Fe3O4@UiO/IKCN Photo-Fenton Degradation of Phenol-Containing Wastewater and Its Mechanism
Phenolic compounds, widely used in petrochemical, textile, and pharmaceutical industries, pose severe risks to ecosystems and human health due to their toxicity and persistence. Traditional Fe2+-mediated Fenton oxidation, while effective, suffers from external H2O2 and Fe2+ addition, low H2O2 utilization, narrow pH adaptability, and iron sludge generation. This study develops a g-C3N4-based heterogeneous photo-Fenton system that operates without external H2O2 or Fe2+ salts, exhibiting a wide pH range and minimal iron sludge. The synthesized Fe3O4@UiO/IKCN catalyst, under visible light, selectively reduces dissolved oxygen to H2O2 via a two-electron pathway and activates it to hydroxyl radicals (·OH), achieving efficient degradation of phenolic compounds. The integration of photocatalytic H2O2 formation and Fenton activation enables sustained production of oxidative species, demonstrating superior performance at circumneutral pH. This work provides new insights into the rational design of heterogeneous Z-scheme photo-Fenton catalysts and offers experimental and theoretical support for photocatalytic H2O2 synthesis and phenolic wastewater treatment.