Facile synthesis of a novel recyclable dual Z-scheme WO3/NiFe2O4/BiOBr composite with broad-spectrum response and enhanced sonocatalytic performance for levofloxacin removal in aqueous solution

In recent decades, the overuse and misuse of antibiotics have caused serious harm to aquatic ecosystems. This work successfully designed a unique recyclable WO3/NiFe2O4/BiOBr (WNB) composite with dual Z-scheme heterojunction to degrade levofloxacin (LEV) in aqueous solution. The results indicated that the as-prepared WNB composite displayed the greatest sonocatalytic activity for LEV degradation. In particular, WNB showed the highest LEV (at 10 mg/L) removal efficiency (97.97 %) within 75 min under ultrasonic irradiation. The significantly enhanced catalytic activity of WNB was attributed to the unique dual Z-scheme structure, which makes it easier for the transfer and the spatial separation of photo-generated electron-hole (e−-h+) pairs, and dramatically increases the carrier lifespan. Furthermore, the ternary composite comprises three different semiconductors from narrow to broad bandgap, which are suitable for harvesting full-spectrum light. The recycle experiments demonstrated the catalyst's excellent sonocatalytic stability and easy recovery, which is attributed to its magnetic property. Furthermore, based on the intermediates identified during the degradation process, a potential mechanism and pathway for LEV degradation were presented. This work provides a unique perspective on designing efficient sonocatalysts for environmental remediation.