Synthesis and characterization of one-dimensional WO2 nanorods

Abstract

One-dimensional ͑1D͒ WO 2 nanorods were synthesized by hot-filament metal vapor deposition at high-pressure Ar flow without using any catalyst. The 1D WO 2 nanorods grew on the roots and were a few micrometers long and 50-100 nm wide. The x-ray diffraction pattern shows that the as-synthesized 1D WO 2 nanorods are the monoclinic structure in space group P2 1 / c, and the roots are the ␤ tungsten crystal of the cubic structure in space group Im3m. Field-emission-gun transmission electron microscopy images and selected-area electron diffraction patterns further confirm that the monoclinic 1D WO 2 nanorods consist of the ͑011͒ planes and preferentially grow along the ͗011͘ direction. According to these results, an uncatalyzed vapor-solid process is suggested to be the mechanism of growth of the as-synthesized 1D WO 2 nanorods. In comparison with the Raman scattering of three-dimensional WO 2 bulk powders, the Raman bands of the 1D WO 2 nanorod are blueshifted and narrower, indicating phonon confinement associated with the 1D WO 2 nanorod.

Low‐Temperature Fabrication of Cold Cathode WO2 Nanowire Arrays on Glass Substrate and Improvement of their Working Performance

“…Previous studies have demonstrated that the tungsten oxide nanowires can exhibit excellent field emission (FE) performances, which intrigues the researchers to explore their applications in cold‐cathode devices. Among various tungsten oxide nanostructures, the researchers found that the WO 2 nanowires exhibited the most excellent FE properties due to their high conductivity . On the other hand, for applications in large‐area cold‐cathode devices, such as X‐ray source and flat panel display, glass substrate is preferred due to its low‐cost and transparency.…”

An efficient methodology for measurement of the average electrical properties of single one-dimensional NiO nanorods

“…In this study, we are able to synthesize large-area arrays of vertical-aligned 1D NiO nanorods using the hot-filament metal-oxide vapor deposition (HFMOVD) technique. This technique has become very important, because it can be used to synthesize a variety of metal-oxide101617181920212223242526 and metal27282930 nanostructures with diverse morphological features and crystalline traits. The 1D NiO nanorods thus produced were then characterized by field-emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), x-ray diffractometry (XRD) and ultraviolet-visible spectroscopy.…”

Magnetic properties of large-area one-dimensional WO2 and MoO2 nanorods

“…Therefore, the XRD result shows that the assynthesized large-area 1D MoO x nanorod is a monoclinic MoO 2 crystal in the space group P2 1 /c and with lattice constants a ¼ 0:5620ð0Þ, b ¼ 0:4860ð0Þ, and c ¼ 0:5630 ð0Þ nm, and b ¼ 120:9401. According to a previous study [6], the 1D WO 2 nanorod consists of the {0 1 1} planes and preferentially grows along the h01 1i direction, indicating that the 1D MoO 2 nanorod also preferentially grows along the h01 1i direction.…”

“…[1]. Due to effects of dimensionality confinement [5] and phonon confinement, [6] one-dimensional (1D) nanostructured materials exhibit singular physical and chemical characteristics that differ from those of bulk materials [6]. Hence, nanostructured tungsten and molybdenum oxides have attracted particular interest for their technological applications.…”