Goldene is a single-layer

allotrope Allotropy or allotropism () is the property of some chemical elements to exist in two or more different forms, in the same physical state, known as allotropes of the elements. Allotropes are different structural modifications of an element: the ...

gold Gold is a chemical element; it has chemical symbol Au (from Latin ) and atomic number 79. In its pure form, it is a brightness, bright, slightly orange-yellow, dense, soft, malleable, and ductile metal. Chemically, gold is a transition metal ...

. The thinnest commercial

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is some 400 times thicker than goldene. It features 9% lattice contraction compared to bulk gold.

History

Goldene was first synthesized as a free-standing material in 2024 by a team at

Linköping University Linköping University (LiU; ) is a public university, public research university based in Linköping, Sweden. Originally established in 1969, it was granted full university status in 1975 and is one of Sweden's largest academic institutions. T ...

in Sweden. A 2022 claim by a team at New York University Abu Dhabi has been disputed as actually containing multiple layers.

Synthesis

The team used a material containing silicene between layers of titanium carbide. Gold layered on top of this combination diffused into the structure and replaced the silicon. Etching away the titanium carbide released free-standing goldene sheets that were up to 100 nanometres wide. The etching was performed using Murakami's reagent, in a 100-year-old technique used to decorate

ironwork Ironwork is any weapon, artwork, utensil, or architectural feature made of iron, especially one used for decoration. There are two main types of ironwork: wrought iron and cast iron. While the use of iron dates as far back as 4000 BC, it was th ...

by Japanese

blacksmiths A blacksmith is a metalsmith who creates objects primarily from wrought iron or steel, but sometimes from other metals, by forging the metal, using tools to hammer, bend, and cut (cf. tinsmith). Blacksmiths produce objects such as gates, gril ...

Surfactant Surfactants are chemical compounds that decrease the surface tension or interfacial tension between two liquids, a liquid and a gas, or a liquid and a solid. The word ''surfactant'' is a Blend word, blend of "surface-active agent", coined in ...

molecules formed a barrier between goldene and the surrounding liquid — to stop the sheets from adhering. The team is exploring the potential for preparing goldene from other non- van der Waals Au-intercalated phases, including developing etching schemes.

Graphene comparison

Forming 2D allotropes of metals such as gold has been difficult because metal atoms tend to cluster together and form nanoparticles instead of nanosheets.

Properties

The material displayed Au 4''f'' binding energy increase of 0.88 eV. The material is a semiconductor, with the valence band maximum 50 meV below the

Fermi level The Fermi level of a solid-state body is the thermodynamic work required to add one electron to the body. It is a thermodynamic quantity usually denoted by ''μ'' or ''E''F for brevity. The Fermi level does not include the work required to re ...

Applications

Potential applications includes sensing and catalysis.

References