Wastewater flocculation substrate derived three-dimensional ordered macroporous Co single-atom catalyst for singlet oxygen-dominated peroxymonosulfate activation

Herein, wastewater flocculation substrate is used as a carbon source to prepare a three-dimensional ordered macroporous (3DOM) structure carbon-based catalyst with the CoN4 coordination active sites (Co-NC-PS) through a hard-template strategy. Abundant single-atom CoN4 active sites endow the Co-NC-PS with splendid performance in degrading organic pollutants by activating peroxymonosulfate (PMS). Experiment results show that the singlet oxygen (1O2) is the main reactive oxygen species (ROSs) for bisphenol A (BPA) degradation. The strong coordination of Co atoms with N atoms not merely avoids the leaching of Co and improves the stability of the catalyst but also establishes stable adsorption configuration and facilitates the generation of 1O2 proven by density functional theory (DFT) calculations. This study provides the design of efficient Co carbon-based catalysts in mint conditions with high stability for water treatment, as well as a new idea for the preparation of high-value-added products from the recycling of flocculated waste.