May 4, 2011
Graphene grown on stainless steel in custom set-up
Graphene – the high-potential allotrope of carbon, which is made of a hexagonal-honeycomb array of sp2 hybridized carbon atoms – has been attracting the attention of nanotechnology researchers for the past couple of decades. The properties of other forms of carbon-like fullerenes (buckyballs-C60), carbon nanotubes and even graphite are derived from the concept of this as then hypothetical single layer of carbon. By the beginning of the previous decade, people started realizing this one atom thick layer. Since then it has been a platform for scientists to think about exotic phenomena like the room-temperature quantum hall effect and half integer quantum hall effect. The material exhibits some superior properties such as the highest mobility for a non-superconducting material along with the highest value for young's modulus, which is a measure of mechanical strength.
Recently Prof. T Pradeep and his team at IIT Madras, India, have devised a method to prepare this wonder material with relatively low expenditure. They made graphene on commercially available stainless steel substrates (SS304, 0.1 mm thick) by a pyrolitic reaction, carried out in a custom hot-wall split tube furnace.
The source of carbon was ethyl alcohol, which was driven by a flow of hydrogen gas at a pressure a little above the atmosphere. The gas mixture was allowed to react with the substrate (SS304), which was heated to a temperature of 850 °C. After 10 minutes of reaction time, the substrate was cooled to room temperature at a rate of 100 °C/minute. The researchers found that this particular cooling rate is crucial for the formation of graphene.
Raman spectroscopy/microscopy was used to confirm the presence of a one atom thick layer of carbon. The role of SS304 composition on the formation of graphene was studied using photoelectron spectroscopy.
A full description of the work can be found in the journal Nanotechnology.
About the author
The research was conducted at the DST Unit of Nanoscience, Department of Chemistry, Indian Institute of Technology Madras, India, which is headed by Prof. T Pradeep. His research focuses on the novel possibilities of nanomaterials in basic science and their applications. One of his key interests is water purification using nanotechnology. Dr C Vijayan is a professor in the Department of Physics at IIT M. Robin John is a graduate student in the Department of Physics at IIT M. A Ashokreddy is a research associate.