Shape-selective catalytic degradation of sulfamethoxazole via singlet oxygen generation by Cu-ZSM-5/Ti3C2 composite

Sulfamethoxazole (SMX), a widely used sulfonamide antibiotic, is a persistent aquatic pollutant due to its resistance to conventional treatment. Here, a Cu-ZSM-5/Ti 3 C 2 composite catalyst was fabricated by electrostatic self-assembly for peroxymonosulfate (PMS) activation. Characterization by XRD, SEM, TEM, XPS, and zeta potential analysis confirmed the successful integration of the components. The catalyst achieved 97.59% removal of 10 mg/L SMX within 30 min. Quenching and EPR results indicated that 1 O 2 was the major reactive species. The enhanced performance under alkaline conditions was associated with the negatively charged composite surface (-38.8 mV at pH 9), the deprotonated state of SMX, and favorable interfacial interactions that may promote preferential oxidation of the isoxazole moiety. Control experiments using a physically mixed sample showed markedly lower activity, especially at pH 11, highlighting the importance of the intimate heterointerface created by self-assembly. The superior activity was attributed to the synergistic interaction between Cu species in Cu-ZSM-5 and Ti-based sites in Ti 3 C 2 . This work provides insight into designing selective PMS activation catalysts for antibiotic-contaminated water treatment.