Nanosized mesoporous iron manganese bimetal oxides anchored on natural kaolinite as highly efficient hydrogen peroxide catalyst for polyvinyl alcohol degradation

In this study, IM@K was prepared by anchoring Fe-Mn bimetal oxide nanoparticles on natural kaolinite through hydrothermal method. And then the degradation efficiency of activating hydrogen peroxide (H2O2) towards polyvinyl alcohol (PVA) was tested. Several catalysts were characterized to investigate the connections between catalytic property and activity. Overall, more hydroxyl groups, larger specific surface area and pore volume of IM@k lead to the greater catalytic activity compared to bare MnFe2O4. In addition, the presence of Na+, K+, Zn2+, Cl-, NO3-, SiO32- and SO42- has little effect on the degradation of PVA. Both Cu2+ and Ni2+ promoted degradation. Nevertheless, F- and HCO3- showed obvious suppression effects. Electron paramagnetic resonance (EPR) and radical quenching experiments proved that the hydroxyl radicals (OH center dot) generated by Fe(III)/Fe(II) and Mn(IV)/Mn(III)/Mn(II) redox reactions are the main free radicals. In summary, IM@k can be used as a kind of clay-based catalyst to activate H2O2 to degrade PVA solution. (C) 2021 Elsevier B.V. All rights reserved.