fotolýza

Fotolýza is a chemical process where molecules are broken down by photons, which are particles of light. This process is a type of photodissociation. The energy from the light is absorbed by the molecule, causing it to break into smaller fragments. The specific bonds that are broken and the resulting fragments depend on the type of molecule and the wavelength of the light.

A well-known example of fotolýza occurs in the Earth's atmosphere. Ozone (O3) molecules in the stratosphere absorb ultraviolet (UV) radiation from the sun. This absorbed energy causes the ozone molecule to split into an oxygen molecule (O2) and a single oxygen atom (O). This reaction is crucial for regulating the amount of UV radiation reaching the Earth's surface. Another significant example is the fotolýza of water molecules, which is the initial step in photosynthesis. In this process, light energy is used to split water into oxygen, protons, and electrons, providing the necessary components for the subsequent stages of photosynthesis.

The efficiency of fotolýza is related to the absorption spectrum of the molecule, meaning the specific wavelengths of light that the molecule can absorb. If the light's energy matches the energy required to break a specific bond, fotolýza is more likely to occur. This process has applications in various fields, including photochemistry, environmental science, and industrial processes.