MIT: New battery technology gobbles up carbon dioxide – Ultimately may help reduce the emission of the greenhouse gas to the atmosphere + Could Carbon Dioxide Capture Batteries Replace Phone and EV Batteries?


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This scanning electron microscope image shows the carbon cathode of a carbon-dioxide-based battery made by MIT researchers, after the battery was discharged. It shows the buildup of carbon compounds on the surface, composed of carbonate material that could be derived from power plant emissions, compared to the original pristine surface (inset) Courtesy of the researchers

Lithium-based battery could make use of greenhouse gas before it ever gets into the atmosphere.

A new type of battery developed by researchers at MIT could be made partly from carbon dioxide captured from power plants. Rather than attempting to convert carbon dioxide to specialized chemicals using metal catalysts, which is currently highly challenging, this battery could continuously convert carbon dioxide into a solid mineral carbonate as it discharges.

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While still based on early-stage research and far from commercial deployment, the new battery formulation could open up new avenues for tailoring electrochemical carbon dioxide conversion reactions, which may ultimately help reduce the emission of the greenhouse gas to the atmosphere.

battery-atmosphereRead Also:  Scientists Have Created Batteries Using Carbon Dioxide From The Atmosphere Which Could Replace Phone And Electric Car Batteries

 

 

 

The battery is made from lithium metal, carbon, and an electrolyte that the researchers designed. The findings are described today in the journal Joule, in a paper by assistant professor of mechanical engineering Betar Gallant, doctoral student Aliza Khurram, and postdoc Mingfu He.

Currently, power plants equipped with carbon capture systems generally use up to 30 percent of the electricity they generate just to power the capture, release, and storage of carbon dioxide. Anything that can reduce the cost of that capture process, or that can result in an end product that has value, could significantly change the economics of such systems, the researchers say.

However, “carbon dioxide is not very reactive,” Gallant explains, so “trying to find new reaction pathways is important.” Generally, the only way to get carbon dioxide to exhibit significant activity under electrochemical conditions is with large energy inputs in the form of high voltages, which can be an expensive and inefficient process. Ideally, the gas would undergo reactions that produce something worthwhile, such as a useful chemical or a fuel. However, efforts at electrochemical conversion, usually conducted in water, remain hindered by high energy inputs and poor selectivity of the chemicals produced.

Gallant and her co-workers, whose expertise has to do with nonaqueous (not water-based) electrochemical reactions such as those that underlie lithium-based batteries, looked into whether carbon-dioxide-capture chemistry could be put to use to make carbon-dioxide-loaded electrolytes — one of the three essential parts of a battery — where the captured gas could then be used during the discharge of the battery to provide a power output.

This approach is different from releasing the carbon dioxide back to the gas phase for long-term storage, as is now used in carbon capture and sequestration, or CCS. That field generally looks at ways of capturing carbon dioxide from a power plant through a chemical absorption process and then either storing it in underground formations or chemically altering it into a fuel or a chemical feedstock.

Instead, this team developed a new approach that could potentially be used right in the power plant waste stream to make material for one of the main components of a battery.

While interest has grown recently in the development of lithium-carbon-dioxide batteries, which use the gas as a reactant during discharge, the low reactivity of carbon dioxide has typically required the use of metal catalysts. Not only are these expensive, but their function remains poorly understood, and reactions are difficult to control.

By incorporating the gas in a liquid state, however, Gallant and her co-workers found a way to achieve electrochemical carbon dioxide conversion using only a carbon electrode. The key is to pre-activate the carbon dioxide by incorporating it into an amine solution.

“What we’ve shown for the first time is that this technique activates the carbon dioxide for more facile electrochemistry,” Gallant says. “These two chemistries — aqueous amines and nonaqueous battery electrolytes — are not normally used together, but we found that their combination imparts new and interesting behaviors that can increase the discharge voltage and allow for sustained conversion of carbon dioxide.”

They showed through a series of experiments that this approach does work, and can produce a lithium-carbon dioxide battery with voltage and capacity that are competitive with that of state-of-the-art lithium-gas batteries. Moreover, the amine acts as a molecular promoter that is not consumed in the reaction.

The key was developing the right electrolyte system, Khurram explains. In this initial proof-of-concept study, they decided to use a nonaqueous electrolyte because it would limit the available reaction pathways and therefore make it easier to characterize the reaction and determine its viability. The amine material they chose is currently used for CCS applications, but had not previously been applied to batteries.

factory-air-pollution-environment-smoke-shutterstock_130778315-34gj4r8xdrgg8mj9r25a0wThis early system has not yet been optimized and will require further development, the researchers say. For one thing, the cycle life of the battery is limited to 10 charge-discharge cycles, so more research is needed to improve rechargeability and prevent degradation of the cell components. “Lithium-carbon dioxide batteries are years away” as a viable product, Gallant says, as this research covers just one of several needed advances to make them practical.

But the concept offers great potential, according to Gallant. Carbon capture is widely considered essential to meeting worldwide goals for reducing greenhouse gas emissions, but there are not yet proven, long-term ways of disposing of or using all the resulting carbon dioxide. Underground geological disposal is still the leading contender, but this approach remains somewhat unproven and may be limited in how much it can accommodate. It also requires extra energy for drilling and pumping.

The researchers are also investigating the possibility of developing a continuous-operation version of the process, which would use a steady stream of carbon dioxide under pressure with the amine material, rather than a preloaded supply the material, thus allowing it to deliver a steady power output as long as the battery is supplied with carbon dioxide. Ultimately, they hope to make this into an integrated system that will carry out both the capture of carbon dioxide from a power plant’s emissions stream, and its conversion into an electrochemical material that could then be used in batteries. “It’s one way to sequester it as a useful product,” Gallant says.

“It was interesting that Gallant and co-workers cleverly combined the prior knowledge from two different areas, metal-gas battery electrochemistry and carbon-dioxide capture chemistry, and succeeded in increasing both the energy density of the battery and the efficiency of the carbon-dioxide capture,” says Kisuk Kang, a professor at Seoul National University in South Korea, who was not associated with this research.

“Even though more precise understanding of the product formation from carbon dioxide may be needed in the future, this kind of interdisciplinary approach is very exciting and often offers unexpected results, as the authors elegantly demonstrated here,” Kang adds.

MIT’s Department of Mechanical Engineering provided support for the project.

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Using one quantum dot to sense changes in another: Applications for developing advanced electronic and photonic devices


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Scanning electron micrograph of InAs self-assembled quantum dot transistor device. Credit: Osaka University

Quantum dots are nanometer-sized boxes that have attracted much scientific interest for use in nanotechnology because their properties obey quantum mechanics and are requisites to developing advanced electronic and photonic devices.

Quantum dots that self-assemble during their formation are particularly attractive as tunable light emitters in nanoelectronic devices and for studying quantum physics because of their quantized transport behavior. It is important to develop a way to measure the charge in a single self-assembled quantum dot to achieve quantum information processing; however, this is difficult because the metal electrodes needed for the measurement can screen out the very small charge of the quantum dot.

Researchers at Osaka University have recently developed the first device based on two self-assembled quantum dots that can measure the single-electron charge of one quantum dot using a second as a sensor.

The device was fabricated using two indium arsenide (InAs)  connected to electrodes that were deliberately narrowed to minimize the undesirable screening effect.

“The two  dots in the device showed significant capacitive coupling,” says Haruki Kiyama. “As a result, the single-electron charging of one dot was detected as a change in the current of the other dot.”

The current response of the sensor quantum dot depended on the number of electrons in the target dot. Hence the device can be used for real-time detection of single-electron tunneling in a quantum dot. The tunneling events of single electrons in and out of the target quantum dot were detected as switching between high and low current states in the sensor quantum dot. Detection of such tunneling events is important for the measurement of single spins towards electron spin qubits.

“Sensing single charges in self-assembled quantum dots is exciting for a number of reasons,” explains Akira Oiwa. “The ability to achieve electrical readout of single electron states can be combined with photonics and used in quantum communications. In addition, our device concept can be extended to different materials and systems to study the physics of self-assembled quantum dots.”

Two quantum dots are better than one: Using one dot to sense changes in another
Real-time traces of the charge sensor quantum dot (QD1) current. Changes in the charge sensor current indicate the increase and decrease of electron number in the adjacent quantum dot (QD2). Credit: Osaka University

An electronic device using self-assembled quantum dots to detect single-electron events is a novel strategy for increasing our understanding of the physics of quantum dots and to aid the development of advanced nanoelectronics and quantum computing.

 Explore further: Simultaneous detection of multiple spin states in a single quantum dot

More information: Haruki Kiyama et al, Single-electron charge sensing in self-assembled quantum dots, Scientific Reports (2018). DOI: 10.1038/s41598-018-31268-x

 

Rapid Nano-filter for clean water: Australian researchers design a rapid nano-filter that cleans dirty water 100X faster than current technology


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The new technology can filter drinking water 100 times faster than current tech. Credit: Free stock photo 

Australian researchers have designed a rapid nano-filter that can clean dirty water over 100 times faster than current technology.

Simple to make and simple to scale up, the technology harnesses naturally occurring nano-structures that grow on .

The RMIT University and University of New South Wales (UNSW) researchers behind the innovation have shown it can filter both heavy metals and oils from water at extraordinary speed.

RMIT researcher Dr. Ali Zavabeti said water contamination remains a significant challenge globally—1 in 9 people have no clean water close to home.

“Heavy  contamination causes serious health problems and children are particularly vulnerable,” Zavabeti said.

“Our new nano-filter is sustainable, environmentally-friendly, scalable and low cost.

“We’ve shown it works to remove lead and oil from water but we also know it has potential to target other common contaminants.

“Previous research has already shown the materials we used are effective in absorbing contaminants like mercury, sulfates and phosphates.

“With further development and commercial support, this new nano-filter could be a cheap and ultra-fast solution to the problem of .”

Quick and not-so-dirty: A rapid nano-filter for clean water
A liquid metal droplet with flakes of aluminium oxide compounds grown on its surface. Each 0.03mm flake is made up of about 20,000 nano-sheets stacked together. Credit: RMIT University

The liquid metal chemistry process developed by the researchers has potential applications across a range of industries including electronics, membranes, optics and catalysis.

“The technique is potentially of significant industrial value, since it can be readily upscaled, the liquid metal can be reused, and the process requires only short reaction times and low temperatures,” Zavabeti said.

Project leader Professor Kourosh Kalantar-zadeh, Honorary Professor at RMIT, Australian Research Council Laureate Fellow and Professor of Chemical Engineering at UNSW, said the liquid metal chemistry used in the process enabled differently shaped nano-structures to be grown, either as the atomically thin sheets used for the nano-filter or as nano-fibrous structures.

“Growing these materials conventionally is power intensive, requires high temperatures, extensive processing times and uses toxic metals. Liquid metal chemistry avoids all these issues so it’s an outstanding alternative.”

How it works

The groundbreaking technology is sustainable, environmentally-friendly, scalable and low-cost.

The researchers created an alloy by combining gallium-based liquid metals with aluminium.

When this alloy is exposed to water, nano-thin sheets of  compounds grow naturally on the surface.

These atomically thin layers—100,000 times thinner than a human hair—restack in a wrinkled fashion, making them highly porous.

Quick and not-so-dirty: A rapid nano-filter for clean water
Microscope image of nano-sheets, magnified over 11,900 times. Credit: RMIT University

This enables water to pass through rapidly while the aluminium oxide compounds absorbs the contaminants.

Experiments showed the nano-filter made of stacked atomically thin sheets was efficient at removing lead from water that had been contaminated at over 13 times safe drinking levels, and was highly effective in separating oil from water.

The process generates no waste and requires just aluminium and , with the liquid metals reused for each new batch of nano-structures.

The method developed by the researchers can be used to grow nano-structured materials as ultra-thin sheets and also as nano-fibres.

These different shapes have different characteristics—the ultra-thin sheets used in the nano-filter experiments have high mechanical stiffness, while the nano-fibres are highly translucent.

The ability to grow materials with different characteristics offers opportunities to tailor the shapes to enhance their different properties for applications in electronics, membranes, optics and catalysis.

The research is funded by the Australian Research Council Centre for Future Low-Energy Electronics Technologies (FLEET).

The findings are published in the journal Advanced Functional Materials.

 Explore further: Liquid metal discovery ushers in new wave of chemistry and electronics

More information: Advanced Functional Materials (2018). DOI: 10.1002/adfm.201804057

 

NREL: Envisioning Net-Zero Emission Energy Systems


NREL researchers contribute to a major journal article describing pathways to net-zero emissions for particularly difficult-to-decarbonize economic sectors

As global energy consumption continues to grow—by some projections, more than doubling by 2100—all sectors of the economy will need to find ways to drastically reduce their carbon dioxide emissions if average global temperatures are to be held under international climate targets. Two NREL authors contributed to a recently published article in Science that examined potential barriers and opportunities to decarbonizing certain energy systems that are essential to modern civilization but remain stubbornly reliant on carbon-emitting processes.

Difficult to Decarbonize Energy Sectors Contribute 27% of Carbon Emissions

Many sectors of the economy, such as light-duty transportation, heating, cooling, and lighting, could be straightforward to decarbonize through electrification and use of low- or net-zero-emitting energy sources. However, some energy uses, such as aviation, long-distance transport and shipping, steel and cement production, and a highly reliable electricity supply, will be more difficult to decarbonize. Together, these sectors contribute 27% of global carbon emissions today. With global demand for many of these sectors growing rapidly, solutions are urgently needed, the article’s authors write.

“The timeframes and economic costs of any energy transition are enormous. Most technologies installed today will have a lifetime of perhaps 30 to 50 years and the transition from research to actual deployment can also be quite lengthy,” said Bri-Mathias Hodge, an author on the paper and manager of the Power Systems Design and Studies Group at NREL. “Because of this we need to be able to identify the most pertinent issues that will need to be solved fairly far in the future and get started now, before we find ourselves heavily invested in even more carbon-intensive, long-term infrastructure.”

Diverse Expert Perspectives Informed Study

Discussion of the article’s underlying issues began at an Aspen Global Change Institute meeting in July 2016. “The diversity and depth of expertise at the workshop—and contributing to the paper—were outstanding,” said Doug Arent, the other NREL researcher to contribute to the paper and deputy associate lab director for Scientific Computing and Energy Analysis. “It was great to hear the different perspectives and learn about new areas that are related to our work at NREL, but that I don’t get to hear about every day at NREL,” added Hodge.

Considering demographic trends, institutional barriers, and economic and technological constraints, the group of researchers concluded that future net-zero emission systems will depend critically on integration of now-discrete energy industries. Although a range of existing low or net zero emitting energy technologies exist for these energy services, they may only be able to fully meet future energy demands through cross-sector coordination. Collaboration could speed research and development of new technologies and coordinating operations across sectors could better utilize capital-intensive assets, create broader markets, and streamline regulations.

Research Should Pursue Technologies and Integration to Decarbonize These Sectors

The article’s authors suggest two broad research thrusts: research in technologies and processes that could decarbonize these energy services, and research in systems integration to provide these energy services in a more reliable and cost-effective way.

The Science article concludes by stating, “if we want to achieve a robust, reliable, affordable, net-zero emissions energy system later this century, we must be researching, developing, demonstrating, and deploying those candidate technologies now.”

Lucid Motors Signs $1bn+ Investment Agreement with Public Investment Fund of Saudi Arabia – SA Enters the EV Race with “Lucid’s Air”


A Major Milestone on the Path to Production of the Lucid Air

Lucid Motors announced today that it has executed a $1bn+ (USD) investment agreement with the Public Investment Fund of Saudi Arabia, through a special-purpose vehicle wholly owned by PIF.

Under the terms of the agreement, the parties made binding undertakings to carry out the transaction subject to regulatory approvals and customary closing conditions.

The transaction represents a major milestone for Lucid and will provide the company with the necessary funding to commercially launch its first electric vehicle, the Lucid Air, in 2020. Lucid plans to use the funding to complete engineering development and testing of the Lucid Air, construct its factory in Casa Grande, Arizona, begin the global rollout of its retail strategy starting in North America, and enter production for the Lucid Air.

Lucid’s mission is to inspire the adoption of sustainable energy by creating the most captivating luxury electric vehicles, centered around the human experience. “The convergence of new technologies is reshaping the automobile, but the benefits have yet to be truly realized. This is inhibiting the pace at which sustainable mobility and energy are adopted. At Lucid, we will demonstrate the full potential of the electric connected vehicle in order to push the industry forward,” said Peter Rawlinson, Chief Technology Officer of Lucid.

Lucid and PIF are strongly aligned around the vision to create a global luxury electric car company based in the heart of Silicon Valley with world-class engineering talent. Lucid will work closely with PIF to ensure a strategic focus on quickly bringing its products to market at a time of rapid change in the automotive industry.

A spokesperson for PIF said, “By investing in the rapidly expanding electric vehicle market, PIF is gaining exposure to long-term growth opportunities, supporting innovation and technological development, and driving revenue and sectoral diversification for the Kingdom of Saudi Arabia.”

The spokesperson added, “PIF’s international investment strategy aims to strengthen PIF’s performance as an active contributor in the international economy, an investor in the industries of the future and the partner of choice for international investment opportunities. Our investment in Lucid is a strong example of these objectives.”

MIT Study: Adding power choices reduces cost and risk of carbon-free electricity


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New MIT research shows that, unless steady, continuous carbon-free sources of electricity are included in the mix, costs of decarbonizing the electrical system could be prohibitive and end up derailing attempts to mitigate the most severe effects of global climate change. Image: Chelsea Turner

To curb greenhouse gas emissions, nations, states, and cities should aim for a mix of fuel-saving, flexible, and highly reliable sources.

In major legislation passed at the end of August, California committed to creating a 100 percent carbon-free electricity grid — once again leading other nations, states, and cities in setting aggressive policies for slashing greenhouse gas emissions. Now, a study by MIT researchers provides guidelines for cost-effective and reliable ways to build such a zero-carbon electricity system.

MIT-Energy-Mix-01_0The best way to tackle emissions from electricity, the study finds, is to use the most inclusive mix of low-carbon electricity sources.

Costs have declined rapidly for wind power, solar power, and energy storage batteries in recent years, leading some researchers, politicians, and advocates to suggest that these sources alone can power a carbon-free grid. But the new study finds that across a wide range of scenarios and locations, pairing these sources with steady carbon-free resources that can be counted on to meet demand in all seasons and over long periods — such as nuclear, geothermal, bioenergy, and natural gas with carbon capture — is a less costly and lower-risk route to a carbon-free grid.

The new findings are described in a paper published today in the journal Joule, by MIT doctoral student Nestor Sepulveda, Jesse Jenkins PhD ’18, Fernando de Sisternes PhD ’14, and professor of nuclear science and engineering and Associate Provost Richard Lester.

The need for cost effectiveness

“In this paper, we’re looking for robust strategies to get us to a zero-carbon electricity supply, which is the linchpin in overall efforts to mitigate climate change risk across the economy,” Jenkins says. To achieve that, “we need not only to get to zero emissions in the electricity sector, but we also have to do so at a low enough cost that electricity is an attractive substitute for oil, natural gas, and coal in the transportation, heat, and industrial sectors, where decarbonization is typically even more challenging than in electricity. ”

Sepulveda also emphasizes the importance of cost-effective paths to carbon-free electricity, adding that in today’s world, “we have so many problems, and climate change is a very complex and important one, but not the only one. So every extra dollar we spend addressing climate change is also another dollar we can’t use to tackle other pressing societal problems, such as eliminating poverty or disease.” Thus, it’s important for research not only to identify technically achievable options to decarbonize electricity, but also to find ways to achieve carbon reductions at the most reasonable possible cost.

To evaluate the costs of different strategies for deep decarbonization of electricity generation, the team looked at nearly 1,000 different scenarios involving different assumptions about the availability and cost of low-carbon technologies, geographical variations in the availability of renewable resources, and different policies on their use.

Regarding the policies, the team compared two different approaches. The “restrictive” approach permitted only the use of solar and wind generation plus battery storage, augmented by measures to reduce and shift the timing of demand for electricity, as well as long-distance transmission lines to help smooth out local and regional variations. The  “inclusive” approach used all of those technologies but also permitted the option of using  continual carbon-free sources, such as nuclear power, bioenergy, and natural gas with a system for capturing and storing carbon emissions. Under every case the team studied, the broader mix of sources was found to be more affordable.

The cost savings of the more inclusive approach relative to the more restricted case were substantial. Including continual, or “firm,” low-carbon resources in a zero-carbon resource mix lowered costs anywhere from 10 percent to as much as 62 percent, across the many scenarios analyzed. That’s important to know, the authors stress, because in many cases existing and proposed regulations and economic incentives favor, or even mandate, a more restricted range of energy resources.

“The results of this research challenge what has become conventional wisdom on both sides of the climate change debate,” Lester says. “Contrary to fears that effective climate mitigation efforts will be cripplingly expensive, our work shows that even deep decarbonization of the electric power sector is achievable at relatively modest additional cost. But contrary to beliefs that carbon-free electricity can be generated easily and cheaply with wind, solar energy, and storage batteries alone, our analysis makes clear that the societal cost of achieving deep decarbonization that way will likely be far more expensive than is necessary.”

Light bulb RE images

A new taxonomy for electricity sources

In looking at options for new power generation in different scenarios, the team found that the traditional way of describing different types of power sources in the electrical industry — “baseload,” “load following,” and “peaking” resources — is outdated and no longer useful, given the way new resources are being used.

Rather, they suggest, it’s more appropriate to think of power sources in three new categories: “fuel-saving” resources, which include solar, wind and run-of-the-river (that is, without dams) hydropower; “fast-burst” resources, providing rapid but short-duration responses to fluctuations in electricity demand and supply, including battery storage and technologies and pricing strategies to enhance the responsiveness of demand; and “firm” resources, such as nuclear, hydro with large reservoirs, biogas, and geothermal.

“Because we can’t know with certainty the future cost and availability of many of these resources,” Sepulveda notes, “the cases studied covered a wide range of possibilities, in order to make the overall conclusions of the study robust across that range of uncertainties.”

Range of scenarios

The group used a range of projections, made by agencies such as the National Renewable Energy Laboratory, as to the expected costs of different power sources over the coming decades, including costs similar to today’s and anticipated cost reductions as new or improved systems are developed and brought online. For each technology, the researchers chose a projected mid-range cost, along with a low-end and high-end cost estimate, and then studied many combinations of these possible future costs.

Under every scenario, cases that were restricted to using fuel-saving and fast-burst technologies had a higher overall cost of electricity than cases using firm low-carbon sources as well, “even with the most optimistic set of assumptions about future cost reductions,” Sepulveda says.

That’s true, Jenkins adds, “even when we assume, for example, that nuclear remains as expensive as it is today, and wind and solar and batteries get much cheaper.”

The authors also found that across all of the wind-solar-batteries-only cases, the cost of electricity rises rapidly as systems move toward zero emissions, but when firm power sources are also available, electricity costs increase much more gradually as emissions decline to zero.

“If we decide to pursue decarbonization primarily with wind, solar, and batteries,” Jenkins says, “we are effectively ‘going all in’ and betting the planet on achieving very low costs for all of these resources,” as well as the ability to build out continental-scale  high-voltage transmission lines and to induce much more flexible electricity demand.

In contrast, “an electricity system that uses firm low-carbon resources together with solar, wind, and storage can achieve zero emissions with only modest increases in cost even under pessimistic assumptions about how cheap these carbon-free resources become or our ability to unlock flexible demand or expand the grid,” says Jenkins. This shows how the addition of firm low-carbon resources “is an effective hedging strategy that reduces both the cost and risk” for fully decarbonizing power systems, he says.

Even though a fully carbon-free electricity supply is years away in most regions, it is important to do this analysis today, Sepulveda says, because decisions made now about power plant construction, research investments, or climate policies have impacts that can last for decades.

“If we don’t start now” in developing and deploying the widest range of carbon-free alternatives, he says, “that could substantially reduce the likelihood of getting to zero emissions.”

David Victor, a professor of international relations at the University of California at San Diego, who was not involved in this study, says, “After decades of ignoring the problem of climate change, finally policymakers are grappling with how they might make deep cuts in emissions. This new paper in Joule shows that deep decarbonization must include a big role for reliable, firm sources of electric power. The study, one of the few rigorous numerical analyses of how the grid might actually operate with low-emission technologies, offers some sobering news for policymakers who think they can decarbonize the economy with wind and solar alone.”

The research received support from the MIT Energy Initiative, the Martin Family Trust, and the Chilean Navy.

Macrocycles power up carbon nanotubes – applications in electronics and sensors – IMDEA


Interlocked molecules tune the electronic properties of nanotubes, allowing researchers to control their catalytic activity

Source: © M Eugenio Vázquez

Positive and negative regulation of carbon nanotube catalysts through encapsulation within macrocycles

Carbon nanotubes are a green alternative to metallic catalysts. However, tuning their activity relies on difficult and invasive chemical processes that normally damage the nanotubes’ structure. Now, only a few years after reporting the first mechanically interlocked nanotube derivatives,1 Emilio Pérez and his team at the IMDEA Nanoscience Institute in Madrid, Spain, have envisioned how to use these non-covalent modifications to power up the catalytic activity of carbon nanotubes.2

Source: © M Blanco et al, 2018, DOI: 10.1038/s41467-018-05183-8

The study encapsulated carbon nanotubes in different macrocycles then tested their catalytic activity

‘Carbon nanotubes have a hard time when they undergo chemical modification,’ explains Pérez. ‘We decided to give interlocked molecules a try, and it worked.’ The researchers mixed some single-walled nanotubes with U-shaped precursors of the macrocycles. Then, as soon as they added a tiny amount of Grubbs catalyst, the rings started surrounding the carbon nanotubes, so they end up covered in macrocyles.

Silvia Marchesan, who investigates carbon nanotubes at the University of Trieste, Italy, describes the strategy as sort of a chemical disguise: ‘You can think of dressing the nanotubes with clothes that temporarily alter their properties.’ She also highlights how clean the process is: ‘They manipulate carbon nanotubes threading them through the macrocycles, leaving the covalent structure of the tubes unaltered.’

Because of their non-covalent nature, Pérez likes to compare these new catalysts to enzymes, ‘although their mechanism of action is totally different’. ‘The macrocycles modify the electronic properties of the nanotube without interfering with the catalytic site – the “naked” carbon nanotubes walls,’ he explains. As a proof of concept, Pérez’s team used their catalysts to reduce nitroarenes. ‘Electron-withdrawing macrocycles slow the reaction down, while electron donor rings quicken it,’ says Pérez. ‘In some examples, the reaction is accelerated up to 15 times its normal speed.’

The interlocked macrocycles also impede the aggregation of carbon nanotubes, which could also boost their catalytic performance. However, Marchesan believes that ‘the trends in enhancement or reduction of the catalytic activity clearly show an effect due to the electronic effects of the macrocycles involved.’ The fact that the interlocked molecules impede aggregation is just ‘a nice additional property to get the best performance out of the nanotubes,’ she adds.

‘Controlling the electronic properties of nanotubes could have implications beyond catalysis,’ explains Pérez. ‘We could engineer modified carbon nanotubes on demand, which could find applications in electronics and sensors,’ he adds. ‘The technique shows great promise, because you have very stable products while keeping the high-surface structure of the nanotubes.’ Marchesan also dreams about the possibilities of mechanically interlocked nanotubes: ‘It is an interesting approach to build complex supramolecular architectures, for instance to create on–off switches.’

References

1. A de Juan et al, Angew. Chem. Int. Ed., 2014, 53, 5394 (DOI: 10.1002/anie.201402258)

2. M Blanco et al, Nat. Commun., 2018, 9, 2671 (DOI: 10.1038/s41467-018-05183-8)

Australian scientists develop nanotechnology to purify water


Scientists in Australia have developed a ground-breaking new way to strip impurities from waste water, with the research set to have massive applications for a number of industries.

Scientists in Australia have developed a ground-breaking new way to strip impurities from waste water, with the research set to have massive applications for a number of industries.

By using a new type of crystalline alloy, researchers at Edith Cowan University (ECU) are able to extract the contaminants and pollutants that often end up in water during industrial processing.

“Mining and textile production produces huge amounts of waste water that is contaminated with heavy metals and dyes,” lead researcher Associate Professor Laichang Zhang from ECU’s School of Engineering technology said in a statement on Friday.

Although it is already possible to treat waste water with iron powder, according to Zhang, the cost is very high.

“Firstly, using iron powder leaves you with a large amount of iron sludge that must be stored and secondly it is expensive to produce and can only be used once,” he explained.

We can produce enough crystalline alloy to treat one tonne of waste water for just 15 Australian Dollars (10.8 US dollars), additionally, we can reuse the crystalline alloy up to five times while still maintaining its effectiveness.” Based on his previous work with “metal glass,” Zhang updated the nanotechnology to make it more effective.

“Whereas metallic glasses have a disordered atomic structure, the crystalline alloy we have developed has a more ordered atomic structure,” he said.

“We produced the crystalline alloy by heating metallic glass in a specific way.””This modifies the structure, allowing the electrons in the crystalline alloy to move more freely, thereby improving its ability to bind with dye molecules or heavy metals leaving behind usable water.”Zhang said he will continue to expand his research with industry partners to further improve the technology.

All-in-one light-driven water splitting with a novel nanocatalyst (photocatalytic splitting of H2O molecules)


solar water splitting c3ee42519c-ga-1024x477

Solar-powered water splitting is a promising means of generating clean and storable energy. A novel catalyst based on semiconductor nanoparticles has now been shown to facilitate all the reactions needed for “artificial photosynthesis”.

In the light of global climate change, there is an urgent need to develop efficient ways of obtaining and storing power from renewable energy sources. The photocatalytic splitting of water into hydrogen fuel and oxygen provides a particularly attractive approach in this context. However, efficient implementation of this process, which mimics biological photosynthesis, is technically very challenging, since it involves a combination of processes that can interfere with each other.
Now, LMU physicists led by Dr. Jacek Stolarczyk and Professor Jochen Feldmann, in collaboration with chemists at the University of Würzburg led by Professor Frank Würthner, have succeeded in demonstrating the complete splitting of water with the help of an all-in-one catalytic system for the first time.
Their new study appears in the journal Nature Energy (“All-in-one visible-light-driven water splitting by combining nanoparticulate and molecular co-catalysts on CdS nanorods”).
solar-powered-water-splitting-device-incorporating-two-separateTechnical methods for the photocatalytic splitting of water molecules use synthetic components to mimic the complex processes that take place during natural photosynthesis.
In such systems, semiconductor nanoparticles that absorb light quanta (photons) can, in principle, serve as the photocatalysts. Absorption of a photon generates a negatively charged particle (an electron) and a positively charged species known as a ‘hole’, and the two must be spatially separated so that a water molecule can be reduced to hydrogen by the electron and oxidized by the hole to form oxygen.
“If one only wants to generate hydrogen gas from water, the holes are usually removed rapidly by adding sacrificial chemical reagents,” says Stolarczyk. “But to achieve complete water splitting, the holes must be retained in the system to drive the slow process of water oxidation.”
The problem lies in enabling the two half-reactions to take place simultaneously on a single particle – while ensuring that the oppositely charged species do not recombine. In addition, many semiconductors can be oxidized themselves, and thereby destroyed, by the positively charged holes.

Nanorods with spatially separated reaction sites

“We solved the problem by using nanorods made of the semiconducting material cadmium sulfate, and spatially separated the areas on which the oxidation and reduction reactions occurred on these nanocrystals,” Stolarczyk explains.
The researchers decorated the tips of the nanorods with tiny particles of platinum, which act as acceptors for the electrons excited by the light absorption. As the LMU group had previously shown, this configuration provides an efficient photocatalyst for the reduction of water to hydrogen. The oxidation reaction, on the other hand, takes place on the sides of the nanorod.
To this end, the LMU researchers attached to the lateral surfaces a ruthenium-based oxidation catalyst developed by Würthner‘s team. The compound was equipped with functional groups that anchored it to the nanorod.
“These groups provide for extremely fast transport of holes to the catalyst, which facilitates the efficient generation of oxygen and minimizes damage to the nanorods,” says Dr. Peter Frischmann, one of the initiators of the project in Würzburg.
The study was carried out as part of the interdisciplinary project “Solar Technologies Go Hybrid” (SolTech), which is funded by the State of Bavaria.
“SolTech’s mission is to explore innovative concepts for the conversion of solar energy into non-fossil fuels,” says Professor Jochen Feldmann, holder of the Chair of Photonics and Optoelectronics at LMU.

 

“The development of the new photocatalytic system is a good example of how SolTech brings together the expertise available in diverse disciplines and at different locations. The project could not have succeeded without the interdisciplinary cooperation between chemists and physicists at two institutions,” adds Würthner, who, together with Feldmann, initiated SolTech in 2012.

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Source: CeNS Center for NanoScience

Malaysia & Taiwan to Spur Growth of NanoTechnology + Bar-Ilan University joins UN nanotechnology lab


NanoVerify, Malaysia & Taiwan to Spur Growth of NanoTechnology, Taiwan NanoTechnology, nanotechnology

Malaysia & Taiwan to Spur Growth of NanoTechnology 

Recently NANOVerify Sdn. Bhd. (NVSB), Malaysia’s first and only nanotechnology verification body, and the Taiwan Nanotechnology Industry Development Association (TANIDA), have announced a mutual nano-verification mark recognition programme that is set to open up trade and drive market penetration of nanotechnology based products in both countries.

The programme enables certified nanotechnology products from the respective verification programmes to receive equal recognition in both Malaysia and Taiwan. This is projected to enable the certification of over 100 new nanotechnology products in Malaysia within the next 12-months, as well as facilitate the entry of more than 20 domestic companies into the Taiwanese market.
Commenting on the announcement of the programme, Johan Iskandar, Managing Director of NVSB, said, “We are proud to unveil this programme as another milestone in our mission to grow nanotechnology domestically and abroad. The nanotechnology industry is thriving with projections valuing the industry at close to RM500 billion globally by 2024. Collaborations between verification bodies such as this will be vital in achieving those projections by increasing awareness and building consumer trust through the rise of certified nano-products on a global scale.”
The programme, endorsed by the TANIDA-NVSB steering committee in conjunction with theAsian Nano Forum (ANF) 2018, in Taipei, Taiwan, allows applicants to enjoy expedited verification processes thanks to integrated test lab facilities. In addition, the synergistic co-operation is focused on developing strategic campaigns to encourage ‘nano-technopreneurs’ and businesses to certify their products in order to differentiate themselves in an increasingly crowded market space.
In collaboration with SIRIM QAS International, NVSB operates the NANOVerify Programme, a voluntary certification programme for processes and products with claims of nano-elements and nano-enhancements. Meanwhile, TANIDA oversees the operations of Taiwan’s NanoMark, for similar verification and recognition.
There are currently 34 certified nanotechnology products in Malaysia, ranging from cosmetics and cleaning solutions to home appliances and fertilizers, with growing interest from industry players.

 

 

 

 

 

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Bar-Ilan University joins UN nanotechnology lab

BINA-INL_signing-768x432Big agreements sometimes start in very small packages. In the case of a new partnership between Israel’s Bar-Ilan University and the United Nations, that package is nano-sized.
” …  INL comprises 100 researchers from 30 countries across Europe. Established 10 years ago by the governments of Spain and Portugal, the UN’s nano lab has an annual budget of €100 million.”