Cathodic Electrodeposition Of Titanium Dioxide Film And Electrochemical Behavior

The TiO₂ film was prepared by means of Cathodic electrodeposition, and the effect of the deposition conditions to the properties of the TiO₂ film were discussed in this paper. The pH value and time for the deposition were the key parameter to control the TiO₂ film. Defferent surface topography of film could be gained by changing the deposition condition. And there was definite correspondence between cyclic voltammetry measure and the surface topography . And the variable range was broad which can be seen by SEM photograph of electrodeposit sintered film. The electrodeposition film was testified to be anatase TiO₂ by XPS ultimate analysis. When the weak diffracting peak of (101) surface of anatase TiO₂ can be detected by XRD. The TiO₂ films were divided into discontinuous mesh structure, aggregate structure and dense structure, according to degree of closenness of loading on ITO.The properties of ITO sheet capacity reactance mostly represented in the high frequency band of the AC resistance, and the information of capacity reactance from the interface between the TiO₂ film and the electrolyte appeared in the frequency band after the HF arc. The TiO₂ film electrode system was studied by R(C(R(QR))) artificial circuit. The value of CPE-n indicate the amount of charge carrier in TiO₂ and separation state of electron-hole. The EIS spectrum contrast of TiO₂ film electrode in light of xenon lamp and natural lighting showed that the light of xenon lamp increase the concentration of charge carrier in TiO₂, which externalized in the Nyquist graph was the radius of impedance arc became shorter. For the interface reaction increasing caused the interface electric double layer compressed and resulted in the interface capacity enhanced. And all the results were coincidental with artificial circuit fitting data.The flat band potential of electrodeposition TiO₂ film and coating TiO₂ film were measured seperately by Mott-Schottky. As the coating TiO₂ film was prepared by sintering the mixture of rutile TiO₂ powder and sol-gel, though there was no diffracting peak of anatase TiO₂, the flat band potential was between that of two crystal form in the test of Mott-Schottky. It indicated that the coating TiO₂ film may be the mixed crystal system of anatase TiO₂ and rutile TiO₂. The flat band potential of electrodeposition TiO₂ film by Mott-Schottky wasn't matching the value in theory.