Using the sap extracted from a seaweed, researchers have partially reduced graphene oxide to produce nanosheets that could be used to make electronic devices such as sensors, fuel cells and solar cells1.

The prevalent technique to produce graphene oxide sheets suffers from problems such as toxicity and possible contamination of graphene. With a view to devising an ecofriendly way of producing graphene oxide, the researchers prepared various saps. They produced a pinkish one (sap 1) by crushing whole plants of the red seaweed Kappaphycus alvarezii. To make other variations they treated this sap with charcoal (sap 2) and heated and freeze-dried it (sap 3).

The researchers tested how effectively solutions of these saps reduced separately synthesized graphene oxide to nanosheets. They found that saps 1 and 3 partially reduced graphene oxide to nanosheets as a result of a synergy between metal salts and organic compounds known as flavonals.

“These graphene sheets could be used to prepare high-tensile materials and devices for biomedical applications, as they are not harmful to living cells,” says lead researcher Kamalesh Prasad.