In-situ synthesis of Z-scheme CeO2@WO3 heterojunction with aromatic rings as electron medium for efficient photocatalytic degradation of perfluorobutane sulfonate

Photocatalytic technology has been proven to be a simple and effective method for degrading recalcitrant organic pollutants. In this study, a series of Z-scheme heterojunction nanocomposites composed of CeO 2 and terephthalic acid-modified WO 3 was prepared and further used as photocatalysts for perfluorobutane sulfonate (PFBS) degradation. In this design, terephthalic acid was used as an electron recombination center and heterojunction mediator, which effectively enhances the migration ability of electron–hole pairs and the physicochemical stability of the catalyst. In addition, in situ synthesis of CeO 2 onto the WO 3 surface by the coordinate bond between terephthalic acid and Ce ions can avoid CeO 2 agglomeration. As a result, the CeO 2 @WO 3 photocatalyst exhibits excellent PFBS degradation ability (94% for CeO 2 @WO 3 vs. 19% for CeO 2 ). After the fifth cyclic degradation experiment, the CeO 2 @WO 3 photocatalyst still maintains stable degradation efficiency. Furthermore, the reaction mechanism of the PFBS in CeO 2 @WO 3 photocatalytic process was analyzed by free radical trapping experiment and liquid chromatography tandem mass spectrometry (LC-MS) technique. This study provides new insights for constructing Z-scheme heterojunction and demonstrates that CeO 2 @WO 3 photocatalysts possess a promising prospect for degrading PFBS pollutants.