Hydrothermal synthesis of one-dimensional tungsten oxide nanostructures was performed using cobalt ammonium sulfate as a structure-directing agent, and the effect of the concentration of cobalt ammonium sulfate on the characteristics of the tungsten oxide nanostructures was investigated. XRD measurements showed that hexagonal tungsten oxide (h-WO3) structures were obtained at a higher concentration of cobalt ammonium sulfate (0.2 M), while cubic tungsten oxide (c-WO3) structures were obtained at a lower concentration of cobalt ammonium sulfate (0.01M). Mixed structures of h-WO3 and c-WO3 were observed at an intermediate concentration of cobalt ammonium sulfate. Morphological studies revealed that h-WO3 appeared as nanowires with a diameter of about 40 nm and an average length of 1 μm. c-WO3 was shaped in pillar-like nanorods with a diameter of about 30 nm. A red-shift in the UV/Vis absorption peak was observed with different phases of tungsten oxide nanostructures.
Bibliographical noteFunding Information:
This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MEST) (Nos. 2011-0029118 and 2012-004416) and an Ajou University Research fellowship of 2010 (Grant No. S-2010-G0001-00058).
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)