Beschreibung:
A novel heterogeneous manganese/graphitic carbon nitride (Mn3O4-CN) catalyst for activating peroxymonosulfate (PMS) was successfully assembled by alkali precipitation. The g-C3N4 improved the surface morphology, microporous structure, surface area and particle size distribution of the composite, and an electron rich center with Mn site was created. The Mn3O4-CN/PMS system exhibited high efficacy and stability when the solution pH varied from 3.0 to 9.0, with more than 90% p-acetaminophen (ACT) removal in 30 min under experimental conditions. A possible reaction mechanism was proposed that mainly involved electron transfer from Mn (II) and Mn (III) to PMS along with the generation of ·O2- and 1O2, and the degradation of ACT was attributed to the 1O2. Specifically, it was found that the degradation rate of phenolic compounds varied with their molecular structure, as followed ACT > bisphenol A (BPA) > p-cresol (MP) > p-chlorophenol (CP) > phenol (Ph) > p-nitrophenol (NP). Further, density functional theory (DFT) calculation indicated that the degradation efficiency of phenols was related to their adsorption energy and Bader charge value. All these results improved our understanding of the Manganese-based PMS non-radical dominated process and could predict the degradation of phenols