Lead
Volatile organic compounds, carbon monoxide and bioaerosols are common airborne pollutants present in the atmosphere that are detrimental to health. Photocatalysis is one of the emerging green processes for air decontamination, because in the presence of daylight photocatalysts will generate highly reactive singlet oxygen that will oxidize airborne pollutants to produce harmless gaseous substances, i.e. carbon dioxide and water vapor, or deactivate the bioaerosols. The corresponding photocatalytic windows offer a transformative self-sustaining technology for self-purifying in-door air to improve air quality. However, common photocatalysts such as titanium oxide (TiO2) utilize UV light (< 320 nm), most of which will be absorbed by the glass windows, and hence, would be ineffective on glass windows for indoor air purification.

Lay summary

Contenu et objectifs du travail de recherché

Our main goal is to develop an emerging photocatalyst that utilize visible light of 420–460 nm, present high thermal and chemical stability and can be coated to transparent glass windows with little affection to the transparency. More specifically, we intend to (i) synthesize the photocatalyst with and without chemical groups that can react with glass, (ii) coat the photocatalyst onto glass slides through three methods that are widely used for industrial manufacturing, including spin coating, drop coating and spray coating, (iii) use artificial sunlight to evaluate the photocatalytic removal efficiency of model airborne pollutants, such as formaldehyde, carbon monoxide and bacteria.


Contexte scientifique et social du projet de recherche

Our work will provide techniques for the fabrication of high transparent photocatalytic windows that use sunlight to improve in-door air quality. While such windows could become ubiquitous, key uses would be in buildings where organic solvents are used, ranging from factories to laboratories, and from beauty salons to shoe-repair shops. Such glass would also be useful in vehicles for removing carbon monoxide and gasoline volatiles, and in hospitals for assisted sterilization of bioaerosols. One of the widely used sterilization methods in hospitals is UV irradiation, which needs to be enclosed to avoid exposure to human. In contrast, our method based on visible light can be applied to normal windows and glass surfaces.


Keywords

Photocatalysis for air purification, singlet oxygen, photocatalyst coated transparent glass windows, removal of gaseous pollutants.


12 décembre 2012