Novel Bi2S3/Bi2WO6 nanomaterials with 2D/3D spatial structure stably degrade veterinary antibiotics under visible light

Abstract In this study, nano-flowers Bi2S3/Bi2WO6 nanomaterial photocatalyst was fabricated by the mild solvothermal-hydrothermal method, which can effectively and stably degrade tetracycline(TC). The crystal structure, element composition chemical, valence state and microscopic morphology of the nanomaterials were characterized by XRD, XPS and SEM. Besides, PL and EIS analysis showed the composites have low recombination rate and impedance. The degradation rate of optimal(30%)Bi2S3/Bi2WO6 to TC is as high as 91.4%, which much higher than pure Bi2WO6 at visible-light. Particularly, the repetitive experiments demonstrated that the photocatalytic activity of Bi2S3/Bi2WO6 can still reach 84.3% and the photocatalyst has no changes in morphology and structure. Combining UV-vis DRS spectrum, Mott-Schottky curve and free radical trapping experiments, a Z-scheme photocatalytic mechanism suitable for this photocatalytic system was deduced. In general, the heterojunction formed by the unique spatial structure promotes the excitation, migration and separation of photo-generated carriers. Finally, this structure can provide more reference when dealing with antibiotics in wastewater.