Flame synthesis of tungsten-doped titanium-dioxide nanoparticles using novel precursor combination of liquid titanium tetra-isopropoxide and solid tungsten mesh

Tungsten-doped titanium-dioxide (W-TiO2) nanoparticles are successfully synthesized using a multiple-diffusion-flame burner with a separate center tube. Vaporized titanium tetra-isopropoxide (TTIP) precursor issues from a center tube to produce TiO2 nanoparticles, while a tungsten mesh, suspended above the surrounding multiple over-ventilated hydrogen diffusion flames, serves as the solid-phase metal doping source. At a lower tungsten loading rate, W-TiO2 nanoparticles are generated, as indicated by an obvious angle shift of 0.15 degrees for the entire x-ray diffraction spectrum. However, at a higher tungsten loading rate, homogenous nucleation of WOx occurs before or concurrently with TiO2 nucleation, producing mixed nanopowders, permitting fewer tungsten ions to be doped into TiO2. Ultraviolet-visible spectroscopic characterization reveals that the as-synthesized W-TiO2 nanoparticles possess augmented absorbing ability in the visible-light wavelength range, where the band gap is reduced from 3.20 to 3.05 eV, compared with that for the nondoped TiO2 nanoparticles.

Automated summary

Tungsten-doped titanium-dioxide nanoparticles are synthesized using a multiple-diffusion-flame burner, showing the effect of tungsten doping on the structure and properties of the nanoparticles. It is found that doping enhances the absorption ability of visible light.