What do the Japanese blacksmiths of the last century and the Swedish researchers of today have in common? Apparently nothing. Yet it is precisely thanks to the encounter between an ancient Japanese forging technique and the most advanced synthesis technologies that the "golden“, a material that could revolutionize the future of gold. As thin as a single atom, but with semiconductor properties, this new "two-dimensional gold". Meanwhile I'll link the study here.
The challenge of creating two-dimensional gold
For years, scientists have tried to create sheets of gold just a single atom thick, but have always struggled with the metal's tendency to clump together. Now the researchers of Linköping University, driven by Shun Kashiwaya e Lars Hultman, they did not give up in the face of this challenge. The key to their success? A mix of intuition, perseverance and… a pinch of luck.
It all started when researchers were working on a conductive material called titanium carbide and silicon, in which the silicon was arranged in thin layers. The idea was to coat this material with gold to create an electrical contact. But when the team exposed the component to high temperatures, something unexpected happened: the silicon layer has been replaced by gold within the base material. This phenomenon, known as intercalation, had led to the creation of titanium carbide and gold. For years, researchers have studied this material without understanding how to “extract” the gold into two-dimensional sheets.
Until, by pure chance, Lars Hultman came across a method used by Japanese craftsmen for over a century.
The method in question is called “Murakami reagent” and is used in the art of Japanese forging to etch carbon residues and change the color of steel, for example in the production of knives. But the blacksmiths' exact recipe could not be applied directly to titanium carbide and gold. Kashiwaya had to experiment with different reagent concentrations and etching times, from one day to several months.
After numerous attempts, the researchers discovered that the key was to use a low concentration of the reagent for a very long time. But it still wasn't enough. The incision had to be made in the dark, since the light would have developed cyanide in the reaction, dissolving the gold. And to prevent the two-dimensional gold sheets from curling, a surfactant had to be added, a long molecule that separates and stabilizes the sheets. All clear? I know I know. If it had been easier they would have discovered it sooner.
Goldene, unique properties and potential applications
The result of this long process, as mentioned, is the golden. The goldene, guys. How nice to handle a term that, you feel, will influence the future. This is a material that could also revolutionize numerous technological sectors. Thanks to its two-dimensional structure, in fact, gold acquires semiconductor properties, with two free bonds that make it extremely versatile.
Among the potential applications of goldene are the conversion of carbon dioxide, catalysis for the production of hydrogen and value-added chemicals, water purification e telecommunications. Furthermore, thanks to this material, the amount of gold needed for current applications could be significantly reduced, with economic and environmental benefits. Researchers at Linköping University are already working to understand whether it is possible to obtain similar results with other noble metals and to identify further future applications of this extraordinary material.
From goldene a lesson in scientific serendipity
The story of the discovery of goldene is not only fascinating for the potential of this new material, but also for what it teaches us about the process of scientific research. Often, great innovations arise from unexpected combinations, from insights that occur while you are working on something completely different, or from the application of ancient knowledge to very modern problems.
It's serendipity, that lucky coincidence that leads to important discoveries almost by chance, provided you have an open mind and the humility to recognize the potential of ideas and methods that might seem very far from your field of research. This is what happened to researchers at Linköping University, who were able to seize the opportunity offered by an ancient Japanese forging technique to solve a cutting-edge problem in materials science.
Banzai!
