Surface Lewis acid sites and oxygen vacancies of Bi2WO6 synergistically promoted photocatalytic degradation of levofloxacin

Ultrathin Bi 2 WO 6 nanosheets with a high concentration of surface oxygen vacancies (BWO-OVs) are successfully constructed for the degradation of levofloxacin (LVX) under visible light irradiation and show a high degradation efficiency of LVX (≈100 %). It is revealed that the oxygen vacancies (OVs) over BWO-OVs nanosheets can not only accelerate the separation of photo-induced electrons and holes, but also activate the O 2 molecules to form O 2 – species. The FTIR spectra and density functional theory deeply demonstrate that piperazine ring and C O groups (carboxylic acid) in LVX can be chemisorbed and activated by surface Lewis acid sites. The EPR results reveal that photo-generated holes, O 2 – and OH species are reactive oxygen species for the photocatalytic degradation of LVX. The possible intermediate is well investigated by LC-MS results combined with the FTIR spectra results. This work provides a new perspective for understanding photocatalytic degradation from the interaction between the active sites of a photocatalyst and antibiotics molecules.