Synthesis and photocatalytic activity of boron and fluorine codoped TiO2 nanosheets with reactive facets

In this study, TiO2 nanosheets codoped with boron and fluorine were prepared by a one-pot hydrothermal method and investigated for photocatalytic dye degradation and disinfection. The as-prepared TiO2 materials were characterized by field emission scanning electron microscope (FE-SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and UV–vis diffuse reflectance spectroscopy (DRS). The results indicate that the as-prepared TiO2 are of nanosheet morphology with anatase phase. The best degradation performance was obtained for square TiO2 nanosheet sized 10nm long on the side and 2.5nm thick. Methylene blue was degraded by 95% in concentration under visible light irradiation for 5h. In addition, TiO2 nanosheets showed good stability after eight cycles of photocatalytic testing. The disinfection study implied that B,F-codoped TiO2 nanosheets could effectively inactivate bacteria within 15min under visible light. The performance of B,F-codoped TiO2 nanosheets is clearly much better than that of F-doped TiO2 nanosheets and commercial Degussa P25.