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Photocatalysis

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Also Known AsHeterogeneous photocatalysis, TiO₂ photocatalysis, advanced oxidation process (photocatalytic)

What is Photocatalysis?

Photocatalysis is the acceleration of a chemical reaction by a photocatalyst — a substance that absorbs light and uses that energy to drive a chemical reaction while itself being regenerated. The most common photocatalyst is titanium dioxide (TiO₂). Upon UV/visible light absorption, TiO₂ generates electron-hole pairs that react with water and oxygen to produce reactive oxygen species (OH•, O₂•⁻) that can oxidize organic pollutants.

Properties & Characteristics

Photocatalyst absorbs photon (hν ≥ Eg). Electron-hole pair generated. Reduction at surface: O₂ + e⁻ → O₂•⁻. Oxidation at surface: H₂O + h⁺ → OH• + H⁺. Reactive oxygen species (ROS) degrade organics. TiO₂ Eg: anatase = 3.2 eV (UV active). Visible-light photocatalysts: doped TiO₂, g-C₃N₄, BiVO₄.

Uses & Applications

Air and water purification (degrading organic pollutants). Self-cleaning surfaces (TiO₂ coatings on glass, tiles). Antibacterial surfaces. Solar hydrogen production (water splitting). CO₂ reduction to fuels. Environmental remediation. Disinfection of water.

Safety Information

UV sources used in photocatalysis: UV-C germicidal — eye and skin hazard. TiO₂ nanoparticles: potential respiratory hazard. Photocatalytic intermediates can be more toxic than parent compounds transiently. Oxidizing radicals (OH•) are non-selective — can damage materials.

Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.

Key Facts

Term Photocatalysis
Synonyms Heterogeneous photocatalysis, TiO₂ photocatalysis, advanced oxidation process (photocatalytic)

Frequently Asked Questions

Photocatalysis is the acceleration of a chemical reaction by a photocatalyst — a substance that absorbs light and uses that energy to drive a chemical reaction while itself being regenerated. The most common photocatalyst is titanium dioxide (TiO₂). Upon UV/visible light absorption, TiO₂ generates electron-hole pairs that react with water and oxygen to produce reactive oxygen species (OH•, O₂•⁻) that can oxidize organic pollutants.

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