Superparamagnetic Fe3O4 nanoparticles as catalysts for the catalytic oxidation of phenolic and aniline compounds.

Fe(3)O(4) magnetic nanoparticles (MNPs) with diameters about 10nm were synthesized successfully and used to remove phenol and aniline from aqueous solution. The results showed that phenol and aniline could be eliminated easily from solution under acidic and neutral conditions in the presence of MNPs and H(2)O(2). When the concentrations of Fe(3)O(4) MNPs and H(2)O(2) were 5gL(-1) and 1.2M, respectively, phenol and aniline could be removed completely after 6h of reaction at 308K, and the total organic carbon (TOC) abatement efficiency for phenol and aniline were 42.79% and 40.38%. Some intermediates such as formic acid, acetic acid, fumaric acid and hydroquinone were detected during reaction. Fe(3)O(4) MNPs exhibited good stability and reusability, also showed excellent catalysis ability to eliminate some substituted phenolic and aniline compounds from solution. Fe(3)O(4) MNPs had good superparamagnetism and was readily separated from solution by applying an external magnetic field. Finally we proposed that phenol and aniline might be degraded by the hydroxyl free radicals (.OH) released from H(2)O(2) in the presence of Fe(3)O(4) MNPs as catalysts.