Gold nanoparticles-modified MnFe2O4 with synergistic catalysis for photo-Fenton degradation of tetracycline under neutral pH

Highlights: • MnFe₂O₄-Au composites were prepared for efficient photo-Fenton degradation of TC. • The surface hydroxyl of MnFe₂O₄ was beneficial to the generation of • OH. • Negative charged or partially polarized AuNPs enhanced the adsorption of H₂O₂. • Synergistic effect of MnFe₂O₄ and AuNPs provided superior catalytic performance. • The h⁺ and e^- were responsible for the high catalytic degradation of TC. To decrease the adverse environmental and health-related effects of antibiotics, a series of MnFe₂O₄-Au (MFO-Au) composites were prepared by simple co-precipitation and photoreduction methods for efficient photo-Fenton degradation of tetracycline (TC). The synergistic effect of MFO and gold nanoparticles (AuNPs) with high absorption of visible light and strong photogenerated carrier separation efficiency endowed MFO-Au₃ an outstanding photo-Fenton catalytic performance for TC degradation in neutral condition. The surface hydroxyl of MFO profited to generation of • OH, and negative charged or partially polarized AuNPs benefited to adsorption of H₂O₂, which had a synergistic effect on enhancing the photo-Fenton catalytic performance of MFO-Au. 88.3% of TC was efficiently removed and about 51.9% of TOC decreased within 90 min. The electron spin resonance and quenching tests suggested that h⁺ and e^- were responsible for the high catalytic degradation and • OH and • O₂^- participated in the photo-Fenton reaction. The toxicity assessment by seed germination experiments showed efficient toxicity reduction of this system. Besides, MFO-Au exhibited high stability, good cycle, relatively economical and practical application performance, which is expected to provide potential guidance for the design and combination of noble nanoparticles with high stability and spinel bimetallic oxides with high catalytic activity in photo-Fenton reactions.