GOLDENE: A sheet of gold that is only one atom thick

Context

For the first time, researchers have made a super thin sheet of gold that is only one atom thick. 

One-Atom Gold Sheet Created with ‘Murakami Method’

• This discovery means that gold can now be made into flat, two-dimensional sheets
• To get a free-standing, one-atom thick gold layer, scientists used “Murakami method” inspired by Japanese technique 
  • They used a special chemical called Murakami’s reagent, similar to how traditional Japanese swords are made.

What is Goldene?

Goldene is a special form of gold called a 2-dimensional allotrope. It shows that it’s a different arrangement of gold atoms.

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• Thickness: It is 400 times thinner than gold leaf
• Structure: It has a unique quality where its structure is 9% smaller compared to regular gold. 
• Properties: New gold form has unique traits like graphene.
  • Gold is typically a metal, but a single-atom thick layer can transform it into a semiconductor.
  • Just like how graphene behaves differently from regular carbon, this new gold behaves differently from standard gold.

• Future Applications of Goldene:

  • Carbon dioxide conversion
  • Hydrogen-generating catalysis
  • Selective production of value-added chemicals
  • Hydrogen production
  • Water purification
  • Telecommunications

Process of Creating Goldene

• Initial Steps: Researchers started by layering a single sheet of silicon atoms between titanium carbide layers.
• Deposition of Gold: Gold was deposited on top of this structure.
  • The gold atoms replaced the silicon atoms and formed a monolayer of gold atoms trapped within.
• Etching Process: The titanium carbide layers were then etched away using an age-old Japanese technique involving Murakami’s reagent.  

Challenges in making Goldene

• Traditional obstacle: Gold tends to cluster together which makes it difficult to create single-atom sheets.
  • Previous 2D Materials: Two-dimensional (2D) materials have been created since the discovery of graphene in 2004 but  producing thin metallic sheets created difficulties due to metals’ tendency to form nanoparticles.
    • Innovative Solution: Researchers from LiU used Murakami’s reagent. 
      • Murakami’s reagent is an ancient Japanese technique, to address this challenge.
    • Murakami’s Reagent in Action
      • Process Complexity: Precision in the etching process was crucial to ensure the successful creation of Goldene.
      • Absence of light: Operations had to be conducted in the absence of light.
        • It added another layer of complexity to the process.

About Gold (Au)

Gold (Au) is a chemical element. It is renowned for its dense, lustrous, and yellow appearance. It Belongs to Group 11 (Ib) and Period 6 of the periodic table.

Physical Properties of Gold (Au):

Here are the physical properties of gold are as follows;

• Appearance: Soft yellow metal.
• Ductility and Malleability: Highest among metals.
• Crystal Structure: Cubic system.
• Conductivity: High thermal and electrical.
• Isotopes: 197Au natural; 19 artificial (185Au to 203Au).
• Radioactivity: Artificial isotopes have half-lives from seconds to 199 days.
• Magnetism: Pure gold and most alloys are nonmagnetic.
• Gold Alloys: Commonly with silver and copper.
• Carat Golds: Expresses gold content (e.g., 24 carats is pure gold).
• Alloying Metals: Forms alloys with many metals like silver and copper.
• Mercury and Gold: Mercury forms amalgams with gold, useful for extraction.

Chemical Properties of Gold (Au):

Here is a summary of the chemical properties of gold:

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