FAQs

What is a self-cleaning photocatalytic thin film?

The self-cleaning photocatalytic thin film is created through deposition of Titania (titanium dioxide/TiO2) on top of inorganic or organic surfaces. The photocatalytic thin film is semi-permanent and efficiency is up to 5 years. Lifespan depends on the photocatalytic thin film thickness and surface friction in high-traffic zones (30-90 days), medium-traffic zones (90-180 days), low-traffic zones (up to 2 years). The chemical reaction begins when photons strike the photocatalyst. The ability to decompose organic substances with UV and/or visible light such as LEDs and fluorescent lamps is continuous and the functional surface maintains long term performance.

The mechanism of action involves several levels. At the level of radicals, when photons reach the self-cleaning photocatalytic thin film, hydroxyl radicals (OH) and super oxide anions are being generated. The two reactants decompose toxic organic substances through the process of oxidation. At the level of molecules, the atomic nucleus is surrounded by orbits where electrons are present. The valance band is where electrons responsible for reactions are revolving. The existence of a conduction band outside the valance band allows energy of light to be applied externally. Once photons become present the electrons are enhanced by extra energy in the valence band and rise to the conduction band. Furthermore, positive holes are created and left behind in the valance band. When this occurs the photocatalytic film establishes an excited state and the positive holes exhibit substantial oxidative power. The moisture on the surface allows to be oxidized by the positive holes forming hydroxyl radicals (OH) which support the self-cleaning photocatalytic activities.