Fe2O3-TiO2 artificial passivation films were formed on Pt substrates by low-pressure metallorganic chemical vapor deposition, and their corrosion resistance and photoelectrochemical properties were examined in acidic, neutral, and alkaline solutions. The corrosion resistance was examined by an anodic polarization test and the photocurrent response by a photoelectrochemical polarization test. The quantum yield maximum of the films depends on the cationic fraction of Ti4+ of the films, XTi. It decreased in the range XTi = 0.0-070, then increased in the range XTi = 0.70-0.95, and finally decreased in the range XTi = 0.95-1.0 with increasing XTi value. The films in the ranges of XTi = 0.0-0.70 and 0.95-1.0 had crystalline structure and the films in the range 0.70-0.95 had amorphous structure. Therefore, the increase in the quantum yield maximum in the range XTi = 0.70-0.95 was attributed to the amorphous structure. Such a change in the quantum yield maximum was independent of solution pH. The corrosion resistance of the films increased with increasing XTi value of the film in a 5.0 M HCl solution. Therefore, the films with XTi = 0.70-0.95 can be concluded to have high quantum yield and high corrosion resistance.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Renewable Energy, Sustainability and the Environment
- Surfaces, Coatings and Films
- Materials Chemistry