Behind the gray appearance of concrete there is a solution that could significantly improve the quality of the air we breathe in closed environments such as road tunnels. Thanks to the genius of the researchers of KICT (Korea Institute of Civil Engineering and Building Technology), a new type of photocatalytic cement can purify the air of dangerous pollutants present in car exhaust fumes.
The meaning of photocatalytic… In music
The term “photocatalytic” comes from two words: “photo,” meaning light, and “catalytic,” which refers to a process that facilitates a chemical reaction. A “photocatalytic” material, therefore, is a material that, when exposed to light, facilitates chemical reactions without being used or consumed in the process.
Imagine a photocatalyst like an orchestra conductor: it doesn't play any instrument, but directs everyone (the polluting molecules). When the lights come on (the light hits the photocatalyst), the conductor begins to conduct (i.e. facilitate chemical reactions), transforming the chaotic music (pollutants) into a harmonious symphony (harmless substances). And the wonderful thing is that the conductor can continue to conduct more or less without ever getting tired.
Photocatalytic Cement: what makes it special?
In this case, the protagonist of the cement developed by Korean researchers is a photocatalyst which, once activated by light, produces oxidizing substances (ROS) powerful enough to convert fine particle precursors, such as nitrogen oxide and sulfur oxide, in harmless compounds.
In summary? Breaks down fine particles.
One year after the first publication of the experimental data (I link them to you here) last month, the research team completed a test of its photocatalytic concrete inside the Banpo Underground Tunnel, in Seoul, South Korea. Despite the absence of natural light, an artificial light source was sufficient to allow the process to work properly, reducing of 18% nitric oxide levels over 24 hours.
The road is marked
It is no surprise that photocatalytic cement, as I wrote to you before, sounds like music to the ears.
The limits to this technology, which was not born today, were of a technical and economic nature, and meant that its production cost prevented its use. This study succeeded in developing a cost-effective technology to produce photocatalysts. As? Starting from sewage sludge.
According to Dr. Jong-Won Kwark, lead researcher on the project, the use of photocatalysts in construction could have an immediate impact on reducing fine particulate matter in our environment.
Let's see: of course, it would be a nice retaliation if from sludge and cement come a way to breathe less polluted air.
