Synthesis of Cu2+-doped Magnetic ZnFe2O4 for Catalyzing PMS to Remove Tetracycline Hydrochloride

To address the limited catalytic activity of ZnFe2O4 in advanced oxidation process (AOP), Cu2+-doped ZnFe2O4 (Cu0.1Zn0.9Fe2O4) was synthesized using a simple one-pot hydrothermal method. Comprehensive characterization tests indicated that Cu2+ ions were doped into the lattice of ZnFe2O4 without changing the crystal structure. The introduction of Cu2+ ions made the sample highly ferromagnetic, with a specific magnetization of 25.7 emu/g. Cu0.1Zn0.9Fe2O4 was employed to catalyze the degradation of tetracycline hydrochloride (TCH). Systematic experiments indicate that the highest TCH removal reached 96.12 %, which was 40 % higher than that of ZnFe2O4. Coexisting inorganic anions in solution had very limited impact on the catalytic performance of Cu0.1Zn0.9Fe2O4. And after 5 cycles, the removal rate of TCH remained 71.06 %. ROS quenching tests suggest that 1O2 and O2•- played a dominant role in the AOP reaction.