Oxygen vacancy enhancing Fenton-like catalytic oxidation of norfloxacin over prussian blue modified CeO2: Performance and mechanism

To develop an efficient heterogeneous Fenton-like catalyst is of great importance for degrading organic pollutants. CeO2 was selected as the catalyst carrier. Prussian blue (PB) was chose as the iron resource for its sensitivity to H2O2 and low toxicity. PB modified CeO2 composite was successfully fabricated and used for Fenton-like oxidation of norfloxacin (NOR) in this study. The characteristics of the catalysts demonstrated that the doping of PB distorted the lattice locally and increased the surface area of CeO2 obviously. The XPS analysis also indicated that chemically supported catalysts PB/CeO2 with more Ce3+ was beneficial to Fenton-like catalytic reaction. The degradation tests showed that the PB/CeO2 significantly enhanced the removal of NOR which indicated a synergistic effect between PB and CeO2. The reason should be mainly attributed to the synergetic catalysis of H2O2 by Fe3+/Fe2+ and Ce3+/Ce4+ redox couples. At the same time, PB/CeO2 composite showed well reusability and wide pH value range of 2-9 with fairly low concentration of iron ions. The reaction mechanisms were identified to be OH oxidation and improvement of oxygen vacancies (OVs).