Photocatalytic recycled aggregate concrete for air-purifying purpose

The relentless expansion of big cities especially metropolis, coupled with rapid economic development brings with it profound consequences, such as rapid depletion of natural resources and increasingly pressing air pollution problems. The combination of TiO2-mediated photocatalysis with recycled aggregate concrete (RAC) represents an environmentally friendly way to alleviate the burden of solid wastes on the environment and concomitantly degrade air pollutants in the surrounding atmosphere. Only solar light is required to fulfill its photocatalytic air-purifying function, greatly bringing down the operation and maintenance costs. This chapter surveys the broad scientific landscape of photocatalytic functional RAC for air purifying purposes, summarizes the state-of-the-art of laboratory investigation, and provides a brief overview on practical applications. Open challenges for future research and application of photocatalytic RAC with respect to air pollutants degradation are also identified.