A dual strategy for synthesizing crystal plane/defect co-modified BiOCl microsphere and photodegradation mechanism insights

Because of different atomic arrangements and/or different exposed atoms on different surfaces of crystalline particles, different physical and chemical properties can be resulted and exhibited. In this work, we prepared BiOCl with {110} crystal facet by introducing urea as the structure-directing agent, and constructed oxygen vacancies (OVs) in BiOCl (110) to form BiOCl (110)-OV. Control of exposure surface can improve photocatalyst activity and the defect level caused by OVs can improve charge separation and light absorption, thereby further enhancing the production of free radicals and the activation of pollutants. Due to the synergistic effect of the hierarchical microsphere structure of BiOCl and OVs, the degradation rate of tetracycline hydrochloride (20 mg/L) in the presence of BiOCl (110)-OV can reach 95.1% after 15 min of the simulated sunlight illumination. This research provides novel ideas for the design and development of photocatalyst with hierarchical structure and oxygen vacancy defects.