Graphene enables capturing light as both wave pattern and particle

A team of researchers from the École polytechnique fédérale de Lausanne (EPFL) in Switzerland claim to have captured the world's first image of light simultaneously showing both wave pattern and particle energy attributes.

The scientists used extremely short pulses of laser light directed at a miniscule nanowire made of silver and suspended on graphene film that acted as an electrical isolator (or metal-graphene dielectric). The nanowire acted as a small antenna that generated radiation patterns with the received laser excitation. The light traveled along the wire in two opposite directions and when these waves bounced back to the middle, they intersected with each other to form a new wave that appeared to be standing in place. This standing wave, radiating around the nanowire, then became the source of light used in the experiment.

Read the full story Posted: Mar 10,2015

Researchers find a way to switch graphene's conductivity

A team of researchers from the University of Pennsylvania, University of California and University of Illinois at Urbana-Champaign has demonstrated a way to change the amount of electrons that reside in a given region within a piece of graphene and have a proof-of-principle in making the fundamental building blocks of semiconductor devices using the 2D material. Their method enables this value to be tuned through the application of an electric field, which means that graphene circuits made in this way could theoretically be manipulated without physically altering the device.

Chemically doping graphene to achieve p- and n-type version of the material (similar to traditional circuits) is possible, but it comes at the price of sacrificing some of its unique electrical properties. A similar effect is possible by applying local voltage changes to the material, but manufacturing and placing the necessary electrodes is complicated. The team of researchers claims it has now come up with a non-destructive, reversible way of doping, that doesn’t involve any physical changes to the graphene.

Read the full story Posted: Mar 10,2015

Penn State University enters industrial partnership with CVD Equipment Corporation

The American CVD Equipment Corporation announced that it is entering into an industrial partnership with Penn State University.

Through the National Science Foundation’s Emerging Frontiers in Research and Innovation (EFRI) program, Penn State University (PSU) has been awarded $1.96 million for 2D Atomic-layer Research and Engineering (2-DARE). This PSU project will leverage CVD Equipment Corporation’s engineering and manufacturing capabilities to advance the deposition technologies and processes for producing novel 2D materials beyond graphene.

Read the full story Posted: Mar 10,2015

Graphenano to supply graphene flakes for cleaning radioactive water in Japan

The Spanish Graphenano is to collaborate with the Tokyo Electric Company on a pilot project to use graphene flakes to clean up the radioactive water in and around the nuclear plant of Fukushima, which suffered extensive damage in the earthquake of 2011.

Four years after the earthquake, there is still a high level of radioactivity in the area. It is planned to use graphene to clean up the water, where Caesium 137 would normally remain harmful for 150 years. Graphene is 60 times more efficient than any other procedure used in traditional cleanup operations, with each kilogram able to absorb 25 grams of radioactive isotopes. Still, the task will take years to complete, with tons of graphene needed to handle the large amounts of radioactive materials in the area.

Read the full story Posted: Mar 10,2015

Glass cages and graphene oxide to improve lithium-sulfur batteries

Researchers from the Bourns College of Engineering at the University of California, Riverside investigated a strategy to improve lithium-sulfur batteries' performance by creating nano-sized sulfur particles, and coating them in glass.

Lithium-sulfur batteries have been attracting attention thanks to their ability to produce up to 10 times more energy than conventional batteries, but one of the main roadblocks to implementing them is a the tendency for lithium and sulfur reaction products (called lithium polysulfides) to dissolve in the battery’s electrolyte and travel to the opposite electrode permanently, which causes the battery’s capacity to decrease over its lifetime. The scientists designed a cathode material in which silica (glass) cages trap polysulfides.. The team used an organic precursor to construct the trapping barrier.

Read the full story Posted: Mar 10,2015

Graphene acts as a perfect separator in a novel light utilization device

Researchers at the Indian Institute of Science (IIS) designed a device based on graphene and metal nanoparticles that shows a significant response to light and is colour sensitive. This may be greatly beneficial for applications like ultra-sensitive photodetectors and efficient solar cells.

The scientists display a device with a large number of stacked silver nanoparticle pairs, all separated precisely by just one-third of a nanometer using graphene. All light interaction related properties are found to be enhanced in this unique device structure. The graphene acts as a perfect spacer and this produces an unprecedented field enhancement of nearly a million times in between the nanoparticles, boosting the interaction with light. As a result, the Raman signal in this device was found to be 100 times more intense. This is of significance because although graphene responds to a large range of light frequencies (colours) and has a very fast response, it does not absorb light very well by itself.

Read the full story Posted: Mar 10,2015

Will unzipped carbon nanotubes replace platinum in fuel cells?

A study conducted at Rice University shows that graphene nanoribbons, formed into a 3D aerogel and enhanced with boron and nitrogen, perform extremely well as catalysts for fuel cells and may even pose an alternative to platinum.

The scientists chemically unzipped carbon nanotubes into ribbons and then turned them into porous metal-free aerogels with various levels of boron and nitrogen, to test their electrochemical properties. It was found that the new material provides a wealth of active sites along the exposed edges for oxygen reduction reactions necessary for fuel cells performance.

Read the full story Posted: Mar 10,2015

Independent quality tests by Cardiff University on Perpetuus' graphene

Scientists from the Cardiff Catalysis Institute at Cardiff University conducted a comprehensive characterisation and analysis of Perpetuus' functionalized graphenes by using XRD, XPS and Raman microscopy techniques.

The results indicated that the proprietary plasma manufacturing process produced friable, highly crystalline, commercial-scale quantities of functionalised graphenes. It was inferred from the study that the plasma technique of graphene production adopted by Perpetuus could generate stacks of below ten layer thickness with high quality domains.

Read the full story Posted: Mar 09,2015

graphene-based catalyst outperforms iron-based one

Researchers at the Case Western Reserve University have made a step towards making low-cost catalysts commercially available, which could, in turn, reduce the cost to generate clean energy from PEM fuel cells--the most common cell being tested and used in cars and stationary power plants.

The researchers examined a non-metal catalyst to perform in acid because the standard bearer among fuel cells, the PEM (proton exchange membrane/polymer electrolyte membrane) cell uses an acidic electrolyte. The catalyst is based on a porous structure, with sheets of nitrogen-doped graphene mixed with carbon nanotubes and carbon black particles in a solution, freeze-dried into composite sheets and hardened.

Read the full story Posted: Mar 09,2015

Graphene studied for use in textiles

The Hohenstein institute, along with the companies IoLiTec Ionic Liquids Technologies from Heilbronn and FUCHSHUBER TECHNO-TEX- from Lichtenstein, and Belgian project partners Centexbel and Soieries Elite, have been working on a research project designed to explore the use of graphene in the textile sector.

The research, called GRAFAT, explores the use of graphene for the surface modification of textiles in heat protective clothing. Using graphene to modify the surface can significantly improve the flame-retardant properties of a textile. Graphene can act as a physical barrier, effectively preventing the penetration of heat and gases. At the same time, graphene also has the potential to prevent the thermal decomposition of the textile. In addition, graphene also improves the textile's resistance to abrasion and rupture.

Read the full story Posted: Mar 09,2015