Scientists finally make ‘goldene’, potentially breakthrough new material

Researchers have managed to create “goldene”, an incredibly thin version of gold.

The work follows the successful production of graphene, which is made out of a single layer graphite atoms. That has been hailed as a miracle material: it is astonishingly strong, and much better at conducting heat and electricity than copper.

Goldene is built on the same principle, with researchers spreading out gold so it is just one atom layer thick. And, similar to graphene, scientists say that the process gives it a variety of new properties that could lead to major breakthroughs.

The new material could be useful in everything from converting carbon dioxide to purifying water and in communications technologies – and much else besides, researchers say. What’s more, much less gold can be used in current technologies that rely on the material.

Researchers suggest that gold could be just one of a range of similar materials. Further work is currently happening to understand if the same findings can be used on other metals.

“If you make a material extremely thin, something extraordinary happens – as with graphene. The same thing happens with gold,” said Shun Kashiwaya, researcher at the Materials Design Division at Linköping University.

“As you know, gold is usually a metal, but if single-atom-layer thick, the gold can become a semiconductor instead.”

Researchers have been trying for years to create thin gold of this kind, but have been foiled by the fact that metal tends to clump up. The breakthrough finally came with a century-old technique inspired by Japanese craftspeople.

It also came about partly by luck. The new material relies on gold being embedded between layers of titanium and carbon in a base material – and that was found when looking for something else.

“We had created the base material with completely different applications in mind. We started with an electrically conductive ceramics called titanium silicon carbide, where silicon is in thin layers,” said Lars Hultman, professor of thin film physics at Linköping University.

“Then the idea was to coat the material with gold to make a contact. But when we exposed the component to high temperature, the silicon layer was replaced by gold inside the base material.”

Researchers had that new material, made by a process called intercalation, for some years. But they could not get the gold itself out of it.

They then borrowed a method from Japanese smiths, called Murakami’s reagent, which etches away the carbon on a material so that it can for example be used to change the colour of steel. Researchers took that recipe and made some modifications to get the gold out.

The findings are described in a new article, ‘Synthesis of goldene comprising single-atom layer gold’, published in Nature Synthesis.