High adaptability and stability FeCo2O4/diatomite composite for efficient peroxymonosulfate activation: Performance, water matrix impact, and mechanism

The adaptability and stability of catalysts guarantee efficient catalytic performance. Hence, we fabricated FeCo 2 O 4 /diatomite for efficient peroxymonosulfate (PMS) activation. Distinct from stacked FeCo 2 O 4 , FeCo 2 O 4 /diatomite possessed a 1.2-fold larger specific surface area (94.84 m 2 g −1 ), achieving 100% ATZ removal within 10 min at 0.2 g L −1 PMS and 0.1 g L −1 FeCo 2 O 4 /diatomite. The system could adapt to a broad pH range (3–11) and complex water matrices, efficiently removing multiple contaminants. High removal performance (>92%) and mineralization (>57%) were maintained after six cycles with minimal leached Co (0.10 mg L −1 ). The conversion between ≡Fe(III)/≡Fe(II) and ≡Co(III)/≡Co(II) could trigger PMS persistently, producing abundant active species, in which SO 4 •− was dominant. Then, intermediates and degradation pathways were proposed based on DFT calculations and ESI-QTOF-MS/MS data. Toxicity analysis showed that most intermediates were more eco-friendly than ATZ. This study developed FeCo 2 O 4 /diatomite with superior catalytic performance, high adaptability, and stability for eliminating refractory organic pollutants.