Graphene oxide and F co-doped TiO2 with (0 0 1) facets for the photocatalytic reduction of bromate: Synthesis, characterization and reactivity.

Graphene oxide (GO) and F co-doped TiO 2 (FGT) particles were controllably synthesized using the hydrothermal method. Transmission electron microscopy (TEM), scanning electron microscopy (SEM), Raman spectroscopy (RS), X-ray photoelectron spectroscopy (XPS), and UV–vis diffuse reflectance spectroscopy (UV–vis DRS) were utilized to characterize the morphologies and properties of the particles. The mechanism of the photocatalytic reduction of bromate by FGT was also discussed. The results show that a narrow band gap for an FGT composite with a cuboid morphology and (0 0 1) facet was found. The transportation of photogenerated electron and the depression of electron-hole pairs recombination were improved by the co-doping of GO and F in TiO 2 . Moreover, high activity was exhibited in the photocatalytic reduction of bromate. Over 90% of bromate could be removed with a 0.05 g/L dosage of 1.0% F and 0.1% GO co-doped TiO 2 composite in 15 min under UV irradiation at an intensity of 26 μW/cm 2 and pH of 5.2. A lower pH was favorable for the photoreduction by affecting the adsorption, which was necessary for the rapid removal. In addition to spherical particles, FGT possesses cuboid morphologies with (0 0 1) and (1 0 1) facets, which would help to promote the migration of electrons and inhibit the recombination of photogenerated electron-hole pairs. The results indicate that FGT is a promising material for bromate reduction in water treatment due to its remarkable efficiency and stability. [ABSTRACT FROM AUTHOR]