We have mentioned new and improved methodes for graphene production in the past, but actually the most widely used method for graphene growth over the past two years has been the so-called ‘chemical vapor deposition method.’ This is, roughly put, the decomposition of carbon-containing gases on copper foil under high temperatures.
Since little was known about the exact process, graphene sheets grown this way often contained defects and the grains were irregularly shaped and of different sizes.
But now recent research published in ACS Nano describes a new approach to growing graphene through the chemical vapor deposition method which results in high-quality graphene with well-defined graphene grains that are perfectly hexagonally shaped.
The research team of the Department of Energy’s Oak Ridge National Laboratory that made the discovery, found that hydrogen rather than carbon dictates the graphene grain shape and size.
Hydrogen seems to contribute to the activation of adsorbed molecules that initiate the growth of graphene as well as to the elimination of weak bonds at the grain edges that control the quality of the graphene. This knowledge allows for great control over graphene grain size and boundaries, which is indispensable for scale-up production of graphene for specified purposes.
© Jorn van Dooren | www.bitsofscience.org