Photocatalytic in situ H2O2 production and activation for enhanced ciprofloxacin degradation over CeO2-Co3O4/g-C3N4: key role of CeO2

The abused ciprofloxacin antibiotics have caused significant environmental damage. Although oxidative degradation of ciprofloxacin exhibits promising efficacy, it often entails excessive energy consumption. Hence, it is necessary to explore an effective and ecologically sustainable degradation strategy. Herein, we demonstrated that g-C3N4 decorated with the coordinated CeO2 and Co3O4 (CeO2-Co3O4/CN) exhibited effective ciprofloxacin photodegradation via in situ H2O2 production and activation mechanism. Results indicate that the introduced CeO2 enhances the transference of photogenerated electrons to O-2 by adjusting the oxygen vacancy of photocatalyst, thereby increasing the generation of superoxide radicals, which in turn generate H2O2, resulting in a 22.4-fold increase in H2O2 generation over g-C3N4. Moreover, the in situ H2O2 generation facilitated by CeO2 is confirmed to be essential for ciprofloxacin degradation via CeO2-Co3O4/CN, as it provides enough oxidant for Co3O4 to activate into hydroxyl radicals for the pollutants degradation. Ultimately, CeO2-Co3O4/CN achieves a ciprofloxacin degradation ratio of 97.7% within 80 min. This study introduces a novel approach that combines H2O2 generation and activation, offering an innovative perspective for achieving clean and efficient purification of antibiotic-contaminated water.