Enhanced degradation of carbamazepine in water over Fe3O4@ZIF-8 nanocomposites with persulfate or peroxymonosulfate as activator

In this work, the Fe3O4@ZIF-8 catalyst was prepared by combining Fe3O4 with ZIF-8 for degrading carbamazepine (CBZ) in water, using activated persulfate (PS) and peroxymonosulfate (PMS). We investigated the optimal catalysts and reaction conditions for using PS or PMS as activators by varying the pH, temperature, catalyst dosage, as well as the dosage of PS and PMS, respectively. The results demonstrated that the CBZ removal rate using Fe3O4@ZIF-8 reached 98.1% after 30 min with a mass ratio of Fe3O4 to ZIF-8 = 3:1, temperature = 40°C, catalyst dosage = 0.50 g·L-1, and PS dosage = 0.25 g·L-1, using pH = 3.0. Characterization results show due to the fact that the presence of ZIF-8 facilitates the dispersion of the catalytic active species Fe3O4, prevents the agglomeration of the active species, increases the number of active species, and improves the catalytic performance. Furthermore, radical quenching assay and electron paramagnetic resonance spectra successfully identified the main oxidizing components generated in the system, namely SO4•− and •OH.