Biokker uses two semiconductors as catalysts (TiO2/ZrO2) and uses photons in the UV range of the solar spectrum as an energy source generating free radicals that act by oxidizing organic compounds and purifying the air.
When the photo-catalyst of TiO2 y ZrO2 absorbs the ultraviolet (UV) light, the absence of an electron occurs in the valence bands or electron-hole pair, contributing to the passage of electric current in the semiconductors.
The electrons of the valence bands of the dioxides are energized if incised by a ray of UV light of an adequate wavelength generating energy, which makes the electrons ascend to the conduction band of both dioxides, creating positive hole pairs and negative charged electrons, regard also called “photo-excitation state”.
The positive gap of titanium dioxide and zirconium forms hydrogen gas and hydroxyl radicals, while the electron-negative reacts with the oxygen molecule to form superoxide anion. This cycle goes on indefinitely as long as there is light available.
The organic molecules are coupled in the same way with the active sites of the catalyst (positive gap and negative electron) and with the free radicals generated on the surface of the dioxides. The result is a complex series of cascade reactions whose final products are CO2 and H2O in trace amounts. Additionally, the complete oxidation of the organic matter causes the photo-catalytic reactor to have self-cleaning properties avoiding the creation of organic deposits on its surface.