Direct Route to Tungsten Oxide Nanorod Bundles: Microstructures and Electro-Optical Properties

Abstract

In the present research, tungsten oxide nanorod bundles were synthesized by a unique plasma arc gas condensation method that was both noncatalytic and template-free. W18O49 nanorod bundles were prepared by directly evaporating tungsten bulk in an oxygen-deficient environment. The as-prepared tungsten oxide nanorod bundles were characterized by FESEM, HRTEM, XRD, UV−visible spectroscopy, and PL measurements. The field-emission property was also evaluated. FESEM images showed bundlelike morphology; XRD and HRTEM results confirmed that the nanorod bundles were in a single-crystalline monoclinic W18O49 phase, with the growth direction along [010]. Also, oxygen deficiencies within the nanostructures induced the red-shift phenomenon and blue emission observed in the UV−visible and photoluminescence spectra. The field-emission measurement showed that the tungsten oxide nanorod bundles exhibited low turn-on and threshold voltages, which were about 3.5 and 4.6 V/μm, respectively. These results indicate that the tungsten oxide nanorod bundles are a promising candidate for field-emitter applications.

Fabrication and optical properties of Ti-doped W18O49 nanorods using a modified plasma-arc gas-condensation technique

“…Details for the experimental procedures used are available elsewhere. 21 The phase identification of the as-prepared nanomaterials was determined by an x-ray diffractometer ͑XRD͒ ͑X'Pert PRO MPD, PANalytical, Phillips͒ with monochromatic Cu K␣ radiation. A field-emission gun scanning electron microscope ͑FEG-SEM͒ ͑LEO 1530͒ was used to observe the surface morphology of the as-prepared nanomaterials.…”

“…21 In the present study, Ti-doped W 18 O 49 nanorods were prepared by evaporating a dual target consisting of tungsten and titanium oxide powders without any catalysts or substrates. The structural and optical properties of the as-prepared nanorods were investigated.…”

Fabrication of highly sensitive gas sensor based on Au functionalized WO3 composite nanofibers by electrospinning

“…Due to both the increase in adsorbed oxygen and the molecules to ions rate of conversion, the degree of electron depletion at the Au/WO 3 interface is higher than that at the pure WO 3 surface. The loading of Au NPs on the surface of WO 3 NFs is expected to induce electronic sensitization, due to the differences in their work functions: Φ(Au)= 5.1 eV and Φ(WO 3 ) = 5.7 eV[36,37]. Furthermore, a Schottky barrier is formed by the presence of Au…”

Synthesis of W17O47 nanothick plates with preferred orientation and their photocatalytic activity

“…Recently, the band gap value of the W 18 O 49 nanorod bundles has been reported ∼2.95 eV. [29] The photocatalytic activity of the W 17 O 47 nanothick plates was evaluated by examining degradation of the MB dye in aqueous solution under UV light irradiation. Figure 7 shows the data of the temporal degradation of MB over the tungsten oxide thin films annealed for 60 min as compared to the sample without annealing treatment.…”