Chapter 15 - Novel photocatalysts for indoor air clean and healthy environments

Abstract

The purpose of this chapter is to present recent developments on novel photocatalytic materials for indoor clean and healthy environments. Since we spend more than c. 85%–90% of our time indoors, substantial efforts have been made to investigate the photocatalytic impact of materials containing (TiO2) or modified (doped) TiO2 towards priority air pollutants like NO, NO2, volatile organic compounds (VOCs), and bioaerosols frequently accumulated at high concentrations in indoor environments. VOCs, for example, aromatic and aliphatic compounds, and carbonyls (formaldehyde) are emitted from building materials, such as coatings, wood-based materials on walls, ceiling, floors, and furniture. Concentration levels in indoor spaces are often several times higher than outdoors. Moreover, bioaerosols, suspensions of airborne pathogens released from living organisms and/or air-conditioning systems contribute to indoor air contamination, thus potential of leading to the transmission of severe diseases. Preliminary evidence indicates that photocatalysis under indoor illumination conditions with novel photocatalysts is a promising approach to improve both air and health quality in indoor environments. In this chapter, modified titania (TiO2) with novel photocatalytic properties under indoor light conditions may lead to smart coatings, which could act as benchmark materials suitable for indoor applications. The properties and applications of transition metal-doped TiO2 photocatalysts tested in lab and in real-scale applications are discussed.