Regulation of ZnFe2O4 synthesis for optimizing photoelectric response and its application for ciprofloxacin degradation: The synergistic effect with peroxymonosulfate and visible light

Abstract

ZnFe2O4 (ZFO) poses great potential to activate peroxymonosulfate (PMS) and responds to visible light. In this work, ZFO was synthesized by a simple one-step hydrothermal method. In order to obtain the most desirable photoelectric performance, hydrothermal reaction parameters including pH, temperature, and time were innovatively regulated. Based on optimized ZFO, the visible light/PMS/ZFO (Vis/PMS/ZFO) system was established, which presented superior degradation efficiency of ciprofloxacin (CIP). It was verified that •OH and 1O2 were the main reactive species for CIP degradation. Besides, visible light was confirmed to promote formation of reactive species and accelerate charge transfer simultaneously. Therefore, the possible mechanism of catalysis was proposed and the enhancement of visible light for the PMS/ZFO system was elaborated. Based on the identified intermediates, three pathways of CIP degradation were illustrated. Moreover, water matrix posed an overall positive impact on CIP degradation. Experiments performing in real wastewater and repeated tests validated wide application of the Vis/PMS/ZFO system. In general, the designed synthesis of ZFO is feasible and the integration of ZFO with visible light for efficient PMS activation is a successful and promising method for wastewater treatment.