Physicochemical Characterization of Photoelectrodes of Ti/TiO 2 Prepared by Thermal Oxidation of Titanium

The preparation and study of supported TiO2 for photocatalytic application in solar cell devices is a relevant research field. Thin films of TiO2 prepared on Ti by thermal oxidation in a wide range of temperatures (450°C - 900°C) were characterized by electrochemical impedance spectroscopy, potentiometry and amperometry. This material presents photoelectrochemical activity, which depends dramatically of the oxidation temperature and the exposition time at the studied temperatures. The flatband potential as well as the donor density and the resistance to the charge transfer were measured. All these parameters are temperature dependent, and the optimal values are observed on the photoelectrodes prepared at 750°C. This result is consistent with the photochemical response reported in the literature for thin films of Ti/TiO2 prepared under similar conditions.