Boosted photocatalytic degradation of norfloxacin on LaOCl/LDH: Synergistic effect of Z-scheme heterojunction and O vacancies

In this work, LaOCl/LDH Z-scheme heterojunction catalyst containing oxygen vacancies were successfully constructed and used for photodegradation of norfloxacin (NOR). The results showed that the removal rate of NOR by LaOCl/LDH was up to 90%, and the reaction rate constant was 2 times than LaOCl and LDH. By exploring factors affecting the photodegradation performance, including pH, catalyst dosage, light intensity and reaction time, the kinetics of the degradation process were investigated in detail. It indicates that the formation of Z-scheme heterojunction enhanced the separation and transfer of photogenerated carriers and enhanced the redox capacity of photocarriers. DFT calculation shows that the oxygen vacancies on LaOCl promoted the absorption of visible light and effectively adsorbing and activating small molecules. In addition, based on LC-MS results, intermediates and a possible pathway for NOR degradation were proposed. The synergistic effect of Z-scheme heterojunction and oxygen vacancies enhanced the photodegradation property of LaOCl/LDH for NOR, which provides a reference for constructing highly efficient photocatalysts.