The Synthesis and Properties of High Surface Area Fe2O3 Materials |
| Z. Surowieca, W. Gacb and M. Wiertel a
aInstitute of Physics, M. Curie-Skłodowska University, pl. M. Curie-Skłodowskiej 1, 20-031 Lublin, Poland bFaculty of Chemistry, M. Curie-Sklodowska University, pl. M. Curie-Skłodowskiej 1, 20-031 Lublin, Poland |
| Full Text PDF |
| Two types of the silica materials were used for the preparation of iron oxides. The MCM-48 type silica support and wide-pore silica gel were impregnated with iron nitrates. The samples were investigated by the nitrogen adsorption/desorption method, X-ray diffraction, scanning electron microscopy, and 57Fe Mössbauer spectroscopy. Redox properties were studied by the temperature programmed reduction method. Strongly dispersed hematite was evidenced on the supports. An application of the MCM-48 silica mesoporous materials led to the development of the oxide phases within the ordered porous structure. The detailed temperature programmed reduction studies evidenced slight differences of the redox properties of the species located within the silica templates and after their removal. Magnetic properties of iron oxides were related to the porous structure of the silica supports. The Mössbauer study of high surface area materials Fe/SiO2 and Fe/MCM-48 type silicate templates revealed existence of ferro- and superparamagnetic phases. The relative contribution of the superparamagnetic doublet component in Mössbauer spectra is 15% and 80% for Fe/SiO2/c and Fe/MCM-48/c samples, respectively. |
| DOI: 10.12693/APhysPolA.119.18 PACS numbers: 76.80.+y, 78.67.Bf, 78.67.Rb, 75.20.-g |