Graphene is one of the most promising new materials. However, researchers around the world are still looking for a low-cost method to produce defect free graphene. Chemists have successfully produced defect free graphene directly from graphite for the first time.

Graphene is one of the most promising new materials. However, researchers around the world are still looking for a low-cost method to produce defect free graphene. Chemists of Friedrich Alexander Universi ä t erlangen-n ü rnberg (Fau) successfully produced defect free graphene directly from graphite for the first time. They recently published their findings in the journal Nature communications.

Graphene is two-dimensional and consists of a single layer of carbon atoms. It is especially good at conducting electricity and heat, transparent, flexible and strong. Graphene's unique properties make it suitable for a wide range of cutting-edge technologies, such as transparent electrodes for flexible displays.

However, the semiconductor industry can successfully use graphene only by improving the size, area and number of defects that affect the conductivity of graphene in the synthesis process. A group of Fau researchers from the chairman of Organic Chemistry II, led by Dr. Andreas Hirsch, recently made a key breakthrough in this field. With the help of the additive benzonitrile, they found a method to directly produce defect free graphene from solution. Their method makes the quality of graphene higher than ever, and it will not produce defects when cutting. It can also set specific electronic characteristics by the number of carriers. In addition, their technology is both low-cost and efficient.

A common method for synthesizing graphene is to chemically exfoliate graphite. In this process, metal ions are embedded into graphite composed of carbon to form so-called block compounds. The separate carbon layer graphene is separated by a solvent. Then, the stable graphene must be separated from the solvent and reoxidized. However, defects in individual layers of carbon, such as hydration and oxidation of carbon atoms in the lattice, can occur in this process. Researchers at the University of Florida have now found a solution to this problem. By adding the solvent benzonitrile, graphene can be removed without forming any additional functional groups, and it is still free of defects.

Professor Hirsch explained: "this discovery is a breakthrough for international experts in the field of reduced graphene synthesis." "Based on this discovery, we are expected to see significant progress in the application of this graphene, which is produced by wet chemical stripping." For example, cutting defect free graphene for semiconductor or sensor technology. "

Additional benefits

The method designed by Fau researchers has another advantage: as long as it is not in contact with oxygen or water, the reduced benzonitrile molecules formed during the reaction will turn red. This color change makes it easy to determine the number of carriers in the system through absorption measurement. Previously, this could only be achieved by measuring the voltage, which means that graphene and battery researchers now have a new method to measure the state of charge.