Study of the photocatalytic degradation pathway of norfloxacin and mineralization activity using a novel ternary Ag/AgCl-CeO 2 photocatalyst

In this study, CeO2 first was prepared via urea hydrolysis and calcination. Ag/AgCl–CeO2 composite photocatalysts were fabricated by in situ interspersal of AgCl on CeO2 and subsequent photoreduction of AgCl to Ag. The Ag/AgCl–CeO2 composites exhibited enhanced photocatalytic activity for the photodegradation of norfloxacin (NOF) under visible light irradiation. A plausible degradation pathway for NOF was proposed via LC-MS analysis. The Ag/AgCl–CeO2 composites exhibited effective mineralization ability toward the NOF molecule degradation based on three-dimensional excitation–emission matrix fluorescence spectroscopy (3D EEMs) and total organic carbon (TOC) analysis. Transient photocurrent response, PL spectrum, and EIS indicate higher photoinduced charge separation efficiency in Ag/AgCl–CeO2 hybrid composites. Active species trapping experiments and an ESR technique confirmed that h+ and O2− were the main active groups involved in photodegradation of organic pollutants. Through the combination of various performance characterization and experimental results, a possible photocatalytic mechanism was proposed. Furthermore, the catalysts displayed excellent reusability and stability in four consecutive cycles. It is expected that the Ag/AgCl–CeO2 hybrid composites could be used as photocatalysts for energy conversion and environmental remediation. This work can also provide a deeper understanding of the degradation pathway for NOF.