Oligolayered Co@MXene with a Co···SO3 cation-π bridge for ultra-rapid catalytic oxidation of a novel “forever chemical” OBS

Sodium p -perfluorous nonenoxybenzene sulfonate (OBS) as a novel alternative to perfluorooctane sulfonate (PFOS), belongs to the family of per- and polyfluoroalkyl substances (PFASs). We demonstrated that Co-based oligolayered MXene (Co@o-MXene) achieved the complete oxidation of OBS during catalytic ozonation with peroxymonosulfate (PMS). The optimized catalyst exhibited 78.5% OBS oxidation in only 2 min, and the oxidation route was thoroughly investigated by Fukui function calculations and QTOF-MS/MS analysis. However, within the fluoroprotein (FP) foam solution, high TOC removal was performed via the newly designed two-stage ozonation process. Systematic studies indicated that OBS can donate electrons through a Co···SO 3 cation-π bridge on the surface of o-MXene/PMS accompanied by the generation of reactive oxygen species (ROS), the strong adsorption energy (Eads) value of PMS, enhanced total density of states (TDOS) and uneven electron density in this reaction system. This work extended the potential of newly developed MXene family materials to decompose PFAS. • Co···SO 3 cation-π interaction enhance the interface electron transfer. • Co@o-Mxene exhibited high catalytic efficiency for OBS degradation. • The double bond and benzene ring were the vulnerable site for ROS attacking. • Both OBS degradation in FP and TOC removal of FP foam could be achieved. • Electron-donating OBS reconstructed HOBE-LUBE and differential charge densities.