Efficient degradation of tetracycline by heterogeneous cobalt oxide/cerium oxide composites mediated with persulfate

The performance of pure cerium oxide (CeO2) and cobalt oxide (Co3O4) in advance oxidation processes cannot meet the growing pursuit of superior catalytic efficiency. In this study, efficient heterogeneous Co3O4/CeO2 (OE) composites were fabricated by a calcination method to activate persulfate (PS) for tetracycline (TC) degradation. Results showed that OE-2/PS system exhibited the highest TC degradation efficiency (79%), while that of CeO2/PS system and Co3O4/PS system was only 22% and 14%, respectively. Co dispersion and turn over frequency demonstrated the superiority of OE-2 composite. Oxidative sulfate radicals (SO4 center dot-) and hydroxyl radicals (HO center dot) generated in the process contributed to the efficient degradation of TC, which was proved by radical scavenging experiment and electron spin resonce experiment. In addition, the high stability and recycling ability of OE-2 composite were proved by the detection of leaching of Co and Ce ions and cycling test.