For the first time, researchers have created a free-standing sheet of gold that is only one atom thick. This makes gold the first metal to be formulated into (freestanding) 2D sheets — opening up a host of exciting possibilities for the future. According to Hultman’s estimates, these sheets of goldene are roughly 100 nanometres thick (a nanometre is a billionth of a metre), approximately 400 times thinner than the thinnest commercially available gold leaf. IS IT THE FIRST 2D MATERIAL TO BE CREATED? It is not that such 2D materials have not been created before. Since the 2004 development of graphene, the atom-thin material made of carbon, scientists have identified hundreds of 2D materials. WAS MAKING ATOM THIN 2D MATERIALS OF METALS CHALLENGING? Coming up with atom-thin metallic sheets has been a challenge, due to metals’ tendency to cluster together to make nanoparticles instead. While scientists have previously produced gold sheets sandwiched between other materials, “goldene is the first free-standing 2D metal. HOW DID THEY CREATE GOLDENE? To create goldene, researchers first sandwiched an atomic monolayer of silicon between layers of titanium carbide. When they deposited gold on top of this sandwich structure, the gold atoms diffused into the material and replaced the silicon atoms, forming a trapped monolayer of gold atoms. Subsequently, scientists etched away the titanium carbide layers to create a free-standing, one atom thick layer of gold. This was done with the help of an age-old Japanese technique used to forge katanas and high-quality knives, using a chemical popularly known as Murakami’s reagent.

POTENTIAL APPLICATIONS

  • Scientists believe that the super thin, super light material can potentially revolutionise the electronics industry.
  • Goldene holds promise as a great catalyst because it’s much more economically viable than thicker, three-dimensional gold.
  • Moreover, the technique used by the scientists to create goldene can, in theory, also be applicable to other metallic objects.
    • The team is already working to make 2D sheets of iridium and platinum.
  • Scientists say that future applications could include carbon dioxide conversion, hydrogen-generating catalysis, selective production of value-added chemicals, hydrogen production, water purification, etc.