GRAPHENE JOURNALS




Graphene is a substance composed of pure carbon, with atoms arranged in a regular hexagonal pattern similar to graphite, but in a one-atom thick sheet. It is very light, with a 1-square-meter sheet weighing only 0.77 milligrams. 
It is an allotrope of carbon whose structure is a single planar sheet of sp2-bonded carbon atoms, that are densely packed in a honeycomb crystal lattice. The term graphene was coined as a combination of graphite and the suffix -ene by Hanns-Peter Boehm, 
who described single-layer carbon foils in 1962. Graphene is most easily visualized as an atomic-scale chicken wiremade of carbon atoms and their bonds. The crystalline or "flake" form of graphite consists of many graphene sheets stacked together. 
The carbon-carbon bond length in graphene is about 0.142 nanometers. Graphene sheets stack to form graphite with an interplanar spacing of 0.335 nm. Graphene is the basic structural element of some carbon allotropesincluding graphite, charcoal, carbon nanotubes and fullerenes. It can also be considered as an indefinitely large aromatic molecule, the limiting case of the family of flat polycyclic aromatic hydrocarbons. 
There is an analog of graphene composed of silicon called silicene.
The Nobel Prize in Physics for 2010 was awarded to Andre Geim and Konstantin Novoselov at the University of Manchester "for groundbreaking experiments regarding the two-dimensional material graphene". 
In 2013, graphene researchers led by Prof. Jari Kinaret from Sweden's Chalmers University, secured a €1 billion grant from the European Union. 
Graphene is a flat monolayer of carbon atoms tightly packed into a two-dimensional (2D) honeycomb lattice, and is a basic building block for graphitic materials of all other dimensionalities. It can be wrapped up into 0D fullerenes, rolled into 1D nanotubes or stacked into 3D graphite 
A single carbon layer of the graphitic structure can be considered as the final member of the series naphthalene,anthracene, coronene, etc. and the term graphene should therefore be used to designate the individual carbon layers in graphite intercalation compounds. Use of the term "graphene layer" is also considered for the general terminology of carbons.
Potential applications
Several potential applications for graphene are under development, and many more have been proposed. These include lightweight, thin, flexible, yet durable display screens, electric circuits, and solar cells, as well as various medical, chemical and industrial processes enhanced or enabled by the use of new graphene materials.
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" It's stronger than STEEL - but less than 1mm thick. Discovered in 2004, Graphene has been hailed as a natural wonder of the materials world destined to transform our lives in the 21st century. It will enable us to build space capsules and passenger planes which weigh only a fraction of their current bulk. "
Graphene's amazing properties excite and confound in equal measure. How can something one million times thinner than a human hair be 300 times stronger than steel and 1,000 times more conductive than silicon? 
The PETRO-CHEMICAL industry are unlikely to welcome graphene - because it will make cars a lot lighter and we'll use a tiny amount of gas to get from A to B in a Graphene car.

Graphene paint could power homes of the future
Houses could be painted with a new super-material that generates electricity from sunlight and can even change colour on request, following new research.



Scientists at the University of Manchester used wafers of graphene, the discovery of which won researchers a Nobel Prize, with thin layers of other materials to produce solar powered surfaces.
The resulting surfaces, which were paper thin and flexible, were able to absorb sunlight to produce electricity at a level that would rival existing solar panels.
These could be used to create a kind of “coat” on the outside of buildings to generate power needed to run appliances inside while also carrying other functions too, such as being able to change colour.
The researchers are now hoping to develop the technology further by producing a paint that can be put onto the outside of buildings.
But the scientists also say the new material could also allow a new generation of super-thin hand-held devices like mobile phones that can be powered by sunlight.
Professor Kostya Novoselov, one of the Nobel Laureates who discovered graphene, a type of carbon that forms sheets just one atom thick, said: “We have been trying to go beyond graphene by combining it with other one atom thick materials.
“What we have been doing is putting different layers of these materials one on top of the other and what you get is a new type of material with a unique set of properties.
“It is like a book – one page contains some information but together the book is so much more.
“We have demonstrated that we can produce a very efficient photovoltaic device. The fact it is flexible will hopefully make it easier to use.
“We are working on paints using this material as our next work but that is further down the line.”
Graphene was first discovered in 2004. Andrew Geim and Professor Novoselov won the 2010 Nobel Prize in Physics for demonstrating its remarkable properties – that it was harder than diamond, transparent and could conduct electricity while only being one atom thick.
Professor Novoselov and colleagues at the University of Singapore found that if they combined layers of graphene with single one atom thick layers of a material known as transition metal dichalcogenides, which react to light, they could generate electricity.
Their findings are published in the journal Science.
Professor Novoselov added: “We are taking about a new paradigm of material science.
“We can make sandwiches of materials and produce any kind of functionality so we can put transistors and photovoltaics to produce power for them.
“The implementations would go much further than simple solar powered cells.”


Graphene: the nano-sized material with a massive future
By Eoghan Macguire and Matthew Knight, CNN | April 30, 2013 -- Updated 1421 GMT (2221 HKT) | CNN) -- 
Ever since it was discovered in 2004, graphene has been hailed as a natural wonder of the materials world destined to transform our lives in the 21st century.
Graphene's amazing properties excite and confound in equal measure. How can something one million times thinner than a human hair be 300 times stronger than steel and 1,000 times more conductive than silicon?
CNN Labs asked the head of MIT's graphene research department, Tomas Palacios, to explain why graphene is such a special material and what we can expect it to do for us in the future.
CNN: What is graphene?
Tomas Palacios (TP): Graphene is a one-atom thick layer of carbon atoms arranged in a honeycomb lattice.
This special atomic arrangement gives graphene truly unique properties. For example electrical currents in graphene move faster than in any other material we know of.
Heat can also move in graphene very fast and it is the best thermal conductor that we have. On top of this, graphene is the thinnest material in the world as well as the strongest, much stronger than steel and, of course, much lighter.
Finally, because it is only one atom thick, it is perfectly transparent and flexible.
CNN: What applications will it have?
TP: The very first application where graphene is going to be used is probably as a replacement for (the relatively expensive metal) indium selenide in solar cells.
After that, I think we will see a new array of communication devices that don't just use graphene but which also use other two-dimensional materials.
Products such as cell phones will be integrated into the likes of the clothes, pieces of paper and in windows.
Another direction is transparent displays. Basically we are going to have electronic displays embedded almost everywhere, in the windows, in our glasses, in the walls, everywhere.
To do this we need very thin materials that are also transparent and graphene could be that material.
CNN: When will products containing graphene be available?
TP: It depends on the specific application. I believe that the use of graphene in solar cells, displays and so on is probably going to be in the marketplace in a couple of years.
More complex applications such as computers or cell phones will probably take longer, maybe within five and ten years.
CNN: What challenges remain for researchers?
TP: One important challenge facing graphene is the way the material is developed.
Graphene was isolated for the first time using the Scotch Tape technique (where ever thinner strips are peeled off a block of graphite using sticky tape) and the quantities we can make in large areas still lag behind this method.
The ambition is that one day graphene will be fabricated in the same way that you print newspapers
Tomas Palacios
There has been a lot of work to try and enhance the manufacturability of graphene and there are a few techniques that look very promising but they are not completely mature yet.
The second challenge is that graphene is a material that is only one atom thick. Anything that you do to it is going to impact its properties.
We still need to understand better how to fabricate graphene devices and how to be gentle enough not to (break) the formula.
CNN: Are production methods improving?
Recently, Samsung Electronics has demonstrated a single layer of graphene which is 30 inches in diameter. So in just a few years we have gone from micro-meter sized flakes all the way to 30 inches.
The ambition is that one day graphene will be fabricated in the same way that you print newspapers -- in a roll to roll process using the same kind of equipment. This will change the entire economics of the electronics industry.
CNN: Are there any other materials like graphene?
TP: Graphene was the first two-dimensional material to be discovered, but it is not the only one. Now there are more than 10 materials that are all two-dimensional with complimentary properties that could be integrated with graphene to provide extra functionality.
Boron nitride for example is also one-atom thick and instead of being a conductor it is an insulator (of heat), the best insulator we know. If you go to three atoms thick we have another material called molybdenum disulfide which is a semi-conductor, like silicon, but lighter and stronger.
These materials can then be combined in order to fabricate completely new material structures that don't exist in nature. I think that that is a very powerful proposition.
I am completely convinced that graphene is going to end up changing our lives
Tomas Palacios
CNN: When will graphene-based products hit main street?
TP: If you look at how long it traditionally takes new materials to make an impact in the market, it typically takes around 20 years.
We need to be patient but things seem to be moving faster than with other materials.
I think the next couple of years will see quite significant improvements in the growth techniques and synthesis of two-dimensional materials.
At a basic research level we are going to see an emphasis on trying to understand what happens when you stack these materials one on top of the other.
That is going to enable a lot of new understanding which will enable completely new devices.
I am completely convinced that graphene is going to end up changing our lives. Exactly how, I don't know and I don't think anyone can know for sure but there is nothing thinner, stronger or more suitable to conduct electricity and that has to be useful for many important things.


Graphene 'Paint' Could Power Future Homes with Solar Energy
First Posted: May 03, 2013 11:44 AM EDT
Graphene is the new wonder material of the future. It can mop up oil spills, be used as lubricant and now, it could be used to power our homes. Researchers have discovered that by combining graphene with other one-atom thick materials, they can create the next generation of solar cells and optoelectronic devices.
Graphene is the world's thinnest, strongest and most conductive material. Not surprisingly, it holds enormous potential to revolutionize a huge number of diverse applications--everything from smartphones to drug delivery and computer chips. In addition, the isolation of graphene has also led to the discovery of a whole new family of one-atom thick materials.
These materials, collectively known as 2D crystals, demonstrate a vast range of superlative properties. When combined in layers, these materials can add new functions to the material with each new addition. Called heterostructures, these layered materials are ideal for creating new devices that can perform a variety of things at once. That's why researchers decided to utilize these heterostructures in particular to design their latest creation.
The researchers combined graphene with monolayers of transition and metal dichalcogenides (TMDC), which allowed them to create very sensitive and efficient photovoltaic devices. These devices could potentially be used as ultrasensitive photodetectors or very efficient solar cells.
"Such photoactive heterostructures add yet new possibilities, and pave the road for new types of experiments," said Kostya Novoselov, one of the researchers, in a news release. "As we create more and more complex heterostructures, so the functionalities of the devices will become richer, entering the realm of multifunctional devices."
Although the applications are exciting, the more interesting point is how this new material could affect the future of sustainable energy. The multi-layered heterostructures could, in theory, be "painted" onto an outside wall and power entire buildings as they absorb the sun's rays. In addition, the material could be used at will to change the transparency and reflectivity of fixtures and windows, which could lead to a whole new era of controlling environmental factors within an office or house.
Don't get excited just yet, though. It will take quite some time before this material could be scaled up to accomplish such feats. In the meantime, we'll have to subsist on standard solar panels in order to harness the sun's energy.
The details of this new material are published in the journal Science.


'White graphene' soaks up pollutants and can be re-used
By Jason Palmer 
A next-generation material first earmarked for use in electronics has proven itself a capable clean-up agent for polluted waters.
Boron nitride, or "white graphene", is similar to its namesake: sheets of atoms laid out like a chain-link fence.
report in Nature Communications shows the material can preferentially soak up organic pollutants such as industrial chemicals or engine oil.
However, it is easier to clean and re-use than other such "nanomaterials".
The family of these materials includes much-touted, carbon-based members such as graphene and nanotubes, and are notable in part for their surface area-to-weight ratio.
That allows them to take up an incredible amount for their size, making them attractive for the clean-up of pollutants.
The new work suggests that a preparation of boron nitride could outperform many nanomaterials and more traditional approaches.
A team from the Institute for Frontier Materials at Deakin University in Australia and the Pierre and Marie Curie University in France started by making porous boron nitride "nanosheets" - wavy, single-atom layers of the material with holes in them.
These porous sheets, which together form a coarse white powder, vastly outperformed sheets that did not have the pores, and commercially available chunks of boron nitride that is not made up of the tiny sheets.
The porous version exhibited high "selective absorption and adsorption" - preferentially picking up organic pollutants and dyes out of water.
Boron nitride outperforms its carbon-based cousin graphene when it comes to soaking up pollutants
The powder soaked up as much as 33 times its own weight in the chemical ethylene glycol and 29 times its own weight of engine oil. Even still, the saturated powder floats on water.
The pollutants could then be driven out of the nooks and crannies of the material by heating it in a commercial furnace, or by simply igniting it - a trick that other, more established materials could only survive a few times before becoming completely clogged up.
"All these features make these porous nanosheets suitable for a wide range of applications in water purification and treatment," the authors wrote.
Francesco Stellacci of EPFL in Switzerland called the work "an excellent paper in a booming field".
"The data reported are indeed excellent and impressive," he told BBC News. "The key question is if this is the material that at the end will be used for remediation."
Prof Stellacci said that a market for such materials does not yet exist, and boron nitride's striking clean-up powers may or may not be enough to establish it as a leading contender, even among nanomaterials.
"I think that at the end it will not be performance that will determine the final material used, but more costs and scalability. I really hope that one of these materials, and maybe this one, will make it," he said.
Graphene Paint Coats Can Capture the Sun's Rays, Usher in New Age of Solar Power [Videos]
Thanks to researchers at the University of Manchester and the National University of Singapore, a splash of paint may both add a decorative flair to a building, and generate solar power. The main ingredient in this eclectic mixture is known as graphene, the strongest material known to humankind presently. Graphene, the first known bendable two-dimensional crystal, also happens to conduct electricity better than copper and measures a scant one atom thin. These thin sheets may be the harbingers of future tech. 


Dr. Michio Kaku, the co-founder of string field theory and holder of the Henry Semat Chair and Professorship in theoretical physics at the City College of New York, explains in a 2011 Big Think-sponsored video: "Think of saran wrap made out of one molecule thick carbon atoms. That graphene is so strong in principle, you could take an elephant, put the elephant on a pencil, suspend the pencil on graphene, and graphene will not break."
Dubbed G research, the field of study has the potential to feed into consumer products with stretchable electrodes, foldable displays, RF applications, touch sensors, and flexible solar panels.


Graphene was first discovered by University of Manchester Professors Konstantin Novoselov and Andre Geim in 2004. The duo came upon the single-atom graphene sheet with a surprisingly simple experiment which requires two materials: a piece of masking tape and graphite. Once the adhesive picks up the graphite fragments, the tape can be used to continually pull apart the sheets until only one is left. Novoselov and Geim were both awarded the Nobel Prize for their research in 2010.
In their latest study, the laureates combined "graphene with monolayers of transition metal dichalcogenides (TMDC)," according to the University of Manchester's official press release.
Since the original discovery of graphene, scientists have found new ways to cultivate a new suite of one-atom thin crystals which can interchange to express different characteristics suited for various industries.
"Such photoactive heterostructures add yet new possibilities, and pave the road for new types of experiments," says Dr. Novoselov. "The functionalities of the devices will become richer, entering the realm of multifunctional devices."
The study was originally published in the journal Science.
Graphene Super-Materials Could Be Future Of Solar Cells, And More
May 3, 2013
Alan McStravick for redOrbit.com – Your Universe Online
In 2004, the pure carbon material known as graphene was isolated by two University of Manchester Nobel Laureates, Andre Geim and Professor Kostya Novoselov, quickly leading to the discovery of a whole new family of one-atom-thick materials.
Now researchers from the University of Manchester and National University of Singapore have shown that by building multi-layered heterostructures of graphene in a three-dimensional stack, materials engineers are able to produce an exciting physical phenomenon that could lead to a variety of new electronic devices.
These new structures could conceivably lead to photovoltaic structures that could be placed on the outer walls of buildings. They would absorb sunlight and convert that energy into electricity capable of powering the entire building. This breakthrough was published recently in the journal Science. In addition to collecting and converting energy, the new structures could factor in environmental conditions like temperature and brightness, directing the energy to change the transparency and reflectivity of individual fixtures and windows.
Graphene is the world’s thinnest, strongest and most conductive material. Products and applications such as smartphones, computer chips, ultrafast broadband and drug delivery are poised to experience major advances as a result of this material and its unique properties.
Graphene’s 2D crystals can demonstrate a host of unique properties. For example, they can aid in conduction or insulation and change from opaque to transparent. As researchers add new layers to the stacks, the structure adopts new functions. For this reason, the team says these heterostructures are ideal for creating novel, multifunctional devices.
Due to the fact the combination of 2D crystals allows researchers to achieve functionality above and beyond what could be available from any of the individual materials, the team says the addition of one to another creates an outcome greater than the sum of its individual parts.
The collaborative research team was able to expand the functionality of these heterostructures into the realm of optoelectronics and photonics. This was achieved through the combination of graphene with monolayers of transition metal dichalcogenides (TMDC). With this combination came the creation of extremely sensitive and efficient photovoltaic devices. Eventual uses for these new devices could be found in the fields of photodetection or much more efficient solar cells.
These new devices involved the layering of TMDC between sheets of graphene. This layering allowed for the combination of the properties of both types of 2D crystals. The TMDC layers are ultra-efficient light absorbers, while the graphene layers act as a transparent conductive structure. The combination of these characteristics allows for further integration of these photovoltaic devices into a much more complex, multifunctional material.
“We are excited about the new physics and new opportunities which are brought to us by heterostructures based on 2D atomic crystals,” said Novoselov. “The library of available 2D crystals is already quite rich, covering a large parameter space.”
“Such photoactive heterostructures add yet new possibilities, and pave the road for new types of experiments,” he continued. “As we create more and more complex heterostructures, so the functionalities of the devices will become richer, entering the realm of multifunctional devices.”
Lead author of the study and University of Manchester researcher Dr. Liam Britnell added, “It was impressive how quickly we passed from the idea of such photosensitive heterostructures to the working device. It worked practically from the very beginning and even the most unoptimised structures showed very respectable characteristics.”
Professor Antonio Castro Neto, Director of the Graphene Research Centre at the National University of Singapore stated, “We were able to identify the ideal combination of materials: very photosensitive TMDC and optically transparent and conductive graphene, which collectively create a very efficient photovoltaic device.”
“We are sure that as we research more into the area of 2D atomic crystals we will be able to identify more of such complimentary materials and create more complex heterostructures with multiple functionalities,” he continued. “This is really an open field and we will explore it.”
'Graphene sandwich' unlocks solar cell properties of 2D crystal
3 May 2013 | By Stuart Nathan
A microscopically thin ‘graphene sandwich’ could form the basis of a new generation of solar cells, according to researchers at the universities of Manchester and Singapore.
Part of a raft of new research into possible uses for the atom-thick sheets of carbon atoms first discovered at Manchester, the new discovery shows how graphene can help harness the properties of light-senstive two-dimensional crystals, which could give rise to devices such as light-sensitive walls that could power whole buildings.
Since Andre Geim and Kostya Novosolev’s discovery that graphene can be made by peeling off single layers of graphite mechanically, several other similar single-layer materials have been found, the team says in a paper published in the journal Science. Moreover, stacking these crystals together with graphene has proved to be a useful way of unlocking the properties of these materials; for example, it’s allowed the team to create materials that could be used in flexible electronics.
The latest research uses a class of materials called transition metal dichalcogenides (TMDCs). These are actually three-layer materials, consisting of a single-atom thick lattice of transition metal atoms between two single-atom layers of sulphur, selenium or tellurium. The bonds within each layer are very strong, but those between the layers are quite weak — a similar structure to graphite. Examples of these materials are tungsten disulphide (WS2), molybdenum disulphide (MoS2) and niobium diselenide (NbSe2).
TMDCs are used industrially as lubricants and to protect surfaces, but they have unusual electronic properties which stem from the way atoms bond to their neighbours within and between the sheets — in particular, they are very good at absorbing light — a 300nm thick film can absorb 96 per cent of the light that shines on it. WS2 is particularly interesting, the team says, because it is a very stable material and the electronic structure of its atoms allow it to absorb visible light.
This means that it should be a very promising candidate for solar cells, but previous attempts to use it failed because it proved very difficult to make the electrons freed by solar photons to flow out of the material.
Graphene seems to be the key to this problem, acting as a transparent electrode on either side of a layer of TMDC in a three-dimensional crystalline sandwich. The graphene has to be ‘doped’ in the same way as semiconductors in an electronic component — replacing some carbon atoms with electron-rich elements in the layer on one side, and electron-poor elements on the other — and the whole structure sandwiched between layers of another material often used with graphene, hexagonal boron nitride, which stabilises it and enhances its properties.
Using WS2 as the TMDC layer, the team, led by lead author Liam Britnell at Manchester, created a PV material which could be made flexible, by mounting it on a PET film, or rigid, by mounting it on silica. These produce ‘suprisingly large’ photocurrents when a laser is shone on them, the team says: currents of up to 3µA were generated by laser power of around 75µW, and the stack showed an extrinsic quantum efficiency — the ratio of free electrons generated to the number of photons hitting the surface — of around 30 per cent.
‘It was impressive  how quickly we passed from the idea of such photosensitive heterostructures to the working device,’ Britnell commented. ‘It worked practically from the beginning, and even the unoptimised structures showed very respectable characteristics.’
Kostya Novosolev believes this could be the beginning of a new phase of graphene research. ‘We are excited about the new physics and new opportunities which are brought to us by heterostructures based on 2D atomic crystals,’ he said. ‘The library of available 2D crystals is already quite rich. As we create more and more complex heterostructures, so the functionalities of the devices will become richer, entering the realm of multifunctional devices.’

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About Octa Dandy Saiyar

Kelahiran Jakarta keturunan asli Bukittinggi, Sumatera Barat .
07 Oktober 1983.



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