Preparation and antibacterial properties of bismuth-rich Bi/Bi4O5I2 photocatalytic materials with surface defects

A series of bismuth modified bismuth iodide flower-like microspheres with rich oxygen vacancies were prepared by solvothermal method. Herein, a mixed solution of propylene glycol and ethylene glycol was used as the solvent. By adjusting the ratio of these two solutions in the solvent, it is not only possible to prepare Bi4O5I2 microspheres containing different concentrations of oxygen vacancies, but also to control the content of Bi. The Bi/ Bi4O5I2 photocatalyst prepared when the ratio of propylene glycol to ethylene glycol was 5:1 in solvent showed excellent optical properties, and more than 99% of E. coli could be inactivated within 30 min under visible light irradiation. The antibacterial mechanism experiment showed that reactive oxygen species were the main substances affecting the antibacterial effect of Bi/ Bi4O5I2, and the scavenging experiment of reactive oxygen showed that •O2 - was the key active substance in the antibacterial process. Finally, it was verified that reactive oxygen species can act on the interior and exterior of bacteria, indicating a more effective antibacterial pathway.