Facile synthesis of a magnetically separable g-C 3 N 4 /CuFe 2 O 4 Z-scheme heterojunction with enhanced visible-light photocatalytic performance for rhodamine B degradation

Abstract Developing efficient and recyclable photocatalysts for visible-light-driven degradation of organic pollutants remains crucial for sustainable water purification. Herein, a magnetically separable g-C 3 N 4 /CuFe 2 O 4 heterojunction nanocomposite was synthesized through a simple solvothermal route. The material was comprehensively characterized by XRD, FTIR, SEM-EDX, BET, UV-Vis DRS, PL, and vibrating sample magnetometer analyses, confirming a well-integrated heterostructure in which CuFe 2 O 4 nanoparticles were uniformly anchored on g-C 3 N 4 nanosheets. The optimized composite (N 3 ) achieved 99.6% degradation of Rhodamine B within 150 min under visible light, with an apparent rate constant of 10.81 × 10 −3 min −1 , which is 5.7 and 52 times higher than pristine g-C 3 N 4 and CuFe 2 O 4 , respectively. Radical-trapping tests revealed that • OH and • O 2 − species dominated the reaction. Band-edge analysis and photoluminescence quenching indicated a direct Z-scheme charge-transfer mechanism, effectively suppressing electron–hole recombination and maintaining strong redox ability. The photocatalyst exhibited excellent magnetic recoverability and retained over 95% of its activity after five cycles. This work demonstrates a facile and scalable approach to designing visible-light-active, magnetically retrievable Z-scheme photocatalysts for efficient wastewater treatment.