Transforming the Urban Jungle: Air-Purifying Concrete

By Heather Hassel-Finnegan | Green Buildings & Architecture, Urban Design

“Lilypad”, a floating city concept by Vincent Callebaut, Architect. The sustainable refuge would mimic plant life by using photocatalytic concrete to purify air.

One of the most innovative trends in the Green Building Industry today is the application of biomimicry principles to the design process. Biomimicry is an emerging field in which nature is used as a model in the design of new materials, structures, and processes. In the simplest terms, someone practicing biomimicry considers a solution to a problem by asking the question “how would nature solve this problem?” For instance, someone designing a building in a drought-prone region may want to design a structure that effectively collects rainwater for later use. That person would ask herself “how does nature collect and recycle water”.

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One of the most exciting building materials to result from a biomimicry design approach is photocatalytic concrete, which has both self-cleaning and air-purifying properties. This technology incorporates titanium dioxide into concrete and concrete coatings, an inspiration that arose when researchers were considering how to artificially replicate the process of plant photosynthesis. In the presence of sunlight, titanium dioxide is capable of capturing and breaking down soot, dirt, mold, fungus, algae, and a range of other compounds that typically build up on urban surfaces.  This drastically reduces the costs of infrastructure maintenance. Even more impressively, titanium dioxide has been shown to decompose pollutants, including several greenhouse gases, into nonhazardous waste products.


The Church of 2000 “Dives in Misericordia” in Rome designed by Richard Meier uses photocatalytic concrete as part of its natural design elements.

Sustainability projects worldwide have incorporated photocatalytic concrete into both highly aesthetic and highly functional designs. The iconic Dives in Misericordia Church in Rome, Italy was one of the first structures in which photocatalytic concrete was used. In Chicago, a green rejuvenation project on Cermak Road used photocatalytic concrete on road surfaces with goal of neutralizing nitrogen oxide emissions from vehicles. There is great potential that significant amounts of surface area in our urban landscapes could be coated with photocatalytic concrete products, especially as the products on the market continue to become more sophisticated and affordable.

About The Author

Heather Hassel-Finnegan
Heather is a Sustainability Specialist working in the healthcare industry. She is a LEED Accredited Professional and holds a Sustainability Professional Certificate. She has a background in Biology and Anthropology, and much of her past work focused on wildlife biology and conservation. Heather resides in the Philadelphia region with her husband and toddler daughters.