Scientists of Northern Illinois University (NIU) announced about a new green, simple, cheaper and safe method for producing the graphene than the used ways like splitting graphite crystals or heating silicon to high temperatures. Ahead of the team is Narayan Hosmane. The new method just involves burning pure magnesium in dry ice, the new carbon is very thin and have several layers.
The new method is not built on a new discovery because it is known that burning magnesium metal in carbon dioxide produces carbon, but the new discovery is that the carbon produced is in the form of layers. The synthetic process can be used to produce few-layer graphene in large quantities. Hosmane’s team had set out to produce single-wall carbon nanotubes, and inadvertently discovered the graphene-production method in the process.
While Zhengzong Sun, a fourth-year graduate student in the lab of Rice chemist James Tour and his colleagues, discovered that putting carbon-rich sources on copper and nickel substrates produced graphene whether single-, bi- or multilayer sheets.
They found that the process adapts easily to producing doped graphene, which allows the manipulation of the material’s electronic and optical properties – an important factor in making switching and logic devices using the material.
For pristine graphene, Sun started with a thin film of poly (methyl methacrylate) (PMMA) – better known as Plexiglass – spun onto a copper substrate that acted as a catalyst. Under heat and low pressure, hydrogen and argon gas was flowed over the PMMA for 10 minutes, reducing it to pure carbon and turning the film into a single layer of graphene. Sun was able to control the thickness of the PMMA-derived graphene by changing the gas-flow rate.
Sun put 10 milligrams of sugar (and later fluorene) on a square-centimeter sheet of copper foil and subjected it to the same reactor conditions as the PMMA. It was quickly transformed into single-layer graphene. Sun said he had expected defects in the final product, given the chemical properties of both substances (a high concentration of oxygen in sucrose, five-atom rings in fluorene); but he found potential topological defects would self-heal as the graphene formed.