Advancing photocatalytic concrete technologies for design, performance and sustainable futures

Photocatalytic concrete technology is gaining attention in sustainable building and infra–structure for its crucial role in catalyzing the decomposition of harmful air pollutants and improving air quality. It incorporates photocatalysts such as Titanium dioxide (TiO2) and Zinc oxide (ZnO) to purify the air and offer self-cleaning capabilities. This review examines the pollutant removal capabilities of photocatalytic concrete, analyses the factors influencing its efficacy, explores different preparation methods and mechanical properties, and includes a life cycle assessment (LCA) to evaluate its environmental impact. Cement-based materials, serving as a carrier for photocatalysts, exhibit varying effects based on the type of photocatalysts, especially different types of TiO2 crystals. Analysis of preparation methods, including mixing, spraying and impregnation, emphasizes the imperative need for research aimed at improving the active lifespan and bonding strength of the coating to the substrate. The discussion covers strategies for enhancing photocatalyst performance through surface modification, addressing the associated technical and future challenges. Innovative methods such as the use of recycled glass to increase nitrogen oxides removal rates and the incorporation of porous materials such as zeolites to increase the photocatalytic efficiency of sulfur dioxide SO2 and CO2 have been evaluated. The TiO2 nanoparticle fraction significantly influences the hydration and overall performance of cement-based materials, with an optimal range of 4–10wt % of the cement mass recommended. LCA analyses indicate the need for exploring more environmentally friendly design options to enhance the application of photocatalytic technology in concrete infrastructure such as roads and building facades.