Researchers from Japan and Korea suggest a new way to make graphene - from rice husk (agricultural "waste"). They say that this method may prove to be an easy, scalable and cheap way to produce graphene. As annual rice husk waste is about 120 million tons a year, it's potential for graphene feed material is large.
Activated carbon has been made for a long time from rice husk ash, but this is the first time that graphene structured have been observed in such rice husk-derived activated carbon. In addition, the researchers found that highly crystalline and atomically clean edges are present in the synthesized materials, even though the graphene sample was prepared at relatively a low temperature of 850°C. These findings suggest that the resulting graphene may find applications in energy storage and conversion devices.
There are still some issues to resolve of course, for example the process (calcination and KOH treatment) makes it difficult to assess the detailed growth mechanism of graphene with its unique structures. In addition the process requires potassium hydroxide (a strong alkali compound) treatment.