Efficient Degradation of Chlortetracycline by Graphene Supported Cobalt Oxide Activated Peroxydisulfate: Performances and Mechanisms

Abstract

Cobalt oxide has good catalytic activity for peroxydisulfate (PDS) activation but poor stability and is vulnerable to inactivation because of agglomeration. In this work, the chlortetracycline (CTC) degradation by peroxydisulfate (PDS) catalysis using the reduced graphene oxide support cobalt oxide (Co3O4/rGO) composite catalyst was investigated. It was found that 86.3% of CTC was degraded within 120 min in the Co3O4/rGO-800/PDS system. The influences of catalyst dosage, PDS concentration, solution pH, and reaction temperature were systematically explored. The excellent removal performance of CTC could be attributed to the synergistic effect between adsorption and catalytic degradation. ≡Co2+ and surface functional groups played as active sites to catalyze PDS, and the circulation of ≡Co2+/≡Co3+ was achieved. Moreover, Co3O4/rGO-800 showed satisfactory reusability after three cycles. This research can provide useful information for the development of efficient PDS catalysts and facilitate insights into CTC degradation mechanism.