Over the last few years there has been a growing interest in the field of semiconductor photochemistry regarding the devel- opment of self-cleaning coatings [1–5]. In particular, increased attention has been focused in the use of photocatalytic titania (TiO2) thin films, mainly due their self-cleaning nature. Under- standing the fundamental process and enhancing the photocat- alytic efficiency of titania photocatalysis has become a major research focus in our team, bearing in mind industrial applications, such as transparent and colourless coatings that possess anti-fogging, self-cleaning or antibacterial activities for general purpose glass windows. Nanocrystalline films of titania are capa- ble of acting as photoactive coatings, because of their intrinsic ability to degrade pollutants dissolved in water [6]. The thin film of titania acts as a photocatalyst for the dissociation and miner- alization of organic impurities on a particular surface, such as glass. The driving force behind this photocatalisation is simply ultra-violet (UV) light and atmospheric oxygen.