Synthesis of magnetite-supported catalysts for phenol oxidation in aqueous solution.

One of the usual ways to degrade phenol contaminant is sulfate radical-based advanced oxidation processes (SR-AOPs). In this study, reactive sulfate radicals have been produced by Co3O4/Fe3O4@nSiO2@mSiO2 catalyst and Fe3O4 nanoparticles. It has been found that the couple of supported cobalt catalyst and peroxymonosulfate (PMS) is highly effective to produce sulfate radicals for phenol oxidation. In contrary to, Fe3O4-PMS system displays much low phenol degradation, and Co3O4/Fe3O4@nSiO2@mSiO2 catalyst shows a good catalytic performance in solution. The properties of this supported catalyst have been characterized by XRD (powder X-ray diffraction), SEM–EDS (scanning electron microscopy–energy-dispersive X-ray spectroscopy), TEM (transmission electron microscopy), and nitrogen adsorption–desorption. This magnetic catalyst is facility separated from the medium by an external magnetic field. Finally, three different methods involving annealing in the air, washing with water and applying ultrasonics was used for regenerating the deactivated catalyst. The heat treatment can recover the catalyst nearly. [ABSTRACT FROM AUTHOR]