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 FeCo2O4/diatomite for efficient peroxymonosulfate (PMS) activation. Distinct from stacked FeCo2O4 , FeCo2O4/ diatomite possessed a 1.2-fold larger specific surface area (94.84 m2 g-1), achieving 100% ATZ removal within 10 min at 0.2 g L-1 PMS and 0.1 g L-1 FeCo2O4/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 equivalent to Fe(III)/equivalent to Fe(II) and equivalent to Co(III)/equivalent to Co(II) could trigger PMS persistently, producing abundant active species, in which SO4 center dot-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 FeCo2O4/diatomite with superior catalytic performance, high adaptability, and stability for eliminating refractory organic pollutants.