Enhanced degradation of sulfamethoxazole in aqueous systems via peroxymonosulfate activation using Co-ZIF-67@Fe-MIL-101 composite catalysts

This study focuses on enhancing the catalytic efficiency and structural stability of Fe-MIL (101) by synthesizing Co-ZIF-67@Fe-MIL (101) through a self-assembly approach for peroxymonosulfate (PMS) activation to degrade sulfamethoxazole (SMX) in water. The findings reveal that applying 100 mg L −1 of Co-ZIF-67@Fe-MIL (101) with 0.4 mM PMS achieved approximately 99.8 % SMX degradation at an initial concentration of 0.04 mM within 10 min, along with an 87.9 % mineralization rate. The activation energy (E a ) was determined to be 42.3 kJ mol −1 , suggesting that the SMX degradation is primarily driven by intrinsic chemical reaction kinetics . The exceptional catalytic performance of Co-ZIF-67@Fe-MIL (101) is attributed to its heterostructure , which enhances active site exposure, electron transfer , and the synergistic interaction between Co-ZIF-67 and Fe-MIL (101). Furthermore, the composite demonstrated notable stability, retaining up to 82 % efficiency over 6 cycles with minimal metal leaching. By-products formed during SMX degradation were identified using liquid chromatography-mass spectrometry (LC-MS), and their ecotoxicity was evaluated using TEST software. This study highlights, for the first time, the potential of Co-ZIF-67@Fe-MIL (101) as an effective catalyst for PMS activation and SMX degradation at low dosages , showcasing its practical applicability due to its reduced metal leaching. • Co-ZIF-67@Fe-MIL(101) achieved 99.8 % SMX degradation via PMS activation. • The composite showed superior stability and reusability compared to single MOFs. • Metal leaching was minimal, meeting environmental protection agency regulations. • 1 O 2 and OH were identified as key reactive species in the PMS activation process.