Scientists create "goldene," an ultrathin version of gold

Scientists have created "goldene," an extremely thin version of gold, following the success of graphene, a material made of single-layer graphite atoms known for its exceptional strength and conductivity.

According to a report in the Independent, goldene is crafted by dispersing gold until it reaches a single layer of atoms in thickness, similar to the process used for graphene.

This technique endows goldene with a range of novel properties, opening doors to potential applications such as communications technologies, water purification, carbon dioxide conversion, and more. Additionally, the creation allows for reduced use of gold in technologies that typically require the metal.

Researchers believe that gold is just the beginning, with the potential for similar methods to be applied to other metals.

Shun Kashiwaya, a researcher at Linkoping University's Materials Design Division, commented on the transformative effects of thinning materials, saying, "If you make a material extremely thin, something extraordinary happens - as with graphene. The same thing happens with gold. Gold, usually a metal, can become a semiconductor when just a single atom layer thick."

While the concept of ultrathin gold has been explored for years, previous attempts were hindered by gold's tendency to clump together. A breakthrough was achieved using a century-old method developed by Japanese artisans, discovered somewhat serendipitously while researching another material. The method involves implanting gold between layers of carbon and titanium in a base material.

Lars Hultman, a professor of thin film physics at Linkoping University, explained the unexpected discovery, saying, "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 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."

For years, the goldene substance was available but extracting the gold proved challenging.

Researchers turned to Murakami's reagent, a technique used by Japanese smiths to remove carbon from materials, to extract the gold. Kashiwaya elaborated on the process, "I tried different concentrations of Murakami's reagent and different time spans for etching. What we noticed was that the lower the concentration and the longer the etching process, the better. But it still wasn't enough."

The etching process required total darkness to prevent the formation of cyanide, which can destroy gold. To stabilize the gold sheets, a surfactant was applied to prevent them from curling. Kashiwaya compared the goldene sheets to "cornflakes in milk," adding, "Using a type of 'sieve', we can collect the gold and examine it using an electron microscope to confirm that we have succeeded. Which we have."