Mechanistically Guided Design of Magnetic CuFeS ₂ /ZIF‐67 for Efficient PMS Activation via Radical and Non‐Radical Pathways Toward Ultra‐Fast Dye Degradation

A well‐structured magnetic CuFeS 2 /ZIF‐67 hybrid catalyst was synthesized by embedding CuFeS 2 nanoparticles into a ZIF‐67 framework for efficient peroxymonosulfate (PMS) activation and ultrafast dye degradation. The redox‐rich Cu─Fe─Co interface promotes rapid electron transfer and continuous PMS activation, resulting in outstanding catalytic performance. Under optimized conditions (catalyst 75 mg L − 1 , PMS 125 mg L − 1 , dye 80 mg L − 1 , pH 6.4, and 20°C), the optimized 0.4‐CuFeS 2 /ZIF‐67 composite achieved 98.06% removal of Reactive Brilliant Blue KN‐R (anthraquinone‐based anionic reactive dye) within 0.5 min, following pseudo‐first‐order kinetics with a high rate constant (k obs = 7.49 min − 1 ). Electron paramagnetic resonance and quenching experiments confirmed the coexistence of radical species (SO 4 • − , •OH, and O 2 • − ) and a non‐radical pathway involving 1 O 2 , with singlet oxygen identified as the dominant oxidant. The enhanced activity originates from the synergistic Cu + /Cu 2 + , Fe 2 + /Fe 3 + , and Co 2 + /Co 3 + redox cycling, while sulfur species (S 2 − /S 2 2 − ) act as electron mediators that promote charge transfer and stabilize active sites during PMS activation. The catalyst retained over 83% activity after repeated cycles with negligible metal leaching (Cu 0.010 mg L − 1 , Fe 0.033 mg L − 1 , Co 0.09 mg L − 1 ). Significant total organic carbon removal (52.81%) demonstrates effective mineralization, highlighting its potential for sustainable wastewater treatment applications.