The portentous graphene it may soon go out of fashion. In fact, what steals the show is now a new and surprising material, made entirely of gold. It’s about the goldenejust developed by researchers at the University of Linköping, in Sweden, who managed to create for the first time gold sheets the thickness of a single atom. A result, just published in the magazine Nature Synthesiswhich gives the metal new properties that make it suitable for several applications, including the conversion of carbon dioxide, the production of hydrogen and other chemicals.
The challenges of creating goldene
So far, the scientific community he had tried to produce goldene without successgiven the trend of atoms of gold to pool. This time, however, the authors of the new study managed to do it using a century-old method used by Japanese blacksmiths. They first used a three-dimensional base material by embedding thin layers of silicon between layers of titanium and carbide, then coating them in gold. “When we exposed the component to high temperatures, the silicon layer was replaced by gold within the base material”commented Lars Hultman, among the authors of the study. The challenge, therefore, was to be able to remove the golden part.
Ancient Japanese art
To achieve this, the research team was inspired by a particular technique used for over a hundred years in the art of Japanese forging: it is called Murakami reagent and is used to remove carbon residues and change the color of steel in the manufacture of knives. “I tried different concentrations of Murakami’s reagent at different time intervals”added lead author Shun Kashiwaya. “What we’ve noticed is that the less concentration and the longer the process, the better.” Finally, the last step was to make the gold sheets stable by adding a surfactant. “The gold foils are in a solution, a bit like cornflakes in milk,” explains the expert. “Using a kind of sieve, we collected the gold and by examining it under an electron microscope we were able to confirm that we succeeded.”
Possible applications
The new properties of goldene are due to the fact that gold in its two-dimensional shape has two free bonds. For this reason, it could eventually be used as a catalyst for carbon dioxide conversion, hydrogen and chemical production, water purification and communication. “If you make a material extremely thin, something extraordinary happens, like with the graphene. The same thing happens with gold. As you know, gold is usually a metal, but if it is a single atom thick, it can become a instead semiconductor”, concludes Kashiwaya. Clearly this is just the beginning for the goldene, and the researchers’ next step will be to continue studying them propertythe potential applications and verify whether their process can also work for other noble metals.
