Showing Spotlights 57 - 64 of 303 in category All (newest first):
Researchers explain how a higher order periodic modulations due to the encapsulation of graphene between hexagonal boron nitride, called supermoire, affects the electronic and structural properties of graphene, as revealed in three recent independent experiments. High quality graphene samples are of high importance for obtaining and exploiting its theoretically described properties. Utilizing an adequate substrate reduces the corrugation and improves otherwise disorder limited properties of graphene.
Jan 29th, 2020
Researchers have produced graphene by molten carbonate electrolytic splitting of CO2 to a nano-thin carbon product (carbon nanoplatelets) comprised of 25 to 125 graphene layers, and subsequent electrochemical exfoliation of the nanoplatelets to graphene in a carbonate soluble aqueous solution. The sole products of the carbon dioxide electrolysis are straightforward: high yield carbon nanoplatelets and oxygen. The carbon nanoplatelets provide a thinner starting point than a conventional graphite reactant to facilitate electrochemical exfoliation.
Dec 2nd, 2019
Graphyne is a little known sibling of graphene. Simulations have shown that graphyne's conduction electrons travel extremely fast - as they do in graphene - but in only one direction. That property could help researchers design faster transistors and other electronic components that process one-way current. Graphyne is distinct in being composed of sp and sp2 carbon atoms, which contrasts with graphene containing only sp2 carbon. The coexistence of sp and sp2 carbons in graphyne gives rise to unique physical properties, such as high conductivity and large carrier mobility.
Oct 31st, 2019
Researchers have developed a method for direct, point-of-use detection of mycotoxins in food. The method is based on the modification of electrolyte operated graphene filed effect transistors that have been specifically functionalized with aptamers by covalent binding. Demonstrating the performance of this method on Ochratoxin A, these sensors show a response time of within 5 minutes with a sensitivity down to 4 pg/ml - that is about three orders of magnitude less than accepted tolerance levels of Ochratoxin A.
Oct 4th, 2019
Researchers demonstrate that the amorphous carbon contaminants on CVD-produced graphene, which could greatly degrade its properties, can be removed by an activated carbon-coated lint roller, relying on the strong interactions between the amorphous carbon and activated carbon. Large-area graphene surfaces treated with this lint roller exhibit a high cleanliness of 99% with a low degree of polymer residue after transfer onto a functional substrate. This superclean graphene has extremely low contact resistance and ultrahigh carrier mobility.
Sep 26th, 2019
To make epoxy-graphene nanocomposites, the graphene nanosheets are commonly mixed homogeneously with the epoxy matrix. However, one of the problems that bedevils these nanocomposites is the issue of agglomeration of the nanofillers. Researchers now report that they have sucessfully tackled this dispersion problem by constructing a continuous graphene-based scaffold. The results show that the team's novel strategy boosts the fracture toughness to about 3.6 times that of pure epoxy.
Sep 25th, 2019
MXenes' inherently good conductivity and excellent volumetric capacitance makes them a very attractive material for fabricating textile-based, wearable electronics (e-textiles) that can be worn like everyday garments. This requires the fabrication of conductive yarns that are robust enough to be suitable for the wear and tear experienced by everyday textiles. A new study demonstrates highly conductive MXene-based yarns that can be washed and knitted just like conventional yarns - offering a potential platform technology for e-textile-based devices with tunable performance.
Sep 11th, 2019
By studying flexible and transparent photodetectors based on single-layer MoS2 under the application of biaxial strain, researchers have developed atomically thin photodetectors whose characteristics can be controlled by means of an externally applied strain. This strain can be reversibly applied through the thermal expansion (shrinkage) of the substrate material, which induces tensile (compressive) biaxial stress. These results emphasize the possibilities of a new kind of electronics - straintronics - in which mechanical deformations are used to modify not only the geometry of the device, but its properties and performance as well.
Aug 22nd, 2019