Coordination Microenvironment Engineering in Nanoconfined Structures Shifts Peracetic Acid Activation toward Broad-Spectrum Radicals for Enhanced Hospital Wastewater Purification

Peracetic acid (PAA) presents a promising solution for hospital wastewater treatment, by integrating direct disinfection with the catalytic generation of oxidative species for pollutant degradation. While nanoconfined catalysts exhibit high efficiency and low metal leaching in PAA activation, their reactive outputs have been largely confined to limited broad-spectrum pollutant removal in such complex wastewater. Herein, we break the traditional paradigm of nanoconfined catalysts favoring nonradical pathways by modulating the iron coordination microenvironment within novel carbon nanotube-confined layered double hydroxides (NC/CoFe-LDHs). The confinement-induced Fe-C coordination stabilizes Fe(II) sites, optimizes PAA adsorption energy, and reduces the Gibbs free energy barrier, collectively promoting formation of ^·OH rather than nonradicals. This strategy achieves both organic radicals (R-O^·) and ^·OH-driven PAA activation, achieving ^·OH yields nearly 7-fold higher than those in unconfined systems. Additionally, Co and modified Fe sites enhance PAA utilization by up to 5.68 folds, improve efficacy factor (EF) by up to 226.5 folds, and boost removal efficiencies for pollutants (by up to 16.7 folds) and pathogenic bacteria. This nanoconfined structure enables continuous 100 h operation in a fixed-bed reactor that achieved >70% removal of dozens of pharmaceuticals in real hospital wastewater along with 100% pathogen disinfection. This work unveils a coordination-mediated pathway-switching mechanism in nanoconfined catalysis and provides a design principle for precise radical control in sustainable water decontamination.