Quick synthesis of nanoscale tungsten oxide particles and rods

Novel Hot Filament Chemical Vapor Deposition (HFCVD) set has been installed and used for quick synthesis of nanoscale tungsten oxide particles and nanorod over large area. The present work addresses two issues: to simplify the deposition processing and to quickly deposit well-aligned nanoscale tungsten oxide rods over large area. An effect of temperature on the synthesis of the nanoscale tungsten oxide rods and particles is studied. Raman spectroscopy (RS), scanning electron microscopy (SEM), energy dispersive X-Ray microanalysis (EDS), X-ray diffraction (XRD), and X ray photoelectron spectroscopy (XPS) have been used to characterize the samples. Experimental results reveal that low-temperature HFCVD yields nanoscale tungsten oxide particles, whereas high temperature of HFCVD results in large crystalline particles with size up to 3mm. Only in the case of temperature around 2200$^{o}$C, large area, well-aligned nanoscale tungsten oxide rods can be obtained.