As work is conducted to reduce the amount of carbon dioxide in the atmosphere in order to limit global warming, scientists are now not only looking for alternative energy sources but also for alternative uses of carbon dioxide.
One possibility could be to see carbon dioxide as an inexpensive raw material for the synthesis of valuable materials, feeding it back into the reusability cycle – maybe even in a profitable way.
During photosynthesis in the leaves of plants, for example, the combination of light, water and carbon dioxide creates biomass, closing the natural material cycle. In this process, it is the job of the metal-based enzyme RuBisCo to absorb the carbon dioxide from the air and make it usable for the further chemical reactions in the plant.
Inspired by this metal enzyme-based natural conversion, researchers at KIT are now presenting a process in which the greenhouse gas carbon dioxide together with hydrogen gas is converted directly into graphene at temperatures of up to 10000C with the help of specially prepared, catalytically active metal surfaces.
Graphene is the two-dimensional form of the chemical element carbon, which has interesting electrical properties.
Several working groups at KIT have collaborated to present a method in the ChemSusChem journal for separating graphene from carbon dioxide and hydrogen by means of a metal catalyst.
“If the metal surface exhibits the correct ratio of copper and palladium, the conversion of carbon dioxide to graphene will take place directly in a simple one-step process,” explains the head of the study, Professor Mario Ruben, from the Molekulare Materialien working group at the Institute of Nanotechnology (INT) and the Institute for Inorganic Chemistry (AOC) at KIT.
In further experiments the researchers were even able to produce graphene several layers thick, which could be interesting for possible applications in batteries, electronic components or filter materials.
The working group’s next research goal is to form functioning electronic components from the graphene obtained.