Is it possible to create sidewalks, buildings and other city structures that help lower air pollution and further clean our cities?
Well believe it or not, the answer could be “yes” – at least according to researchers at a company called Graphene Flagship partners.
Working with experts from a number of prestigious universities including the Israeli Institute of Technology, University of Bologna, and University of Cambridge, among others, the firm has developed a graphene-titania photocatalyst that degrades up to 70 percent more atmospheric NOx than standard nanoparticles in tests on real air pollution.
Although the level of air pollution in the U.S. has dropped dramatically in recent decades, it nevertheless remains a top priority of environmental and health officials. Thus, researchers are continually seeking new and improved ways to reduce harmful pollutants like NOx and volatile organic compounds in the atmosphere. Using photocatalysts such as titania might be a great way to accomplish this, according to the researchers.
How did the researchers develop their process? As reported in Science Daily, they did so in the following manner:
By performing liquid-phase exfoliation of graphite — a process that creates graphene — in the presence of titania nanoparticles, using only water and atmospheric pressure, they created a new graphene-titania nanocomposite that can be coated on the surface of materials to passively remove pollutants from the air. If the coating is applied to concrete on the street or on the walls of buildings, the harmless photodegradation products could be washed away by rain or wind, or manually cleaned off.
As for how they could apply this technology, Xinliang Feng, Graphene Flagship Work Package Leader for Functional Foams and Coatings, explains:
“Photocatalysis in a cementitious matrix, applied to buildings, could have a large effect to decrease air pollution by reducing NOx and enabling self-cleaning of the surfaces — the so-called “smog-eating” effect. Graphene could help to improve the photocatalytic behaviour of catalysts like titania and enhance the mechanical properties of cement.
In this publication, Graphene Flagship partners have prepared a graphene-titania composite via a one-step procedure to widen and improve the ground-breaking invention of “smog-eating” cement. The prepared composite showed enhanced photocatalytic activity, degrading up to 40% more pollutants than pristine titania in the model study, and up to 70% more NOx with a similar procedure.
Click here to read the full story at Science Daily.