Do you remember the discovery of graphene, the world's first two-dimensional material? Scientists tear graphite with bare hands with scotrange tape, and finally obtain graphene that is only one atom thick, and won the Nobel Prize in Physics. Recently, Swedish scientists have accidentally prepared two-dimensional gold composed of a single layer of gold atoms, which is believed to give gold more new properties, or will open up a new field of two-dimensional world, bringing a variety of major breakthrough applications.
Although gold can be beaten into gold leaf, it is almost impossible to make it an atom thick because gold can easily clump together. All previous efforts by scientists have failed, either a few atoms thick or covered with other materials that cannot be separated.
Swedish scientists did not intend to make two-dimensional gold at first, but wanted to coat a layer of gold on the conductive ceramic titanium silicon carbide as a contact point for electrons.
In order to extract this two-dimensional gold from titanium-silicon carbide, scientists thought of many ways and spent several years without success, until they found an old process that began to be used in Japan in forging knife technology more than 100 years ago - Murakami reagent, a process that can etch away carbon and titanium residues to form a unique pattern on the knife.
The scientists experimented with various reagent formulations and etching times, and the etching had to be carried out in complete darkness due to the production of a by-product called potassium ferrocyanide, which in turn dissolves gold when exposed to light.
After several months of etching, they finally obtained a monoatomic thick two-dimensional gold, but that was not the end of the story, as the flakes of gold had a tendency to curl and clump, and they added surfactants to separate and stabilize the long molecules of the flakes to prevent them from folding and sticking together.
In this way, through painstaking efforts, scientists finally prepared a single layer of two-dimensional gold, which was named goldene. Scientists describe the golden goldene floating in solution as beautiful as corn flakes floating in milk.
Because gold has two free bonds when unfolded in two dimensions and exhibits the characteristics of semiconductors, it may have broad applications in the fields of carbon dioxide conversion, hydrogen catalysis, selective production of value-added chemicals, hydrogen production, water purification, communications, etc., and may bring major technological breakthroughs.
In addition, because gold ene is very thin, only one atom thick, it can be used in a variety of existing gold applications, which can greatly reduce the amount of gold used and save the cost of using this expensive metal.
The study, which has been published in the April 16 issue of Nature Synthesis, demonstrates the agreement between theoretical simulations and experimental results and points out key steps for the successful preparation of stabilized goldene. The discovery of this new material not only opens up new avenues for the application of gold, but also provides new perspectives for the study of other two-dimensional materials, and scientists are experimenting with other precious metals in two dimensions, which, if successful, could open up a new realm of two-dimensional worlds.