Chemical and biological air remediation by photocatalytic building materials

Photocatalytic building materials emerge as an alternative technology to improve air quality and prevent environmental and health problems. The photocatalytic oxidation process involves a semiconductor, generally TiO2, which, in the presence of oxygen and radiation of energy equal to or greater than the bandgap, generates electron–hole pairs capable of oxidizing a wide range of pollutants or removing pathogenic microorganisms from air streams. This chapter presents some case studies related to photocatalytic building materials, both at laboratory and real scales, applied to the chemical and biological remediation of indoor and outdoor air. Many types of construction materials have been analyzed, such as concrete, cement, coatings, papers, and paints, among others, formulated with different doped or commercially available TiO2 under UV and/or visible radiation. The advantages and limitations of this technology for the control of atmospheric pollution are presented and the main operating variables that affect the air decontamination process are discussed.