Photochemical air pollution is an atmospheric phenomenon in which primary pollutants, principally nitrogen oxides (NOx) and volatile organic compounds (VOCs), undergo sunlight-driven photochemical reactions to form a complex mixture of secondary pollutants. Key products include ozone (O₃) in the troposphere, peroxyacyl nitrates (PANs), aldehydes, organic nitrates, and secondary organic aerosols. These reactions are initiated by NO₂ photolysis, generating ozone and radical species (e.g., OH, HO₂, RO₂) that propagate non-linear reaction chains. Photochemical air pollution is characterized by strong diurnal and seasonal patterns and is sensitive to precursor emissions, meteorology, and atmospheric oxidizing capacity.
As the adoption of cleaner-burning engines and electric vehicles drives fossil fuel emissions lower, scientists have discovered that a surprising pollution source is playing a significant role in cooking up ozone in the air ...
Environment
Mar 13, 2025
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40
Sunlight has a major influence on chemical processes. Its high-energy UV radiation in particular is strongly absorbed by all materials and triggers photochemical reactions of the substances present in the air. A well-known ...
Optics & Photonics
Apr 10, 2024
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73
Typically, beautiful white wall paint does not stay beautiful and white forever. Often, substances from the air accumulate on its surface. This can be a desired effect because it makes the air cleaner for a while—but over ...
Nanomaterials
Mar 25, 2024
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127
