MOLYBDENUM OXIDE MONOLAYERS AT THE RUTILE (110) SURFACE STUDIED BY ELECTROCHEMICAL AND XPS METHODS

Molybdenum oxide monolayers were deposited on a (110) surface of rutil e monocrystal by heating the crystal with surface covered by MoO3 powd er. The monolayer character of such deposited molybdenum oxide layers was confirmed both by XPS measurements as well as by measuring the cha rge of monolayer reduction/oxidation. Two-step reduction of surface mo lybdenum was observed, the first step may be ascribed to the redox tra nsformation Mo+6/Mo+5, the second most probably to the redox transform ation Mo+5/Mo+3. The potential of the first redox transformation, expr essed on the electron energy scale, was found to be located in the ban d gap of TiO2 semiconductor, close to the conduction band edge, the se cond one within the conduction band.