Oxygen vacancy-rich CoCeOx nanofiber as robust peroxymonosulfate activators for thiamethoxam degradation

Abstract

Developing advanced catalysts for neonicotinoid pesticide degradation is crucial importance in addressing environmental contamination. Herein, we designed oxygen vacancy (O_v)-rich CoCeO_x solid solution nanofibers via electrospinning and calcination. The optimized lattice stress and O_v density enable synergistic Ce³⁺/Ce⁴⁺ and Co²⁺/Co³⁺ redox cycles to drive radical generation, resulting in the exceptional performance in peroxymonosulfate activation for thiamethoxam degradation (achieving >71% removal within 60 min). The system exhibits broad pH adaptability and strong resistance to general anions and humic acid. Furthermore, mechanistic studies reveal that SO₄^·– serves as primary reactive species during the advanced oxidation processes, while O_V facilitates thiamethoxam adsorption and electron transfer. Remarkably, CoCeO_x composites maintain higher stability with <9% efficiency loss after 5 cycles via suppressed metal leaching with solid-solution. Intermediate analysis addresses critical insights into neonicotinoid pesticide degradation pathways. This work presents an effective heterogeneous catalytic system for pesticide remediation in complex water environments.