Synthesis, characterization, and inelastic neutron scattering study of hydrogen insertion compounds of VO2(rutile)

Hydrogen insertion compounds, HxVO2 (rutile) (0 < x < 0.37), have been prepared at ambient temperatures both chemically, by hydrogen spillover, and electrochemically, with subsequent characterization by powder X-ray diffraction and chemical analysis. For HxHO2 (0.16 < x < 0.37), distortion of the monoclinic parent oxide occurs to give an orthorhombic rutile-related structure with lattice parameters similar to those of VO2−x(OH)x formed by the high-pressure, high-temperature decomposition of ammonium metavanadate, reported previously. The vibrational spectrum of H0.3VO2 has been measured using inelastic neutron scattering spectroscopy. The spectrum and the corresponding vibrational analysis further confirm that the hydrogen insertion compound can be formulated as an oxyhydroxide.