UPS study of the thermal reduction of fully oxidized V2O5/TiO2(0Â 0Â 1)-anatase model catalysts

The thermal reduction of thin vanadium oxide layers (8 and 16 Å) deposited with magnetron sputtering on mineral anatase TiO2(0 0 1) was examined with ultraviolet photoelectron spectroscopy (UPS). Completely oxidized vanadium oxide layers were deposited. During heating, the vanadium oxide layers reduced and evaporated, the thinnest vanadium oxide layer (8 Å) even vanished. A re-oxidation of the heated 16 Å V2O5/TiO2 could not restore the reduced vanadium oxide completely to V5+.