Enhancing heterogeneous Fenton-like catalysis through pyrrolidine modification of FeO-CuO composites with oxygen-vacancy defects.

Enhancing the generation of reactive hydroxyl radicals (•OH) is crucial for overcoming the limitations of the low reactivity of heterogeneous Fenton Fe-based catalysts. Researchers have explored various methods to modify catalyst structures to enhance reactivity, yet often at the expense of stability. Herein, suitable carbon and nitrogen-codoped FeO-CuO composites were synthesized via pyrolysis method, demonstrating high Fenton reaction activity and remarkable stability. Experimental findings and density functional theory calculations (DFT) revealed that the presence of oxygen vacancies on the catalyst surface facilitated an increase in exposed FeNC active sites, promoting electron transfer and the accelerating the rate of •OH generation. Moreover, carbon and nitrogen, particularly in the form of pyrrole nitrogen bonded to Fe imparted exceptional stability to the FeNC active sites, mitigating their dissolution. Additionally, the Fe-based catalysts exhibited strong magnetism, enabling easy separation from the reaction solution while maintaining a high degradation efficiency for various organic pollutants, even in the presence of multiple anions. Furthermore, a comprehensive mechanism for methylene blue (MB) degradation was identified, enhancing the potential practical applications of these catalysts.