Emerging Phosphate-Functionalized Co3O4/Kaolinite Composites for Enhanced Activation of Peroxymonosulfate

The Fenton-like reaction, as one of the most efficient strategies to generate radical species for the degradation of environmental pollutants, has attracted considerable attention. However, engineering low-cost catalysts with excellent activity by phosphate surface functionalization has seldom been used for the activation of peroxymonosulfate (PMS). Herein, emerging phosphate-functionalized Co3O4/kaolinite (P-Co3O4/Kaol) catalysts have been prepared by hydrothermal and phosphorization. Kaolinite nanoclay with rich hydroxyl groups plays a vital role in realizing phosphate functionalization. The results indicate that P-Co3O4/Kaol shows superior catalytic performance and excellent stability to the degradation of Orange II, which could be attributed to the existence of phosphate that promotes the adsorption of PMS and the electron transfer of Co2+/Co3+ cycles. Furthermore, the •OH radical was identified as the dominating reactive species for the degradation of Orange II compared to the SO4•- radical. This work could offer a novel preparation strategy for emerging functionalized nanoclay-based catalysts for effective pollutant degradation.