Rational design of core-shell polyvinylpyrrolidone (PVP)-MIL-101(Fe)@CoZn-ZIF nanocomposites for peroxymonosulfate activation toward 4-nitrophenol degradation

Designing stable and efficient heterogeneous catalysts for peroxymonosulfate (PMS) activation remains a critical challenge in advanced oxidation processes. Herein, we prepared a polyvinylpyrrolidone (PVP)-modified MIL-101(Fe)@CoZn-ZIF (PVP-MCZ) core-shell nanocomposite that synergistically combined enhanced catalytic activity with exceptional stability. The PVP-MCZ catalyst achieved complete degradation of 4-nitrophenol (4-NP) (20 mg/L) within 15 min, while suppressing metal leaching (<0.5 mg/L). Comprehensive characterization (XPS, EPR) revealed a dual-pathway mechanism: (i) radical-dominated SO 4 − generation via Co 2+ /Co 3+ and Fe 2+ /Fe 3+ redox cycling, and (ii) non-radical 1 O 2 production from PMS self-decomposition. This work provides a scalable strategy to design MOF-based catalysts for sustainable water remediation.