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

Abstract

Magnetic CoFe2O4 nanoparticles have received considerable attention as an activator for peroxymonosulfate (PMS) in the degradation of tetracycline. However, it is still challenging to construct CoFe2O4 composites with good dispersion and highly exposed reactive sites. Herein, the KOH fiber-functionalized MXene matrix decorated by cobalt ferrite nanoparticles (denoted as CoFe2O4@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 CoFe2O4@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 Ti2+/Ti4+, Co2+/Co3+ and Fe3+/Fe2+, 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, CoFe2O4@Alk-MXene/PMS emerges as a promising catalytic system for TC removal.