Diamonds made from graphene have been a reality since last year, when a team from the Institute of Basic Sciences in South Korea chemically converted a sheet into this crystalline form of carbon that can be described as a sheet diamond. But since 2014, scientists at the American Rice University already knew how to do this, but without chemistry; now, they did it.
Led by materials scientist Boris Yakobson, the team was able to synthesize nanodiamonds (called diamonds) by joining two layers of graphene in a cubic network using, in addition to heat, pressure and the reaction of the material itself to the process (mechanochemistry).
“Until now, diamonds were made by converting two-layer graphene using chemistry. Combining them using local pressure and the mechanochemistry that the process triggers seems like a promising way to try, ”says Yakobson.
Chemistry on an industrial scale
Diamonds form a thin, flexible and almost unbreakable film like diamonds, with applications in nanoelectronics and nano-optics, as semiconductor. Its production is still at the nanoscale: two sheets of graphene are inserted between layers of hydrogen or fluorine.
Then, from a single pressure point, the hydrogen or fluorine atoms covalently bond to the surfaces, generating carbon-carbon connections between the layers, in a reaction that spreads throughout the material.
Published in Small magazine, the process worked on a double layer of graphene, but now the Rice team hopes to be able to repeat it with an increasing number of sheets. In the next step, which is to get diamonds on an industrial scale, perhaps chemistry is needed.
“In thicker films, the barrier increases rapidly with the number of layers. It can be reduced with the use of external pressure, but it and also chemistry must work together to obtain a 2D diamond ”, added the study’s co-author, materials scientist Pavel Sorokin.