For faster, larger graphene add a liquid layer
Millimetre-sized crystals of high-quality graphene can be made in minutes instead of hours using a new scalable technique, Oxford University researchers have demonstrated.
In just 15 minutes the method can produce large graphene crystals around 2-3 millimetres in size that it would take up to 19 hours to produce using current chemical vapour deposition (CVD) techniques in which carbon in gas reacts with, for example, copper to form graphene.
Graphene promises to be a 'wonder material' for building new technologies because of its combination of strength, flexibility, electrical properties, and chemical resistance. But this promise will only be realised if it can be produced cost-effectively on a commercial scale.
The researchers took a thin film of silica deposited on a platinum foil which, when heated, reacts to create a layer of platinum silicide. This layer melts at a lower temperature than either platinum or silica creating a thin liquid layer that smooths out nanoscale 'valleys' in the platinum so that carbon atoms in methane gas brushing the surface are more inclined to form large flakes of graphene.
A report of the research is published in the journal Nature Communications.
more
http://www.ox.ac.uk/news/2015-07-15-faster-larger-graphene-add-liquid-layer