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graphenequan 033116

 

A Rice University laboratory has found a way to turn common carbon fiber into graphene quantum dots, tiny specks of matter with properties expected to prove useful in electronic, optical and biomedical applications.

The Rice lab of materials scientist Pulickel Ajayan, in collaboration with colleagues in China, India, Japan and the Texas Medical Center, discovered a one-step chemical process that is markedly simpler than established techniques for making  quantum dots. The results were published online this month in the American Chemical Society’s journal Nano Letters.

“There have been several attempts to make graphene-based quantum dots with specific electronic and luminescent properties using chemical breakdown or e-beam lithography of graphene layers,” said Ajayan, Rice’s Benjamin M. and Mary Greenwood Anderson Professor of Mechanical Engineering and Materials Science and of Chemistry. “We thought that as these nanodomains of graphitized carbons already exist in carbon fibers, which are cheap and plenty, why not use them as the precursor?”

Quantum dots, discovered in the 1980s, are semiconductors that contain a size- and shape-dependent . These have been promising structures for applications that range from computers, LEDs, and lasers to medical imaging devices. The sub-5 nanometer carbon-based quantum dots produced in bulk through the wet chemical process discovered at Rice are highly soluble, and their size can be controlled via the temperature at which they’re created.

Graphene quantum dots: The next big small thing
Green-fluorescing graphene quantum dots created at Rice University surround a blue-stained nucleus in a human breast cancer cell. Cells were placed in a solution with the quantum dots for four hours. The dots, each smaller than 5 …more

The Rice researchers were attempting another experiment when they came across the technique. “We tried to selectively oxidize carbon fiber, and we found that was really hard,” said Wei Gao, a Rice graduate student who worked on the project with lead author Juan Peng, a visiting student from Nanjing University who studied in Ajayan’s lab last year. “We ended up with a solution and decided to look at a few drops with a .”

The specks they saw were bits of graphene or, more precisely, oxidized nanodomains of graphene extracted via chemical treatment of carbon fiber. “That was a complete surprise,” Gao said. “We call them quantum dots, but they’re two-dimensional, so what we really have here are graphene quantum discs.” Gao said other techniques are expensive and take weeks to make small batches of graphene quantum dots. “Our starting material is cheap, commercially available . In a one-step treatment, we get a large amount of quantum dots. I think that’s the biggest advantage of our work,” she said.

Graphene quantum dots: The next big small thing
Dark spots on a transmission electron microscope grid are graphene quantum dots made through a wet chemical process at Rice University. The inset is a closeup of one dot. Graphene quantum dots may find use in electronic, optical and …more

Further experimentation revealed interesting bits of information: The size of the dots, and thus their photoluminescent properties, could be controlled through processing at relatively low temperatures, from 80 to 120 degrees Celsius. “At 120, 100 and 80 degrees, we got blue, green and yellow luminescing dots,” she said.

They also found the dots’ edges tended to prefer the form known as zigzag. The edge of a sheet of graphene — the single-atom-thick form of carbon — determines its electrical characteristics, and zigzags are semiconducting.

Their luminescent properties give graphene quantum dots potential for imaging, protein analysis, cell tracking and other , Gao said. Tests at Houston’s MD Anderson Cancer Center and Baylor College of Medicine on two human breast cancer lines showed the dots easily found their way into the cells’ cytoplasm and did not interfere with their proliferation.

“The green quantum dots yielded a very good image,” said co-author Rebeca Romero Aburto, a graduate student in the Ajayan Lab who also studies at MD Anderson. “The advantage of graphene dots over fluorophores is that their fluorescence is more stable and they don’t photobleach. They don’t lose their fluorescence as easily. They have a depth limit, so they may be good for in vitro and in vivo (small animal) studies, but perhaps not optimal for deep tissues in humans.

“But everything has to start in the lab, and these could be an interesting approach to further explore for bioimaging,” Romero Alburto said. “In the future, these graphene could have high impact because they can be conjugated with other entities for sensing applications, too.”

Explore further: Single Atom Quantum Dots Bring Real Devices Closer (Video)

More information: Nano Lett., Article ASAP DOI: 10.1021/nl2038979

Provided by:Rice University

invisibleink

 

Ciphers and invisible ink – many of us experimented with these when we were children. A team of Chinese scientists has now developed a clever, high-tech version of “invisible ink”. As reported in the journal Angewandte Chemie, the ink is based on carbon nitride quantum dots. Information written with this ink is not visible under ambient or UV light; however, it can be seen with a fluorescence microplate reader. The writing can be further encrypted or decrypted by quenching or recovering the fluorescence with different reagents.

Fluorescing security inks are primarily used to ensure the authenticity of products or documents, such as certificates, stock certificates, transport documents, currency notes, or identity cards. Counterfeits may cost affected companies lost profits, and the poor quality of the false products may damage their reputations. In the case of sensitive products like pharmaceuticals and parts for airplanes and cars, human lives and health may be endangered. Counterfeiters have discovered how to imitate UV tags but it is significantly harder to copy security inks that are invisible under UV light.
Researchers working with Xinchen Wang and Liangqia Guo at Fuzhou University have now introduced an inexpensive “invisible” ink that increases the security of encoded data while also making it possible to encrypt and decrypt secure information.
The new ink is based on water-soluble quantum dots, nanoscopic “heaps” of a semiconducting material. Quantum dots have special optoelectronic properties that can be controlled by changing the size of the dots.

The scientists used quantum dots made from graphitic carbon nitride. This material consists of ring systems made of carbon and nitrogen atoms linked into two-dimensional molecular layers. The structure is similar to that of graphite (or graphene), one of the forms of pure carbon, but also has semiconductor properties.
Information written with this new ink is invisible under ambient and UV light because it is almost transparent in the visible light range and emits fluorescence with a peak in the UV range. The writing only becomes visible under a microplate reader like those used in biological fluorescence tests. In addition, the writing can be further encrypted and decrypted: treatment with oxalic acid renders it invisible to the microplate reader. Treatment with sodium bicarbonate reverses this process, making the writing visible to the reader once more.
Explore further: Luminescent ink from eggs
More information: Zhiping Song et al. Invisible Security Ink Based on Water-Soluble Graphitic Carbon Nitride Quantum Dots, Angewandte Chemie International Edition (2016). DOI: 10.1002/anie.201510945
Journal reference: Angewandte Chemie Angewandte Chemie International Edition
Provided by: Angewandte Chemie

China LI Battery 033116 56efc495569e8

Recently, researchers at Tsinghua University, China have proposed a graphene-based nanostructured lithium metal anode for lithium metal batteries to inhibit dendrite growth and improve electrochemistry performance. They report their findings in Advanced Materials, published on March 16, 2016.

“Widely used lithium-ion batteries cannot satisfy the increasing requirement of energy storage systems in portable electronics and electric vehicles. New anode batteries, like Li-S and Li-air batteries, are highly sought. Lithium metal provides an extremely high theoretical specific capacity, which is almost 10 times more energy than graphite,” said Prof. Qiang Zhang, at the Department of Chemical Engineering, Tsinghua University. “However, the practical applications of lithium metals are strongly hindered by lithium dendrite growth in continuous cycles. This induces safety concerns. The lithium dendrites may cause internal short circuits resulting in fire. Furthermore, the formation of lithium dendrites induces very low cycling efficiency.” The dendrite growth and unstable solid electrolyte interphase consume large amount of lithium and electrolyte, and therefore leading to irreversible battery capacity losses. Consequently, inhibiting the dendrites growth is highly expected.

Many approaches have been proposed to retard the growth of dendrites through electrolyte modification, artificial solid electrolyte interphase layers, electrode construction, and others. “We noticed that by decreasing the local current density heavily, lithium dendrite growth could be efficiently inhibited. Based on this concept, we employed unstacked graphene with an ultrahigh specific surface area to build a nanostructured anode. And it turned out to be a very efficient idea,” said Rui Zhang, a Ph.D. student and the first author. “Additionally, we have employed the dual-salt electrolyte to acquire more stable and more flexible solid electrolyte interphase, which can protect the lithium metal from further reactions with electrolyte.”

This graphene-based anode offered great improvement, including (1) ultralow local current density on the surface of graphene anode (a ten-thousandth of that on routine Cu foil-based anodes) induced by the large specific surface area of 1666 m2 g-1, which inhibited and brought uniform lithium deposition morphology; (2) high stable cycling capacity of 4.0 mAh mg-1 induced by the high pore volume (1.65 cm3 g-1) of unstacked graphene, over 10 times of the graphite anode in lithium-ion batteries (0.372 mAh mg-1); (3) high electrical conductivity (435 S cm-1), leading to low interface impedance, stable charging/discharging performance, and high cycling efficiencies.

“We hope that our research can point out a new strategy to deal with the dendrite challenge in lithium metal anodes. The ultralow local current density induced by conductive nanostructured anodes with high specific surface area can help improve the stability and electrochemistry performance of lithium metal anodes,” said Xin-Bing Cheng, a co-author of the work. Future investigation is required to design preferable anode structures and to produce more protective solid electrolyte interphase layers. The researchers also call for additional study of the diffusion behavior of Li ions and electrons in the process of lithium depositing and stripping to advance the commercial applications of lithium metal anodes.

Explore further: Nanostructure enlightening dendrite-free metal anode

More information: R. Zhang, X.-B. Cheng, C.-Z. Zhao, H.-J. Peng, J.-L. Shi, J.-Q. Huang, J. Wang, F. Wei, Q. Zhang. Conductive Nanostructured Scaffolds Render Low Local Current Density to Inhibit Lithium Dendrite Growth. Adv. Mater. 2016, 28, 2155-2162. DOI: 10.1002/adma.201504117.

Grid-scale approach to rechargeable power storage gets new arsenal of possible materials.

MIT-Calcium-Liquid_0

Liquid metal batteries, invented by MIT professor Donald Sadoway and his students a decade ago, are a promising candidate for making renewable energy more practical. The batteries, which can store large amounts of energy and thus even out the ups and downs of power production and power use, are in the process of being commercialized by a Cambridge-based startup company, Ambri.

Now, Sadoway and his team have found yet another set of chemical constituents that could make the technology even more practical and affordable, and open up a whole family of potential variations that could make use of local resources.

The latest findings are reported in the journal Nature Communications, in a paper by Sadoway, who is the John F. Elliott Professor of Materials Chemistry, and postdoc Takanari Ouchi, along with Hojong Kim (now a professor at Penn State University) and PhD student Brian Spatocco at MIT. They show that calcium, an abundant and inexpensive element, can form the basis for both the negative electrode layer and the molten salt that forms the middle layer of the three-layer battery.

That was a highly unexpected finding, Sadoway says. Calcium has some properties that made it seem like an especially unlikely candidate to work in this kind of battery. For one thing, calcium easily dissolves in salt, and yet a crucial feature of the liquid battery is that each of its three constituents forms a separate layer, based on the materials’ different densities, much as different liqueurs separate in some novelty cocktails. It’s essential that these layers not mix at their boundaries and maintain their distinct identities.

It was the seeming impossibility of making calcium work in a liquid battery that attracted Ouchi to the problem, he says. “It was the most difficult chemistry” to make work but had potential benefits due to calcium’s low cost as well as its inherent high voltage as a negative electrode. “For me, I’m happiest with whatever is most difficult,” he says — which, Sadoway points out, is a very typical attitude at MIT.

Another problem with calcium is its high melting point, which would have forced the liquid battery to operate at almost 900 degrees Celsius, “which is ridiculous,” Sadoway says. But both of these problems were solvable.

First, the researchers tackled the temperature problem by alloying the calcium with another inexpensive metal, magnesium, which has a much lower melting point. The resulting mix provides a lower operating temperature — about 300 degrees less than that of pure calcium — while still keeping the high-voltage advantage of the calcium.

The other key innovation was in the formulation of the salt used in the battery’s middle layer, called the electrolyte, that charge carriers, or ions, must cross as the battery is used. The migration of those ions is accompanied by an electric current flowing through wires that are connected to the upper and lower molten metal layers, the battery’s electrodes.

The new salt formulation consists of a mix of lithium chloride and calcium chloride, and it turns out that the calcium-magnesium alloy does not dissolve well in this kind of salt, solving the other challenge to the use of calcium.

But solving that problem also led to a big surprise: Normally there is a single “itinerant ion” that passes through the electrolyte in a rechargeable battery, for example, lithium in lithium-ion batteries or sodium in sodium-sulfur. But in this case, the researchers found that multiple ions in the molten-salt electrolyte contribute to the flow, boosting the battery’s overall energy output. That was a totally serendipitous finding that could open up new avenues in battery design, Sadoway says.

And there’s another potential big bonus in this new battery chemistry, Sadoway says. “There’s an irony here. If you’re trying to find high-purity ore bodies, magnesium and calcium are often found together,” he says. It takes great effort and energy to purify one or the other, removing the calcium “contaminant” from the magnesium or vice versa. But since the material that will be needed for the electrode in these batteries is a mixture of the two, it may be possible to save on the initial materials costs by using “lower” grades of the two metals that already contain some of the other.

“There’s a whole level of supply-chain optimization that people haven’t thought about,” he says.

Sadoway and Ouchi stress that these particular chemical combinations are just the tip of the iceberg, which could represent a starting point for new approaches to devising battery formulations. And since all these liquid batteries, including the original liquid battery materials from his lab and those under development at Ambri, would use similar containers, insulating systems, and electronic control systems, the actual internal chemistry of the batteries could continue to evolve over time. They could also adapt to fit local conditions and materials availability while still using mostly the same components.

“The lesson here is to explore different chemistries and be ready for changing market conditions,” Sadoway says. What they have developed “is not a battery; it’s a whole battery field. As time passes, people can explore more parts of the periodic table” to find ever-better formulations, he says.

“This paper brings together innovative engineering advances in cell design and component materials within a strategic framework of ‘cost-based discovery’ that is amenable to the massive scale-up required of grid-scale applications,” says Richard Alkire, a professor of Chemical and Biomolecular Engineering at the University of Illinois, who was not involved in this research.

Because this work builds on a base of well-developed electrochemical systems used for aluminum production, Alkire says, “the path forward to grid-scale applications can therefore take advantage of a large body of existing engineering experience in areas of sustainability, environmental, life cycle, materials, manufacturing cost, and scale-up.”

The research was supported by the U.S. Department of Energy’s Advanced Research Projects Energy (ARPA-E) and by the French energy company Total S.A.

Solar Fuels Artificial Leaf 032516 160321110445_1_540x360A team at the HZB Institute for Solar Fuels has developed a process for providing sensitive semiconductors for solar water splitting (“artificial leaves”) with an organic, transparent protective layer. The extremely thin protective layer made of carbon chains is stable, conductive, and covered with catalysing nanoparticles of metal oxides. These accelerate the splitting of water when irradiated by light. The team was able to produce a hybrid silicon-based photoanode structure that evolves oxygen at current densities above 15 mA/cm2. The results have now been published in Advanced Energy Materials.

Solar Fuels Artificial Leaf 032516 160321110445_1_540x360

The illustration shows the structure of the sample: n-doped silicon layer (black), a thin silicon oxide layer (gray), an intermediate layer (yellow) and finally the protective layer (brown) to which the catalysing particles are applied. The acidic water is shown in green.
Credit: M. Lublow

The “artificial leaf” consists in principle of a solar cell that is combined with further functional layers. These act as electrodes and additionally are coated with catalysts. If the complex system of materials is submerged in water and illuminated, it can decompose water molecules. This causes hydrogen to be generated that stores solar energy in chemical form. However, there are still several problems with the current state of technology. For one thing, sufficient light must reach the solar cell in order to create the voltage for water splitting — despite the additional layers of material. Moreover, the semiconductor materials that the solar cells are generally made of are unable to withstand the typical acidic conditions for very long. For this reason, the artificial leaf needs a stable protective layer that must be simultaneously transparent and conductive.

Catalyst used twice

The team worked with samples of silicon, an n-doped semiconductor material that acts as a simple solar cell to produce a voltage when illuminated. Materials scientist Anahita Azarpira, a doctoral student in Dr. Thomas Schedel-Niedrig’s group, prepared these samples in such a way that carbon-hydrogen chains on the surface of the silicon were formed. “As a next step, I deposited nanoparticles of ruthenium dioxide, a catalyst,” Azarpira explains. This resulted in formation of a conductive and stable polymeric layer only three to four nanometres thick. The reactions in the electrochemical prototype cell were extremely complicated and could only be understood now at HZB.

The ruthenium dioxide particles in this new process were being used twice for the first time. In the first place, they provide for the development of an effective organic protective layer. This enables the process for producing protective layers — normally very complicated — to be greatly simplified. Only then does the catalyst do its “normal job” of accelerating the partitioning of water into oxygen and hydrogen.

Organic protection layer combines excellent stability with high current densities

The silicon electrode protected with this layer achieves current densities in excess of 15 mA/cm2. This indicates that the protection layer shows good electronic conductivity, which is by no means trivial for an organic layer. In addition, the researchers observed no degradation of the cell — the yield remained constant over the entire 24-hour measurement period. It is remarkable that an entirely different material has been favoured as an organic protective layer: graphene. This two-dimensional material has been the subject of much discussion, yet up to now could only be employed for electrochemical processes with limited success, while the protective layer developed at HZB works quite wel . Because the novel material could lend itself for the deposition process as well as for other applications, we are trying to acquire international protected property rights,” says Thomas Schedel-Niedrig, head of the group.


Story Source:

The above post is reprinted from materials provided by Helmholtz-Zentrum Berlin für Materialien und Energie. Note: Materials may be edited for content and length.


Journal Reference:

  1. Anahita Azarpira, Thomas Schedel-Niedrig, H.-J. Lewerenz, Michael Lublow. Sustained Water Oxidation by Direct Electrosynthesis of Ultrathin Organic Protection Films on Silicon. Advanced Energy Materials, 2016; DOI: 10.1002/aenm.201502314
MSU Fibers 032516 160324104809_1_540x360A microbial protein fiber discovered by a MSU’s Gemma Reguera transports charges at rates high enough to be applied in manmade nanotechnologies.
Credit: Kurt Stepnitz

“This microbial nanowire is made of but a single peptide subunit,” said Gemma Reguera, lead author and MSU microbiologist. “Being made of protein, these organic nanowires are biodegradable and biocompatible. This discovery thus opens many applications in nanoelectronics such as the development of medical sensors and electronic devices that can be interfaced with human tissues.”

Since existing nanotechnologies incorporate exotic metals into their designs, the cost of organic nanowires is much more cost effective as well, she added.

How the nanowires function in nature is comparable to breathing. Bacterial cells, like humans, have to breathe. The process of respiration involves moving electrons out of an organism. Geobacter bacteria use the protein nanowires to bind and breathe metal-containing minerals such as iron oxides and soluble toxic metals such as uranium. The toxins are mineralized on the nanowires’ surface, preventing the metals from permeating the cell.

Reguera’s team purified their protein fibers, which are about 2 nanometers in diameter. Using the same toolset of nanotechnologists, the scientists were able to measure the high velocities at which the proteins were passing electrons.

“They are like power lines at the nanoscale,” Reguera said. “This also is the first study to show the ability of electrons to travel such long distances — more than a 1,000 times what’s been previously proven — along proteins.”

The researchers also identified metal traps on the surface of the protein nanowires that bind uranium with great affinity and could potentially trap other metals. These findings could provide the basis for systems that integrate protein nanowires to mine gold and other precious metals, scrubbers that can be deployed to immobilize uranium at remediation sites and more.

Reguera’s nanowires also can be modified to seek out other materials in which to help them breathe.

“The Geobacter cells are making these protein fibers naturally to breathe certain metals. We can use genetic engineering to tune the electronic and biochemical properties of the nanowires and enable new functionalities. We also can mimic the natural manufacturing process in the lab to mass-produce them in inexpensive and environmentally friendly processes,” Reguera said. “This contrasts dramatically with the manufacturing of humanmade inorganic nanowires, which involve high temperatures, toxic solvents, vacuums and specialized equipment.”

This discovery came from truly listening to bacteria, Reguera said.

“The protein is getting the credit, but we can’t forget to thank the bacteria that invented this,” she said. “It’s always wise to go back and ask bacteria what else they can teach us. In a way, we are eavesdropping on microbial conversations. It’s like listening to our elders, learning from their wisdom and taking it further.”


Story Source:

The above post is reprinted from materials provided by Michigan State University. Note: Materials may be edited for content and length.


Journal Reference:

  1. Sanela Lampa-Pastirk, Joshua P. Veazey, Kathleen A. Walsh, Gustavo T. Feliciano, Rebecca J. Steidl, Stuart H. Tessmer, Gemma Reguera. Thermally activated charge transport in microbial protein nanowires. Scientific Reports, 2016; 6: 23517 DOI: 10.1038/srep23517
GNT Thumbnail Alt 3 2015-page-001Advancements in nanotechnology could fundamentally change global approaches to manufacturing, medicine, healthcare, and the environment.

 

In this lecture Dr. Eric Drexler, Senior Visiting Fellow, Oxford Martin School, will look at current advances in the field of advanced nanotechnology, and the impacts and potential applications of their widespread implementation, and Dr. Sonia Trigueros, Co-Director of the Oxford Martin Programme on Nanotechnology, and Oxford Martin Senior Fellow, will consider how targeted nanomedicine could change how we treat disease in the future.

Published on Jan 28, 2016

 

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NSF supports national efforts to bolster water security and supply.
Credit and Larger Version

Today, at the White House Water Summit, the National Science Foundation (NSF) joins other federal agencies to emphasize its commitment to a sustainable water future.March 22, 2016

Access to affordable clean water is vital for energy generation, food cultivation and basic life support. With drought pressure and population demands, water is an increasingly precious resource.

The California drought and Flint water emergency show some of the consequences of clean water shortages. Low-cost, low-energy technologies for both water quality testing and water treatment must be developed to overcome economic barriers and secure America’s future.

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NSF supports national efforts to bolster water security and supply by investing in fundamental science and engineering research.

“Routine and reliable access to safe drinking water is one of the greatest achievements in human history, thanks to science and engineering research,” said Pramod Khargonekar, NSF assistant director for Engineering. “To ensure this accessibility continues, contributions from all research areas — from engineering and physical sciences to the biological and social sciences — are essential. As such, NSF is uniquely positioned to advance water innovations.”

For decades, NSF has funded researchers across disciplines to investigate fundamental water questions and propose novel solutions to challenges.

Despite the importance of water to life on Earth, major gaps exist in our understanding of water availability, quality and dynamics, as well as the impact of human activity and a changing climate on the water system. These gaps must be filled in order to create new concepts for water desalination, purification, reuse and treatments.

Water report60_l“To take on the most urgent challenge facing the world today, NSF and our partner agencies are funding researchers to explore interactions between the water system and land-use changes, the built environment, ecosystem functions and services, and climate change through place-based research and integrative models,” said Roger Wakimoto, NSF assistant director for Geosciences. “Through these activities, we are enabling a new interdisciplinary paradigm in water research.”

NSF-funded demonstrations at today’s White House event:

  • An interactive augmented reality sandbox exhibit to help teach the public about watersheds, lake sciences, and environmental stewardship.
    • The project, led by NSF-funded researcher Louise H. Kellogg, is a collaboration between university scientists and pubic science centers. Partners include University of California, the Davis W. M. Keck Center for Active Visualization in Earth Sciences, the Tahoe Environmental Research Center, the Lawrence Hall of Science, ECHO Lake Aquarium & Science Center, and Audience Viewpoints.
  • A novel technology that uses sound waves to isolate and remove particles from fluids.
    • Jason Dionne of FloDesign Sonics Inc. is supported by the NSF Small Business Innovation Research program to commercialize the technology, which offers a potentially more efficient and environmentally benign method to purify water.
  • The launch of two “smart markets” for water leasing in the country: for groundwater trading in western Nebraska, and for surface-water trading in central Washington State.
    • Mammoth Trading is creating smart markets to automate the process of checking complex regulatory rules for trading and to generate the highest economic gains among participants. By monetizing the value of conserved water, water leases generate a potential new revenue for water users and reward innovation in water use at the farm level. Mammoth Trading’s markets will be available in over 500,000 acres of irrigated farmland. Mammoth Trading grew out of NSF-funded research, which was commercialized through the NSF Innovation Corps (I-Corps™) program.
  • A book series and curriculum to teach children about the water cycle.
    • NSF supports 25 Long-term Ecological Research (LTER) projects across the country and in Antarctica to study ecological processes. The LTER network enables these sites to serve as local and regional “schoolyards” to promote understanding of environmental processes among K-12 students. One outreach tool they employ is the LTER Schoolyard Series, which includes hands-on activity guides and integrates with federal and state science standards.

New NSF investments announced today:

  • $20 million to support cutting-edge water-research projects through the NSF Experimental Program to Stimulate Competitive Research program.
    • Research teams will apply a systems-based, highly integrated approach to determine when and where the impacts of extreme events cascade through the combined social-ecological system. An integrated model of the watershed will be used to test management scenarios and identify strategies for maintaining infrastructure, environmental health and drinking water quality in the face of extreme weather events.
  • $2 million to educate technicians for high-technology fields that drive our nation’s economythrough the NSF Advanced Technology Educationprogram.
    • A project to enhance marine and environmental science education at the five minority-serving community colleges of the Pacific Islands.
      • American Samoa Community College, the College of Micronesia — FSM, the College of the Marshall Islands, Northern Marianas College and Palau Community College will receive support for curriculum development, faculty professional development, internships and field experiences for students, and strengthened scientific infrastructure. Robert Richmond of University of Hawaii, Honolulu is the award’s primary investigator.
    • A college course to increase student engagement and learning around the Hoosick Falls water crisis.
      • The Village of Hoosick Falls in New York recently discovered unsafe concentrations of perfluorooctanoic acid in its public water system. With NSF support, an interdisciplinary group of scientists led byDavid Bond of Bennington College will develop a course to train students in the effective use of science and technology related to water safety.
  • Two workshops planned on new water technologies and systems to give new meaning to the word “wastewater.”
    • Wastewater treatment plants are not only vital to the protection of human health and the environment, but also present opportunities to recover energy and other valuable resources — creating a world-class water infrastructure while reducing the costs to run it. Recognizing this, NSF, the Department of Energy, the Environmental Protection Agency, and the U.S. Department of Agriculture, with the Water Environment Research Foundation, are developing a National Water Resource Recovery Test Bed Facility network and directory to connect researchers, new technology providers and other innovators in the water-resource recovery industry with test facilities appropriate for their needs. NSF is planning two workshops, in May and June 2016, to support the development of appropriate metrics and structure possibilities for the network.
  • A new Nanotechnology Signature Initiative on water sustainability through nanotechnology.
    • Federal agencies participating in the National Nanotechnology Initiative will support a new initiative to focus on applying the unique properties of materials that occur at the nanoscale to increase water availability, improve water delivery and use efficiency, and enable next-generation water-monitoring systems. Participating agencies include the Department of Energy, the Environmental Protection Agency, NASA, the National Institute of Standards and Technology, NSF and the Department of Agriculture.
  •  A new video series to broaden awareness.
    • The series will build on the popular 2013Sustainability: Water episodes to explore how cutting-edge science and engineering research can transform how the country understands, designs and uses water resources and technologies. The videos will be produced by NBC Learn, the educational arm of NBCUniversal News Group, and will be shared in classrooms and with the public across a variety of platforms in the fall of 2016. The four-part series will promote public awareness of:
      • Water resources, the variability of these resources, and water infrastructure designs and needs.
      • Water conservation in rural and urban settings.
      • Water treatment, including purification and desalination techniques.
      • Water quality issues, including salinization and control.
  • Innovative solutions from community college students at the nexus of food-water-energy.
    • NSF and the American Association of Community Colleges have chosen 10 finalists in the second annual Community College Innovation Challenge, which calls on students enrolled in community colleges to propose innovative science, technology, engineering and mathematics (STEM)-based solutions to perplexing, real-world problems.

Significant ongoing NSF investments:

  • Engineering Research Centers for responsible water use.
    • The Engineering Research Center for Re-inventing the Nation’s Urban Water Infrastructure(ReNUWIt), a research partnership among University of California, Berkeley, Colorado School of Mines, New Mexico State University and Stanford University, is facilitating the improvement of the nation’s existing urban water systems through the development of innovative water technologies, management tools and systems-level analysis. This year, ReNUWIt will help advance urban water governance by releasing a set of decision-support tools that will allow utilities to quantify regional urban water resiliency and sustainability; promote the diversification of urban water supply portfolios by enabling virtual trading in regions with shared water resources; and support integrated management of water reuse and stormwater recharge systems.
    • The Nanosystems Engineering Research Center for Nanotechnology Enabled Water Treatment Systems(NEWT), led by Rice University in partnership with Arizona State University, the University of Texas at El Paso and Yale University, is enabling off-grid drinking water. The NEWT Nanosystems ERC is pursuing high-performance and easy-to-deploy water treatment systems that can turn both wastewater and seawater into clean drinking water. The modular treatment systems, which will need less energy and fewer chemicals, will safely enlist the selective properties of reusable engineered nanomaterials to provide clean water at any location or scale.
  • Ongoing grants to study the food-energy-water nexus.
    • NSF has funded 17 grants, totaling $1.2 million, to support workshops on the interactions of food, energy and water, or FEW. Additionally, $6.4 million will supplement existing grants, enabling scientists to conduct additional research.
  • Ongoing grants to study water sustainability and climate.
    • NSF and the U.S. Department of Agriculture’s National Institute for Food and Agriculture have made three sets of awards, the latest totaling $25 million, in the joint Water Sustainability and Climate program. The funding fosters research on how Earth’s water system is linked with climate change, land use and ecosystems.
  • Special report on clean water technologies.
    • Beyond the White House, NSF-funded clean water-related research activities are happening now across the country. Engineers improve lives every day by imagining and creating innovative new technologies and tools. Today, NSF launches a new special report on future engineering solutions for clean water: NSF.gov/water.

Watch the White House Water Summit live atWhiteHouse.gov/live.

Join the conversation online with the hashtag#WHWaterSummit.

-NSF-

Program Contacts

JoAnn Slama Lighty, NSF, (703) 292-5382, jlighty@nsf.gov
Thomas Torgersen, NSF, (703) 292-8549, ttorgers@nsf.gov

Related Websites
Sustainability: Water: https://www.nbclearn.com/sustainability-water
NSF special report: Cleaner water, clearer future:http://www.nsf.gov/water
New grants foster research on food, energy and water: a linked system: http://www.nsf.gov/news/news_summ.jsp?cntn_id=135642
NSF and NIFA award $25 million in grants for study of water sustainability and climate:http://www.nsf.gov/news/news_summ.jsp?cntn_id=132501
On World Water Day, scientists peer into rivers to answer water availability questions:http://www.nsf.gov/discoveries/disc_summ.jsp?cntn_id=137901

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newfuelcelld 031516A powdery mixture of graphene-wrapped magnesium nanocrystals, produced at Berkeley Lab, is stable in air. The mixture’s energy properties show promise for use in hydrogen fuel cells. Credit: Eun Seon Cho/Berkeley Lab

Hydrogen is the lightest and most plentiful element on Earth and in our universe. So it shouldn’t be a big surprise that scientists are pursuing hydrogen as a clean, carbon-free, virtually limitless energy source for cars and for a range of other uses, from portable generators to telecommunications towers—with water as the only byproduct of combustion.

While there remain scientific challenges to making -based energy sources more competitive with current automotive propulsion systems and other energy technologies, researchers at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) have developed a new materials recipe for a battery-like cell—which surrounds hydrogen-absorbing magnesium nanocrystals with atomically thin graphene sheets—to push its performance forward in key areas.

The graphene shields the nanocrystals from oxygen and moisture and contaminants, while tiny, natural holes allow the smaller hydrogen molecules to pass through. This filtering process overcomes common problems degrading the performance of metal hydrides for .

These graphene-encapsulated magnesium crystals act as “sponges” for hydrogen, offering a very compact and safe way to take in and store hydrogen. The nanocrystals also permit faster fueling, and reduce the overall “tank” size.

“Among metal hydride-based materials for hydrogen storage for vehicle applications, our materials have good performance in terms of capacity, reversibility, kinetics and stability,” said Eun Seon Cho, a postdoctoral researcher at Berkeley Lab and lead author of a study related to the new fuel cell formula, published recently in Nature Communications.

New fuel cell design powered by graphene-wrapped nanocrystals
Thin sheets of graphene oxide (red sheets) have natural, atomic-scale defects that allow hydrogen gas molecules to pass through while blocking larger molecules such as oxygen (O2) and water (H2O). Berkeley Lab researchers encapsulated …more

In a hydrogen fuel cell-powered vehicle using these materials, known as a “metal hydride” (hydrogen bound with a metal) fuel cell, hydrogen gas pumped into a vehicle would be chemically absorbed by the magnesium nanocrystaline powder and rendered safe at low pressures.

Jeff Urban, a Berkeley Lab staff scientist and co-author, said, “This work suggests the possibility of practical hydrogen storage and use in the future. I believe that these materials represent a generally applicable approach to stabilizing reactive materials while still harnessing their unique activity—concepts that could have wide-ranging applications for batteries, catalysis, and energetic materials.”

The research, conducted at Berkeley Lab’s Molecular Foundry and Advanced Light Source, is part of a National Lab Consortium, dubbed HyMARC (Hydrogen Materials—Advanced Research Consortium) that seeks safer and more cost-effective hydrogen storage, and Urban is Berkeley Lab’s lead scientist for that effort.

The U.S. market share for all electric-drive vehicles in 2015, including full-electric, hybrids and plug-in hybrid vehicles, was 2.87 percent, which amounts to about 500,000 electric-drive vehicles out of total vehicle sales of about 17.4 million, according to statistics reported by the Electric Drive Transportation Association, a trade association promoting electric-drive vehicles.

Hydrogen-fuel-cell vehicles haven’t yet made major in-roads in vehicle sales, though several major auto manufacturers including Toyota, Honda, and General Motors, have invested in developing hydrogen fuel-cell vehicles. Indeed, Toyota released a small-production model called the Mirai, which uses compressed-hydrogen tanks, last year in the U.S.

A potential advantage for hydrogen-fuel-cell vehicles, in addition to their reduced environmental impact over standard-fuel vehicles, is the high specific energy of hydrogen, which means that can potentially take up less weight than other battery systems and fuel sources while yielding more electrical energy.

A measure of the energy storage capacity per weight of hydrogen fuel cells, known as the “gravimetric energy density,” is roughly three times that of gasoline. Urban noted that this important property, if effectively used, could extend the total vehicle range of hydrogen-based transportation, and extend the time between refueling for many other applications, too.

More R&D is needed to realize higher-capacity hydrogen storage for long-range vehicle applications that exceed the performance of existing electric-vehicle batteries, Cho said, and other applications may be better suited for hydrogen fuel cells in the short term, such as stationary power sources, forklifts and airport vehicles, portable power sources like laptop battery chargers, portable lighting, water and sewage pumps and emergency services equipment.

Cho said that a roadblock to metal hydride storage has been a relatively slow rate in taking in (absorption) and giving out (desorption) hydrogen during the cycling of the units. In fuel cells, separate chemical reactions involving hydrogen and oxygen produce a flow of electrons that are channeled as electric current, creating water as a byproduct.

The tiny size of the graphene-encapsulated nanocrystals created at Berkeley Lab, which measure only about 3-4 nanometers, or billionths of a meter across, is a key in the new fuel cell materials’ fast capture and release of hydrogen, Cho said, as they have more surface area available for reactions than the same material would at larger sizes.

Another key is protecting the magnesium from exposure to air, which would render it unusable for the fuel cell, she added.

Working at The Molecular Foundry, researchers found a simple, scalable and cost-effective “one pan” technique to mix up the graphene sheets and magnesium oxide nanocrystals in the same batch. They later studied the coated nanocrystals’ structure using X-rays at Berkeley Lab’s Advanced Light Source. The X-ray studies showed how pumped into the fuel cell mixture reacted with the magnesium nanocrystals to form a more stable molecule called magnesium hydride while locking out oxygen from reaching the magnesium.

“It is stable in air, which is important,” Cho said.

Next steps in the research will focus on using different types of catalysts—which can improve the speed and efficiency of chemical reactions—to further improve the fuel cell’s conversion of electrical current, and in studying whether different types of material can also improve the fuel cell’s overall capacity, Cho said.

Explore further: Hydrogen released to fuel cell more quickly when stored in metal nanoparticles

More information: Eun Seon Cho et al. Graphene oxide/metal nanocrystal multilaminates as the atomic limit for safe and selective hydrogen storage, Nature Communications (2016). DOI: 10.1038/ncomms10804

Smokestack Emissions Nano Carbon Capture id42759

“Our climate change solution is two fold: To transform the greenhouse gas carbon dioxide into valuable products and to provide greenhouse gas emission-free alternatives to today’s industrial and transportation fossil fuel processes,” Stuart Licht, professor of chemistry at George Washington University

An interdisciplinary team of scientists has worked out a way to make electric vehicles that are not only carbon neutral, but carbon negative, capable of actually reducing the amount of atmospheric carbon dioxide as they operate. They have done so by demonstrating how the graphite electrodes used in the lithium-ion batteries that power electric automobiles can be replaced with carbon material recovered from the atmosphere.

The recipe for converting carbon dioxide gas into batteries is described in a paper published in the March 2 issue of the journal ACS Central Science (“Carbon Nanotubes Produced from Ambient Carbon Dioxide for Environmentally Sustainable Lithium-Ion and Sodium-Ion Battery Anodes”).

Converting Carbon Dioxide into BatteriesThe Solar Thermal Electrochemical Process (STEP) converts atmospheric carbon dioxide into carbon nanotubes that can be used in advanced batteries. (Image: Julie Turner, Vanderbilt University)

“Our climate change solution is two fold: To transform the greenhouse gas carbon dioxide into valuable products and to provide greenhouse gas emission-free alternatives to today’s industrial and transportation fossil fuel processes,” Stuart Licht, professor of chemistry at George Washington University said.

“In addition to better batteries other applications for the carbon nanotubes include carbon composites for strong, lightweight construction materials, sports equipment and car, truck and airplane bodies.” The unusual pairing of carbon dioxide conversion and advanced battery technology is the result of a collaboration between Dr. Licht, and the laboratory of assistant professor of mechanical engineering Cary Pint at Vanderbilt University. Licht adapted the lab’s solar thermal electrochemical process (STEP) so that it produces carbon nanotubes from carbon dioxide and with Pint by incorporating them into both lithium-ion batteries like those used in electric vehicles and electronic devices and low-cost sodium-ion batteries under development for large-scale applications, such as the electric grid. In lithium-ion batteries, the nanotubes replace the carbon anode used in commercial batteries.

The team demonstrated that the carbon nanotubes gave a small boost to the performance, which was amplified when the battery was charged quickly. In sodium-ion batteries, the researchers found that small defects in the carbon, which can be tuned by STEP, can unlock stable storage performance over 3.5 times above that of sodium-ion batteries with graphite electrodes. Most importantly, both carbon-nanotube batteries were exposed to about 2.5 months of continuous charging and discharging and showed no sign of fatigue.

Published on Feb 25, 2016: Video interview with Cary Pint explaining this research.

Scientists from Vanderbilt and George Washington universities have worked out a way to make electric vehicles not just carbon neutral but carbon negative by demonstrating how the graphite electrodes used in the lithium-ion batteries can be replaced with carbon recovered from the atmosphere.

“This trailblazing research has achieved yet another amazing milestone with the incorporation of the carbon nanotubes produced by Stuart Licht’s STEP reduction of carbon dioxide process into batteries for electric vehicles and large scale storage,” said Michael King, chair of GW’s Department of Chemistry. “We are thrilled by this translation of basic research into potentially useful consumer products while mitigating atmospheric carbon dioxide buildup. This is a win-win for everyone!”
The researchers estimate that with a battery cost of $325 per kWh (the average cost of lithium-ion batteries reported by the Department of Energy in 2013), a kilogram of carbon dioxide has a value of about $18 as a battery material – six times more than when it is converted to methanol – a number that only increases when moving from large batteries used in electric vehicles to the smaller batteries used in electronics.

And unlike methanol, combining batteries with solar cells provides renewable power with zero greenhouse emissions, which is needed to put an end to the current carbon cycle that threatens future global sustainability.

Licht also proposes a modified flue system for combustion plants that incorporates this process could be self-sustaining, as exemplified by a new natural gas power plant with zero carbon dioxide emissions. That’s because the side product of the process is pure oxygen, which plants could then use for further combustion. The calculated total cost per metric tonne of CNTs would be much less expensive than current synthetic methods.
“This approach not only produces better batteries but it also establishes a value for carbon dioxide recovered from the atmosphere that is associated with the end-user battery cost unlike most efforts to reuse CO2 that are aimed at low-valued fuels, like methanol, that cannot justify the cost required to produce them,” said Pint.
Source: Vanderbilt University

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