Highly efficient activation of peroxymonosulfate by illite-based ultrafine cobalt oxide for the degradation of polyvinyl alcohol

A catalyst was prepared using illite coated with Co 3 O 4 to activate peroxymonosulfate (PMS) for polyvinyl alcohol (PVA) degradation. The variance of valence of specific elements, functional groups, surface morphology, and pore structure of fresh illite, fresh Co 3 O 4 @illite and used Co 3 O 4 @illite were also investigated, reflecting the excellent stability of the Co 3 O 4 @illite catalyst. Degradation experiments confirmed that OH ∙ ${\mathit{OH}}^{\bullet }$ , 1 O 2 , and SO 4 ∙ - ${\mathit{SO}}_4^{\bullet -}$ produced by oxygen cavitation reaction acted a significant part in PVA degradation. Moreover, when initial pH = 7, catalyst dosage = 2.0 g/L, PMS concentration = 40 g/L, T = 298 K, the best PVA removal efficiency was got. Also, the adding of H 2 PO 4 − and Cl − concentration could inhibit the degradation of PVA at first and then promoted, while the addition of other ions (i.e., HCO 3 − and CO 3 2− ) always inhibited degradation reaction. The transformation products on the possible degradation pathway of PVA were then proposed. The strategy of this study gave a new perspective for the coming design of the natural-mineral-based catalysts to effectively treat waste through the Fenton like processes.