Recent advances in titania-based composites for photocatalytic degradation of indoor volatile organic compounds

Indoor air pollutants can cause severe health problems, specifically in terms of toxicological impacts on human. Every day, a complex mixture of many air pollutants is emitted from various sources and subject to atmospheric processes that can create varied classes of pollutants such as carboxylic acids, aldehydes, ketones, peroxyacetyl nitrate, and hydrocarbons. To adhere to indoor air quality standards, a number of techniques such as photocatalytic oxidation of various volatile organic compounds (VOCs) have been employed. Among these techniques, titania (TiO2) based photocatalytic reactions have proven to be the best benchmark standard approach in the field of environmental applications. Over the last 45 years, TiO2-based photocatalytic reactions have been explored for the degradation of various pollutants. This review discusses the indoor air quality profile, types of indoor pollutants, available indoor air cleaning approaches, and performance of TiO2- based catalysts. Finally, we have presented the perspectives on the progress of TiO2 induced photocatalysis for the purification of indoor air.