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

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 ZnYxFe2-xO4 (x = 0, 0.25, 0.5 and 0.75) catalysts, ZnY0.25Fe1.75O4 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 ZnY0.25Fe1.75O4/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 (kobs) was positively correlated with the content of Ov in ZnYxFe2-xO4 catalysts. The enhancement of catalytic activity of ZnY0.25Fe1.75O4 was closely associated with Ov 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 ZnY0.25Fe1.75O4 were investigated to assess the practical application potential.