The effect of different morphology of fluoride-mediated TiO2 based on Ostwald ripening on photocatalytic activity

The morphology of the catalyst is one of the important factors affecting the photocatalytic activity. In this work, fluoride-mediated TiO2 with different morphologies was successfully prepared based on Ostwald ripening. In particular, the morphology and structure of the TiO2 sample can be adjusted according to different ionic environments. Combining experiments and characterization, the regulation mechanism of different fluorides on the morphology and structure of TiO2 was proposed, and the transport behavior of photogenerated carriers was evaluated. The results show that the morphology and structure have a greater impact on the photocatalytic activity of TiO2. The hollow structure can promote the separation and transfer of carrier and enhance the light collection ability. The surface fluoride as an electron trap can reduce the carrier recombination rate, which is beneficial to the photocatalytic activity of the as-prepared sample. The hollow structure sample shows a good photocatalytic efficiency in the photocatalytic removal of Hg0 in the gas phase, reaching about twice the commercial P25. Finally, the photocatalytic mechanism of the catalyst and the electron-hole migration path are proposed. This research provides new ideas for the design of hollow TiO2 microspheres, which can be widely used in the field of catalysis.