Synthesis and photocatalysis of flaky flower TiO 2 with sphere structure

The synthesis of nanocrystals with hierarchical structure is a well-known challenge in many fields of science and technology. In the present work, we making use of tetrabutyl titanate as a titanium source, hydrofluoric acid as an additive, successfully prepared flaky flower titanium dioxide (TiO2) with sperical nanostructures by the solvothermal method. Then we calcined some of the samples. It was found that the calcined sample presented higher crystallinity by X-ray diffraction (XRD). A series of scanning electron microscopy (SEM) characterization results indicate that the calcination causes the sheet-like structure of the sample to become larger and thicker. And the exposed specific surface area became larger. The Brunauer–Emmett–Teller N2 gas adsorption–desorption isotherms characterization results also further demonstrate that the calcined samples have a larger specific surface area than the sample before calcined. The photocatalytic activity was evaluated by measuring the degradation rate of methylene blue under UV–vis light irradiation. The results show that anatase TiO2 after calcination exhibit higher photocatalytic activity than the sample before calcination in the degradation of methylene blue under UV–vis light irradiation. It can be attributed to the synergetic effect of the architecture, high crystallinity, large specific surface areas and ostwald ripening. Scheme 1. Schematic illustration of the morphological evolution.