CoFe2O4/WS2 as a highly active heterogeneous catalyst for the efficient degradation of sulfathiazole by activation of peroxymonosulfate

In this study, MFe2O4/WS2 (M = Co, Cu, Mn, Ni) catalysts were synthesized to activate peroxymonosulfate (PMS) for sulfathiazole (STZ) degradation by decorating with WS2 on the surface of a series of spinel-type transition metal oxides. It was found that the CoFe2O4/WS2/PMS exhibited a greater ability to degrade sulfathiazole (STZ) than other systems. More specifically, the catalyst facilitated Fe3+/Fe2+ recycling to activate PMS efficiently and maintained synergies between CoFe2O4 and WS2 to degrade pollutants. The CoFe2O4/WS2 dosage, PMS concentration, solution pH, inorganic anions, and natural organic matter, which could affect the catalytic efficiency, were inspected. The experimental results manifested that the catalyst displayed outstanding performance in the pH range from 5 to 9. Besides, electron paramagnetic resonance spectroscopy and radical quenching experiments confirmed the presence of HO•, SO4•−, O2•−, and 1O2. Based on detected intermediates, the plausible degradation pathway of STZ was proposed.