Effective removal of Eriochrome black T by a novel ZnxCu01-xFe2O4/C3N4 composite under simulated visible light irradiation

Abstract A new ZnxCu1−x Fe2O4/C3N4 composite was successfully prepared through a precipitation-assisted calcining technology. The characterization of the as-synthesized catalysts was performed using various analytical techniques. When compared with pure g-C3N4, pristine ZnFe2O4 and bare CuFe2O4, the ZnxCu1−xFe2O4/g-C3N4 composite exhibits higher photo-catalytic degradation of Eriochrome black T (EBT) under a visible light irradiation. When the molar ratio of Zn/Cu (1/1) and the mass ratio of ZnxCu01−xFe2O4 (50%) in the hybrid nanocomposite, ZnxCu1−xFe2O4/g-C3N4 composite exhibits high EBT removal efficiency of 99.73% by adding sodium persulfate (SPS) in waste water within 120 min of the photocatalytic degradation experiment. Enhanced the visible light absorption ability and the suppression of photoexcited charge carriers is also achieved by forming heterojunctions between Zn0.5Cu0.5Fe2O4 and g-C3N4. The Zn0.5Cu0.5Fe2O4/g-C3N4 exhibited 2.91 times higher degradation efficiency than Zn0.5Cu0.5Fe2O4 nanoparticles and 1.96 times higher degradation efficiency than g-C3N4. The trapping experiments were performed by adding different eliminating agents and it shows that the photodegradation of EBT was mainly caused by electron hole (h+), superoxide ion(·O2−) and sulfate radical (·SO4−). Among these resctive species, electron holes (h+) are the predominant reactive species. This study provided a promising approach for the treatment of contaminated water using ZnxCu1−xFe2O4/g-C3N4 as a photocatalyst.