Enhanced activation of peroxymonosulfate using Y³⁺ substituted magnetic nanostructured ZnFe₂O₄ for carbamazepine...

The catalytic performance of magnetic nanostructured ZnFe₂O₄ can be feasibly improved by metal cations doping. In this work, Y³⁺ doping at B-site of ZnFe₂O₄ was successfully synthesized and used to activate peroxymonosulfate (PMS) for carbamazepine (CBZ) degradation. Among the ZnY_xFe_2-xO₄ (x = 0, 0.25, 0.5 and 0.75) catalysts, ZnY_0.25Fe_1.75O₄ achieved the best catalytic activity, with a CBZ removal efficiency of 91.0 % after 60 min reaction. The control experiments indicated that the removal of CBZ in ZnY_0.25Fe_1.75O₄/PMS system was mainly attributed to the heterogeneous catalysis rather than the homogeneous catalysis by the leached metal ions. With free radicals quenching experiments and EPR tests, O₂•^- and ¹O₂ were mainly responsible for the degradation of CBZ. Significantly, the correlation between Y doping and catalytic activity was explored, and the results suggested that reaction rate constant (k_obs) was positively correlated with the content of O_v in ZnY_xFe_2-xO₄ catalysts. The enhancement of catalytic activity of ZnY_0.25Fe_1.75O₄ was closely associated with O_v which facilitated the adsorption of PMS, promoted the production of O₂•^- and ¹O₂ and accelerated the electron transfer in the system. Finally, the reusability and universality of ZnY_0.25Fe_1.75O₄ were investigated to assess the practical application potential.