Catalytic oxidation of naproxen in cobalt spinel ferrite decorated Ti₃C₂T_x MXene activated persulfate system: Mechanisms and pathways

Naproxen (NPX) is a nonsteroidal anti-inflammatory drug that, at concentrations of 20 ng/L to several µg/L in aqueous environments, can cause detrimental effects to human and ecosystem health. A heterogeneous nanocatalyst composed of two-dimensional MXene nanosheets functionalized with CoFe₂O₄ nanoparticles was fabricated by liquid self-assembly for the activation of persulfate (PS) to degrade NPX. Approximately 99.1% of NPX was degraded within 90 min with the addition of 0.5 mM PS at 1 g/L of CoFe₂O₄@MXene dosage. To better understand the removal process, different influencing parameters, including the solution pH, catalyst dosage, and PS concentration, during NPX removal were studied. Radical scavenging and electron spin resonance experiments revealed that both radical (i.e., O₂^[rad]−, ^[rad]OH, SO₄^[rad]−, and S₂O₈^[rad]−) and nonradical (i.e., ¹O₂) pathways were involved in the catalytic degradation of NPX. The results suggest that CoFe₂O₄@MXene/PS is a promising catalytic system for the treatment of water polluted with NPX.