Scientists at the University of Leeds have created a new form of gold, which is just 0.47 nanometres thick. This is for the first time that scientists have created the thinnest unsupported gold ever.
The newly formed gold material consists of two layers of atoms sitting on top of one another. Thus it is regarded as 2D. Experiments affirmed that the material is ten times more proficient as a catalytic substrate than the currently used gold nanoparticles, which are 3D materials with the majority of atoms residing in bulk rather than at the surface.
Also, the material can potentially be the basis of artificial enzymes that could be applied in rapid, point-of-care medical diagnostic tests and water purification systems.
The lead author of the paper, Dr. Sunjie Ye, from Leeds’ Molecular and Nanoscale Physics Group and the Leeds Institute of Medical Research, said: “This work amounts to a landmark achievement. Not only does it open up the possibility that gold can be used more efficiently in existing technologies, but it is also providing a route which would allow material scientists to develop other 2D metals.”
“This method could innovate nanomaterial manufacturing.”
Synthesizing the gold nanosheet takes place in an aqueous solution and begins with chloroauric acid, an inorganic substance that contains gold. It is decreased to its metallic form within sight of a ‘confident agent’ – a chemical that urges the gold to frame as a sheet, only two atoms thick.
Due to its nanoscale dimensions, the material appears green in the water. Thus, scientists also dubbed it as gold nanoseaweed. The images captured by the electron microscope reveal the way the gold atoms have formed into a highly organized lattice. Other images show gold nano seaweed that has been artificially colored.
The images can be seen here.
Professor Stephen Evans, head of the Leeds’ Molecular and Nanoscale Research Group who supervised the research, said the considerable gains that could be achieved from using these ultra-thin gold sheets are down to their high surface area to volume ratio.
He said: “Gold is a highly effective catalyst. Because the nanosheets are so thin, just about every gold atom plays a part in the catalysis. It means the process is highly efficient.”
Professor Evans said: “Our data suggests that industry could get the same effect from using a smaller amount of gold, and this has economic advantages when you are talking about precious metal.”
“I think there will inevitably be comparisons made between the 2D gold and the very first 2D material ever created – graphene, which was fabricated at the University of Manchester in 2004.
“The translation of any new material into working products can take a long time, and you can’t force it to do everything you might like to. With graphene, people have thought that it could be good for electronics or transparent coatings – or as carbon nanotubes that could make an elevator to take us into space because of its super strength.
“I think with 2D gold we have got some very definite ideas about where it could be used, particularly in catalytic reactions and enzymatic reactions. We know it will be more effective than existing technologies – so we have something that we believe people will be interested in developing with us.”
The announcement that the ultra-thin metal had been successfully synthesized was made in the journal Advanced Science.