Recyclable dual Z-scheme CFO-BFO-CN heterostructure for visible-light photocatalytic activation of peroxydisulfate toward ciprofloxacin degradation

Photocatalysis coupled with PDS activation is promising for eliminating persistent antibiotics in water, whereas rational design of efficient, visible-light-active and reusable photocatalysts is still difficult. A magnetic dual Z-scheme CFO-BFO-CN heterojunction was synthesized by hydrothermal method. The material exhibited outstanding activity toward ciprofloxacin degradation under visible light. In the presence of PDS, 99.5% ciprofloxacin was removed within 30 min, with a reaction rate 3 times that of binary BFO-CN. The dual Z-scheme structure accelerated charge separation and maintained strong redox properties. Metal redox cycles worked with photoelectrons to activate PDS and produce abundant active species. The system possessed good mineralization ability, pH tolerance, anti-interference performance and cycling stability. After seven consecutive runs, the catalyst still kept intact structure. With easy magnetic recovery, high activity and stability, CFO-BFO-CN has great application potential in wastewater purification. This work provides a new idea for designing dual Z-scheme photocatalysts for antibiotic wastewater treatment via PDS activation.