Characterization Of Tungsten Oxide Research Articles

Deposition and characterization of tungsten oxide (WO3) nanoparticles incorporated diamond-like carbon coatings using pulsed-DC PECVD

In this study a novel approach using pulsed-DC plasma enhanced chemical vapour deposition (DC-PECVD) to incorporate tungsten oxide nanoparticles into diamond-like carbon coatings (DLC) thin film deposited on tappet valve (metallic substrate) was successfully achieved. The DLC-W film obtained by incorporating WO3 nanoparticles into DLC was characterized using scanning electron microscope/energy dispersive spectroscopy (SEM/EDS), X-ray diffraction (XRD), Raman spectroscopy, scratch test, Rockwell C indention test and nano-hardness measurement. The thickness, hardness and elastic modulus were measured as 789.11 ± 16 nm, 18.64 ± 0.11 GPa and 152.03 ± 2.1 GPa respectively. The ID/IG was 0.95, D and G peaks positioned at 1341.66 and 1562.17 cm−1 respectively and W2C was observed from the XRD. The coating had a low apparent COF of 0.075 and excellent adhesion properties.

Synthesis and Characterization of Tungsten Oxide Nanoscaled Fibers

Synthesis and Characterization of Tungsten Oxide Nanoscaled Fibers

Solvothermal synthesis and characterization of tungsten oxides with controllable morphology and crystal phase

Tungsten oxides with various morphologies and crystal phases were synthesized by solvothermal reactions at 200 °C for 7–12 h using different solvents. The morphology and crystal phase of tungsten oxides changed depending on the solvents, i.e., spherical particles of ca. 1 μm in diameter consisting of nanowires, spindle shaped bundles of ca. 1 μm in length consisting of nanowires and accumulations consisting of micrometer sized plates and/or rods of tungsten oxides were obtained using ethanol, 1-propanol and water–ethanol mixed solution, respectively. When water–ethanol mixed solution was used, the crystallinity of tungsten oxide increased but the specific surface area greatly decreased. Crystallinity of tungsten oxides had more important effects on the NO degradation under light irradiation. The product using 42.9 vol.% water–ethanol mixed solvent consisted of the mixture of anhydrous tungsten oxide and hydrous tungsten oxide with preferential orientation of (0 0 2) plane and small band gap energy (2.43 eV), and showed higher photocatalytic degradation of NO even though it had a much smaller specific surface area than those prepared using ethanol and 1-propanol.