Field-assisted adsorption of oxygen on rutile surfaces by an atomic force microscope

Using an atomic force microscope (AFM) with a conductive cantilever of Au coated Si, a negative voltage is applied to the TiO2 surface in air. Current flowing at an interface of TiO2 and Au is significantly decreased by repeating the application of a negative voltage to the TiO2 surface. In an AFM topograph and conductivity map, a strong attractive force and zero current appear on the specific area of the TiO2 surface which has been scanned at -5.0 V. These results suggest that chemisorption states, O2-, are formed at the TiO2 surface by scanning at -5.0 V.