Publication Highlight

RASEI Fellows Collaboration in CHOISE Twists Halide Perovskites From a Distance

Daniel Morton — Fri, 25 Oct 2024 22:31:11 +0000

RASEI Fellows Collaboration in CHOISE Twists Halide Perovskites From a Distance Daniel Morton Fri, 10/25/2024 - 16:31

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RASEI Researchers unlock a 'new synthetic frontier' for quantum dots

Daniel Morton — Thu, 24 Oct 2024 19:50:17 +0000

RASEI Researchers unlock a 'new synthetic frontier' for quantum dots Daniel Morton Thu, 10/24/2024 - 13:50

Lauren Scholz

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University of Chicago Press Release

In a breakthrough for nanotechnology, researchers have discovered a new way to synthesize quantum dot nanocrystals using molten salt as a medium. Traditional methods to create these materials required organic solvents, which cannot withstand the high temperatures needed for certain semiconductor materials, particularly those combining elements from groups III and V on the periodic table. By using superheated molten sodium chloride, scientists were able to synthesize these semiconductor nanocrystals, paving the way for improved applications in fields like quantum computing, LED lighting, and solar technology.

Led by a team from the University of Chicago and collaborating institutions, including RASEI Fellows Sadegh Yazdi and Gordana Dukovic, this novel method also opens new avenues for materials science by enabling the synthesis of previously inaccessible nanocrystal compositions. The technique addresses long-standing challenges by providing a high-temperature environment without degrading the materials. Researchers hope this advance will contribute to new types of devices and materials, marking a significant expansion in the range of accessible quantum dot technologies.

For a more information, please see the press release from The University of Chicago.

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Discovery could lead to longer-lasting EV batteries, hasten energy transition

Anonymous — Thu, 12 Sep 2024 06:00:00 +0000

Discovery could lead to longer-lasting EV batteries, hasten energy transition Anonymous (not verified) Thu, 09/12/2024 - 00:00

Mike Toney explores how lithium-ion batteries self-discharge to improve future designs

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Probing intermediate configurations of oxygen evolution catalysis across the light spectrum

Anonymous — Mon, 09 Sep 2024 06:00:00 +0000

Probing intermediate configurations of oxygen evolution catalysis across the light spectrum Anonymous (not verified) Mon, 09/09/2024 - 00:00

Mapping a route for more efficient production of sustainable fuels

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Find out more about CEDARS

This perspective article, led by RASEI Fellow Tanja Cuk, brings together researchers at six research institutions from across the United States, to describe how advances in spectroscopy and theory can map out the elementary details of the oxygen evolution reaction, a critical reaction to enable the production of fuels from sustainable energy sources.

The oxygen evolution reaction (or OER for short), is a critical step in the creation of sustainable, decarbonized fuels, such as hydrogen. Water (H₂O) can be split into hydrogen (H₂) and oxygen (O₂) using electricity. This process pulls apart strong chemical bonds – it takes a lot of energy! If we can better understand this process, we can make it more efficient, which will enable us to create clean fuels and store renewable energy, like solar and wind power, to smooth out variations in the supply. Specifically, the OER is the half-reaction that occurs at the anode (positive electrode) during electrolysis, in which the water molecules are oxidized to produce oxygen gas (O₂), protons (H⁺), and electrons. Though this sounds straightforward, the process involves multiple intermediates, or steps, many of which are currently poorly defined. Understanding this complex process requires a collaborative approach. Jin Suntivich (Cornell University) and Dhananjay Kumar (North Carolina A&T) bring expertise in making advanced materials and electrochemistry, Geoffroy Hautier (Dartmouth College) and Ismaila Dabo (Carnegie Mellon University) develop theoretical models, and Ethan Crumlin (Lawrence Berkeley National Laboratory), Tanja Cuk (CU Boulder), and Jin Suntivich use X-ray and optical spectroscopy to visualize the small molecular intermediates.

Imagine that you have to drive from Denver, Colorado, to Greensboro, North Carolina. If someone gave you a map that only showed your starting location and destination, it would be quite difficult. You would know that you had to head east, but you wouldn’t know what roads to take, which were the fastest moving, or where any good stops were along the way. You could probably get there, but you would get lost a few times on the way, use some of the slow roads, and maybe be stuck staying in places you didn’t want to. It would be a very inefficient journey. Now compare this to using a modern navigation app, one that has details of every road along the way, the speed limits, the traffic levels, where all the gas stations are, the good restaurants and coffee shops, and good places to stop for the night. You would be far more efficient (and happy) using the navigation app.

It is the same with a chemical reaction. If you understand the elementary steps of a reaction, you can design a system that is more efficient and effective at getting to the final product. Creating this ‘map’ for the OER is a central mission of the Center for Electrochemical Dynamics and Reactions on Surfaces (CEDARS). CEDARS is a Department of Energy funded Energy Frontier Research Center (EFRC), that brings together twelve research groups at five universities and two DOE national labs across the chemical, materials, and computational sciences. CEDARS is headed by Director Dhananjay Kumar at North Carolina A&T, with a strong program in thin materials research. This is the first EFRC awarded to an HBCU as a lead institution in the country. There are several challenges that need to be overcome before the OER process can be scaled up. Currently OER is expensive, energy intensive and not reliable for continuous long-term operation. OER requires large inputs of electricity, the catalysts used in the reaction are based on scarce materials that are unstable under long-term exposure to the harsh conditions present in the OER process. By better understanding the elementary steps of the OER reaction researchers can design cheaper, more efficient processes.

RASEI Fellow, and Associate Director of CEDARS Tanja Cuk explains that there have been a series of proposed oxygen-related intermediates (e.g. OH*, O*, O-O), but it has been hard to capture experimental evidence for them and the elementary steps that create them. “The article is a perspective on how to get at the intermediates and their dynamics within the buried electrode-electrolyte interface. The approach involves model crystalline materials, targeted spectroscopies to isolate the intermediates, and theoretical investigations that predict how they appear in the electrochemistry and the spectroscopy. We also use materials that bind the intermediates at different strengths, so that they appear statically and transiently.” This fundamental and basic energy sciences approach combines expertise from across CEDARS bringing together computational theoretical modeling, materials synthesis, and spectroscopy. The diversity of institutions involved has already provided for many student and postdoctoral exchanges that further deepen the background of the team and broaden the scope of the research. Just last month the Center Director and his graduate student visited NREL and CU to test the samples made at NCAT.

Precise control of the materials under investigation is required for effective characterization and theoretical modeling. Dhananjay Kumar, Jin Suntivich, and collaborators within CEDARS use a process called epitaxial layer deposition, a procedure where a thin crystalline layer is grown on top of a substrate. For these investigations the epitaxial layers are the OER catalysts made from ruthenium and titanium oxides that are then tested electrochemically. Geoffroy Hautier is a materials theorist who uses computational models to calculate the structure and defects that intermediates create in the materials and their impacts on x-ray and optical spectra. Ismaila Dabo takes these configurations and creates a model of the electrical and water environment around the electrode interface, describing a more realistic environment for the OER processes. To provide a more detailed understanding, the theoretical models are tested and refined based on feedback from advanced spectroscopic observations. The spectroscopies highlight static spectra of intermediate coverages and transient intermediates during OER. Jin Suntivich brings expertise in combining in-situ electrochemistry with non-linear optical techniques; Ethan Crumlin develops in-situ and time-resolved x-ray spectroscopies; Tanja Cuk combines in-situ electrochemistry with ultrafast optical spectroscopy. Integrating the computational advances with the experimental observations provides a powerful toolkit. Accurate interpretation of the spectral observations relies on the findings from the computational techniques.

While the ‘map’ for the OER has not been solved, this interdisciplinary and fundamental approach to interrogating the OER process is providing invaluable insights into how different catalysts bind to the intermediates and how this impacts different reaction pathways. By characterizing the nature of the intermediates bound to the catalyst an understanding of their equilibrium behavior during the OER process can be developed. The CEDARS team are already thinking about next steps for this powerful approach. These include understanding the non-equilibrium dynamics of these intermediates by fully time resolved x-ray and optical probes and investigating more complex material structures. The observations from these ‘in-process’ reactions will help define the roadmap to a more efficient and cost-effective approach to generate clean fuels from renewable energy sources.

NATURE ENERGY, 2024 | https://doi.org/10.1038/s41560-024-01583-x

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The Green Paradox: How Stranded Assets are slowing down the Clean Energy Transition

Daniel Morton — Fri, 30 Aug 2024 20:44:57 +0000

The Green Paradox: How Stranded Assets are slowing down the Clean Energy Transition Daniel Morton Fri, 08/30/2024 - 14:44

Daniel Morton

Read the full paper here

As we transition to a clean energy economy many of the existing fossil-based industries have assets, such as oil and gas that is still in the ground and the associated infrastructure, that are going to be left behind. Instead of winding down the consumption of fossil fuels as we transition, demand is increasing, which is causing a rise in carbon emissions.

RASEI Fellow Don Grant (CU Boulder), in collaboration with Tyler Hansen (Dartmouth College), Andrew Jorgenson (University of British Columbia), and Wesley Longhofer (Emory University), used a broad range of analyses on a worldwide dataset of power plant’s CO₂ emissions to explore this so-called Green Paradox.

One of the core pillars of the Paris Agreement laid out for the global transition to a clean energy economy is that a significant portion of the currently owned fossil fuel reserves must remain in the ground, causing such assets to become ‘stranded’. Much of the research around how we make this critical transition assumes that the prospect of such stranded fossil fuel assets will compel actors to divest away from resources and infrastructures associated with high emissions and replace them with clean innovations that will form the foundation of a different way of generating energy. However, not everyone is so optimistic. A more pessimistic prediction warns that these high-carbon sunset industries, in coalition with sympathetic policy makers, and supportive financiers are acting in a more defensive mode and are actively resisting the energy transition. A key issue that apparently galvanizes all the stakeholders is the right of each country, and corporation, to extract as much profit as possible from the existing fossil reserves. Essentially to extract and profit from all the oil and gas, and not leave it in the ground.

“We have found that in anticipation of stronger climate policies many power plants are adopting what we might call a ‘use it or lose it’ approach – they are burning fossil fuels as fast as possible while they still can. This has some real consequences for a countries ability to mitigate climate change in the future.”

As more and more of the regulations and policies prescribed by the Paris Agreement come into action, fossil energy companies are not taking anticipatory action. Instead of divesting away from high-emission technologies in favor of more renewable energy sources, they are accelerating the extraction of fossil fuels, maximizing their profit before those resources are deemed worthless. “We have found that in anticipation of stronger climate policies many power plants are adopting what we might call a ‘use it or lose it’ approach – they are burning fossil fuels as fast as possible while they still can. This has some real consequences for a countries ability to mitigate climate change in the future.” explains Don Grant.

While several previous studies have explored the theoretical factors that are driving these decisions, this is the first empirical study to explore how this acceleration in asset extraction impacts the pollution level of downstream consumers, such as power plants, in anticipation of stronger climate policies. It required a team that brought together various perspectives to tackle these questions, Grant explains a little more about how the team came together “Andrew Jorgenson and Wesley Longhover, are both sociologists and we have worked together for close to a decade looking at super polluting power plants. We recently wrote a book called Super Polluters. We brought in Tyler Hanson, an economist, because he recently published some very interesting work on stranded assets. When we started to ask questions about stranded assets, we knew that we needed to go outside our discipline and tap into the expertise of an economist.” By bringing in the economist’s perspective for this research the team was able to develop an understanding of how to both theorize the stranded assets and how to measure them. This approach provides the first study that can offer some empirical evidence to begin to resolve the debate around the green paradox.

This has been hard to analyze since data on power plants’ CO₂ emissions have been lacking. The team constructed a global dataset that contains information from nearly 12,000 individual power plants in operation in 2009 and 2018, including their CO₂ emissions, technical specifications, and environmental characteristics. Those included in the study were responsible for 88% of the world’s electricity-based CO₂ emissions. With this comprehensive dataset in hand two hypotheses around the green paradox were tested.

Power plants will pollute at higher levels in countries with more at-risk fossil fuel reserves because these countries are more likely to exercise regulatory leniency to soften the otherwise disruptive effects of stranded assets on their economy (government revenues, employment, and energy security).
Assuming that most power plants are locked into long-term fossil fuel contracts and many of the fuels that they have acquired are from their host country, then in countries with more at-risk assets, power plants will have a vested interest in shifting the processing of fossil fuels forward to capitalize on their purchase of coal, oil, and gas, and use their plant equipment while they still can.

Consistent with both predictions, their findings indicate that not only do power plants release more CO₂ in countries where more fossil fuel assets are in jeopardy of being stranded, but in those same countries, plants also operate at closer to full capacity, causing them to emit CO₂ at even higher levels. “Imagine that you have a cell phone contract that lasts for 12 months,” suggests Don, “and you get 10,000 h, or a certain amount of data in that contract. Then you’re told that the company is going to fold sometime in the near future. What would you do? You would use them up.”

“This is a business-driven decision, and until countries put together policies to compensate fossil fuel industries and utilities for stranded assets, one might expect this process to continue”.

Resolving the debate around the green paradox and its societal impacts needs to happen soon. “Companies are doubling down. Until now it has been something of a conceptual debate and this is the first study that can offer some empirical evidence to begin to resolve this dispute” explains Don. There is more at stake than just resolving a debate. “This is a business-driven decision, and until countries put together policies to compensate fossil fuel industries and utilities for stranded assets, one might expect this process to continue”.

By exploring the empirical evidence behind the Green Paradox, this research moves the debate forward. With proof that this is happening, we must now think about how to influence this situation. “We are just beginning to figure out how you might address this, and researchers are starting to tackle these questions” says Don. A critical part in accelerating an equitable clean energy transition is making sure that countries who are dependent on such stranded assets are compensated and incentivized. Otherwise, they will extract every last drop of their fossil fuels.

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Stronger Together: Coupling Excitons to Polaritons for Better Solar Cells and Higher Intensity LEDs

Anonymous — Tue, 06 Aug 2024 06:00:00 +0000

Stronger Together: Coupling Excitons to Polaritons for Better Solar Cells and Higher Intensity LEDs Anonymous (not verified) Tue, 08/06/2024 - 00:00

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Highlighting Opportunities for Manufacturing Perovskite Solar Panels with a Long-Term Outlook

Anonymous — Tue, 23 Jul 2024 06:00:00 +0000

Highlighting Opportunities for Manufacturing Perovskite Solar Panels with a Long-Term Outlook Anonymous (not verified) Tue, 07/23/2024 - 00:00

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Converting captured carbon to fuel: Study assesses what’s practical and what’s not

Anonymous — Mon, 22 Jul 2024 06:00:00 +0000

Converting captured carbon to fuel: Study assesses what’s practical and what’s not Anonymous (not verified) Mon, 07/22/2024 - 00:00

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How much energy can offshore wind farms in the US produce? New study sheds light

Anonymous — Thu, 25 Apr 2024 23:43:55 +0000

How much energy can offshore wind farms in the US produce? New study sheds light Anonymous (not verified) Thu, 04/25/2024 - 17:43

RASEI Fellow Julie Lundquist highlights the importance of using simulation tools to determine the locations of installing wind turbines

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Bacterial Disco Lights: Using light to control the movement and arrangement of cyanobacteria to form liquid crystalline active matter

Anonymous — Tue, 02 Apr 2024 06:00:00 +0000

Bacterial Disco Lights: Using light to control the movement and arrangement of cyanobacteria to form liquid crystalline active matter Anonymous (not verified) Tue, 04/02/2024 - 00:00

Daniel Morton

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This collaboration, between a bacterial biochemist and a condensed-matter physicist, use light to control the movement and arrangement of cyanobacteria, forming two- and three-dimensional nematic liquid crystalline states that could provide significant opportunities to regulate the behavior of the bacterial systems and open up new areas in bio-manufacturing that use carbon dioxide as the feedstock for the production of oxygen, biofuels, or biomaterials.

Cyanobacteria are one of the most ancient forms of life, dating back to ~3.5 billion years ago. Highly abundant, these bacterial dinosaurs use carbon dioxide and light as inputs and convert them to energy, motion, and oxygen. The term ‘Active Matter’ is used to describe systems that take in and dissipate energy at the level of constituent particles and, in the process, perform systematic movements. Essentially all forms of life can be considered active matter. Injecting energy into an active matter system often leads to emergent collective phenomena, think flocks of birds or schools of fish. Though there has been extensive research on the photosynthetic action of cyanobacteria, quantitative exploration of the motion, arrangement, and potential collective behavior of cyanobacteria is relatively unexplored. Intrigued by exploring these phenomena further, two RASEI Fellows formed an unusual partnership to investigate.

In 2018 RASEI Fellows Jeff Cameron and Ivan Smalyukh were awarded a grant from the DOE to build a specialized microscope system for imaging photosynthetic microbes. The system includes an ultrafast laser system that enable multi-photon excitation in the pigments in the cyanobacterial cells, a technique that was essential for this investigation. Cameron, a member of the Department of Biochemistry, is an expert in cyanobacteria and photosynthesis, while Smalyukh, a member of the Department of Physics, is an expert in condensed matter physics, with a specialty in liquid crystals. The unusual nature of this partnership is not lost on them. “Normally Biochemistry and Physics are separated, making close collaboration difficult” explains Cameron, “especially when close experimental collaboration is needed, requiring routine access to environmental chambers and biological research labs as well as advanced laser labs”. A key feature in how RASEI is setup is the co-location of multidisciplinary researchers. Cameron notes “This enables researchers to work hand-in-hand on studies that would simply not be possible if the two labs were on opposite sides of campus”.

Working together the findings from this team were conclusive; the cyanobacteria danced to the light! When a localized light was introduced to the bacteria, they harvested energy from the light through photosynthesis and used the energy generated to move towards the light. Experiments were done in two modes, one where the bacteria were confined to a two-dimensional plane, and the second where they could move in three-dimensions. In the two-dimensional system as the density of bacteria in the colony increased in the illuminated area emergent collective behavior emerged, with the bacteria forming a nematic arrangement, similar to that observed in synthetic liquid crystals. This emergent behavior was found to develop dramatically over time, with the direction, orientation, and trajectory of the cyanobacteria all changing, thought to be driven by an optimization toward enhanced light energy intake. Expanding this to the three-dimensional studies the team found that the cyanobacteria stacked on top of each other to form 3D active nematic slabs. The specialized microscope system enabled the teams to effectively explore these three-dimensional structures, even looking at cross-sectional views of the emergent behaviors. Comprehensive studies explored a range of properties of these emergent ‘Flocks of Cyanobacteria’, including examining transitions between fluid and gel states, the impacts of introducing defects, interactions between polydomain systems, and movement around foreign objects.

Precise control of biological systems is the ‘holy grail’ in biomanufacturing. Spatial patterning of the cyanobacteria impacts the structural and functional properties of the bacteria. Cyanobacteria only require carbon dioxide, water, and light, and can produce biofuels, commodity chemicals, and minerals, all while pulling carbon dioxide out of the air and producing oxygen. Understanding, and more importantly being able to reliably control, the optimal conditions for these bio-manufacturing to operate has the potential to enable new avenues to utilize these biological systems in benefiting society and the environment.

Armed with an enhanced understanding of how these bacteria move and can be controlled by light, the team is excited by the possibilities. Smalyukh explains “Our discovery of out-of-equilibrium active matter phase transitions in filamentous cyanobacteria systems may find utility in commanding collective behavior of cyanobacteria, with potential biotechnological utility ranging from control of bacterial mats and blooms, to oxygen generation an inhibition of toxin production”. Cameron adds “the possibilities are endless-once we can control the growth and orientation of biology, we can create novel materials and start to think about entirely new, environmentally-friendly, biomanufacturing opportunities.”

There is something poignant when you consider employing these ancient lifeforms, that were responsible for the Great Oxidation Event, profoundly changing life as we know it, as active agents in pulling carbon dioxide, the key causative greenhouse gas in the climate crisis, out of our atmosphere. The understanding and control made possible through the investigations described here bring this one step closer.

NATURE COMMUNICATIONS MATERIALS, 2024, 5, 37

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