Pavements that combat pollution

The Germans gave us the first MP3 file, the programmable computer and the athletic shoe. Now they have a new trick up their sleeve: the paving slab that cleans the air.

The idea came about because of concerns over the rising levels of toxic nitrogen oxide in the atmosphere, for which road traffic is the main culprit.

Nitrogen oxide is a harmful greenhouse gas that is broken down naturally in the atmosphere, but at snail pace: it stays around for a staggering 120 years. In response to this, a group of German researchers from the Fraunhofer Institute for Molecular Biology and Applied Ecology IME put on their thinking caps and came up with the “Air-Clean” paving slabs.

These ingenious paving slabs have their own special cement formula that breaks down nitrogen oxide into harmless nitrates. They’re coated in titanium dioxide nanoparticles (TiO2), which use sunlight to speed up the break down of the toxic gas. The nitrates released are harmless and experiments have shown that they break down nitrogen oxide 70% faster than it naturally breaks down when there is no wind. 

The Gothaer Platz in Erfurt has already been paved with Air-Clean slabs and Petersberger Straße in the city of Fulda is set to be paved. So thanks to the Germans, we’re on the way to saving the world, one paving slab at a time.

By Vi Nguyen

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