WATER DECONTAMINATION BY SUNLIGHT-DRIVEN FLOATING
PHOTOCATALYTIC SYSTEMS

Photocatalysis is the acceleration of a photoreaction in the presence of a catalyst. Heterogeneous photocatalysis employs a solid photocatalyst, such as a metal-oxide semiconductor, which absorbs light with an energy equal or greater than its band gap, resulting in the generation of charge carrier species.

As a result, highly oxidizing species are formed that can oxidize organic pollutants. The reduction of inorganic pollutants (such as heavy metals) can also take place via mechanisms activated by photogenerated electrons.

The most used photocatalysts usually take advantage only of the UV portion of the solar spectrum, which accounts for 5% of the overall solar energy. For this reason, research has been focused on the development of new Visible Light Responsive (VLR) photocatalytic materials in order to use the vast abundance of outdoor solar light instead of artificial UV light.

The SUNFLOAT device is aiming to turn polluted water into irrigation-grade or drinking grade water, in places where no centralized water purification facilities are available. This requires a highly efficient system which can properly exploit the photocatalytic properties of the active phase by tapping into solar light as an inexpensive energy source, available also at remote locations, and distributing the active phase onto a suitable floating support, enabling an easy recovery and reactivation of the active phase.