New use discovered for graphene

Graphene has been found to be adept at filtering subatomic particles, by a team of UK scientists.

This means other uses have been found for the wonder material discovered in 2004, in this instance, simplifying production of heavy water and cleaning nuclear waste.

Professor Irina Grigorieva, from the University of Manchester, said: “We were stunned to see that a membrane can be used to separate subatomic particles.

“It is a really simple set up. We hope to see applications of these filters not only in analytical and chemical tracing technologies but also in helping to clean nuclear waste from radioactive tritium.”

Membranes made from graphene were able to separate protons from heavy water. This discovery means heavy water production could be 10 times simpler, cheaper and less energy intensive.

Deuterium – also known as heavy hydrogen, due to an additional neutron in its nucleus – is used for analytical and chemical tracing as well as heavy water needed for nuclear fission. It acts as a neutron moderator to slow down neutrons so they react with uranium-235, allowing for nuclear fission to happen. Tritium is another radioactive product that would need to be safely removed from a nuclear plant.

The researchers tested if deuterons – deuterium nuclei – could pass through monolayers. They were expecting the nuclei to pass through graphene as existing theory did not predict otherwise.  However, they found deuterons were effectively sieved with a high separation efficiency.

This process can be scaled up easily and they were able to build centimetre sized devices which could produce hydrogen from a hydrogen and deuterium mix. The devices were produced using chemical-vapour-deposition.

Dr Marcelo Lozada-Hidalgo, University of Manchester postdoctoral researcher and first author of the paper, said: “This is really the first membrane shown to distinguish between subatomic particles, all at room temperature.

“Now that we showed that it is a fully scalable technology, we hope it will quickly find its way to real applications.”

The research was published in Science.