Graphene is one of the most promising new materials. However, researchers across the globe are still looking for a way to produce defect free graphene at low costs. Chemists at Friedrich-Alexander Universiät Erlangen-Nürnberg (FAU), Germany have now succeeded in producing defect-free graphene directly from graphite using benzonitrile.
Conventionally, graphene is synthesized through chemicalexfoliation of graphite. The individual layers of graphene are then separated using solvents. The stabilized graphene is separated from the solvent and then reoxidized. However, defects in the individual layers of carbon, such as hydration and oxidation of carbon atoms in the lattice, can occur during this process.
In the new process, the addition of benzonitrile removes graphene without formation of additional functional groups. Therefore, no defects are formed in graphene and it allows specific electronic properties to be set through the number of charge carriers. The technique is also low-cost and efficient.
The method has another advantage; the reduced benzonitrile molecule formed during the reaction turns red as long as it does not come into contact with oxygen or water. This change in colour allows the number of charge carriers in the system to be determined easily through absorption measurements. This facilitatesgraphene and battery researchers to measure the charge state without measuring voltage.