Recent Advances on TiO 2 Thin Film Based Photocatalytic Applications (A Review)

Titanium dioxide (TiO₂) is one of the most important materials to be employed as a photocatalyst for environmental protection and other applications. Owing to its certain important combination of properties, TiO₂ in the form of thin film has been found to be more attractive for a great variety of applications including photocatalytic degradation of organic pollutants in water as well as in air, dye sensitized solar cells (DSSCs), anti-fogging, superhydrophilic, photochromic, and optical applications. Although, a great number of techniques have been employed so far to fabricate TiO₂ thin films, the cost of these thin films has not only been found to be dictated by the sophistication of the preparation method involved but also by the quick recombination of photo-generated electron/hole pairs, backward reactions involved, and the poor response of TiO₂ to the visible light. Even though, metal loading, metal ion doping, anion doping, dye sensitization, composite semiconducting phenomenon, metal ion-implantation, addition of sacrificial reagents and carbonate salts to the reaction mixtures, etc., have been employed to improve the efficiency of the photocatalytic applications of TiO₂ thin films, a clear-cut relationship between the properties of TiO₂ thin films and their performance in a given application is yet to be established. In this article, some of the latest developments accomplished in the fabrication techniques, in the characterization and in the understandings of property and performance relationship of TiO₂ thin film have been presented and discussed while citing certain of important references.