Emerging Phosphate-Functionalized Co 3 O 4 /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 Co 3 O 4 /kaolinite (P-Co 3 O 4 /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-Co 3 O 4 /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 Co 2+ /Co 3+ cycles. Furthermore, the • OH radical was identified as the dominating reactive species for the degradation of Orange II compared to the SO 4 •- radical. This work could offer a novel preparation strategy for emerging functionalized nanoclay-based catalysts for effective pollutant degradation.