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

Abstract

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, ·O₂ ⁻/·OH/¹O₂ were generated in CuO-MnFe₂O₄/H₂O₂ system, ·OH and ¹O₂ were main active species. XPS analysis indicated that there existed a synergistic effect between CuO and MnFe₂O₄, while the generated ¹O₂ 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.

Graphical Abstract

Keywords:

• CuO-MnFe₂O₄ nanoparticles
• peroxide
• sulfamethoxazole
• synergistic effect

Additional information

Funding

This work was supported by the National Key R&D Program of China (2017YFC0806305), the Natural Science Foundation of China (No. 51508564), Graduate Research and Innovation Project of Chongqing City (No. CYB16126 & CYS17301) and Military Logistics Research Project (No. CHJ13J021 & BY114J005).