The Electrochemical and Photoelectrochemical Behavior of Passivated Ti in Nitric Acid Solutions

The electrochemical and photoelectrochemical behavior of passivated Ti electrodes in nitric acid solutions was studied and compared with the behavior of the electrodes passivated in sulfuric acid under the same conditions. The donor density and flatband potentials were calculated from the capacitance measurements. The use of high intensity pulse lasers allowed photoelectrochemical investigations with proton energies smaller than the bandgap. The behavior of the passive films on Ti in nitric acid was not comparable with its behavior in H 2 SO 4 . The anomalous behavior of Ti passivated in nitric acid was discussed, and a model for the band structure of the passive film was suggested