ACS Nano http://dx.doi.org/10.1021/nn202625c (2011)

Graphene — a one-atom-thick layer of carbon arranged in a honeycomb structure — can be synthesized by exfoliation or various chemical methods. However, many of these methods use purified chemicals such as methane gas or poly(methyl methacrylate) as the carbon source. James Tour and colleagues of Rice University have now synthesized pristine graphene using inexpensive carbon sources such as waste materials, insects and food.

Tour and co-workers placed about 10 mg of either a piece of cookie, blades of grass, dog faeces or polystyrene plastic on top of a copper foil that was contained in a quartz boat. The sample was annealed for 15 min under hydrogen and argon gas flow using procedures that are similar to growing poly(methyl methacrylate)-derived graphene. X-ray photoelectron spectroscopy and Raman spectroscopy confirmed that the graphene, which was mostly deposited on the backside of the copper foil, was pristine and of high quality with few defects. Further analysis by selected-area diffraction pattern in a transmission electron microscope confirmed the hexagonal lattice structure of the graphene.

Although the mechanism for how the growth occurs remains to be explored, the use of waste materials to produce high-quality graphene may offer a way to recycle carbon from impure sources.