Ozone activation over core-shell nanoreactors for enhanced organic pollutants degradation: Surface-bound superoxide...

The ubiquity of conventional radical-mediated oxidation pathways in ozone-based advanced oxidation processes (AOPs) fundamentally limits their practical efficacy, particularly in achieving efficient organic degradation while minimizing interference from complex water matrices. To address this challenge, a novel core-shell nanoreactor (FeMn-700) was constructed through controlled pyrolysis of FeMn Prussian blue analogue (PBA) precursors for catalytic ozonation. This architecture creates a confined microenvironment where synergistic interactions between Fe/Mn active sites and reactants enable surface-mediated oxidation mechanisms. The FeMn-700/O₃ system demonstrated exceptional performance, achieving complete removal of phenol (20.0 mg L^-1) within 20.0 min with a remarkable rate constant (k) of 0.66 min^-1. Crucially, the nanoconfinement effect confers superior tolerance to diverse ionic interference and maintains 100.0 % efficiency in real water matrices (lake water, rainwater, sea water, tap water and secondary settling tank water). Mechanistic studies reveal that spatial confinement facilitates reactant enrichment and promotes surface-bound superoxide radical (O₂^•-) formation, bypassing conventional bulk-phase ^•OH pathways. Toxicity evaluation revealed substantial reduction in ecotoxicity during degradation, confirming effective detoxification. This work provides new insights into the design of confined catalytic systems for water remediation, offering a promising solution to overcome the matrix interference limitations of conventional AOPs.