What Is Graphene? Properties, Synthesis & Applications, and Characteristics

Over the last few decades, we have heard a lot about the incredible benefits of graphene. The invention of this chemical creates buzz in many industries and unlocks new possibilities for next-generation innovations.

Understanding Of Graphene

Graphene is a material that is composed of carbon atoms grouped in the form of a hexagonal lattice. Besides, this arrangement results in a monolayer of an atom thick. It is acquired from the most copious substance in nature, graphite, which may be found in mines of our pencils. And, you know, one millimeter of graphite includes three million layers of graphene.

In the exploitation process, graphite oxide produces thin graphene sheets that scientists can further modify according to their industrial applications.

With the passage of time, researchers have also designed methods like Graphene on Copper Foil through chemical vapor deposition (CVD). In another approach, they use graphene on PET substrates to produce flexible films that are highly used in optoelectronics.

Graphene is one of the ultra-light materials, with just 0.77 milligrams per square meter. Additionally, it’s a single 2D sheet that offers the highest surface area of all materials for further tailoring and performance. Moreover, graphene sheets are flexible and can stretch up to 20% of their initial size without any fear of breaking. It is highly impermeable, and even helium atoms can’t go through it.

Read Also: Introduction to Graphene Oxide

Major Properties of Graphene

Let’s see why the industries have a fascination with graphene stems. From its remarkable properties:

Mechanical Strength

Graphene is one of the strongest materials in history; it is also 200 times stronger than steel. Additionally, the single sheet of graphene material can provide resistance against immense stress while remaining flexible.

Furthermore, its strength comes from the sp2 carbon-carbon bonds in the lattice. This durable yet lightweight material doesn’t break even when stretched like steel. Beyond this durability, the mechanical strength makes it a useful component for structural reinforcement.

Electrical Conductivity

The exceptional electron mobility also makes it demanding in the electronics industry. Electrons can move through it without any resistance or hurdle, which is why it becomes the best material to replace silicon in microprocessors and transistors.

Additionally, graphene material conducts electricity better than copper and opens advanced opportunities in semiconductors and electronics.

Thermal Conductivity

Graphene dispels heat more effectively than most metals. It is known to have a thermal conductivity of around 3000-5000 W/m. K For a clear image, how does it pass more effectively to others? Here are some ranges of metals’ thermal conductivity.

• Copper: ~400 W/m. K
• Aluminum: ~ 235 W/m. K
• Iron: ~ 80 W/m. K
• Stainless steel: ~ 15W/m. K
• Lead: ~35W/m. K

Although stainless steel is used in cookware and copper is considered the best metallic heat conductor, graphene outperforms by nearly 10X. Therefore, experts use it for CVD graphene (chemical vapor deposition graphene) in electronic applications where heat management becomes imperative. However, it’s mandatory to purchase these chemicals from authentic graphite oxide suppliers.

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Optical Transparency

Graphene is an ultra-thin but visible material, and it absorbs about 2.3% white light, which is a much better option for the 2D material.

Moreover, the unique balance between transparency and conductivity is crucial for applications in solar cells, touchscreens, and sensors. Regardless of absorbing light, it is still quite transparent to the human eye, which allows it to be used for various purposes.

Chemical Tunability

Graphene can be chemically adapted and transformed for targeted applications. Through the chemical tunability, scientists may tailor graphene’s behavior, turning it from a superb conductor into a semiconductor. 

For instance, carboxyl graphene has carboxyl functional groups that increase its interaction with polymers and boost performance in coatings. Along with the chemical modification, you may even increase its biocompatibility for medical uses.

Graphene Synthesis Method and Approaches

Producing the graphene effectively and at scale is a challenging task for manufacturers. Thus, with the multiple synthesis approaches, the issue has been resolved.

Top-Down Approaches

The top-down approach begins the process with bulk graphite and breaks it down into smaller layers until single-layer or a few-layer graphene sheets are acquired. This process is the oldest method of graphene synthesis.

Mechanical Exfoliation

The pioneer methods in the top-down approaches that experts use to show the existence of graphene are mechanical exfoliation. In this process, scientists peeled the thinnest layers of graphite with the help of adhesive tape.

The unsuppressed benefits of this method are to produce high-quality and porous graphene. In contrast, it’s extremely slow and suitable for large-scale production.

Read Also: Graphene and Its Application in Electronics

Liquid-Phase Exfoliation (LPE)

In the LPE process, graphite is mixed into special liquids and exposed to ultrasonification, which uses high-frequency sound waves. These sound waves create microscopic bubbles that burst with strong energy and gently shake apart the graphite layer. 

Consequently, it peels off the thin graphene sheets from the bulk graphene. Therefore, LPE is the most widely explored method to generate graphene on a large scale. LPE can generate a momentous amount of graphene at a relatively low cost.

For this reason, this way of synthesizing graphene appeals for commercial uses where quantity matters more than quality. Sometimes, graphene produced with this approach contains irregular thickness, defects, and wrinkles due to aggressive mechanical forces.

Chemical Oxidation and Reduction Method

One of the most preferred methods to produce large-scale graphene is through the chemical reduction of graphene oxide. Conventionally, toxic dropping agents like sodium borohydride and hydrazine were used. However, these chemicals show serious environmental risks. 

In this regard, research is now turning to eco-friendly alternatives to overcome the bad impact. Use of ascorbic acid (vitamin C) and grape extracts has been successfully applied as low-cost reducing agents.

These green approaches not only reduce the hazards of these products but also enable scalable and high-quality greenhouse production. This shift unlocks the possibilities and options to highlight green chemistry to shape the future of graphene manufacturing. It can lower the electrical conductivity compared to pristine graphene.

Bottom-Up Approaches

Bottom-up techniques focus on building a graphene atom by atom from carbon-based precursors. This method allows scientists better control over the quality and structure of graphene for high performance.

Read Also: Graphene: A Complete Chemical History

Thermal Chemical Vapor Deposition (TCVD)

Chemical Vapor Deposition (CVD) is a bottom-up technique that experts avoid breaking or peeling and growing thin films through carbon-based gases. It includes the hydrocarbon gases at high temperatures inside a chamber.

• Ethanol
• Acetylene
• Methane

It releases carbon atoms and then deposits onto a catalyst substrate, where they self-assemble times into the graphene lattice. Here, the metal substrates act as catalysts and strongly affect the quality of the graph.

The most commonly used substrates in thermal CVD graphene are copper and nickel. Copper is preferred when the synthesis goal is single layers and obtaining defect-free graphene. On the other hand, nickel allows the growth of thicker films, but controlling uniformity is harder.

Sometimes, graphene films often suffer from defects like folds and wrinkles that reduce the performance capacity. Thus, researchers achieved a single fold-free crystal graphene on Cu-Ni(111), which means copper nickel alloy with surface orientation of (111). 

Some research shows a large-scale monolayer graphene on flexible Cu foils with excellent conductivity (~125 Ω/sq) and high transparency (97.4%). You can get this type of graphene from the Trustworthy CVD Graphene Suppliers for optoelectronics devices.

Plasma Chemical Vapor Deposition (PCVD)

Plasma CVD is a bottom-up method where scientists use plasma, which means ionized gas, to break down the hydrocarbon gases into responsive carbon species. This process doesn’t require the extreme heat because plasma provides the required energy.

PCVD ensures the graphene growth at much lower temperatures as low as 317 °C -450°C while maintaining good transparency (78% - 95%). The main challenge of this process is to control the plasma damage, rather than to reshape the surface into scalable and low-cost graphene electronics.

Read Also: Graphene: Super Strength for the 21st Century

Thermal Decomposition of Silicon Carbide (SiC)

In the range of bottom-up methods, one more name is the thermal decomposition of silicone carbide (SiC). This method removes the need for post-growth transfer as well.

When SiC is heated ( 1100-1650 °C), silicon atoms evaporate due to their higher vapor pressure, and the remaining carbon atoms self-settle into graphitic layers. Researchers like Emtsev et al. Shows the growth of large-area monolayer graphene at 1650°C, while using an argon atmosphere to enhance surface smoothness.  

Apart from that, Ni-Cu-coated SiC allowed water-scale graphene growth at lower temperatures (~1100 °C), which enables this technique to be highly suitable and efficient for device-grade applications.

Molecular Assembly

Another method to produce high-quality graphene is molecular assembly, which is also a bottom-up approach where graphene sheets are built through organic chemistry. This method relies on assembling smaller carbon-based molecules into the honeycomb lattice structure of graphene.

The molecular assembly approach allows scientists to control the shape, size, and edge structure of graphene sheets at the atomic level. Top-down methods don’t allow scientists to control these features. Due to its customizable properties, researchers can “program” graphene to have optical, electronic, and mechanical properties.

The molecular assembly process achieves exact structural designs that involve individual carbon atoms. Also, this process to tailor graphene ensures precision for very specific applications like nanoelectronics or molecular sensors.

Application of Graphene in Industries

The insane chemical properties make this chemical imperative and beneficial in multiple sectors. From electronics to solar panels, it will be possible to increase its efficiency and produce more energy. Let’s dive into the details to know the real applications of graphene.

Graphene For Security Labels 

An initial example of a graphene application is on the safety labels. Many times, you can see clothes and electronics with shiny, iridescent tags that basically trigger an alarm if the customer tries to leave the store without safe disconnection.

The graphene inks can print tiny circuits that are cheap, flexible, and nearly indestructible. Besides, the label can be bent, wrinkled, and folded, and still work perfectly. This example is capable of showing that materials are not limited to use in “lab research”; instead, they transform our lives with their magic.  

Read Also: Graphene-like Materials

Graphene in Medical Sensors

The high-performance graphene material detects the minimal amount of substances. Graphene is an ultra-thin and sensitive material that can detect a single molecule in a large volume.

A grapevine-based biosensor can recognize biomarkers of cancer or even levels in diabetic patients, even with low concentrations. Early diagnosis has a better chance of a smooth cure and treatment. Here are some major medical areas that have proven the benefits of graphene.

• The graphene-based electrical biosensor may be helpful in the early detection of malaria parasites. Graphene “drums” listen to bacteria’s nanomotions to reveal whether antibiotics are working faster than traditional tests.
• It heals the bones naturally, and 3D graphene scaffolds turn stem cells into bone-forming cells, opening doors for next-gen bone regeneration.
• Graphene coatings with antibacterial agents stop biofilms for around 96 hours of infection-free protection.   
• Laser-induced graphene in masks kills 99.9998% of bacteria in just 10 minutes, so it helps people to fight against pandemics.

Use for Sports and Padel Blades 

In the sports sector, researchers incorporate graphene in many product compositions to enhance their efficiency and performance. Padel Baldes are the perfect example where experts use graphene on both faces of the blade, the surface, on the frame, and even on the foam as well.

It makes the impact area tougher to create resistance to cracks. Besides, it adds graphene here to improve the stability and stiffness, which gives players more control over the damage during powerful shots. Many companies advertise the graphene in their designs because it ensures durability from the selling points.

Batteries and Supercapacitors

Lithium-based batteries are considered the leading candidates for energy storage. However, it shows some challenges, such as solid electrolyte buildup and dendrite formation, that reduce their efficiency.

Read Also: Graphene and Its Uses in Organic Solar Cells

Research shows that laser-induced grooving with porous silicon oxide improves the coulombic efficiency to 99.3% as compared to bare electrodes. Similarly, integration of a graphene oxide membrane and laser-scribed graphene with 3D structures reduced capacity decay and achieved 1160mAh/g capacity with 80.4% retention after 100 cycles.

Despite this, graphene supercapacitance outperforms activated carbon due to its massive surface area (2630m²/g) and longer cycle life. Beyond this, the graphene-metal-based organic hybrid device ensures 73Wh/kg energy density and retains 88% capacity after 10 cycles.

Composites and Coatings

By adding small amounts of graphene to metals, ceramics, and plastics, scientists improve the durability and quality without increasing the weight. Therefore, it’s a highly preferable substance in industries like sports equipment, automotive, and aerospace.

In these industries, graphene can enhance the quality of coatings and make them corrosion-resistant as well. Along with ensuring the resistance, it still enhances the conductivity and makes it perfect for advanced manufacturing. So, get this graphene from the certified graphene suppliers who can maintain the same quality of supply.

Read Also: Graphene, E-textiles, and the Future of Fashion

Characteristics That Set Apart Graphene

Afterward, all the details here are some characteristics that make graphing one of the best options for the industries.

• It is ultra-thin yet has superb strength from other metals and chemicals.
• Transparent but highly conductive.
• Flexible in nature without compromising the strength.
• Chemically tuned for particular applications with specific chemicals and methods.

All these qualities show that the hype of graphene is real in the advanced manufacturing industries. The importance of graphene extends beyond just lab work and research; it also makes our lives easier. ACS Material is one of the Best Graphene Product Suppliers, whether you need any form, such as CVD graphene or coal graphene.

Wrap Up Things

The above discussions provide a clear explanation of graphene, including its properties, synthesis, applications, and characteristics, which can help you make informed decisions about incorporating it into your composition. High electrical and thermal conductivity, flexibility, and strength increase its demand in industries.

There are many industries, such as medical, aerospace, sports equipment, batteries, and electronics, that utilize them to achieve their incredible benefits for human beings. Furthermore, graphene is truly a gem material that unlocks the door for more futuristic research and possibilities.

You can check out the Graphene Series of ACS Materials to get high-quality materials with authentication. Stay connected on X(Twitter) and Facebook to know updates, offers, and more information regarding advanced chemical supplies and materials.  

FAQ

Q. What’s the nature of graphene: “conductivity” or “flexibility”?

A. Graphene becomes the talk of the town due to its high conductivity, flexibility, lightweight, and insulating durability. Therefore, both terms are used to explain the nature of graphene.

Q. Is the graphene synthesis expensive?

A. Yes, the cost of single-layer graphene synthesis is high currently due to the need for advanced tools and methods. 

Q. Can graphene be a replacement for silicone in electronics?

A. Although graphene has high electron mobility, it is not a direct replacement for silicon in the electronics industry. It also has some limitations on which research is going for positive results.

Q. What are the methods to produce graphene?

A. The primary ways of producing graphene are top-down and bottom-up. However, the top-down approach includes mechanical exfoliation, liquid phase exfoliation, and chemical reduction. In contrast, bottom-up approaches include thermal chemical vapor deposition(TCVD), plasma chemical vapor deposition(PCVD), molecular assembly, and thermal deposition of silicon carbide.

Q. Why does graphene matter a lot nowadays for industries?

A. Incredible properties like high conductivity, flexibility, ultra-lightweight, and increased durability create a buzz about graphene in the market.