The metals chemical states in hydrated vanadium oxides

The X-ray photoelectron spectroscopy (XPS) spectra of hydrated vanadium oxides (VO)Mo(x)V(12-x)center dot nH(2)O (x = 0, 1, 2, 3) were studied to provide the vanadium ions reduction ratio (RR) = V(4+)/(V(4+) + V(5+)) dependence on the molybdenum ions concentration and thermal treatment. The vanadium valence does not depend on Mo doping (x <= 3) and is strongly dependent on calcinations above the oxygen desorption temperature.