Pyridine-functionalized iron phthalocyanine activates peroxymonosulfate for efficient catalytic degradation of carbamazepine

Abstract

Recently, (PMS)-based advanced oxidation processes (AOPs) for the removal of organic pollutants in water have garnered widespread attention. In this study, oxalyl chloride (COCl) is connected with 4-aminopyridine (py) through an amide bond to prepare py–COCl, and then py–COCl is coordinated with iron phthalocyanine (FePc) to prepare a FePc–py–COCl composite catalyst. Characterization studies such as FTIR, XRD and XPS proved the successful preparation of the catalyst. Catalytic experiments discovered that FePc–py–COCl can efficiently activate PMS and completely degrade carbamazepine (CBZ) within 15 min when the PMS concentration is 0.8 mM. The influences of the PMS concentration, pH and inorganic salt on the FePc–py–COCl/PMS catalytic system were discussed. Additionally, through free radical quenching experiments, methyl phenyl sulfoxide (PMSO) probing methods, and electron paramagnetic resonance, it was found that the degradation of CBZ is the result of the synergistic action of Fe(IV)O, SO₄˙⁻, ˙OH, ¹O₂ and O₂˙⁻, among which ¹O₂ and O₂˙⁻ are the main active substances.