What is Graphene? Its Properties, Manufacturing, and Applications

Graphene (/ˈɡræfiːn/)[1] is a carbon allotrope consisting of a single layer of atoms arranged in a honeycomb planar nanostructure. The name “graphene” is derived from “graphite” and the suffix -ene, indicating the presence of double bonds within the carbon structure.

Graphene is known for its exceptionally high tensile strength, electrical conductivity, transparency, and being the thinnest two-dimensional material in the world.[4] Despite the nearly transparent nature of a single graphene sheet, graphite (formed from stacked layers of graphene) appears black because it absorbs all visible light wavelengths. On a microscopic scale, graphene is the strongest material ever measured.

Graphene is a remarkable material composed of a single layer of carbon atoms arranged in a two-dimensional honeycomb lattice. It is the basic structural element of other carbon allotropes such as graphite, carbon nanotubes, and fullerenes.

Graphene is a material that is extracted from graphite and is made up of pure carbon, one of the most important elements in nature and which we find in daily objects like the lead of a pencil.

Here’s a detailed introduction to graphene:

1. Structure

Atomic Composition: Pure carbon atoms.
Lattice: Hexagonal (honeycomb) arrangement.
Thickness: One atom thick (~0.345 nm), making it effectively two-dimensional.

2. Discovery

Year: 2004
Researchers: Andre Geim and Konstantin Novoselov at the University of Manchester.
Method: Mechanical exfoliation (also known as the “Scotch tape method”) from graphite.
Nobel Prize: Awarded in Physics in 2010 for their groundbreaking work.

3. Properties

Graphene stands out for being tough, flexible, light, and with a high resistance. It’s calculated that this material is 200 times more resistant than steel and five times lighter than aluminum.

With these properties, graphene has applications in the energy, construction, health, and electronics sectors. For instance, magnetic graphene could transform this electronics industry by making devices more comfortable and accessible for everyone.

Graphene is known for its exceptional physical and chemical properties:

Electrical

- High electrical conductivity.
- Electrons behave as massless Dirac fermions — they move through graphene as if they have no mass.
- Exhibits the quantum Hall effect even at room temperature.

Thermal

- Very high thermal conductivity (~5000 W/m·K), superior to copper.

Mechanical

- Extremely strong (about 200 times stronger than steel by weight).
- High tensile strength and flexibility.
- Young’s modulus: ~1 TPa (terapascal).

Optical

- Nearly transparent, absorbing only ~2.3% of white light.
- Useful for touchscreens and optical electronics.

Chemical

- High surface area (2630 m²/g).
- Can be functionalized for chemical sensing, catalysis, or energy storage.

4. Applications

Graphene’s unique characteristics make it promising in various fields:

Electronics: Transistors, flexible displays, conductive inks.
Energy: Batteries, supercapacitors, solar cells.
Composites: Lightweight, strong materials in aerospace and automotive.
Sensors: Biological, chemical, and gas sensors due to its sensitivity.
Biomedical: Drug delivery, biosensing, antibacterial coatings.
Water Filtration: Graphene oxide membranes for desalination and purification.

Graphene in the energy sector

The use of graphene in the manufacturing of rechargeable batteries could be a great leap towards energy efficiency. This material would prevent devices overheating, so they would be tougher and lighter.

Applied to different materials in our homes, it could contribute to a better thermal regulation of the home and a saving in the air conditioning of spaces. For example, using paint with graphene.

Lastly, and with a much more ambitious outlook, it’s believed that this innovation could be a turning point in the renewable energy sector as the use of this material could generate much more energy than is produced today.

Graphene in construction

The use of graphene applied to construction promises to improve the insulation of buildings. And not just that, but they could be more resistant to corrosion, dampness, and fire, and therefore tougher and more sustainable.

Construction materials would be perfected and eco-friendly components would be used, such as “green concrete,” an eco-efficient material that is more sustainable and resistant than the current one.

Graphene in health

The applications of graphene in the health and medicine sectors are also fascinating. Thanks to the properties of graphene, stronger, more flexible, and lighter hearing aids could be developed. We could even be speaking about making bones and muscles that would be introduced through surgical operations.

Still in the research phase, it’s believed that graphene oxide could be a good ally in the diagnosis of diseases and their subsequent treatment. This is an element that’s obtained when graphene is oxidized, converting it into a material with extraordinary mechanical properties.

Graphene in electronics

The characteristics of graphene could change the electronics sector completely. With the application of this material, smaller, lighter, tougher, and more efficient devices could be manufactured, impossible to obtain with the components that are used today.

Furthermore, graphene applied to electronic circuits would make devices ‘immune’ to dampness, one of the main causes of deterioration. In addition, it has excellent thermal and electrical conductivity, which is 1,000 times better than that of copper.

5. Challenges

Production: Scaling up high-quality, defect-free graphene remains complex.
Integration: Incorporating graphene into existing technologies and manufacturing lines is nontrivial.
Cost: Although improving, cost-effective mass production is still a hurdle.

Graphene History

Early Theoretical Predictions

1947: Philip R. Wallace, a Canadian physicist, developed the first theoretical description of graphene while studying the electronic properties of graphite.

Although graphene itself was not isolated, Wallace’s work laid the theoretical foundation for understanding graphene’s electronic structure.
1960s-1970s:
Scientists began discussing two-dimensional crystals theoretically. However, the prevailing belief (based on thermodynamics) was that strictly two-dimensional materials could not exist in free-standing form at room temperature because they would be too unstable.

Initial Experiments and Precursors

Graphite Studies:
Graphite has long been known and studied — it is essentially many layers of graphene stacked together (held by weak van der Waals forces).
Carbon Nanotubes and Fullerenes (1980s-1990s):
These carbon forms (rolled graphene sheets and spherical carbon molecules, respectively) fueled interest in low-dimensional carbon structures.

Graphene Isolation

2004 — Breakthrough:
Andre Geim and Konstantin Novoselov at the University of Manchester managed to isolate single-layer graphene for the first time.
- Method: Mechanical exfoliation, often nicknamed the “Scotch tape method”: peeling thin layers off graphite using adhesive tape and transferring them onto a silicon dioxide substrate.
- Key Achievement: They were able to both identify and study individual graphene layers.
Properties Found:
- Extremely high electron mobility.
- Unique quantum behavior (massless Dirac fermions).
- Remarkable mechanical strength.

Recognition and Nobel Prize

2010:
Geim and Novoselov were awarded the Nobel Prize in Physics:

“For groundbreaking experiments regarding the two-dimensional material graphene.”

Their work opened the floodgates to a massive global research effort into graphene and 2D materials.

Development and Commercialization

2010s:
- Rapid increase in research publications and patents on graphene.
- Efforts to find scalable production methods like:
  - Chemical Vapor Deposition (CVD)
  - Liquid-phase exfoliation
  - Chemical reduction of graphene oxide.
- Applications started emerging in flexible electronics, energy storage, composite materials, and biomedical devices.
Government and Industry Investment:
- 2013: The European Union launched the Graphene Flagship — a €1 billion research initiative to take graphene from the lab to society.
- Various national and corporate programs also began investing heavily in graphene research and commercialization.

Today

Graphene is now produced in tons annually.
Still, challenges remain:
- Consistent high-quality production.
- Cost-effective large-scale integration into commercial products.
Research has expanded into other 2D materials (e.g., molybdenum disulfide, hexagonal boron nitride) leading to the broader field of “2D Materials Science.”

Graphene