Flower-like and hollow sphere-like WO3 porous nanostructures: Selective synthesis and their photocatalysis property

Nanoflake-based flower-like and hollow microsphere-like hydrated tungsten oxide architectures were selectively synthesized by acidic precipitation of sodium tungstate solution at mild temperature. Several techniques, such as X-ray diffraction, scanning electron microscopy, thermogravimetric-differential thermalgravimetric analysis, transmission electron microscopy, and Brunauer–Emmett–Teller N2 adsorption–desorption analyses, were used to characterize the structure and morphology of the products. The experimental results show that the nanoflake-based flower-like and hollow sphere-like WO3·H2O architectures can be obtained by changing the concentration of sodium tungstate solution. The possible formation process based on the aggregation–recrystallization mechanism is proposed. The corresponding tungsten oxide three-dimensional architectures were obtained after calcination at 450 °C. Finally, the obtained WO3 three-dimensional architectures were used as photocatalyst in the experiments. Compared with WO3 microflowers, the as-prepared WO3 hollow microspheres exhibit superior photocatalytic property on photocatalytic decomposition of Rhodamine B due to their hollow porous hierarchical structures.