Activation of peroxymonosulfate by nitrogen-doped carbon-supported CoZn bimetallic catalyst for acetaminophen degradation

To address severe metal leaching of cobalt-based catalysts and low activity of zinc-based catalysts, this work constructs a nitrogen-doped carbon-supported CoZn bimetallic catalyst (CoZn-NC). The N-doped carbon support provides stable anchoring for active sites, regulates metal electronic structure via N atoms and inhibits nanoparticle agglomeration. Combined with Co-Zn synergy, high activity and stability are achieved. Under 0.15 g·L⁻¹ catalyst, 0.40 mM PMS and initial pH 6.7, CoZn-NC degrades 99% of 10 mg·L⁻¹ ACT within 2 min with a rate constant of 3.275 min⁻¹, 9.95 and 14.12 times that of Co-NC and Zn-NC, respectively. Co leaching is 94.2% lower than monometallic Co-NC, and Zn leaching is also reduced. The catalyst retains high activity at pH 3–11 and shows excellent resistance to common anions and cations. Quenching tests and EPR confirm multiple reactive species synergistically participate in degradation. This work demonstrates that combining heteronuclear bimetallic synergy with N-doped carbon support effectively suppresses metal leaching while maintaining high activity, offering a feasible pathway for designing low-environmental-risk advanced oxidation catalysts.