Underneath mechanisms into the super effective degradation of PFOA by BiOF nanosheets with tunable oxygen vacancies on exposed (101) facets

Construction of surface defects or/and exposed reactive facets is a promising strategy to improve the performance of photocatalysts. In this study, BiOF photocatalysts with tunable oxygen vacancies on the exposed (101) facets were successfully prepared by adjusting the concentration of ethylene glycol (EG). The prepared product with 50 % EG in the solution displayed remarkable photocatalytic activity for the recalcitrant pollutant perfluorooctanoic acid (PFOA), which could be completely decomposed within 6 h. The appropriate concentration of oxygen vacancy and the exposed (101) facets synergistically promoted the electron transfer from the defective surface to O-2. Moreover, the oxygen vacancy introduced an intermediate band, which narrowed the bandgap and lowered the energy required for electron transition. DFT calculations and LC-MS-MS results revealed the principal-attack-sites of various active substances and figure out the entire PFOA degradation pathways. These profound findings are instrumental for a comprehensive understanding of the degradation process of PFOA in photocatalytic systems.

Automated summary

The construction of surface defects and exposed reactive facets is an effective strategy to enhance photocatalyst performance. In this study, BiOF photocatalysts with tunable oxygen vacancies on the (101) facets were prepared by adjusting the concentration of ethylene glycol. The appropriate concentration of oxygen vacancies and exposed facets promoted electron transfer and introduced an intermediate band, resulting in improved photocatalytic activity for degrading perfluorooctanoic acid (PFOA). DFT calculations and LC-MS-MS results were used to identify active sites and degradation pathways of PFOA, providing valuable insights for understanding the photocatalytic degradation process.