Effects of BixOyIz Self‐Combination and Integration With Magnetic CoFe2O4 on the Enhanced Removal Efficiencies for Tetracycline Residues

ABSTRACT The Bi x O y I z and CoFe 2 O 4 combination enhances photocatalytic degradation of tetracyclines (TCs). Three TC antibiotics including TC, oxytetracycline (OTC), and chlortetracycline (CTC) with high concentration (50 mg L −1 ) were utilized as target pollutant. Bi 5 O 7 I/Bi 4 O 5 I 2 , with its Z‐scheme, improves removal efficiency to 1.6 times that of Bi 5 O 7 I and 1.4 times that of Bi 4 O 5 I 2 . Ternary Bi 5 O 7 I/Bi 4 O 5 I 2 /CoFe 2 O 4 (I/I/Co) composites further increase efficiency, with I/I/Co‐2 achieving 1.6 times that of I/I‐2. The improved performance is due to an optimized microstructure, which promotes light absorption and carrier transfer. CoFe 2 O 4 nanoparticles on nanosheets create a double‐Z band structure, enhancing redox activity. Radical trapping experiments indicated the major active species (•O 2 − , OH − , and h + ) in photocatalytic process of I/I/Co‐2. Based on their enhanced removal efficiencies for high‐concentration TCs, proper magnetic separation capacity, and recycling performance, the practical applications of I/I/Co composites to treat real TC wastewater might be implemented.