Nanoarchitectonics of ternary Zn-Mn-Co oxides for efficient peroxymonosulfate activation and antibiotics degradation via accelerating electron transfer

Abstract

In this work, a new nanoarchitectonics of ZnO/Mn3O4/Co3O4 (ZnMnCoO) was prepared by solvothermal and calcining processes, and used to degrade tetracycline (TC) with peroxymonosulfate (PMS) as oxidant. Coupling of trace Co3O4 (1.48 wt% Co) and difference in work functions of ZnO, Mn3O4, Co3O4 enabled ZnMnCoO to possess good PMS activation performance. 97.8% of TC was degraded in 30 min with reactive rate constant of 0.166 min–1, which was 2.6 and 1.4 times higher than those of Mn3O4/PMS and ZnO/Mn3O4/PMS systems, respectively. It was found that SO4•–, O2•−, 1O2, and complex-mediated electron transfer played the main roles in oxidizing TC. In addition, ZnMnCoO was attached to a polytetrafluoroethylene microfiltration membrane to degrade TC via a flow-through device, and 92.4% of TC (10 ppm TC, tap water) and 78.2% of total organic carbon were removed in 120 min. This study designs a novel composite with low Co content to efficiently activate PMS and degrade antibiotics.