Mechanistically Guided Design of Magnetic CuFeS2/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. Graphical A magnetic CuFeS 2 /ZIF-67 hybrid catalyst enables ultrafast peroxymonosulfate activation through synergistic Cu─Fe─Co interfacial redox cycling and rapid electron transfer. Dominant singlet oxygen and radical pathways achieve rapid dye degradation, substantial mineralization, excellent recyclability, and low metal leaching, demonstrating strong potential for sustainable wastewater remediation under mild operating conditions.