S-doped rich-defect cobalt-based carbon catalyst derived from cobalt phthalocyanine as catalysts of peroxymonosulfate for degradation of tetracycline hydrochloride from water

Abstract

Organic pollution is a serious problem in the water environment. Peroxymonosulfat (PMS)- based advanced oxidation processes (AOPs) is the optimal way to treat such pollution. To better activate PMS, the S-doped cobalt-based carbon catalysts are attracting considerable attention. In this work, a mixture of cobalt phthalocyanine (CoPc) and thiourea was used as precursor to prepare CoPc-S-800 under Ar atmosphere at 800℃. Subsequently, CoPc-S-800 was used to activate PMS for degrading tetracycline hydrochloride (TC• HCl). In addition, experiments and X-ray photoelectron spectroscopy (XPS) showed that the introduction of S can promote the redox cycle of CO (III)/CO (II). Electron paramagnetic resonance (EPR) suggested that •OH, SO4• −, O2• − and 1O2 played important roles in TC• HCl degradation. This study investigated the influence of pH, different sources of water, and anions/cations/halogen ions on TC• HCl degradation. The results showed the CoPc-S-800/PMS system maintained excellent performance. This study provides a new strategy for TC• HCl degradation using cobalt-based carbon catalysts with CoPc as precursor. This work also elucidates the reaction mechanism of PMS activation by the catalyst.