Hydrothermal synthesis of vanadium-based layered compound with 1 nm basal spacing

Vanadium-based layered compounds were synthesized from a reaction between a mmonium vanadate and supercritical/non-supercritical water. The hydrotherma l conditions were as follows: treatment temperature of 773 K and pressure o f 30 to 100 Mpa. We characterized specimens by scanning electron microscopy , energy dispersive X-ray spectroscopy (EDX), X-ray diffractometry, transmi ssion electron microscopy and thermogravimetry. Then we determined the cond ition of repeatable synthesis of the layered compound with a 0.98 nm basal spacing. The compound included no impurity, at least at the sensitivity of EDX. The compound showed good stability up to 500 K. We infer the chemical formula of the compound to be V2O5 - 0.5H(2)O.