Dutch scientists have created an air-purifying concrete that can reduces the nitrogen oxide found in tailpipe emissions by up to 45-percent.
Last fall, researchers at the Eindhoven University of Technology resurfaced a busy highway with over 1,000 square meters of air-purifying concrete stones. The air-purifying stones are made with titanium dioxide. The material is a photocatalytic that captures nitrogen oxide from the air and converts it into a harmless nitrate using the sun. An identical area was re-surfaced with normal paving stones.
Air-purity measurements found the NOx content was 25-percent to 45-percent lower in areas using the new concrete stones.
“The air-purifying properties of the new paving stones had already been shown in the laboratory, but these results now show that they also work outdoors”, said prof. Jos Brouwers.
Along with NOx reduction, the concrete stones naturally break down algae and dirt which means they are always clean. The air-purifying concrete can also be mixed with asphalt when an asphalt surface is preferred. And they can even be used for self-cleaning and air-purifying walls.
The cost of the stones only raise road-building costs by 10-percent.