Cobalt-Enhanced Mass Transfer and Catalytic Production of Sulfate Radicals in MOF-Derived CeO2 • Co3O4 Nanoflowers for Efficient Degradation of Antibiotics

Antibiotics discharge has been a critical issue as the abuse in clinical disease treatment and aquaculture industry. Advanced oxidation process (AOPs) is regarded as a promising approach to degrade organic pollutants from wastewater, however, the catalysts for AOPs always present low activities, and uncontrollable porosities, thus hindering their further wider applications. In this work, an aliovalent-substitution strategy is employed in metal-organic framework (MOF) precursors assembly, aiming to introduce Co(II/III) into Ce-O clusters which could modify the structure of the clusters, then change the crystallization, enlarge the surface area, and regulate the morphology. The introduction of Co(II/III) also enlarges the pore size for mass transfer and enriches the active sites for the production of sulfate radicals (SO) in MOF-derived catalysts, leading to excellent performance in antibiotics removal. Significantly, the CeO•CoO nanoflowers could efficiently enhance the generation of sulfate radical SO and promote the norfloxacin removal efficiency to 99% within 20 min. The CeO•CoO nanoflowers also present remarkable universality toward various antibiotics and organic pollutants. The aliovalent-substitution strategy is anticipated to find wide use in the exploration of high-performance MOF-derived catalysts for various applications.