Low-Carbon Embodied, Self-Cleaning, and Air-Purifying Building Envelope Components Using TiO2 Photocatalysis, 3D Printing, and Recycling

This perspective article describes the past, present, and future directions on TiO2 photocatalysis, 3D concrete printing, and recycling for developing innovative building envelope components from façade skins. Using a methodology consisting of three phases, first the historical evolution of TiO2 photocatalysis, 3D concrete printing, and recycling policies was investigated. Second, the rationale and positioning with regard to the state of the art were developed. Third, the cementitious mix design assessment for 3D printing of the building envelope components, evaluation of the photocatalytic activity, evaluation of the self-cleaning and air-purifying properties, and environmental and health assessment of the building envelope components were identified and discussed as major issues in developing innovative building envelope components that have the potential to mitigate urban air pollution, reduce building maintenance activities, and reduce building embedded carbon while, for example, recycling significant amounts of construction and demolition waste.