Cinnamon for dye-removing, antioxidant graphene
doi:10.1038/nindia.2015.71 Published online 27 May 2015
Researchers have used cinnamon bark extract to synthesize reduced graphene oxide1. This compound can remove harmful dyes and free radicals, making it potentially useful for cleaning contaminated environmental samples1.
Current methods for synthesizing graphene employ hazardous chemicals such as hydrazines, borohydrides and hydroquinones. It is difficult to purify graphene made from mixtures of such chemicals.
To devise an ecofriendly way to make graphene, the researchers prepared cinnamon bark extract and mixed it with graphene oxide. They found that reducing agents in the bark extract converted graphene oxide into few-layer reduced graphene oxide.
The scientists probed the efficiencies of the oxide to remove dyes by dissolving graphene in separate solutions containing malachite green and methylene blue. They observed that the graphene removed both dyes in 40 minutes in the absence of visible and ultraviolet light.
The researchers claim that the graphene removed both dyes by adsorbing dye molecules on its surfaces. In addition, the graphene showed antioxidant activity by scavenging the free radical 1, 1-diphenyl-2-picrylhydrazyl (DPPH).
The researchers claim that their technique is the first environmental-friendly method for efficiently reducing graphene.
1. Suresh, D. et al. Cinnamon supported facile green reduction of graphene oxide, its dye elimination and antioxidant activities. Mater. Lett. 151, 93–95 (2015)