In situ photoreduction of palladium metal-oxygen vacancy Bi2O2(OH)NO3 and its synergistic enhancement mechanism of tetracycline photodegradation

Aiming at the challenges such as wide band gap, limited surface reactivity, and sluggish reaction kinetics of the promising Aurivillius compound Bi2O2(OH)NO3 (BON). Our endeavors culminated in the successful creation of layered BON nanoplates featuring surface oxygen vacancies and Pd nanoparticles deposition by UV light irradiation, elegantly designated as Pd-OVs BON. This accomplishment was realized through the adept application of a two-step photoreduction technique, skillfully executed in both pristine water and ethanol-water environments. We then evaluated the effectiveness of Pd-OVs BON in degrading a series of tetracycline antibiotics. Our evaluation involved a comprehensive approach, encompassing systematic morphology characterization and photoelectrochemical analysis. Additionally, we investigated how surface oxygen vacancies and the plasma effects of Pd impact the separation and transport of photogenerated carriers, as well as the photocatalytic performance. The outcomes of this study indicate that Pd-OVs BON holds substantial potential for the photodegradation of antibiotics. Its layered nanoplates structure enhances the specific active surface area of BON, while the surface oxygen vacancies generated through photoreduction create more active sites for catalyzing antibiotic degradation reactions. Furthermore, the introduction of Pd nanoparticles onto the OVs-BON surface during the secondary photoreduction process induces localized surface plasmon resonance. This phenomenon broadens the photocatalyst's responsiveness to a wider range of light wavelengths, enabling efficient utilization of visible light and facilitating the effective decomposition of antibiotic molecules.