In-situ fabricating CoFe2O4/g-C3N4 PMS activator for ultra-efficient degradation diverse pollutants: Mechanism and toxicity insight

In-situ preparing robust CoFe 2 O 4 /PCN PMS activator for multi-pollutant degradation. • Complete degradation TC within 3 min with the rate constant 24-fold higher than CN • Degradation intermediates, routes and toxicity were explored • Wide light absorption, exposed active sites, and charge behavior boost photocatalysis Facing the urgent environmental crisis, it is imperative to create an efficient and robust technology for treating diverse pollutants in aquatic environments. Herein, a CoFe 2 O 4 /PCN composite was designed via a facile in-situ growth method, in which CoFe 2 O 4 uniformly grows on carbon nitride. This architecture not only forms a close interface that facilitates efficient charge separation and migration, but also introduces abundant mixed-valence metal sites, that serve as superior active centers for peroxymonosulfate (PMS) activation and subsequent organic pollutant removal. Specifically, under visible light, the optimized catalyst can 100% degrade TC within 3 min (complete degrade rhodamine B within 20 s, methyl orange within 40 s, and methylene blue within 3 min), and the rate constant was 24-fold higher than pristine CN, surpassing most reported catalysts. The catalyst also demonstrates excellent recyclability and broad pH adaptability. The mechanism behind the performance enhancement stems from the significantly broadened light absorption (supported by UV–vis DRS), fully exposed active sites (evidenced by SEM/TEM/AFM and N₂ adsorption), and enhanced charge behaviors (supported by PCR, EIS, PL/TRPL and KPFM), especially caused by strong internal electric field. At last, the active species, degradation intermediates and their toxicity were investigated using TC degradation as a model, coupled with DFT theoretical calculations. This work proposes a rational design strategy toward constructing efficient and robust photocatalysts, revealing significant promise for water remediation. Download: Download high-res image (269KB) Download: Download full-size image