Sonochemical synthesis of mesoporous iron oxide and accounts of its magnetic and catalytic properties

Synthesis of mesoporous iron oxides has been reported using a sonochemical technique. Iron(III) ethoxide was used as an inorganic precursor and CTAB as an organic structure directing agent. After sonication the surfactant was removed by calcination and solvent extraction methods. FTIR spectra demonstrated the removal of the surfactant from the pores of the mesoporous iron oxide. The calcinated material was characterized by XRD, TEM, TGA, and BET surface area measurements. The surface area after solvent extraction is found to be 274 m²/g. The magnetic and catalytic properties of the materials have been studied. The as-prepared amorphous Fe₂O₃ has shown a paramagnetic behavior, while after calcination at 350 °C it changes to γ-Fe₂O₃ with good magnetic properties. The catalytic activity of mesoporous iron oxide was studied in the reaction of cyclohexane oxidation under mild conditions. The mesoporous Fe₂O₃ catalyst has shown high conversion of cyclohexane into cyclohexanone and cyclohexanol, with a high selectivity.