Fabrication of Sustainable Ternary Magnetic BiOCl/BiOBr/CuFe₂O₄ Heterostructures for Degradation of Tetracycline

A ternary BiOCl/BiOBr/CuFe₂O₄ (CBCF) nanocomposite was successfully synthesized by integrating CuFe₂O₄ nanospheres with BiOCl and BiOBr. The properties of the synthesized photocatalysts were characterized thoroughly using corresponding techniques to confirm the successful formation of the heterostructure. Photocatalytic experiments revealed that the BiOCl/BiOBr/CuFe₂O₄ composite achieved a TC degradation efficiency of 87.4% within 180 min under visible light irradiation, significantly outperforming its individual components and binary counterparts. ESR (electron spin resonance) and active species trapping tests verified the reactive oxygen species (ROS) were superoxide radicals (·O₂^-), holes (h⁺), and hydroxyl radicals (·OH), with ·O₂^- as the most critical active species in the photodegradation. Experimental and DFT studies supported the formation of a favorable Type-I/S-scheme charge transfer pathway in the heterostructure. Additionally, the saturation magnetization of CBCF-0.15 was measured to be 12.35 emu/g, which enabled its excellent recyclability through magnetic separation. The material maintained 78.2% retention of the catalytic activity after four cycles. This work highlights a promising strategy for designing efficient, magnetically recoverable, and environmentally benign photocatalysts for antibiotic wastewater treatment.