Bi2O3/TiO2 photocatalytic film coated on floated glass balls for efficient removal of organic pollutant

A novel photocatalytic reactor was designed for the photo-degradation of organic pollutants with floated glass balls on the solution surface, which were constantly rotated by the air pumping and coated with Bi2O3/TiO2 film. The uniform and stable Bi2O3/TiO2 film was prepared by the facile sol-gel method at the optimal conditions of Bi Bi2O3 content (1.0 mol%) and the three coating times with the film thickness of 210 nm. It was uniformly distributed and stably combined with the surface of the glass ball. Modification of Bi2O3 significantly improved the visible light absorption of TiO2 film and inhibited the photo-induced charges, promoting the photo-degradation activity. More importantly, the air pumping at the bottom of the reactor impelled the constant rotation of floated glass balls. It could realize the uniform aqueous membrane on the catalyst film to improve the efficient contact between catalyst and organics and to utilize the irradiation light efficiently, inhibiting the light shield effect of dyeing wastewater and facilitating the photo-degradation. Moreover, the Bi2O3/TiO2 photocatalytic film in this photocatalytic reactor exhibited high durability and prevented the leakage of catalyst, providing a potential for the practical applications in the future.