A recently discovered form of carbon graphite, material in pencil lead, has turned out to have properties that could revolutionize the development of green energy and electric cars. Researchers have discovered that graphene allows positively charged hydrogen atoms or protons to pass through it despite being completely impermeable to all other gases, including Hydrogen. The implication of the discovery are immense as it could dramatically increase efficiency in fuel cells, which generate electricity directly from hydrogen, the breakthrough raises the prospect of extracting hydrogen fuel from air and burning it as carbon free source of energy in a fuel cell producing electricity and water without wasting waste products.
Ever since the discovery of graphene 10 years ago, it has astonished scientists, it’s the thinnest known material, a million times thinner than the human hair, yet it is 200 times stronger than steel, as well as being the world’s best conductor of electricity.
Until now, being permeable to protons was not considered a practical possibility, but an international team of scientists led by Noble Prize winner of 2010, Sir Andre, has shown that one-atom thick crystal acts like a chemical filter. It allows the free passage of protons but forms an impenetrable barrier to other atoms and molecules.
“There have been three or four scientific papers about theoretical predictions for how easy or how hard it would be for a proton to go through graphene and these calculations give numbers that take billions and billions of years for a proton to go through the same membrane,” said Sir Andrei.
“It’s just so dense an electronic field it just doesn't let anything through. But it’s a question of numbers, no more than that. This makes a difference between billions of years and a reasonable time for penetration. There is no magic,” he said.
The study, published in journal Nature, shows that graphene and a similar single-atom thick baron nitrite allowed the buildup of protons on the other side of a membrane, yet prevented anything else from crossing over into a collecting chamber. In their scientific paper, the researchers speculate that there could be many applications in the field of hydrogen fuel cells and in technology for collecting hydrogen gas from the atmosphere, which will open up a new source of clean energy.
Graphene is tough, 200 times stronger than steel, yet very light. It is considered the first two-dimensional material because it forms sheets of crystals that are just one atom thick. It is also a perfect conductor of electricity, so is useful for anything involving electronics, such as phones which can be bent, and wearable electric devices attached to clothing. Medical applications include, it’s possible to use it as a material for delivering drugs to damaged sites of the body , which could open avenue for treating patients with brain conditions such as cancer. Can also be used to purify water. Scientists also believe that graphene’s high strength and low weight can be harnessed in the making of new composite materials and polymers for transport industry, making travel safer and more efficient.
Graphene-based cheap solar cells.
Today’s solar cells are made out from silicon that is too expensive, Because of that cost, researchers have been looking for affordable alternatives, settling on indium tin oxide used inside hybrid or nano-structured solar cells. Though indium tin oxide is becoming more prevalent, it is used in making items like smartphones screens which makes it more expensive. The solution of all this, is the wonder material, graphene which MIT researchers have been working on and now they are a step closer.
Silvija, associate professor of materials science and engineering said, the new graphene based solar cells are more lighter, flexible and have higher mechanical strength. Building semiconducting nano-structures on graphene surface has been difficult due to graphene being highly stable and inert. So, rather than to use different material entirely or attempt to change the properties of graphene itself, the team coated the surface with polymers that then allowed them to attach zinc oxide nano-wires to it, and then either a layer of lead-sulfide quantum dots or P3HT, which is a polymer that responds to light waves. Though the graphene was covered in layers of polymers and either quantum dots or P3HT, it kept its own properties providing all the advantages to graphene.
The team pointed out that graphene material can easily be applied to common surface, like glass or plastic, coupled with the cell’s flexibility and relative inexpensiveness, this means that solar cells could be conceivably be purchased by consumers and installed in regular homes, currently the group hasn't proven that the technique can be scaled to create large solar cells, having only made proof-of-concept devices about half an inch in size.
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