Enhancement of H2O2 decomposition by the synergistic effect on CuO-MnFe2O4 nanoparticles for sulfamethoxazole degradation over a wide pH range

Advanced treatment of micro-polluted water is a hot research topic at present. The construction of transition metal oxide-based Fenton-like reaction can effectively remove antibiotics from micro-polluted water. Magnetic CuO-MnFe2O4 nanoparticles, a type of nontoxic trimetallic transition metal oxides, is a promising heterogeneous catalyst for H2O2 activation over a wide pH range. In this study, the activation of H2O2 by CuO-MnFe2O4 nanoparticles is evaluated using sulfamethoxazole as a model reactant. The as-prepared CuO-MnFe2O4 nanoparticles exhibited excellent capability for sulfamethoxazole degradation over a wide pH range. Under the optimal conditions (0.5 g/L catalyst, 10 mM H2O2 and 5 mg/L SMX), 99.2% removal efficiency and 58.5% TOC removal were achieved within 30 minutes. According to quenching experiments and ESR analysis, center dot O-2(-)/center dot OH/O-1(2) were generated in CuO-MnFe2O4/H2O2 system, center dot OH and O-1(2) were main active species. XPS analysis indicated that there existed a synergistic effect between CuO and MnFe2O4, while the generated O-1(2) were probably derived from lattice oxygen and hydroxylate oxygen in CuO-MnFe2O4 nanoparticles. The CuO-MnFe2O4 nanoparticles are effective, environmental friendliness and low-cost catalysts for H2O2 activation over a wide pH range. These features make CuO-MnFe2O4 nanoparticles be a promising heterogeneous catalyst in Fenton-like reaction to process sulfamethoxazole in micro-polluted water.