Photocatalytic‐Self‐Fenton‐PMS Synergy in Fe/Fe₂O₃@COF Heterojunctions Catalysts for Efficient Tetracycline Removal

ABSTRACT Covalent organic frameworks (COFs) are really starting to shine as star materials in environmental catalysis. Nevertheless, a high electron‐hole recombination speed severely impairs their photocatalytic efficacy. The study innovatively employed an in situ photo deposition technique to construct the Fe/Fe 2 O 3 @COF heterojunction. The characterization findings indicate that the incorporation of Fe/Fe 2 O 3 enhanced the number of active sites, accelerated the Fe 2+ /Fe 3+ redox cycle, and improved the ability to separate photogenerated electron‐hole pairs. At the same time, it adjusted the COF's self‐Fenton catalytic effect, peroxymonosulfate (PMS) activation, and photocatalytic characteristics. In performance assessments, the rate constant for Fe/Fe 2 O 3 @COF reached 4.06 × 10 −2 min −1 , exceeding that of the unmodified COF by a factor of 4.17. Furthermore, the heterojunction exhibited excellent reusability. Superoxide radicals (•O 2 − ) and hydroxyl radicals (•OH) play a crucial role in the degradation process. The study offers an original approach to improving the catalytic properties of iron‐based materials and COFs via heterojunction engineering, offering a practical and environmentally responsible technique to break down antibiotics in wastewater.