Researchers at the University of Leeds have created a new form of gold that is only two atoms thick. This is the thinnest unsupported gold ever created. The thickness of the gold is only 0.47 nanometers or one million times thinner than a human fingernail.
The material is regarded as 2D because it has only two layers of atoms sitting atop each other. All of the atoms in the new form of gold are surface atoms; the team notes there are no bulk atoms hidden beneath the surface. The team who created the new form of gold says that it could have wide-scale applications in the medical device and electronics industries.
The incredibly thin material could also be used as a catalyst to speed up chemical reactions in a range of industrial processes. The ultra-thin gold is ten times more efficient as a catalytic substrate than the larger gold nanoparticles used in industry today, according to lab tests.
The new material may also form the basis of artificial enzymes for possible use in rapid, point-of-care medical diagnostic tests and water purification systems. According to lead study author Dr. Sunjie Ye, the material also opens up the possibility that gold can be used more efficiently in existing technologies. The tech could also provide a way for material scientists to develop other 2D metals.
Synthesizing the gold nanosheet happens in an aqueous solution and starts with chloroauric acid, which is an inorganic substance that contains gold. The substance is reduced to its metallic form in the presence of a “confinement agent,” which is a chemical that encourages gold to form as a sheet only two atoms thick. Since the material appears green in the water and has a frond-like shape, the researchers describe it as gold nanoseaweed.