Understanding the synergistic effect of hydrated electron generation from argon plasma catalysis over Bi₂O₃/CeO₂ for perfluorooctanoic acid dehalogenation: Mechanism and DFT study

Pseudo-photocatalysis driven by argon-plasma-system (AP) is a new approach toward the promotion of reactive species production for water remediation. Here, we investigated the synergistic effect between AP and catalyst by altering the oxygen vacancies (O_V) concentration of CeO₂/Bi₂O₃ for stimulating the hydrated electrons (e_aq^–) production for PFOA removal. The soft X-ray total fluorescence yield (TFY) analysis and DFT calculation revealed the formation of the built-in electric field in the Bi/Ce_0.43 interface can enhance interfacial electron migration with direction from Bi₂O₃ toward CeO₂, simultaneously promoting the e_aq^– generation. Notably, AP-Bi/Ce_0.43 (0.1488 min⁻¹, E_EO = 0.43 kW mg⁻¹) exhibited excellent PFOA removal kinetic performance with almost 5.7 times faster and 72.6% lower energy consumption than sole AP (0.0261 min⁻¹, E_EO = 1.57 kW mg⁻¹), respectively. The multiple-plasma-jet continuous-flow-experiments results illustrated the scalability of AP-Bi/Ce_0.43 for PFOA destruction. Our findings demonstrate fundamental insights into the synergistic effect of PFOA removal in AP catalysis.