Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Drexel engineers 'sandwich' atomic layers to make new materials for energy storage

17.08.2015

The scientists whose job it is to test the limits of what nature--specifically chemistry-- will allow to exist, just set up shop on some new real estate on the Periodic Table. Using a method they invented for joining disparate elemental layers into a stable material with uniform, predictable properties, Drexel University researchers are testing an array of new combinations that may vastly expand the options available to create faster, smaller, more efficient energy storage, advanced electronics and wear-resistant materials.

Led by postdoctoral researcher Babak Anasori, PhD, a team from Drexel's Department of Materials Science and Engineering created the material-making method, that can sandwich 2-D sheets of elements that otherwise couldn't be combined in a stable way. And they proved its effectiveness by creating two entirely new, layered two-dimensional materials using molybdenum, titanium and carbon.


Drexel University engineers have created a layered material of molybdenum and titanium by using a new process they invented to etch a MAX phase into a two-dimensional, layered MXene.

Credit: Drexel University

"By 'sandwiching' one or two atomic layers of a transition metal like titanium, between monoatomic layers of another metal, such as molybdenum, with carbon atoms holding them together, we discovered that a stable material can be produced," Anasori said. "It was impossible to produce a 2-D material having just three or four molybdenum layers in such structures, but because we added the extra layer of titanium as a connector, we were able to synthesize them."

The discovery, which was recently published in the journal ACS Nano, is significant because it represents a new way of combining elemental materials to form the building blocks of energy storage technology--such as batteries, capacitors and supercapacitors, as well as superstrong composites--like the ones used in phone cases and body armor.

Each new combination of atom-thick layers presents new properties and researchers suspect that one, or more, of these new materials will exhibit energy storage and durability properties so disproportional to its size that it could revolutionize technology in the future.

"While it's hard to say, at this point, exactly what will become of these new families of 2-D materials we've discovered, it is safe to say that this discovery enables the field of materials science and nanotechnology to move into an uncharted territory," Anasori said.

Mastering Materials

Combining two-dimensional sheets of elements in an organized way to produce new materials has been the goal of Drexel nanomaterials researchers for more than a decade. Imposing this sort of organization at the atomic level is no easy task.

"Due to their structure and electric charge, certain elements just don't 'like' to be combined," Anasori said. "It's like trying to stack magnets with the poles facing the same direction--you're not going to be very successful and you're going to be picking up a lot of flying magnets."

But Drexel researchers came up with a clever way to circumvent this chemistry challenge. It starts with a material called a MAX phase, which was discovered by Distinguished Professor Michel W. Barsoum, PhD, head of the MAX/MXene Research Group, more than two decades ago. A MAX phase is like the primordial ooze that generated the first organisms--all the elements of the finished product are in the MAX phase, waiting for the researchers to impose some order.

That order was imposed by Michel W. Barsoum, PhD and Yury Gogotsi, PhD, Distinguished University and Trustee Chair professor in the College of Engineering and head of the Drexel Nanomaterials Group, when they first created a stable, two-dimensional, layered material called MXene in 2011.

To create MXenes, the researchers selectively extract layers of aluminum atoms from a block of MAX phase by etching them out with an acid.

"Think of MXene synthesis like separating layers of wood by dunking a plywood sheet into a chemical that dissolves the glue," Anasori said. "By putting a MAX phase in acid, we have been able to selectively etch away certain layers and turn the MAX phase into many thin 2-D sheets, which we call MXenes."

As far as energy storage materials go, MXenes were a revelation. Prior to their discovery, graphene, which is a single sheet of carbon atoms, was the first two-dimensional material to be touted for its potential energy storage capabilities. But, as it was made up of only one element, carbon, graphene was difficult to modify in form and therefore had limited energy storage capabilities. The new MXenes have surfaces that can store more energy.

An Elemental Impasse

Four years later, the researchers have worked their way through the section of the Periodic Table with elements called "transition metals," producing MAX phases and etching them into MXenes of various compositions all the while testing their energy storage properties.

Anasori's discovery comes at a time when the group has encountered an obstacle on its progress through the table of elements.

"We had reached a bit of an impasse, when trying to produce a molybdenum containing MXenes," Anasori said. "By adding titanium to the mix we managed to make an ordered molybdenum MAX phase, where the titanium atoms are in center and the molybdenum on the outside.

The Next Frontier

Now, with the help of theoretical calculations done by researchers at the FIRST Energy Frontier Research Center at the Oak Ridge National Laboratory, Drexel's team knows that, in principle, it can use this method to make as many as 25 new materials with combinations of transition metals, such as molybdenum and titanium, that previously wouldn't have been attempted.

"Having the possibility to layer different elements at the thinnest form of material known to the scientific community leads to exciting new structures and allows unprecedented control over materials properties," Barsoum said. "This new layering method gives researchers an unimaginable number of possibilities for tuning materials' properties for a variety of high-tech applications."

Anasori plans to make more materials by replacing titanium with other metals, such as vanadium, niobium, and tantalum, which could unearth a vein of new physical properties that support energy storage and other applications.

"This level of structural complexity, or layering, in 2-D materials has the potential to lead to many new structures with unique control over their properties," Gogotsi said. "We see possible applications in thermoelectrics, batteries, catalysis, solar cells, electronic devices, structural composites and many other fields, enabling a new level of engineering on the atomic scale."

Media Contact

Britt Faulstick
bef29@drexel.edu
215-895-2617

 @DrexelNews

http://www.Drexel.edu/ 

Britt Faulstick | EurekAlert!

Further reports about: MXene Titanium acid batteries carbon atoms energy storage material materials method molybdenum transition

More articles from Materials Sciences:

nachricht New value added to the ICSD (Inorganic Crystal Structure Database)
27.03.2017 | FIZ Karlsruhe – Leibniz-Institut für Informationsinfrastruktur GmbH

nachricht Argon is not the 'dope' for metallic hydrogen
24.03.2017 | Carnegie Institution for Science

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Northern oceans pumped CO2 into the atmosphere

27.03.2017 | Earth Sciences

Fingerprint' technique spots frog populations at risk from pollution

27.03.2017 | Life Sciences

Big data approach to predict protein structure

27.03.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>