Surface Modification Of TiO₂ Nanoporous Film And Its Photoelectrochemical Properties

The use of small organic molecular other than organic dyes to modify TiO₂ has attracted more and more research interests in recent years. Numbers of molecules including benzoic acid, phthalic acid, salicylic acid, catechol, ascorbic acid, and dopamine have been successfully used to modify the TiO₂ surface. In most cases, however, particulate TiO₂ was used; few works have been done with TiO₂ thin film. Meanwhile, organic molecules that hold -OH or -COOH functional group are generally used, whereas few work performed with other organic molecule. In this thesis, a new route was used to modify the TiO₂ nanoporous film with pyridine molecule.Surface modification of TiO₂ porous thin film with pyridine was preceded by reacting pyridine molecular with TiO₂ surface Ti dangling bond, which was generated by treating the TiO₂ porous film at ca. 400°C under vacuum. FTIR and XPS analysis suggest that pyridine ring is chemical bond to Ti atom via a Ti-N bond.The surface modification is found to increase the absorbance of the TiO₂ porous film in visible region as compared to the unmodified porous...