2D Cobalt-carbon–nitrogen loaded 3D Prussian blue analogues enhances peroxymonosulfate activation for bisphenol A Degradation: Singlet oxygen dominated nonradical pathway

Abstract

Singlet oxygen (1O2) dominated peroxymonosulfate (PMS)-based advanced oxidation processes (AOPs) is an effective technology for the removal of electron-rich organic contaminants. However, the highly selective generation of 1O2 is limited by the development of catalysts. Herein, a two-dimensional (2D) cobalt-carbon–nitrogen loaded three-dimensional (3D) Prussian blue analogue (CoCN@PBA-P) material was synthesized by the one-step method using hematite with different morphologies as the precursor. The two atomically dispersed Co sites in three CoCN@PBA-P were demonstrated that could effectively activate PMS to degrade bisphenol A (BPA) in different and complex environmental backgrounds. The quenching, probe quantitative, and EPR results indicated the dominant role of 1O2 in CoCN@PBA-P/PMS system, and the steady-state concentration of 1O2 can achieve 4.0 × 10-9-1.3 × 10-8 M. Importantly, the role of Co as the active site was verified by screening experiments, and the mechanism of CoCN@PBA-P activate PMS was revealed by experimentally and theoretically, and the pathway to generate 1O2 is *HSO5→*SO4+OH–→*SO4+*OH→*O→1O2 (* represents that the species is bound to the active site). Finally, the analysis of degradation intermediates and their toxicity showed that the whole process is harmless to the environment. This work provides a new perspective to the design of 2D@3D materials and their application in PMS-based AOPs.