Studies on fabrication of urchin‐like WO₃·H₂O hollow spheres and their photocatalytic properties

Abstract

Urchin-like tungsten oxide hydrate (WO 3 ·H 2 O) hollow spheres were successfully synthesized via a selfsacrifice template method at low temperature. The effects of reaction parameters on the preparation were studied in solution. The growth mechanism was also proposed on the basis of experimental results. In addition, the acid amount and temperature have important effects on size control of the as-obtained samples. The achieved nanoarchitectures have typical diameters of 4-6 μm with nanoflakes of several nanometers at surface. Crystal structure, morphology, and composition of final nanostructures were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Degradation experiments of organic contaminant were also performed on samples of hollow spheres and walnut-like structures under visible-light illumination. Hollow sphere sample exhibited better photocatalytic capability than walnut-like sample. Possible mechanism was studied for WO 3 ·H 2 O assisted photocatalytic degradation of organic contaminant under visible light.

Controlled synthesis of monodisperse WO3·H2O square nanoplates and their gas sensing properties

“…The morphological parameters such as size, shape and facet of tungsten oxide particles are critically important in its applications such as sensing properties [19,20]. Recently, in order to control the morphology and size of tungsten oxides, many efforts have been devoted to the syntheses route [21][22][23] As a result, a variety of chemical or physical methods have been applied to synthesize special nanostructures and morphologies such as nanowires [24,25], nanorods [26,27], nanotube [28], nanoplates [29,30], nanocuboids [31,32], hexagonal nanodisks [33], nanospheres [34] and hollow spheres [35].…”

One-Step, Solventless, and Scalable Mechanosynthesis of WO3·2H2O Ultrathin Narrow Nanosheets with Superior UV–Vis-Light-Driven Photocatalytic Activity

“…Photocatalytic degradations of RhB in the presence of tungsten trioxide hydrates with different morphologies and derived from various synthetic methods are summarized in Table . As presented in Table , synthesis and photocatalytic activity of tungsten trioxide hydrates (WO 3 · m H 2 O, m = ∼2) with different morphologies have been well investigated; however, the reported synthetic approaches focus on the liquid-phase routes, − mainly in solvothermal/hydrothermal methods. , These documents usually selected the RhB solution with concentrations lower than 20 mg L –1 to evaluate photocatalytic activity of the samples. In our experiment, the 100 mL of RhB solution with a concentration of 100 mg L –1 had to be chosen for evaluating photocatalytic activity of the 50 mg of WO 3 ·2H 2 O ultrathin nanosheets, as the colors of RhB solution faded so quickly when the RhB solution with a lower concentration was used, indicating a highly efficient capacity for removal of RhB from aqueous solution.…”

Synthesis of WO3·H2O nanoparticles by pulsed plasma in liquid

“…In the published literature, most of the reported hydrates were mixed with other components such as WO 3 and Ag, 6,14 and the hydrates that were investigated were usually in the forms WO 3 $0.33H 2 O and WO 3 $0.5H 2 O. [15][16][17] Only recently, Q. Zeng et al 18 reported the photocatalytic properties of pure WO 3 $H 2 O hollow spheres. However, the synthesized spheres only showed high photocatalytic efficiency in acid solutions.…”