Hierarchical nano-vesicles with bimetal-encapsulated for peroxymonosulfate activation. Singlet oxygen-dominated oxidation process

Abstract

Hierarchical nano-vesicles with bimetal-encapsulated (FeCu1.5O3@NV) was designed for peroxymonosulfate (PMS) activation with the 1O2-dominated oxidation process. Different from previous core–shell metal-loaded catalysts, FeCu1.5O3 was encapsulated in hollow zeolite spheres, and these zeolite sphere units assembled to construct hierarchical nano-vesicles. Owning to mesoporous shell and abundant interior cavity, FeCu1.5O3@NV could enrich reactants in cavity for enhancing the contact with active sites. The flexible surface of bimetal oxides strengthened the affinity with surface adsorbates and substrates, accelerating the electron transfer between reactants. DFT calculation indicated that FeCu1.5O3@NV possessed strong binding affinity for BPA and PMS, facilitating PMS activation and BPA degradation inside of hollow sphere units. Being attributed to the synergistic effect of bimetal redox couples and hierarchical nano-vesicle structure, large amounts of 1O2 could be generated through two pathways for BPA degradation. The first pathway is the reaction between bimetal redox couples and PMS, and the second is the chain reaction of O2•−. Due to bimetal oxides uniformly encapsulated in hierarchical nano-vesicles, FeCu1.5O3@NV possessed high catalytic stability with negligible metal leaching. Even after 5 cycles, BPA removal could still remain 100%.