Nanocrystals are so useful that they formed the basis of the 2023 Nobel Prize in Chemistry. But despite their usefulness, scientists have so far been able to make these microscopic crystals from only a limited palette of materials. A group of chemists at the University of Chicago and Argonne National Laboratory has announced a way to make nanocrystals from a useful class of materials known as metal nitrides—a previously impossible task.

Bacterial cellulose—nature’s own polymer scaffold—is gaining attention as a renewable feedstock for supercapacitor electrodes. With modern devices demanding fast charge, high power bursts, and long cycle life, researchers are searching for electrode materials that combine performance with sustainability.

A new systematic literature review led by Prof. Dahlang Tahir at Hasanuddin University, Indonesia, maps how bacterial cellulose-derived carbon (BCC) is turned into energy-storage electrodes—and why some fabrication paths outperform others. The study synthesizes evidence from the scientific record to clarify which processing choices control electrochemical behavior.

The review focuses on BCC as a precursor to porous carbon. Bacterial cellulose forms a naturally pure, interconnected network of nanoscale fibers, and heat treatment can convert that architecture into carbon structures with tunable porosity—critical for charge storage. The authors emphasize that electrical performance is not just a matter of “making carbon,” but of preserving and engineering the fiber network before carbonization.

Across 49 Scopus-indexed journal articles, the team compares major strategies including direct carbonization, chemical activation to enlarge pore systems, heteroatom doping to modify surface chemistry, and composite fabrication with materials that can add rapid redox (pseudocapacitive) contributions.

A recurring message is the importance of pre-carbonization drying. Freeze-drying appears as the most commonly used approach because it limits collapse of the wet nanofiber structure during water removal. Since pore architecture governs ion access and charge transport, maintaining nanoscale structure can translate into higher effective capacitance.

The review also distinguishes test formats. Three-electrode measurements are frequently reported, but two-electrode devices better represent real supercapacitor operation, where electrode–electrode interactions shape performance.

When processing is optimized, the results point toward a pathway for BCC-based electrodes to rival or surpass commercial activated carbon under comparable conditions. Activation and heteroatom doping generally increase accessible surface area and create additional active sites, while composites often achieve the strongest capacitance by combining electrical double-layer effects with fast surface reactions.

Yet the authors warn that progress is constrained by inconsistent experimental reporting, uneven protocols, and limited mechanistic understanding. To move beyond laboratory demonstrations, they call for predictive design, data-driven structure–performance models, scalable carbonization methods, and robust flexible devices resistant to deformation and humidity.

Subject of Research: Supercapacitor electrodes using bacterial cellulose-derived carbon
Article Title: Bacterial cellulose-derived carbon electrodes for supercapacitors: Fabrication strategies, electrochemical performance, and mechanical properties — A review
News Publication Date: 9 June 2026
Web References: https://doi.org/10.1016/j.est.2026.123044
References: 10.1016/j.est.2026.123044
Image Credits: Lightenoughtotravel from Wikimedia Commons

Keywords

bacterial cellulose; supercapacitors; porous carbon; freeze-drying; chemical activation; heteroatom doping; electrode materials; two-electrode testing; pseudocapacitance; sustainable energy storage

A meteorite recovered immediately upon its fall to Earth on July 16, 2024, is helping NASA scientists uncover new clues about ancient water, the chemical evolution of primitive asteroids, and the ingredients that may have helped make life possible throughout the early solar system.

This rapid recovery began when an amateur astronomer in New Jersey quickly recognized that a newly fallen meteorite had landed on his property. Recognizing its scientific value and wearing protective gloves, he collected the fragments and stored them in aluminum foil and glass containers, which preserved delicate minerals and organic compounds that are often altered by moisture, weather, and contamination.

As the meteorite fell to Earth, cameras across New Jersey captured its fiery passage through the atmosphere. Scientists used these observations to reconstruct the fireball’s trajectory and, after recovering the meteorite, combined this data with laboratory analyses to determine where in the solar system the rock most likely originated. In a study published Wednesday in the journal Science Advances, researchers found evidence that ancient salty water altered minerals within the meteorite’s parent asteroid, preserving unique minerals and a rich inventory of organic compounds.

“When we have both a documented fireball and a quick recovery of its meteorite, we can learn not only what the rock is made of, but where it came from in the asteroid belt,” said Peter Jenniskens, meteor astronomer at both NASA’s Ames Research Center in California’s Silicon Valley and the SETI Institute, and lead author of the study.

Named for the township where it was recovered, the Hillsborough meteorite belongs to a class of carbon-rich meteorites known as CM carbonaceous chondrites. These primitive rocks preserve some of the oldest materials in the solar system, recording the chemical processes that shaped asteroids more than 4.5 billion years ago.

While examining the unusually pristine meteorite, researchers found a mosaic of tiny broken-up rocks and noticed that some contained unusually high concentrations of sodium — an unexpected finding for this type of meteorite. The surprising signal prompted a closer investigation using powerful electron microscopes that allowed scientists to examine the meteorite from the millimeter scale down to individual atoms. By combining observations across multiple scales, researchers reconstructed the history of the minerals and the fluids that once flowed through them.

These analyses revealed microscopic fractures filled with sodium-rich material left behind by ancient brines. Unlike pure water, brines contain dissolved salts that allow them to transport elements and chemically alter the rocks they move through. In the case of the Hillsborough sample, those ancient fluids altered the asteroid’s minerals and left behind chemical evidence that remained preserved for billions of years.

Scientists were also able to detect fragile sodium-carbonate salts that normally react with moisture in Earth’s atmosphere before they can be studied. Jangmi Han, a paper co-author and mineralogist at NASA’s Johnson Space Center in Houston, identified evidence of ancient brines preserved within microscopic fractures. Similar salts were identified in samples returned from the asteroids Bennu and Ryugu by NASA’s OSIRIS-REx mission and JAXA’s (Japan Aerospace Exploration Agency) Hayabusa2 mission. However,Hillsborough marks the first time the salts have been identified in a CM carbonaceous chondrite meteorite, offering a new glimpse into the surfaces of the primitive asteroids that produced these meteorites.

Together, these findings suggest that ancient, salt-rich brines were more widespread among primitive asteroids than previously recognized, and provide scientists with new opportunities to compare how water altered different asteroid bodies across the early solar system.

“The chips of the most salt-rich bits of this meteorite are quite comparable to the samples returned by the Hayabusa2 and OSIRIS-REx missions,” said Mike Zolensky, a meteorite researcher at NASA Johnson and co-author of the study. “They’re not identical. They’re different in some very interesting ways, but they’ve seen very similar processes.”

Scientists expected Hillsborough to contain a rich suite of organic compounds because it is a CM carbonaceous chondrite. What made the meteorite exceptional was how quickly it was recovered, allowing researchers to study those compounds before prolonged exposure to Earth’s environment could contaminate the sample.

“One of the big surprises for me when we analyzed a small chip of the Hillsborough meteorite was the complexity of amino acids and other organic compounds,” said Danny Glavin, senior scientist in the Astrobiology Analytical Laboratory at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and co-author of the study.

Its diversity of amino acids and other organic compounds is, comparable to the Murchison meteorite, a nearly 100-kilogram carbonaceous chondrite that fell in Australia in 1969 and became the benchmark for extraterrestrial organic chemistry.

“It’s just more proof that the chemical building blocks of life could have been delivered — and are still being delivered — to Earth today by these carbonaceous asteroid fragments,” said Glavin, who was a co-investigator on OSIRIS-REx, leading an international team that studied the organic composition of the samples delivered to Earth from asteroid Bennu in 2023.

Understanding the Hillsborough meteorite required expertise from multiple scientific disciplines.

Astronomers reconstructed the meteorite’s journey through space, finding evidence that it may have originated from the Erigone asteroid family in the inner asteroid belt, home to the asteroid Donaldjohanson, which was visited in 2025 by NASA’s Lucy spacecraft. Mineralogists identified evidence of ancient brines preserved within microscopic fractures, while organic chemists analyzed the meteorite’s inventory of amino acids and other organic compounds.

“Together, those complementary studies are helping scientists build one of the clearest pictures yet of how primitive asteroids such as the asteroid Erigone evolved chemically over billions of years,” said Jenniskens.

Researchers continue to study the Hillsborough meteorite, revealing new details about how water transformed primitive asteroids and shaped the early solar system.

By tracing the history of water on primitive asteroids, scientists are learning how water and the chemical ingredients for life were distributed throughout the early solar system.

“If you follow the water through the solar system, you’re actually following life,” Zolensky said. “Following the history of water through the solar system is an essential part of understanding the origin of life.”

For more information on NASA’s astromaterials research and exploration, visit:

https://science.nasa.gov/astromaterials

Karen Fox / Molly Wasser
Headquarters, Washington
240-285-5155 / 240-419-1732
karen.c.fox@nasa.gov / molly.l.wasser@nasa.gov

Victoria Segovia
NASA’s Johnson Space Center, Houston 281-483-5111
victoria.segovia@nasa.gov

In the past weeks, two sites in the United States have halted operations.

© Maddie McGarvey for The New York Times

US rare earths produced by Washington-backed companies are flowing to Japan and South Korea, as American demand has yet to materialize despite the Trump administration’s push to develop a national supply chain.

Rare earths products produced by MP Materials, Energy Fuels and Phoenix Tailings—which together have won billions of dollars in US government support—are being sold to companies in Asia, where the scale of magnet manufacturing remains larger than the nascent production in the US.

China’s lock on global supplies of rare earths and critical minerals has become a national security concern in the US and other Western nations, since Beijing started restricting access to them. The metals are crucial to 21st-century technology and are used in the manufacturing of everything from weapons guidance systems to electric vehicle batteries.

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© David McNew / Contributor

US rare earths produced by Washington-backed companies are flowing to Japan and South Korea, as American demand has yet to materialize despite the Trump administration’s push to develop a national supply chain.

Rare earths products produced by MP Materials, Energy Fuels and Phoenix Tailings—which together have won billions of dollars in US government support—are being sold to companies in Asia, where the scale of magnet manufacturing remains larger than the nascent production in the US.

China’s lock on global supplies of rare earths and critical minerals has become a national security concern in the US and other Western nations, since Beijing started restricting access to them. The metals are crucial to 21st-century technology and are used in the manufacturing of everything from weapons guidance systems to electric vehicle batteries.

Read full article

Comments

© David McNew / Contributor

A single machine learning model just turned one of condensed matter physics’ most persistent problems into a navigable map.

In a study published in National Science Review, researchers led by Nanjing University used AI to sort millions of magnetoresistance curves into 13 clean categories, then charted exactly how tuning a material’s electronic properties pushes it from one behavior to another.

The work targets the anomalous Hall effect, a decades-old phenomenon that governs how electrons move through certain magnetic materials, and it could hand physicists a shortcut to some of the most sought-after states in modern electronics.

A Problem Too Complex to Map by Hand

The anomalous Hall effect occurs when electrons moving through a magnetic material exhibit behavior beyond the predictions of the conventional Hall effect. Standard Drude theory predicts that resistance should shift as electrons move through a magnetic field. Anomalous Hall systems break that rule, producing resistance curves with double peaks, plateaus, and non-saturating shapes that shift with the material’s band structure and the way its electrons scatter.

The challenge becomes even greater when multiple electron energy bands are active near the Fermi level. Each additional parameter increases the difficulty of interpreting the resulting resistance curves, and until now, constructing a comprehensive map linking electronic properties to resistance behaviors has not been possible.

The Nanjing team set out to create that map. They generated more than 2.27 million magnetoresistance curves from a two-band model spanning five electronic parameters, then set an unsupervised algorithm loose on the dataset with no instructions beyond finding the pattern.

Millions of Curves

Every curve in the dataset collapsed into just 13 distinct types, a verdict so blunt that even the researchers seemed surprised. A trained neural network took over from there, sorting new curves into those same 13 categories with 99% accuracy and turning what had looked like an unruly set of data into something closer to a field guide.

Next, the team created phase diagrams and topological networks to visualize how changing just one parameter could shift a material from one type of resistance curve to another. Instead of a fixed chart, the result is more like an interactive roadmap; adjust a setting, and you can see the transition happen in real time.

To check whether any of this held up outside a computer model, the researchers tested their framework against real measurements from gated Fe5GeTe2 nanoflakes, a magnetic material whose properties can be tuned electrically. The experimental data closely matched the AI-generated phase diagrams, providing the model with a real-world anchor rather than a purely theoretical one.

“This is just the beginning. We believe this framework can be extended to a wide range of intricate models and will help uncover many more complex problems in condensed matter physics,” said Hongtao Yuan, professor at Nanjing University and an author of the study.

A Map That Points to New Physics

The significance of this work extends beyond classification. The phase diagrams indicate which parameter combinations are likely to produce large magnetoresistance, including giant magnetoresistance, a phenomenon already used in hard drive technology. These maps also identify regions where the quantum anomalous Hall effect may occur, a state in which an electric current flows along the edges of a material without energy loss due to resistance.

That kind of lossless conduction has long been seen as a target for low-power electronics, but identifying the narrow parameter windows that produce it has historically relied on trial-and-error. A phase diagram that predicts those windows in advance changes the search from guesswork into targeting.

“Our model provides a framework for comprehensively addressing the complex magnetoresistance behavior in anomalous Hall systems, and serves as a platform for predicting parameter regions that may host intriguing quantum phenomena such as giant magnetoresistance,” said author of the study Ganyu Chen.

The team frames the two-band model as a starting point rather than a finished tool. The same machine-learning approach, they note, should extend to more complex systems beyond ferromagnets, including topological insulators and superconducting junctions, areas of physics that have their own tangled, high-dimensional parameter spaces still waiting for a map. Whether AI-built phase models can keep pace with that added complexity, or whether some of these systems will require entirely new modeling strategies, remains an open question the field is only beginning to test.

Austin Burgess is a writer and researcher with a background in sales, marketing, and data analytics. He holds an MBA, a Bachelor of Science in Business Administration, and a data analytics certification. His work focuses on breaking scientific developments, with an emphasis on emerging biology, cognitive neuroscience, and archaeological discoveries.

Building electronic devices often requires stacking different crystalline materials on top of one another with atomic precision. This process, called heteroepitaxy, works best when the two crystals share similar atomic patterns. When their symmetries differ, the upper crystal tends to grow in several orientations at once instead of a single one, creating defects that degrade device performance. Engineers have long dealt with this problem by treating the surface of the lower crystal beforehand, for example by etching steps into it, exposing it to plasma, or adding a buffer layer, to help the two materials bond more effectively. Now, a team of researchers explores ¹ a different route: rather than forcing the two crystals to fit together, it takes advantage of a crystal that is naturally flexible at the atomic scale.

Flexible by design

The material at the center of this approach is a layered compound called TaCo₂Te₂. Like graphite, its layers are held together by weak van der Waals forces, which makes it easy to combine with other materials without demanding a perfect chemical match. Unlike most layered crystals, though, its atoms are not arranged in a perfectly regular pattern. At room temperature they undergo a small, periodic shift known as a Peierls distortion, a phenomenon first described in the 1930s by the physicist Rudolf Peierls, who showed that in some materials the electrons and the surrounding lattice can lower their combined energy by nudging atoms slightly out of their ideal positions. When TaCo₂Te₂ is heated above about 523 kelvin, or 250 degrees Celsius, this distortion disappears and the crystal adopts a more symmetric structure, although traces of the original pattern linger as fleeting, temperature-driven fluctuations.

These fluctuations are not random. Calculations of how the crystal vibrates, backed up by Raman spectroscopy and electron diffraction experiments, show that the lattice is especially unstable along one crystallographic direction, meaning atoms can shift more easily there than in the perpendicular direction. This directional softness turns out to be the key ingredient that controls how a second material grows on the surface.

Heating TaCo₂Te₂ also sets its atoms in motion across the surface. Tantalum atoms drift away, while cobalt and tellurium reorganize into a thin crystalline layer whose composition resembles cobalt telluride. Rather than clumping into isolated islands, this new layer spreads sideways first and only then thickens, producing a smooth, continuous interface with the crystal beneath it, a layer-by-layer growth style that electron microscopy confirms is energetically favorable.

Directionally locked

The most striking result is that the new crystal does not settle into just any orientation. Even though its symmetry differs from that of the underlying TaCo₂Te₂, it becomes directionally locked. Along one in-plane direction, the atomic spacings of the two materials match closely, giving a tight, well-ordered registry. Along the perpendicular direction the mismatch is far larger, but this happens to be exactly the direction where TaCo₂Te₂ is most flexible, thanks to its lattice instability. Instead of rotating to relieve that mismatch, as symmetry-mismatched interfaces typically do, the interface absorbs it through a gentle, ongoing structural adjustment. The result is a crystal that stays aligned while only one direction bears most of the strain.

That flexible direction does not settle into a simple repeating pattern either. Instead, it forms what is called a one-dimensional incommensurate superlattice: the repeating atomic spacings of the two crystals never line up exactly, yet they stay locked together over long distances. Physicists have long recognized this kind of arrangement as an efficient way to accommodate mismatched lattice spacings without piling up large numbers of defects, since the strain is spread out through a slowly changing modulation rather than concentrated at sharp boundaries. Diffraction measurements and a geometric analysis of the two lattices both confirm that no perfectly repeating, shared lattice can account for what is observed, so the incommensurate description fits best.

Directional lattice instability is key

To check that the lattice instability is truly responsible for this behavior, the same experiment was repeated with a closely related compound, TaNi₂Te₂, which has nearly the same crystal structure but lacks the structural instability. Under similar heating, a surface layer still forms, but its orientation varies from spot to spot, and rotational disorder sets in. This comparison shows that matching crystal symmetry is not enough on its own to produce a locked, well-ordered interface. The directional lattice instability is the extra ingredient that guides the growth.

The local reconstruction effect

One more effect helps stabilize the interface. Even above the temperature where the bulk crystal should be fully symmetric, the atomic layers right beneath the interface partly slip back into the low-temperature distorted structure. This local reconstruction stays confined to the surface rather than spreading through the whole crystal, and it appears to strengthen the bond between the two materials, keeping the aligned structure stable even at high temperature.

As we have just seen, structural instabilities, usually considered as a liability because they signal that a crystal is on the verge of changing shape, can instead become useful design tools. A substrate whose atoms rearrange more easily in certain directions can guide the growth of otherwise incompatible materials, producing well-aligned interfaces without extensive surface treatment. This idea could widen the range of material combinations available for future electronic, optical, and quantum devices, where the atomic arrangement at an interface often determines how well the whole device performs.

Author: César Tomé López is a science writer and the editor of Mapping Ignorance

Disclaimer: Parts of this article may have been copied verbatim or almost verbatim from the referenced research paper/s.

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