spectroscopies, and also with FE-SEM. The presence of AOT influenced the shape of β-FeOOH particles and led to the formation of microporous α-Fe2O3. The preferential adsorption of sulfonate/sulfate groups played an important role in these effects. Generally, the 57Fe Mössbauer and optical spectra were sensitive to low crystallinity, as well as to the particle size and shape.

► Influence of the AOT surfactant on the forced hydrolysis of FeCl3 solutions.
► Dependence of the microstructural properties of the precipitates on the concentration of AOT and the time of precipitation.
► Explanation of the formation of different particle's shape and porous hematite microstructure by the preferential adsorption of sulfonate/sulfate groups and less by influence of organic part of AOT.
► Sensitivity of optical spectra on the phase and microstructural properties of the precipitates.