Enhanced norfloxacin degradation by visible-light-driven Mn3O4/γ-MnOOH photocatalysis under weak magnetic field

A valence-state heterojunction Mn 3 O 4 /γ-MnOOH was synthesized for norfloxacin (NOR) degradation under concurrent visible light and magnetic field. The charge carriers could transfer between the valence state components facilely, inhibiting recombination of photo-induced electron-holes significantly. Efficient NOR degradation by Mn 3 O 4 /γ-MnOOH was realized at 98.8% (rate constant of 0.0720 min −1 ) within 60 min under magnetic field assisted visible light. In neutral media, the positively charged NOR and negatively charged Mn 3 O 4 /γ-MnOOH would arrange in an oriented manner in the presence of magnetic field, providing more active sites for NOR during photocatalysis . Moreover, the opposite Lorentz forces contributed to the attractive interactions between NOR and Mn 3 O 4 /γ-MnOOH, accelerating NOR degradation with lower active energy. Quenching experiment showed that ∙O 2 − and h + played dominant roles in NOR degradation. Attractively, this study shed new lights on an innovative strategy of magnetic field assisted photocatalysis for refractory contaminants remediation from water.