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 (OV) concentration of CeO2/Bi2O3 for stimulating the hydrated electrons (eaq- ) 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/Ce0.43 interface can enhance interfacial electron migration with direction from Bi2O3 toward CeO2, simultaneously promoting the eaq- generation. Notably, AP-Bi/Ce0.43 (0.1488 min-1, EEO = 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, EEO = 1.57 kW mg- 1), respectively. The multiple-plasma-jet continuous-flow-experiments results illustrated the scalability of AP-Bi/Ce0.43 for PFOA destruction. Our findings demonstrate fundamental insights into the synergistic effect of PFOA removal in AP catalysis.

Automated summary

In this study, the synergistic effect between argon-plasma-system (AP) and catalysts in promoting the production of reactive species for water remediation was investigated. By altering the oxygen vacancies concentration of CeO2/Bi2O3 catalyst, the production of hydrated electrons was stimulated for PFOA removal. The results showed that the built-in electric field in the Bi/Ce0.43 interface enhanced electron migration and eaq- generation, leading to improved PFOA removal efficiency.