Inorganic Nanosheets Enhance Batteries

A graphene inspired electrode material that could help batteries hold more power has been developed by Chinese scientists. The large surface area of these cobalt oxide nanosheets is key to their electrochemical performance.

Batteries are a cornerstone of modern life with most smartphones and laptops using rechargeable lithium ion batteries. As technology advances, the search is on for batteries that can pack more energy into the same space.

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Technique lets researchers grow nanosheets like never before - Opening a plethora of possibilities for novel nanomaterials

After six years of painstaking effort, a group of University of Wisconsin-Madison materials scientists believe their breakthrough in growing tiny sheets of zinc oxide could have huge implications for the future of nanomaterial manufacturing—and in turn, on a host of electronic and biomedical devices.

The group, led by Xudong Wang, an associate professor of materials science and engineering at UW-Madison, and postdoctoral researcher Fei Wang, has developed a novel technique for synthesizing two-dimensional nanosheets from compounds that do not naturally form the atomic-layer-thick materials. It is the first time such a technique has been successful, and the researchers described their findings 20, January, 2016, in the journal Nature Communications.


Ref: Nanometre-thick single-crystalline nanosheets grown at the water–air interface.Nature Communications (20 January 2016) | DOI: 10.1038/ncomms10444 (Open Access) | PDF


To date, the preparation of free-standing 2D nanomaterials has been largely limited to the exfoliation of van der Waals solids. The lack of a robust mechanism for the bottom-up synthesis of 2D nanomaterials from non-layered materials has become an obstacle to further explore the physical properties and advanced applications of 2D nanomaterials. Here we demonstrate that surfactant monolayers can serve as soft templates guiding the nucleation and growth of 2D nanomaterials in large area beyond the limitation of van der Waals solids. One- to 2-nm-thick, single-crystalline free-standing ZnO nanosheets with sizes up to tens of micrometres are synthesized at the water–air interface. In this process, the packing density of surfactant monolayers adapts to the sub-phase metal ions and guides the epitaxial growth of nanosheets. It is thus named adaptive ionic layer epitaxy (AILE). The electronic properties of ZnO nanosheets and AILE of other materials are also investigated.

New Ultrathin, Sticky Coating Prevents Infection From Burns

by Michael Keller

Scientists report they have made a new wound dressing for burn victims that can coat even the toughest nooks and crannies to prevent infection. 

Using a biodegradable polyester called poly(L-lactic acid), or PLLA, chemist Yosuke Okamura has developed a sticky coating called nanosheets that can be applied to any part of the body without adhesive. The nanosheet is like plastic wrap and forms a barrier that bacteria can’t penetrate to infect a patient.

“The nanosheets can adhere not only to flat surfaces, but also to uneven and irregular surfaces without adding any adhesives,” Okamura said.

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XSEM photograph of carbon nanosheets (CNSs); a relatively new type of carbon nanomaterial with fascinating properties yet to be unraveled. CNSs consist of multiple layers of graphene which are structured in such a way that they are oriented vertically on the substrate. While the basal planes are nearly inert, the edge planes contain many open graphitic layers and steps, which can easily be (bio)functionalized, and which show remarkable electrocatalytic and biosensing properties. Scale bar corresponds to 2 µm.

Hemp nanosheets could be utilized as green supercapacitors - The revolution continues

As hemp makes a comeback in the U.S. after a decades-long ban on its cultivation, scientists are reporting that fibers from the plant can pack as much energy and power as graphene, long-touted as the model material for supercapacitors. They’re presenting their research, which a Canadian start-up company is working on scaling up, at the 248th National Meeting & Exposition of the American Chemical Society (ACS), the world’s largest scientific society.

David Mitlin, Ph.D., explains that supercapacitors are energy storage devices that have huge potential to transform the way future electronics are powered. Unlike today’s rechargeable batteries, which sip up energy over several hours, supercapacitors can charge and discharge within seconds. But they normally can’t store nearly as much energy as batteries, an important property known as energy density. One approach researchers are taking to boost supercapacitors’ energy density is to design better electrodes. Mitlin’s team has figured out how to make them from certain hemp fibers — and they can hold as much energy as the current top contender: graphene.