Classification and application of graphene

The main classification
single-layer graphene
single-layer graphene
(Graphene)
: refers to a two-dimensional carbon material consisting of a layer of carbon atoms that are periodically tightly stacked in a benzene ring structure, i.e. a hexagonal hive structure.
Double Graphene
Double Graphene
: A two-dimensional carbon material consisting of two layers of carbon atoms that are periodically and tightly stacked in a benzene ring structure
, i.e. a hexagonal hive structure, stacked in different stacking modes, including AB stacking, AA stacking, etc.
S-layer graphene
S-layer graphene
(Few-layer)
: refers to a two-dimensional carbon material
China
) consisting of 3-10 layers of carbon atoms that are periodically and tightly stacked in a benzene ring structure (i.e., hexagonal hive structure).
multi-layer graphene
multi-layer graphene also known as thick layer graphene
(multi-layer graphene)
: refers to the thickness of more than 10 layers of benzene ring structure (i.e., hexagonal honeycomb structure) periodic tight stacking of carbon atoms in different stacking methods (including ABC stacking, ABA stacking, etc.) composed of a two-dimensional carbon material.
Main Applications
With the gradual breakthrough of mass production and large-size challenges, the pace of industrialization of graphene is accelerating, based on existing research results, the first areas to achieve commercial applications may be mobile devices, aerospace, new energy batteries.
basic
graphene is of special significance to the basic research of physics, which makes some quantum effects that can only be proved theoretically can be verified experimentally. In two-dimensional graphene, the mass of electrons does not seem to exist, a property that makes graphene a rare condensed matter that can be used to study relativity quantum forces , since massless particles must move at the speed of light and must be described in relativity quantum terms, providing theoretical physicists with a new direction of study: experiments that would have required giant particle accelerators could be conducted in small laboratories.
the zero-energy gap are mainly single-layer graphene, an electronic structure that seriously affects the role of gas molecules on their surfaces. The enhanced function of single-layer graphene surface reaction activity compared to body phase graphite is shown by the hydrogenation reaction and oxidation reaction of graphene, which shows that the electronic structure of graphene can change the activity of its surface. In addition, the electronic structure of graphene can be induced by gas molecular adsorption and corresponding changes, which not only change the concentration of the carrier, but also can be doped with different graphene.
sensor
graphene can be made into chemical sensors, this process is mainly through the surface adsorption performance of graphene to complete, according to some scholars can be found that the sensitivity of graphene chemical detectors can be compared with the limits of single-molecule detection. Graphene's unique two-dimensional structure makes it very sensitive to its surroundings.graphene is the ideal material for electrochemical biosensors, which are medically sensitive to dopamine, glucose, etc.
infrared beam excitation plasma graphene sensor schematic
transistor
graphene can be used to make transistors, which still work steadily on a scale close to a single atom due to the high stability of the graphene structure. In contrast, the current silicon-based transistors lose stability at a scale of about 10 nanometers, and the ultra-fast reaction speed of the electron field in graphene allows transistors made from them to reach very high frequencies of operation. IBM, for example, announced in February 2010 that it would increase the operating frequency of graphene transistors to 100GHz, more than silicon transistors of the same scale.
flexible displays
the future of mobile device displays with the attention of bendable screens at the Consumer Electronics Show. Flexible display of the future market is broad, as the basic material graphene prospects are also optimistic. For the first time, South Korean researchers have created a flexible transparent display made up of multiple layers of graphene and fiberglass polyester substrates. Researchers at Samsung University in South Korea and Chengjuan University created a television-sized piece of pure graphene on a 63-centimeter-wide flexible transparent fiberglass polyester board. They say it is by far the largest graphene block in the "big block". They then used the graphene block to create a flexible touch screen. In theory, researchers say, people can roll up their smartphones and leave them behind like pencils.
flexible display
new energy
new energy battery is also one of the earliest commercial areas of graphene. The Massachusetts Institute of Technology has successfully developed flexible photovoltaic panels with graphene nanocoated surfaces that can significantly reduce the cost of manufacturing transparent, deformable solar cells that can be used in small digital devices such as night vision goggles and cameras. In addition, the successful research and development of graphene super-battery also solves the problem of insufficient capacity and long charging time of new energy vehicle batteries, which greatly accelerates the development of new energy battery industry. This series of research results paves the way for the application of graphene in the new energy battery industry.
graphene-based super capacitor structure and graphene theoretical energy density
saldwater desalination
graphene filters at different voltages use more than other desalination technologies. Graphene oxide film in the water environment and water close contact, can form about 0.9 nanometers wide channel, less than this size of ions or molecules can pass quickly. By mechanical means to further compress the capillary channel size in graphene film, control the aperture size, can efficiently filter the salt in seawater.
hydrogen storage material
graphene has the advantages of light weight, high chemical stability and high ratio surface area, making it the best candidate for hydrogen storage material.
hydrogen storage material
space
due to high conductivity, high strength, ultra-thin and other characteristics, graphene in the field of aerospace military application advantages are also very prominent. In 2014, NASA developed graphene sensors for use in space that can detect trace elements in the Earth's high-altitude atmosphere, structural defects in spacecraft, and more. Graphene will also play a more important role in potential applications such as ultralight aircraft materials.
responsive element
a new sensor with graphene as the photosynthel element material, it is expected that through special structure, the photosynthelization capacity than the existing CMOS or CCD is increased by thousands of times, and the loss of energy is only 10% of the original. It can be used in monitor and satellite imaging, cameras, smartphones, etc.
Composites
graphene-based composites are an important research direction in the field of graphene applications, which show excellent performance in energy storage, liquid crystal devices, electronic devices, biological materials, sensing materials and catalyst carriers, and has broad application prospects. At present, the research of graphene composite materials mainly focuses on graphene polymer composites and graphene-based inormeric nanocomposites, and with the deepening of graphene research, the application of graphene enhancer in block metal-based composites has been paid more and more attention. Multi-functional polymer composites made of graphene and high-strength porous ceramics enhance many of the special properties of composites.composite
bio
graphene is used to accelerate bone differentiation of human bone marrow-filled stem cells, as well as to make biosensors that extend graphene on silicon carbide. Graphene can also act as a neural interface electrode without altering or damaging performance, such as signal strength or scar tissue formation. Graphene electrodes are much more stable in the body than tungsten or silicon electrodes due to their flexibility, bioacciability and conductivity. Graphene oxides are very effective in inhibiting the growth of E. coli and do not harm human cells.
Prospects
Graphene research and application development continue to heat up, graphite and graphene-related materials are widely used in battery electrode materials, semiconductor devices, transparent displays, sensors, capacitors, transistors and so on. In view of the excellent performance of graphene materials and their potential application value, a series of important advances have been made in many disciplines such as chemistry, materials, physics, biology, environment, energy, etc. The researchers are working on different ways to prepare high-quality, large-area graphene materials in different fields. And through the continuous optimization and improvement of graphene preparation process, reduce graphene preparation costs so that its excellent material performance has been more widely used, and gradually towards industrialization.
China also has a unique advantage in graphene research, from a production point of view, as a raw material for graphene production graphite, in China's energy storage is rich, low price. It is to see the application prospects of graphene, many countries have set up graphene-related technology research and development centers, try to use graphene commercialization, and then in the industrial, technical and electronic related fields to obtain potential application patents. For example, the European Commission has set up a special research and development programme to allocate 1 billion euros over the next 10 years as a "future flagship technology project". The Uk government has also invested in the Creation of the National Graphene Institute (NGI) in an effort to bring the material from the laboratory to production lines and markets in the coming decades.
graphene is expected to become a new generation of devices in many applications, in order to explore the broader applications of graphene, but also need to continue to seek more excellent graphene preparation process, so that it can be better used.  Although graphene from synthesis and confirmation of existence to today only a short period of more than ten years, but has become this year's scholars research hot spot. Its excellent optical, electrical, electrical, thermal properties prompt researchers to continue to study it in depth, with the preparation of graphene methods are constantly being developed, graphene will be more widely used in the near future in various fields.
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