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Large, stable pieces of graphene made with a unique edge



Different patterns are created at the edges of the nanograph. Zigzags are particularly interesting – and particularly unstable. FAU scientists have now succeeded in creating stable carbon layers with this pattern at their edges. Credit: FAU / Konstantin Amsharov

Bay, fjord, bay, armchair, and zig-zag-chemists use expressions like those that describe shapes that have taken on the edge of a nanographer. Graphene consists of a monolayer carbon structure in which each carbon atom is surrounded by three others. This creates a sample resembling a honeycomb, with the atoms in each corner. Nanographene is a promising candidate who will bring microelectronics to the nano and probably replace the silicon.


The electronic properties of the material very much depend on its shape, size and, above all, on its edge – that is, how the edges are structured. Particularly suitable is a perimeter circumferential path – in this configuration, the electrons that act as charge carriers are more mobile than other marginal structures. This means that when using nanoelectronic components, zigzag grain particles can allow higher frequencies for switches.

Material scientists who want to research only a zigzag nanographer face the problem that this form makes compounds unstable and difficult to manufacture in a controlled manner. However, this is a prerequisite if the electronic properties are to be explored in detail.

Scientists led by dr. Konstantin Amsharov from the presidency of Organic Chemistry II has only succeeded in doing so. Their research was now published in 2006 Natural communications. Not only have they discovered a direct method for zigzag nanotube synthesis, they achieve a yield of almost 100 percent and are suitable for large-scale production. In the laboratory, they have already produced a technically relevant quantity.

A highly sought-after sample of the zigzag can be found in either the folded rows of hairs (blue and purple) or the four limb stars that surround the central point of four graphene blades (red and green). Credit: FAU / Konstantin Amsharov

Researchers first produced precursor molecules, which then formed together in the form of honeycombs in several cycles in a process known as cyclization. Eventually, graphene fragments are made from oblique arrays of quadrupeds or square stars that surround the central point of four bristles, with a sought-after zigzag pattern at the edges. The product crystallizes directly, even during synthesis. In their solid state, the molecules are not in contact with oxygen. In solution, however, oxidation causes the structures to disintegrate rapidly.

This approach allows scientists to produce large pieces of graphene while maintaining control over their shape and circumference. This breakthrough in graphene research means scientists should soon be able to produce and examine a number of interesting nanographic structures, a crucial step in using nanoelectronic components.


Explore the following:
Holey graphene as a holy grail alternative to silicone chips

More information:
Dominik Lungerich et al., Dehydration p-extension to nanoparticles with zigzagging edges, Natural communications (2018). DOI: 10.1038 / s41467-018-07095-z

Reference number:
Natural communications

Provides:
University of Erlangen-Nuremberg


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