Efficient degradation of tetracycline by cobalt ferrite modified alkaline solution nanofibrous Ti3C2Tx MXene activated peroxymonosulfate system: Mechanism analysis and pathway

Magnetic CoFeO nanoparticles have received considerable attention as an activator for peroxymonosulfate (PMS) in the degradation of tetracycline. However, it is still challenging to construct CoFeO composites with good dispersion and highly exposed reactive sites. Herein, the KOH fiber-functionalized MXene matrix decorated by cobalt ferrite nanoparticles (denoted as CoFeO@Alk-MXene) was developed by electrostatic self-assembly method. The layered fibrotic structure effectively disperses and fixes cobalt ferrite nanoparticles, increasing the exposure of reactive sites. The as-prepared CoFeO@Alk-MXene material exhibited rapid removal of 100% tetracycline hydrochloride (TC-HCl) within 10 minutes by activating PMS, leveraging the excellent conductivity of alkalized MXene and the efficient activation of transition metal atoms. The experimental and theoretical analysis revealed that the electron transfer process of Ti/Ti, Co/Co and Fe/Fe, as well as the free radical and non-free radical attack behaviors produced by the adsorption of PMS by the composite, are the primary mechanisms for achieving rapid removal of pollutants. A comprehensive degradation mechanism and potential pathways were proposed based on these findings. Overall, CoFeO@Alk-MXene/PMS emerges as a promising catalytic system for TC removal.