Tungsten oxide (WO3) and tungsten blue oxide (WO3-x) were synthesized using sub and supercritical water and methanol. Crystalline tungsten oxides were formed with subcritical water at 250°C, which shows lower production temperature compared to conventional solid-state methods. Glycerol hydrothermal reduction and supercritical methanol were both found to be effective in obtaining crystalline tungsten blue oxides and this is a great advantage since hydrogen is not required in the process. The synthesized particles were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and near edge X-ray absorption fine structure (NEXAFS). NEXAFS results showed that sub and supercritical methanol was more effective in reduction of tungsten oxides compared to glycerol hydrothermal reduction.
Bibliographical noteFunding Information:
This work was supported by the Green City Technology Flagship Program funded by Korea Institute of Science and Technology (Project No. 2E25640).
© 2016 Elsevier B.V. All rights reserved.
- Supercritical methanol
- Supercritical water
- Tungsten blue oxide
- Tungsten oxide
ASJC Scopus subject areas
- Chemical Engineering(all)
- Condensed Matter Physics
- Physical and Theoretical Chemistry