Synergistic activation of peroxymonosulfate via oxygen vacancy-rich CoxMn3-xO4/montmorillonite catalyst for environmental remediation

Layered montmorillonite with abundant hydroxyl groups was employed as a supporting matrix to anchored oxygen vacancy-rich Co1.3Mn1.7O4 nanoparticles (CM/Mt) for environmental remediation. The optimal CM/Mt. composite could efficiently degrade bisphenol A (BPA) in the presence of peroxymonosulfate to exhibit the highest degradation efficiency of 98% within 21 min, which was about 1.4-fold higher than that of pristine Co1.3Mn1.7O4 nanoparticles. The junction of montmorillonite and Co1.3Mn1.7O4 nanoparticles boosts the specific surface area and provides more hydroxyl anchored sites by effectively reducing the grain size and agglomeration of Co1.3Mn1.7O4, which was conducive to the enrichment of pollutants and provides sufficient active sites for the degradation reaction. The liquid chromatogram and mass spectra were adopted to characterize the intermediates and degradation routes for the BPA degradation process. Radical quenching and EPR results confirm that the 1O2 was the dominant active species in the oxidation process, which benefited from the existence of abundant oxygen vacancies in the CM/Mt. composite. This work not only provides a new high-efficiency clay-based catalyst for PMS activation, but also explores a kind of high value-added product of montmorillonite.