Degradation of diphenhydramine by photo-Fenton using magnetically recoverable iron oxide nanoparticles as catalyst

摘要

Iron oxide nanoparticles, with size ranging from 50 to 100 nm, were synthesized by a solvothermal method. The amounts of iron(III) chloride precursor (from 2.5 to 10.0 mmol) and sodium hydroxide (between 10 and 30 mmol) were varied along with the synthesis temperature (180 or 200 °C). Depending on the synthesis conditions, samples with magnetic properties consisting of magnetite (Fe3O4), or by a mixture of magnetite and maghemite (γ-Fe2O3), and samples with no magnetism consisting of hematite (α-Fe2O3), were obtained. The catalytic activity of the materials was studied for the degradation of diphenhydramine using the photo-Fenton process. All materials performed well on the degradation of this emerging pollutant. The best compromise between catalytic activity and stability was obtained with pure magnetite nanoparticles prepared at 180 °C from a 4:1 molar ratio between sodium hydroxide and iron(III) chloride.