Biomimetic synthesis of nanostructured WO3 · H2O particles and subsequent thermal conversion to WO3.

Nanostructured tungsten oxide (WO3) particles were prepared in aqueous solution by mimicking biomineralization. Precursor WO3 · H2O particles were generated by ageing a 60°C (NH4)10W12O41 · 5H2O solution containing gelatin. This was followed by heating to 600°C in air for thermal conversion to WO3. The addition of gelatin led to the formation of layered structures consisting of WO3 · H2O platy particles, which contained segmented, block-like nanoscale units. The macroscopic layered structure was preserved after thermal conversion to WO3, while the morphology of the block-like units changed to orthogonally crossed nanorods.