Sol-Gel Production and XPS Study of Sodium-Vanadium Oxide Bronze β-Phase

Abstract

A β-phase of sodium-vanadium oxide bronze thin film has been synthesized by using sol-gel technology from V2O5 and Na2SO4. The powders of these materials in suitable proportion were dissolved in hydrogen peroxide and heated up to 350 K for the dissociation of peroxide complexes. The obtained gel was deposited onto a metallic substrate and dried in air at room temperature. The produced xerogel was heated up to 580 K in air atmosphere for the removal of water from xerogel. Starting materials, xerogel, as well as a final product were investigated by means of X-ray photoelectron spectroscopy method. X-ray photoelectron spectra testify that the chemical bonds of vanadium, oxygen and sodium in the bronze differ from the similar bonds in the starting materials. The sulphur presence was detected in the xerogel but not in the final bronze composition.

Resistance switching of epitaxial VO2/Al2O3 heterostructure at room temperature induced by organic liquids

“…We found 1/2 and 3/2 spin-orbit doublet components of the V 2p photoelectrons at 523.6 eV and 515.7 eV, respectively. 44,46 Additionally, we found a peak at 517.1 eV corresponding to V 5+ ions. Integrating the area of the V 5+ peaks from 527 eV to 511 eV, we roughly estimated the V 5+ ion concentration to be 37.62% without polar liquids (Fig.…”

“…38,[44][45][46] Figs. 5(c)-5(e) show the Lorentzian-Gaussian fits of V 2p peaks for the VO 2 film without polar liquids, with cyclohexane, and with ethylene glycol, respectively.…”

Defected vanadium bronzes as superb cathodes in aqueous zinc-ion batteries

“…The same results of mixed valence states can be also found in other reported works on pre-intercalated vanadium oxides. 42,43,44 Furthermore, proportion calculations of varied V species peak areas indicate that the average oxidation states were V 4.65+ and V 4.74+ for Od-NVO . nH2O and NVO, respectively.…”