fotokatalyytiset

Fotokatalyytiset refers to processes driven by photocatalysis. Photocatalysis is a chemical reaction that is caused or accelerated by light. In photocatalysis, a substance called a photocatalyst absorbs light energy and uses it to initiate or speed up a chemical reaction. These reactions often involve the degradation of organic pollutants, water splitting to produce hydrogen, or the conversion of carbon dioxide into useful fuels.

The photocatalyst itself is not consumed in the reaction, meaning it can be reused. Common photocatalysts include titanium dioxide (TiO2), zinc oxide (ZnO), and cadmium sulfide (CdS). The effectiveness of a photocatalyst depends on several factors, including its band gap energy, surface area, and crystal structure. When light strikes the photocatalyst, it excites electrons, creating electron-hole pairs. These charge carriers then migrate to the surface of the photocatalyst, where they can react with adsorbed molecules, leading to chemical transformations.

Applications of photocatalysis are diverse and include air and water purification, self-cleaning surfaces, solar fuel production, and even in some medical treatments. For example, photocatalytic coatings on windows can break down dirt and pollutants, keeping the glass clean. In environmental remediation, photocatalysis can be used to decompose harmful organic compounds in wastewater. The ongoing research in this field aims to develop more efficient and cost-effective photocatalysts and to expand their range of applications.