Researchers at the University of Leedsin the UK have created a 2D gold which is just two atoms (0.47nm) thick - the thinnest unsupported gold ever created.
The material is regarded as 2D because it is just two layers of atoms sitting on top of one another. This means all the atoms are surface atoms, so there are no 'bulk' atoms hidden beneath the surface. This could have wide-scale applications in the medical device and electronics industries. The flakes are also flexible, meaning they could form the basis of electronic components for bendable screens, electronic inks and transparent conducting displays.
Laboratory tests show that the 2D gold is 10 times more efficient as a catalytic substrate than the currently used gold nanoparticles, which are 3D materials with the majority of atoms residing in the bulk rather than at the surface. Scientists believe the new material could also form the basis of artificial enzymes that could be applied in rapid, point-of-care medical diagnostic tests and in water purification systems.
"This work amounts to a landmark achievement," said Dr Sunjie Ye, from Leeds' Molecular and Nanoscale Physics Group and the Leeds Institute of Medical Research. "Not only does it open up the possibility that gold can be used more efficiently in existing technologies, it is providing a route which would allow material scientists to develop other 2D metals and could innovate nanomaterial manufacturing."
Synthesising the gold nanosheet takes place in an aqueous solution and starts with chloroauric acid, an inorganic substance that contains gold. It is reduced to its metallic form in the presence of a 'confinement agent' - a chemical that encourages the gold to form as a sheet, just two atoms thick.
Because of the gold's nanoscale dimensions, it appears green in water - and given the shape of the flakes, the researchers describe it as gold nanoseaweed.