In-situ construction of Bi4O5I2/COF S-scheme heterojunction for enhanced photocatalytic degradation of tetracycline

Covalent organic frameworks (COFs) are promising materials for wastewater purification owing to their wide photoresponse range, abundant active sites, adjustable porosity, and efficient electron transfer. In this work, a novel S-scheme heterojunction was constructed by coupling bismuth-rich bismuth iodide oxide Bi 4 O 5 I 2 with functional β-ketoenamine COFs (TATP) via in-situ solvothermal reaction. The optimized composite 2-TPBI exhibits enhanced photocatalytic activity, achieving 88.55 % TC removal within 120 min under visible light irradiation. This performance enhancement is attributed to improved light absorption and efficient spatial separation of photogenerated charge carriers by the S-scheme heterojunction. This work opened up a new avenue for designing high-performance heterostructured photocatalysts through an inorganic/organic coupling strategy for efficient wastewater remediation.