EU-funded scientists have invented a new way of creating atom thin nano-sheets with the potential to enable the next generation of electronic and energy storage technologies needed, for example, to power electric cars. The research was funded in part by the PEPINEN ('Processing and electron probing inorganic nanostructures for emerging nanotechnologies'), which clinched a EUR 168 256 Marie Curie grant under the EU's Seventh Framework Programme (FP7). The research was recently published in the journal Science.
Researchers from the Centre for Research on Adaptive Nanostructures and Nano-devices (CRANN) at Trinity College Dublin in Ireland and the University of Oxford in the UK have discovered how to split layered materials to give atom thin nano-sheets. Using these sheets, they have created a range of novel two-dimensional nano-materials possessing chemical and electronic properties that could enable new electronic and energy storage technologies.
For decades, researchers have tried to create nano-sheets from layered materials in order to unlock their unusual electronic and thermoelectric properties. However, previous methods were time-consuming, laborious or of very low yield and so unsuited to most applications. In this latest study, scientists developed nano-sheets from a variety of materials using common solvents and ultrasound, employing devices similar to those used to clean jewellery. According to them, the new method is 'simple, fast, and inexpensive, and could be scaled up to work on an industrial scale'.
'Our new method offers low costs, a very high yield and a very large throughput: within a couple of hours, and with just one milligram (mg) of material, billions and billions of one-atom-thick nanosheets can be made at the same time from a wide variety of exotic layered materials,' explained Dr Valeria Nicolosi, Royal Academy of Engineering Research Fellow in the University of Oxford's Department of Materials.
She said these new materials are also suited for use in next generation batteries known as 'supercapacitors', which can deliver energy thousands of times faster than standard batteries, enabling new applications such as electric cars. Many of these new atomic layered materials are very strong and can be added to plastics to produce super-strong composites, Dr Nicolosi explained. These will be useful in a range of industries from simple structural plastics to aeronautics.
Her colleague, Professor Jonathan Coleman, Principal Investigator at CRANN and Trinity College Dublin's School of Physics, said: 'Of the many possible applications of these new nano-sheets, perhaps the most important are as thermoelectric materials,' adding that 'these materials, when fabricated into devices, can generate electricity from waste heat.'
Dr Coleman gave the example of how in gas-fired power plants approximately 50% of energy produced is lost as waste heat, while for coal and oil plants the figure is up to 70%. 'However, the development of efficient thermoelectric devices would allow some of this waste heat to be recycled cheaply and easily, something that has been beyond us, up until now,' he explained.
According to the scientists, their research can be compared to the work regarding the two-dimensional material graphene, which won the Nobel Prize in 2010. Graphene has generated significant interest because when separated into individual flakes, it has exceptional electronic and mechanical properties that are very different to those of its parent crystal, graphite, they explained. However, graphite is just one of hundreds of layered materials, some of which may enable powerful new technologies.