Rutgers researchers invent new method for producing graphene
Rutgers University engineers successfully produced high-quality graphene, a material with potential uses in next generation electronics and energy devices using a conventional microwave oven.
The discovery was the combined contribution of post-doctoral associates and undergraduate students under the supervision of Manish Chhowalla, a professor and associate chair in the Department of Materials Science and Engineering. Their study was published in the scientific journal Science.
The research group was composed of students from Rutgers, researchers from the Ulsan National Institute of Science and Technology and the University of Montpellier in France.
It is a two-dimensional carbon sheet with the thickness of an atom, stronger than steel and highly conductive, according to a scientific paper from 2010.
The properties of the material intrigued the science and engineering community, though producing large amounts of pristine graphene is still a puzzle in the material sciences community, according to the paper coauthored by Chhowalla.
A method discovered in 1859 by B.C. Brodie, a chemist and professor at Oxford University, used chemicals to exfoliate the separate graphene sheets from graphite.
“A method to make graphene from graphite used today is a modified version of (Brodie's) method,” Chhowalla said.
The process to separate the sheets of graphene from graphite adds oxygen to it, making graphene oxide. Graphene oxide doesn’t have the same properties that pristine graphene does.
The hexagon structures that give graphene its high conductivity and strength properties are distorted by oxygen groups, according to the paper.
Jacob Kupferberg, a School of Engineering senior, was in charge of creating the graphene fibers that would be used in the experiment.
The process of removing some of the oxygen from the fibers leaves reduced graphene oxide. The reduction of oxygen is crucial because without it the graphene could not conduct electricity, he said.
That means it would not absorb the microwave radiation required to heat up the graphene to 3000 degrees Kelvin and further reduce the oxygen amount through that heat. This causes the oxygen to burn out quicker and the carbon to rearrange into high-quality hexagonal lattices, he said.
The group then would have to prove that the graphene is high quality using a Raman Spectrometer. A Raman laser is shot at the graphene producing a good image of the carbon hexagonal lattice. The graphene is then used to make a transistor to observe if the electrons move quickly, he said.
“For many applications like water purification, batteries, catalysis and composites you need tons and tons of high-quality graphene, so manufacturing methods to achieve this must be developed to realize these applications,” Chhowalla said.
The problem that stands in the way of graphene being used in commercial products is the difficulty of producing enough of it to test large-scale prototypes, he said.
Despite a growing market, the push for a solution for graphene’s lack of supply will continue. There has been extensive experimental research with large corporations like IBM continuing to invest in alternative materials in their silicon-based microchips.
Similarly, Intel has been investing heavily into packing as many semiconductors onto a silicon chips, but progress through miniaturization is proving more difficult, according to the Wall Street Journal.
While the Rutgers discovery is a promising step towards its potential commercialization, it is very early to consider it for commercial use, Chhowalla said.
“It’s rare that research at the University level gets immediately translated into big industries. The discoveries in academia often set the scientific and engineering foundation that lead to new technologies,” he said.
Chhowalla's group is interested in the applications of graphene for energy storage and catalysis for generating clean energy, he said.
The Rutgers Engineers received funding from National Science Foundation, Rutgers Energy Institute, U.S. Department of Education and Rutgers Aresty Research Assistant Program.
Hernan Guarderas is a School of Arts and Sciences senior, majoring in journalism and media studies. He is a contributing writer for The Daily Targum. See more on Twitter @hguarderas93.