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Tungsten trioxide (WO3) has attracted considerable attention due to its promising and remarkable properties. In this study, we have prepared WO3 nanostructures via a simple chemical method using tungsten carbide (WC) as a precursor. This novel approach has many advantages such as high yields, simple methodology and easy work up. The X-ray diffraction (XRD) pattern initially revealed the formation of the intermediate phase of tungsten trioxide hydrate (WO3.H2O), then the complete transformation to pure WO3 after annealing at 600°C for 5h in air atmosphere. The prepared WO3 nanostructures crystallized into a monoclinic phase. The Scanning electron microscopy (SEM) image indicates the exceptional porous morphology, which consisted of hollow sphere-like shape with a uniform distribution. Fourier transform infrared (FTIR) spectroscopy confirmed the structural composition and the purity of the formed WO3. The experimental results proved that our simple approach offers a promising route to prepare WO3 nanostructures as high performance material for advanced applications.

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The proposed work focuses on the effects of growth time and annealing on the physico-chemical performance of vanadium oxides nanostructures (VO-NSs) films synthesized by a novel single reaction microwave synthesis. Thin films of VO-NSs were produced on glass substrates by varying the growth time and annealing temperature. Structural studies revealed that VO-NSs of synthesized films of VO 2 (B) + V 6 O 13 , VO 2 (B), V 3 O 7 and V 2 O 5 were crystallized in the form of monoclinic, monoclinic, tetragonal and orthorhombic structures with predominant orientation along ( 110), ( 110), ( 330) and ( 001) lattice plane, respectively. SEM analysis revealed that the VO-NSs thin films are dense and have uniform morphological characteristics. Furthermore, Raman spectroscopy show that all the samples undergo changes in intensities and peak positions that reflect changes in electronic structure and the vibrational properties. Our results demonstrate that the control of time and annealing treatment has a significant effect on the stoichiometry and the crystallinity leading to the control of the structure, size and morphology of VO-NSs. Moreover, the I-V curves were clearly linear and symmetrical with respect to both axes, with increasing the growth time and annealing treatment are two crucial parameters to improve the electrical conductivity, which influences the electrical properties and affects the behavior of the synthesized nanostructures. This synthesis approach offers a novel and simple route to produce one-dimensional nanostructured metal oxides, which are suitable for a wide range of applications, especially energy storage devices.

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