REDOX TRANSFORMATIONS OF VANADIUM SPECIES AT THE RUTILE SURFACE

Redox transformations of vanadium species, deposited on the surface of a rutile monocrystal by annealing rutile with V2O5 were investigated by cyclic voltammetry. Two different vanadium species were observed at the surface: first, present in the crystal lattice of rutile, which u ndergoes the redox transformation V4+/V3+ only, and the second, presen t at the surface, which undergoes both the V5+/V4+ and V4+/V3+ redox t ransformations. The latter appears only when the subsurface layer beco mes saturated with the former.