Enhanced tetracycline degradation efficiency by CoFe2O4 decorated TA-ZIF-8 catalyst via activating peroxymonosulfate under confinement effect

Spinel oxides can be considered effective heterogeneous catalysts in activating peroxymonosulfate (PMS) for wastewater decontamination . However, the intrinsic characteristics of agglomeration and metal ion leaching impede its further application. In this work, to further improve the catalytic efficiency and stability of the catalyst, ZIF-8 was employed as the candidate and further etched by tannic acid (TA) to obtain a core-shell structure with less mass transfer resistance. Following this, CoFe 2 O 4 was anchored on TA-ZIF-8 matrix via a hydrothermal method. Benefiting from the tailored core-shell structure and high activity of CoFe 2 O 4 , the as-prepared CoFe 2 O 4 @TA-ZIF-8 catalyst shortened the mass transfer distance of radical to target pollutant, thus realizing high radical utilization efficiency. Accordingly, 98.1% of tetracycline (TC) can be eliminated in 30 min with kinetic constants 3.15 times higher than pristine CoFe 2 O 4 . Besides, the TC degradation efficiency can still maintain 84.1% after five consecutive cycles with cobalt leaching lower than 0.306 mg/L, showing favorable stability compared with pristine CoFe 2 O 4 . Furthermore, electron paramagnetic resonance (EPR) and quenching experiments exhibited that singlet oxygen and sulfate radicals play dominant roles in TC degradation processes. This work fabricates an efficient CoFe 2 O 4 @TA-ZIF-8 heterogeneous catalyst for degrading refractory TC, which may possess potential applications in wastewater treatment .