Described by Nature As the ‘gold-plated cousin of graphene’, Goldene is a one-atom-thick sheet of gold created by scientists at Linköping University (LiU) in Sweden.
It has unique properties that researchers believe could pave the way for applications such as carbon dioxide conversion, hydrogen production, water purification and communications.
Shun Kashiwaya, researcher at the Materials Design Division at LiU, explains: “When you make a material extremely thin, something extraordinary happens. Just like with graphene, the same thing happens with gold. As you know, gold is usually a metal, but when it is only one atomic layer thick, the gold can become a semiconductor instead.”
An accidental discovery
Historically, attempts to create single-atom gold plates have been hampered due to the metal’s tendency to clump together. However, Goldene’s successful creation was achieved through an ancient Japanese forging technique called Murakami’s reagent, which etches away carbon residue. For this task, the team used an oxidizing reagent.
To produce Goldene, the researchers used a three-dimensional base material with layers of gold sandwiched between titanium and carbon.
However, there was an element of serendipity in Goldene’s creation, as Lars Hultman, professor of thin-film physics at LiU, admits. “We had created the base material with completely different applications in mind. We started with an electrically conductive ceramic called titanium silicon carbide, where silicon is in thin layers. Then the idea was to cover the material with gold to make contact. But when we exposed the part to high temperatures, the silicon layer in the base material was replaced by gold.”
The LiU researchers now plan to turn their attention to investigating whether other precious metals could undergo a similar process and yield even more unimaginable applications.
Funding for this research was provided by a range of institutions, including the Swedish Research Council, the Swedish Government’s Strategic Research Area in Materials Science and Linköping University.