Environmentally adaptable Fe/Pd bimetallic catalysts immobilized in ZIF-8 for efficient degradation of sulfadiazine through dual-pathway activation of PMS.

In this study, A bimetallic Fe/Pd@ZIF-8 catalyst (with a Fe/Pd mass ratio of 1000:1) was constructed for peroxymonosulfate (PMS) activation to degrade sulfadiazine (SDZ). Within 30 min, SDZ removal reached 96.7 % (kobs = 0.6608 min-1), accompanied by 77 % total organic carbon (TOC) reduction. Quenching experiments and electron paramagnetic resonance (EPR) analysis confirmed that 1O2 and SO4•- were the predominant reactive species involved in the oxidative process. Notably, this study successfully incorporated trace amounts of Pd and Fe in a synergistic manner onto the ZIF-8 support, enabling efficient PMS activation with minimal consumption of noble metals, thus presenting a novel strategy for catalyst design. The Fe/Pd@ZIF-8/PMS system also exhibited excellent performance in different real water matrices and broad-spectrum degradation of bisphenol A (96.4 %), 2,4-dichlorophenol (83.0 %), and ofloxacin (97.6 %). After three consecutive cycles, the SDZ removal efficiency was still 71.5 %, confirming the catalyst's stability. Density functional theory (DFT) and liquid chromatography-mass spectrometry analyses identified the vulnerable sites of SDZ and proposed four degradation pathways, while ECOSAR prediction suggested that some intermediates might pose potential ecological risks. Overall, this study demonstrates the high efficiency, environmental adaptability, and reusability of Fe/Pd@ZIF-8 for PMS activation, highlighting its potential for practical applications in antibiotic pollution control.