Peroxymonosulfate activation using CoFe2O4/Fe2O3 nanocomposite for Acid Orange removal

Abstract

Herein, mixed–metal nanocomposite catalysts with various compositions (CoFe₂O₄/xFe₂O₃; x = 0, 0.25, 0.50, 0.75 and 1) were successfully fabricated by a co–precipitation method. The composition and morphology of the catalyst were systematically characterized. The catalyst with the highest Co content (CoFe₂O₄), exhibited the greatest efficiency for the acid orange 7 (AO7) degradation via peroxymonosulfate (PMS) activation. The effects of several experimental parameters including pH, CoFe₂O₄ loading, and PMS dosage on AO7 degradation were studied, and the catalytic activity was found to increase with the mentioned parameters. Moreover, CoFe₂O₄ displayed adequate reusability and was able to degrade AO7 for at least four consecutive cycles. In addition, the total organic carbon (TOC) removal of CoFe₂O₄ was determined while the catalyst stability was observed from the metal leaching in the treated solution. Furthermore, the magnetism of CoFe₂O₄ provides facile separation of the catalyst from the treated solution. Sulfate radicals (SO₄^•–) were identified as the main reactive species responsible for AO7 degradation.