Efficient polyvinyl alcohol degradation via peroxymonosulfate activated by natural illite supported CoNi3O4 nanosheets

Abstract

In this study, natural illite supported CoNi3O4 nanosheets (CN@I) were fabricated using a simple one-step coprecipitation process and tested for their ability to activate peroxymonosulfate (PMS) for polyvinyl alcohol (PVA) degradation. The probable activation mechanism of PMS by CN@I might be ascribed to the natural mineral carrier effect, numerous surface-bonded and structural hydroxyl groups, and efficient bonding with Co or Ni ions, according to density function theory (DFT) calculations. It is deduced from the results of electron paramagnetic resonance (EPR) and radical quenching tests that both the radical (•OH and SO4•-) and non-radical (1O2) pathways were engaged in the CN@I/PMS degradation of PVA. In addition, the possible degradation pathways of PVA were proposed based on the DFT calculation. The optimum operational conditions, impacts of ions and the reusability of catalyst during CN@I/PMS degradation of PVA degradation were further investigated. This work provides an interesting direction for the use of natural mineral-based catalysts to activate PMS for the treatment of PVA wastewater.