New photocatalytic compounds
The term “photocatalysis” refers to a phenomenon by which a substance alters the speed of a chemical reaction. This substance, called “photocatalyst“, is activated on simple exposure to light, whether natural or artificial.
The most common example of a photocatalytic reaction is photosynthesis. In this extraordinary biological process, chlorophyll is the photocatalytic substance which, activated by sunlight, transforms the metabolic water of the plant and carbon dioxide in the air into substances the plant itself needs.
The ability of these substances to react under the action of light has, nowadays, many applications. One of these is the use of photocatalysts in air and water treatment processes, in order to remove pollutants harmful to humans and the environment. New highly photocatalytic inorganic nanoparticles (approx. 20 nm) with a large surface area (approx. 220m2/g), in fact, induce the formation of strong oxidising reagents, able to attack and degrade many organic and inorganic pollutants.
The same semiconductor oxides, suitably diluted in an aqueous solution, are used in the renewable energy field.
Applied to photovoltaic panels, they eliminate the layer of dust that settles on the panels, caused mainly by air pollution, which increases their efficiency (by approx. 3.5% annually).
Finally, various photocatalysts are also used in the construction sector. If applied to exterior surfaces, they perform a protective function. They eliminate organic dirt and neutralise the proliferation of bacteria and mould, making surfaces much cleaner and greatly reducing maintenance. They are therefore able to protect and preserve the characteristics, also aesthetic, of buildings and monuments.
- Hi-Tech Ambiente
- http://cityfactor.it/energia-solare-a-torino-emissioni-ridotte-di-850mila-kg/ (Photo)
- http://www.workinnovationgroup.com/nanotecnologia-e-applicazioni.html (Photo)