Controlled synthesis of porous flower-like TiO₂ nanostructure with enhanced photocatalytic activity

Flower-like TiO₂ nanostructures were successfully synthesized via the urea homogeneous precipitation method using (NH₄) ₂TiF₆ as a titanium source in aqueous solution. This approach was simple, environmentally friendly and without using template. The flower-like TiO₂ nanostructures were characterized in detail with scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and UV-vis spectrum, respectively. The flower-like TiO₂ nanostructures, with diameters ranging from 150-300 nm, were assembled by primary nanoparticles and the length of the petals was approximately 60 nm. Interestingly, the surface of the flower-like TiO ₂ nanostructures appeared to have many pores with diameters of 10-13 nm after the sample being calcined at 550 °C, while the morphologies and sizes of the TiO₂ samples did not change. The photocatalytic activity of the as-prepared samples was evaluated by photo-degradation of rhodamine B (RhB) from aqueous solution at ambient temperature. The flower-like porous TiO₂ samples exhibited much higher photocatalytic activity than the flower-like TiO₂ samples. All these advantages showed a bright future for this flower-like porous photocatalyst in environmental protection.