Mn-Enhanced Cobalt Silicate-Activated Peroxymonosulfate for Tetracycline Degradation: Inheriting Merit and Offsetting Deficiency of Oxygen Vacancies

Abstract

Recently, the merits of Vo in catalytic areas were studied in detail, and the deficiency of Vo has also attracted much attention. However, when exploring the enhanced mechanism of bimetals for PMS activation, the effect of bimetals on the deficiency of Vo was usually ignored, especially in some Vo-rich bimetallic systems. Herein, the Co–Mn bimetallic silicate system was constructed to elucidate the effect and mechanism. MnCoSi has an edge over CoSi in the degradation performance of TC (0.02325 min–1 up to 0.07952 min–1). The result was assignable to the fact that the introduction of Mn brought more Vo and enhanced the positive effect of Vo. More importantly, the formation of heterogeneous active sites enhanced the adsorption of metal sites to PMS and compensated for the deficiency of Vo. This study enriched the enhancement mechanism of bimetallic systems and provided a theoretical basis for the optimization of catalysts rich in Vo.