The POM@MOF hybrid derived hierarchical hollow Mo/Co bimetal oxides nanocages for efficiently activating peroxymonosulfate to degrade levofloxacin

Abstract

Herein, we reported the design and fabrication of polyoxometalates coupling metal-organic framework (POM@MOF) hybrids derived hierarchical hollow Mo/Co bimetal oxides nanocages (Mo/Co HHBONs) for the peroxymonosulfate (PMS) activation to degrade levofloxacin (Lev). The Mo/Co HHBONs are hollow nanocages with high specific-surface areas and hierarchical micropores, mesopores, and macropores. In addition to compositional modulation, polyoxometalate (H3PMo12O40·nH2O) exhibited striking effect on the textural properties of Mo/Co HHBONs. The Mo/Co HHBONs had outstanding catalytic activity with first order-kinetics that were 6 − 10 times higher those previously reported. They exhibited good adaptability over a pH range of 3 − 11, as well as excellent universality and reusability. By altering the surface porosity, electronic structure, and oxygen vacancies of Co3O4, hetero-metal Mo doping induced Mo/Co HHBONs significantly promote the generation of reactive oxygen species, including •OH, SO4•−, O2•−, and 1O2. Density functional theory indicated that Mo/Co HHBONs had better adsorption, enhanced electron-transfer abilities, and a longer O-O bond length than did Co3O4, for improved catalytic reactivity. This research provides a new strategy to design the POM@MOF hybrids derived hierarchical hollow nanocages with highly PMS activating capacity for the removal of antibiotics and other refractory contaminants.