Formation of tungsten oxide nanostructures by laser pyrolysis: stars, fibres and spheres

Abstract

In this letter, the production of multi-phase WO3 and WO3-x (where x could vary between 0.1 and 0.3) nanostructures synthesized by CO2-laser pyrolysis technique at varying laser wavelengths (9.22-10.82 mm) and power densities (17-110 W/cm2) is reported. The average spherical particle sizes for the wavelength variation samples ranged between 113 and 560 nm, and the average spherical particle sizes for power density variation samples ranged between 108 and 205 nm. Synthesis of W18O49 (= WO2.72) stars by this method is reported for the first time at a power density and wavelength of 2.2 kW/cm2 and 10.6 μm, respectively. It was found that more concentrated starting precursors result in the growth of hierarchical structures such as stars, whereas dilute starting precursors result in the growth of simpler structures such as wires.

Effect of Accelerated Thermal Ageing on the Selective Solar Thermal Harvesting Properties of Multiwall Carbon Nanotube/Nickel Oxide Nanocomposite Coatings

“…Asymmetrical broadening is ascribed to phonon confinement [12], a phenomenon that results from reduction of particle sizes. This phenomenon is observed in particles with diameter between 5 nm and 20 nm [13][14][15][16][17][18][19]. The spectra confirm that the NiO particles are indeed nanosized probably less than 20 nm in diameter.…”

Electrical and optical properties of mixed phase tungsten trioxide films grown by laser pyrolysis

“…The spectra from either spot had different Raman shifts, indicating the possibility of mixed phases. This could be due to the Gaussian intensity profile of the laser used in the synthesis [18]. There is also a mixture of several shaped nano-and microstructures as seen in the SEM micrographs of Figure 5.…”

“…Therefore, much opportunity exists to try different synthesis techniques depending on the application of the product materials. Here we concern with laser pyrolysis to synthesize WO 3 nanostructures because this technique does not allow the reactants to make contact with any side-walls, and so the products are of high purity and quality [16][17][18]. It is also shown here how individual nanostructures are isolated for possible sensing applications.…”

Synthesis and characterization of potential iron–platinum drugs and supplements by laser liquid photolysis

“…Researchers using laser pyrolysis have tried to synthesize different nanostructures of nanowires, stars, fibers, and spheres. [36][37][38] They proposed a mechanism for nanowire formation and advanced a potential explanation for the manner of growth of nanowires from laser pyrolysis. Their model was founded on basic statistical mechanics theory.…”