Category: Chemistry

Nature is full of masters of disguise. From the chameleon to arctic hare, natural camouflage is a common yet powerful way to survive in the wild. But one animal might surprise you with its camouflage capabilities: the squid.

Capable of changing color within the blink of an eye, squid, along with their cephalopod relatives octopi and cuttlefish, have used their natural camouflage to survive since the age of the dinosaurs. However, scientists still know very little about how it all works.

Leila Deravi aims to change that.

An associate professor of chemistry and chemical biology at Northeastern University, Deravi’s recently published paper in the Journal of Materials Chemistry C sheds new light on how squid use organs that essentially function as organic solar cells to help power their camouflage abilities. Deravi says it’s a breakthrough in how humans understand these “super-charged animals,” one that could impact how we humans interact with the world.

Deravi has long been fascinated by cephalopods, particularly squid. Her Biomaterials Design Group at Northeastern is focused on investigating how these animals camouflage, with the aim of using those natural mechanisms to create new biomaterials.

More recently, her lab has been looking at one specific part of squid biology— chromatophores—which is where the latest discovery was made.

Chromatophores are pigmented organs that sit all over the squid’s skin. They have muscle fibers on the outside that are filled with neurons, allowing the animal to neuromuscularly open and control these pigment sacks based on what’s in their environment.

Together with iridophores, which act as a kind of photo filter, adding greens and blues to the chromatophores’ reds, yellows and browns, they give squid the ability to change color within hundreds of milliseconds, distributing the color all over their body.

“To have something sense the colors around it and distribute [them] within hundreds of milliseconds is really insane,” Deravi says. “It’s not something that’s easy to do, especially in a living system that’s under water.”

It has been commonly understood that chromatophores are a kind of colorant that operate similar to pixels in a TV display, but Deravi found that they are much more. Her latest research reveals that chromatophores are light sensors that help power squid and their natural camouflage.

“It can see whatever light is on the outside and convert that light into energy and then harvest that energy to help distribute camouflage,” Deravi says.

To test this idea, Deravi and her team built a squid-powered solar cell. They used conductive glass, semiconductors, electrolytes and the chromatophores’ pigmented nanoparticles taken from dissected squid to create a circuit. By focusing solar simulated light on the glass, they activated the circuit and measured how much energy it was putting out.

“We found that the more granules you put into there, the higher the photocurrent response is,” Deravi says. “It’s a direct indication that the pieces of the chromatophore are actually converting the light from the sun’s simulated light to the voltage, which can complete the circuit and then be harvested, potentially, for a power supply in the animal.”

The discovery marks the first time anyone has made a connection between the chromatophores in a cephalopod and their ability to generate current.

Uncovering the secrets behind how cephalopods camouflage has a number of applications for humans. Deravi’s lab has already used its findings to design wearable UV sensors that can help prevent skin cancer and produce more environmentally and human-friendly sunscreen, as Deravi has done with her startup, Seaspire.

What’s particularly remarkable, she says, is how efficient this biological system is. Squid are able to change color and distribute that change over their entire body while under water, using very little energy.

Understanding more about how squid use their organic solar cells could help a burgeoning field like wearable electronics where size, weight and power distribution are constant concerns. The squid might be the key to developing a truly “living digital skin,” she says.

“If you think about fully wearable stuff, you just have to think about how to make it the most energetically favorable in order to be fully interactive with the surroundings,” Deravi says. “We’re trying to tap into what the blueprint is that the animal uses to do this and how that correlates to adapting to the environment as well.”

More information: Taehwan Kim et al, Cephalopod chromatophores contain photosensitizing nanostructures that may facilitate light sensing and signaling in the skin, Journal of Materials Chemistry C (2025). DOI: 10.1039/D4TC04333B

Provided by Northeastern University 

What if plastics could self-destruct when their time as a useful product ends? Scientists at Sandia National Laboratories are exploring this concept in one of their latest projects.

“Many researchers are trying to discover better ways to break down and recycle plastics. It’s a very busy area of research right now,” Sandia organic materials scientist Brad Jones said. “We at Sandia were thinking about how we could contribute to this area.”

When Jones, Oleg Davydovich, Samuel Leguizamon, Koushik Ghosh and former Sandia postdoctoral researcher Matthew Warner combined their expertise, they developed a concept they hope will be groundbreaking.

The problem with plastic

Plastic does not naturally biodegrade. The Environmental Protection Agency cites research indicating that once in the environment, plastics can take between 100 and 1,000 years to decompose. Over time, these plastics often fragment into smaller pieces, entering oceans, land, wildlife and humans.

Society is also highly dependent on plastic products with short lifespans, such as plastic packaging, which is among the most difficult to recycle. Current recycling methods involve reforming plastic into new objects by shredding and melting, but the plastic’s chemical structure remains unchanged. The challenge is finding a way to force plastic to break down through chemical alterations more quickly and efficiently.

Jones said that much of the current research focuses on creating different mixtures and compounds that break down plastic from the outside in. A common method involves placing plastics in a reactor and exposing them to a compound that facilitates breakdown.

Sandia’s team thought up a different approach.

“What if we could use those same compounds and somehow build them into a plastic product?” Jones said. “Rather than having to stick them in a reactor and treat them afterward, maybe we could somehow activate the compounds when ready and break down the plastic from the inside out.”

The science behind the idea

The idea seems logical, but how can it be achieved? With support from Sandia’s Laboratory Directed Research and Development program and technology maturation funds, the team got to work turning their idea into reality.

“We are doing something called microencapsulation,” Jones explained. “We are building plastics that contain the compounds that will eventually break them down. Through our process, we can keep the plastic’s original composition intact by building a barrier between the compound and the plastic itself, until we are ready to activate it.”

Jones said all plastic products are formulated with additives. These additives change the color, make a plastic more stable, or change the material properties or flow characteristics.

“Our vision for this technology is to formulate a plastic with an additive that will eventually break it down,” he said.

To prevent unintentional breakdown, the microencapsulation would be designed to release its contents only when the plastic is exposed to a very specific trigger, such as heat, a certain wavelength of light or a combination. This is where the team’s expertise in chemistry comes into play.

Putting the concept to the test

With the idea in hand, the team had to test their concept.

They began with a form of plastic, polybutadiene rubber, which is the most widely used synthetic rubber in the world and most commonly used in car tires. The team has significant experience with Grubbs catalysts, known for effectively breaking down polybutadiene rubber.

Despite its effectiveness, the Grubbs catalyst never gained traction for dealing with the rubber waste problem.

“We suspect it’s because you need fairly large amounts of the expensive catalyst and a significant amount of solvent to infuse the catalyst into rubber,” Jones explained. “That’s why we thought it would be a good model to prove the benefits of our idea by microencapsulating the catalyst and formulating it into the rubber. This reduces the amount of catalyst needed, eliminates the solvent and allows the user to trigger the breakdown on demand.”

Through testing, the team’s concept has proven successful. Tests demonstrated the ability to break down rubber at different temperatures, and the ability to easily recycle the material into new rubber. That isn’t possible with traditional processes.

What’s next
The team said the next step is to further develop this idea, including reaching out to plastic manufacturers as potential partners.

While there is still a lot of work ahead, the team is encouraged by their findings thus far.

“What I love about this project is that it’s a way to apply a lot of different chemistries to a problem,” Leguizamon said. “This is something that isn’t already done. It’s a relatively simple idea that addresses a lot of significant challenges.”

Davydovich, who has been interested in polymer science throughout his entire career, sees a way to use the science to significantly help the world.

“Making degradable polymers is work we can apply to real-world plastics,” he said. “We can solve problems that are more tangible to the everyday person.”

Jones often gets questions from family and friends about his work at Sandia. While he can’t always share details, he is proud to discuss this project: “This is the first thing I mention when they ask, because it’s something we can be personally proud of. The plastic waste crisis is something the average person is aware of and understands. It’s a huge existential crisis and we are trying to find a solution.”

Provided by Sandia National Laboratories

A Chinese research team has developed a single-step femtosecond laser 4D printing technology that enables rapid and precise micro-scale deformation of smart hydrogels. This innovation, inspired by the hierarchical structure of butterfly wings, holds significant promise for applications in flexible electronics and minimally invasive medicine.

The findings were published online in ACS Materials Letters on February 17.

Led by Prof. Liu Lianqing from the Shenyang Institute of Automation of the Chinese Academy of Sciences and Prof. Li Wenjung from the City University of Hong Kong, the researchers drew inspiration from the wing structure of Papilio maackii, a butterfly species known for its remarkable balance of lightness and toughness.

They discovered that the honeycomb-like pores and reinforced textures of butterfly wings work synergistically to dissipate mechanical stress during flight. Mimicking this natural design, the researchers employed femtosecond laser technology to sculpt pH-responsive hydrogel structures with a pre-programmed mechanical gradient.

By adjusting laser scanning modes, they encoded alternating soft and rigid regions into the material, effectively embedding a “deformation code.” Experimental results and finite element analysis demonstrated that when exposed to an acidic environment, the hydrogel automatically folds within one second, shrinking to just 25% of its original volume.

The key breakthrough lies in its single-step fabrication. Unlike traditional methods that require layering multiple materials to achieve deformability, this approach directly encodes mechanical heterogeneity during printing. As a result, the hydrogel exhibits dual functionality—sensing environmental changes and actuating structural responses.

In medical demonstrations, smart hydrogel dressings were shown to autonomously enwrap biomembranes with micron-level precision in response to pH shifts. For sensing applications, the material’s fluorescence intensity fluctuated by up to 110% during acid-base transitions, highlighting its potential as an adaptive sensor.

This streamlined 4D printing approach marks a significant advance in micro/nanoscale manufacturing, unlocking novel applications for responsive hydrogel systems—from adaptive medical devices to eco-friendly flexible electronics.

More information: Jianchen Zheng et al, 4D Printed Butterfly-Inspired Hydrogel Structures: Simple Strategies for Multiform Morphing, ACS Materials Letters (2025). DOI: 10.1021/acsmaterialslett.4c02589

A new University of Maryland study has revealed a coordinated dance of microscopic particles—breaking up and clustering back together in just seconds—after receiving electrical and chemical stimuli. This work represents a new class of materials that mimic the behaviors of living organisms, known as “active matter.”

Like the skins of chameleons and octopuses, which respond to external stimuli by changing colors, active matter can display dynamic and autonomous behavior including motility, assembly and swarming. The study, led by Associate Professor Taylor Woehl and published in Nature Communications, revealed a new mechanism to activate these properties within seconds.

Practical applications of the discovery could include national defense or sustainability technology—think windows in which smart materials array themselves to automatically block light, or active camouflage that constantly helps troops blend with their environment.

Woehl and colleagues in the Department of Chemical and Biomolecular Engineering demonstrated a method that consists of shocking microscopic particles in liquid with an electrical current, driving the particles to assemble into crystals that disassemble and reassemble in a repeating cycle, essentially dancing to the tune of electrically stimulated chemical reactions, Woehl said.

While previous research has shown similar behavior in such particles, it required actively changing the stimulus over time—a process similar to programming a robot. This new method causes this cycle to occur independently by applying a constant stimulus.

“In that way, it’s more similar to a biological system, but what’s really happening in the background are chemical reactions telling these particles what to do,” said Woehl.

Additionally, biological cells use chemical signals to replicate, move and perform functions autonomously and within time scales of minutes. Previous attempts at using chemical signals to entice active matter to exhibit similar dynamic behavior have resulted in systems with very slow response times of hours to days. Likewise, prior methods using electric voltage to coordinate clustering of microscopic particles have lacked control over how long the particles cluster.

Woehl’s method overcomes these hurdles by combining electric voltage and chemical signals to enable coordinated clustering of microscopic particles with precise control over response time.

The study was a collaboration between Woehl and Associate Professor Paul Albertus’ research group, with Albertus contributing theoretical modeling to understand how the electrical voltage controlled the chemical stimulus. This enabled predictions of how changes in the electric stimulus would impact solution acidity and thus the response of the microscopic particles.

More information: Medha Rath et al, Transient colloidal crystals fueled by electrochemical reaction products, Nature Communications (2025). DOI: 10.1038/s41467-025-57333-4

Journal information: Nature Communications 

Provided by University of Maryland 

A new study by researchers at the University of Illinois Urbana-Champaign describes a breakthrough in the field of organic solar cells (OSCs), bringing the technology one step closer to commercial viability.

OSCs are a compelling technology that can turn any surface into a power generator. Their lightweight, transparent and foldable properties make them ideal for many applications where traditional silicon solar cells are impractical: think backpacks and tents outfitted with OSCs that can generate power on demand in the field, or windows that turn sunlight into electricity thanks to solar cells that are invisible to the naked eye.

But while OSCs offer many advantages over silicon solar cells and perform well in laboratory settings, they remain non-ideal for real world use because their efficiency and stability drop substantially during the manufacturing process.

To address this problem, the researchers—led by chemical and biomolecular engineering professor Ying Diao—zeroed in on the molecular assembly process during fabrication. An OSC is composed of several nanometer-thin layers of film. By manipulating the processing conditions when printing the films, they can force the molecules to adopt different structures, said Alec Damron, co-first author on the paper published in Advanced Materials.

“The ink evaporates while we’re printing, so—depending on how fast we print and how slow the evaporation—we can lock the assembly into different stages,” Damron said. “What we saw in this paper was that when you print our films slowly, as opposed to quickly, that allows for the evaporation portion of the physics to dominate and it will force the polymers to assemble into liquid crystals before a film forms.”

This finding was important because the liquid crystal structures resulted in better OSC stability and efficiency when compared to cells fabricated using random aggregation pathways. Further manipulation during the process resulted in liquid crystal assembly pathways that were either achiral or chiral. Both resulted in a clear improvement in efficiency and stability of the OSC, but the chiral—or helical—structure yielded the best results.

“We discovered that chiral assembly of conjugated donor polymers improves the crystalline packing and phase-separated structure of the film,” said Azzaya Khasbaatar, the other co-first author on the paper. “Improving film crystallinity not only enhances efficiency by improving charge transport but also makes the films much more morphologically robust/stable.”

Overall, the researchers demonstrated that achiral liquid crystal pathways show a 20% improvement in efficiency and three-fold improvement in stability when compared to random aggregation assemblies. When printed with a helical structure, that number increased to 56% higher efficiency and 50 times more stable. These numbers are promising for successful manufacturing.

“This trend that we saw in improved performance through the liquid crystal phase versus the random fiber aggregation is general and can be applied to various types of organic solar cell materials,” Damron said. “Since that relationship has been established, it is possible to start from that as a baseline and to continue building up on the engineering side of things.”

Before their work, Diao said that very little was known about what happens between the time you apply the ink to a substrate and when you print the device, calling it a “black box.”

“People mainly focus on the material side and then the device side, but the middle is neglected,” Diao said. “And that’s something we basically shed light on. We’re lifting the curtain on the hidden process and, by doing so, we are providing pathways to creating better devices.”

More information: Azzaya Khasbaatar et al, Lyotropic Liquid Crystal Mediated Assembly of Donor Polymers Enhances Efficiency and Stability of Blade‐Coated Organic Solar Cells, Advanced Materials (2025). DOI: 10.1002/adma.202414632

Journal information: Advanced Materials 

Provided by University of Illinois at Urbana-Champaign 

Harnessing moisture from air, Northwestern University chemists have developed a simple new method for breaking down plastic waste.

The non-toxic, environmentally friendly, solvent-free process first uses an inexpensive catalyst to break apart the bonds in polyethylene terephthalate (PET), the most common plastic in the polyester family. Then, the researchers merely expose the broken pieces to ambient air. Leveraging the trace amounts of moisture in air, the broken-down PET is converted into monomers—the crucial building blocks for plastics. From there, the researchers envision the monomers could be recycled into new PET products or other, more valuable materials.

Safer, cleaner, cheaper and more sustainable than current plastic recycling methods, the new technique offers a promising path toward creating a circular economy for plastics. The study was recently published in Green Chemistry.

“The U.S. is the number one plastic polluter per capita, and we only recycle 5% of those plastics,” said Northwestern’s Yosi Kratish, the study’s co-corresponding author. “There is a dire need for better technologies that can process different types of plastic waste. Most of the technologies that we have today melt down plastic bottles and downcycle them into lower-quality products.

“What’s particularly exciting about our research is that we harnessed moisture from air to break down the plastics, achieving an exceptionally clean and selective process. By recovering the monomers, which are the basic building blocks of PET, we can recycle or even upcycle them into more valuable materials.”

“Our study offers a sustainable and efficient solution to one of the world’s most pressing environmental challenges: plastic waste,” said Naveen Malik, the study’s first author. “Unlike traditional recycling methods, which often produce harmful byproducts like waste salts and require significant energy or chemical inputs, our approach uses a solvent-free process that relies on trace moisture from ambient air. This makes it not only environmentally friendly but also highly practical for real-world applications.”

An expert in plastic recycling, Kratish is a research assistant professor of chemistry at Northwestern’s Weinberg College of Arts and Sciences. Kratish co-led the study with Tobin J. Marks, the Charles E. and Emma H. Morrison Professor of Chemistry at Weinberg and a professor of materials science and engineering at Northwestern’s McCormick School of Engineering. At the time of the research, Malik was an postdoctoral fellow in Marks’ laboratory; now he is a research assistant professor at the SRM Institute of Science and Technology in India.

The plastic problem

Commonly used in food packaging and beverage bottles, PET plastics represent 12% of total plastics used globally. Because it does not break down easily, PET is a major contributor to plastic pollution. After use, it either ends up in landfills or, over time, degrades into tiny microplastics or nanoplastics, which often end up in wastewater and waterways.

Finding new ways to recycle plastic is a hot topic in research. But current methods to break down plastics require harsh conditions, including extremely high temperatures, intense energy and solvents, which generate toxic byproducts. The catalysts used in these reactions are also often expensive (like platinum and palladium) or toxic, creating even more harmful waste. Then, after the reaction is performed, researchers have to separate the recycled materials from the solvents, which can be a time-consuming and energy-intensive process.

In previous work, Marks’ group at Northwestern became the first to develop catalytic processes that do not require solvents. In the new study, the team again devised a solvent-free process.

“Using solvents has many disadvantages,” Kratish said. “They can be expensive, and you have to heat them up to high temperatures. Then, after the reaction, you are left with a soup of materials that you have to sort to recover the monomers. Instead of using solvents, we used water vapor from air. It’s a much more elegant way to tackle plastic recycling issues.”

An ‘elegant’ solution

To conduct the new study, the researchers used a molybdenum catalyst and activated carbon—both of which are inexpensive, abundant and non-toxic materials. To initiate the process, the researchers added PET to the catalyst and activated carbon and then heated up the mixture. Polyester plastics are large molecules with repeating units, which are linked together with chemical bonds. After a short period of time, the chemical bonds within the plastic broke apart.

Next, the researchers exposed the material to air. With the tiny bit of moisture from air, the material turned into terephthalic acid (TPA)—the highly valuable precursor to polyesters. The only byproduct was acetaldehyde, a valuable, easy-to-remove industrial chemical.

“Air contains a significant amount of moisture, making it a readily available and sustainable resource for chemical reactions,” Malik said. “On average, even in relatively dry conditions, the atmosphere holds about 10,000 to15,000 cubic kilometers of water. Leveraging air moisture allows us to eliminate bulk solvents, reduce energy input and avoid the use of aggressive chemicals, making the process cleaner and more environmentally friendly.”

“It worked perfectly,” Kratish said. “When we added extra water, it stopped working because it was too much water. It’s a fine balance. But it turns out the amount of water in air was just the right amount.”

Endless advantages

The resulting process is fast and effective. In just four hours, 94% of the possible TPA was recovered. The catalyst is also durable and recyclable, meaning it can be used time and time again without losing effectiveness. And the method works with mixed plastics, selectively recycling only polyesters. With its selective nature, the process bypasses the need to sort the plastics before applying the catalyst—a major economic advantage for the recycling industry.

When the team tested the process on real-world materials like plastic bottles, shirts and mixed plastic waste, it proved just as effective. It even broke down colored plastics into pure, colorless TPA.

Next, the researchers plan to increase the scale of the process for industrial use. By optimizing the process for large-scale applications, the researchers aim to ensure it can handle vast quantities of plastic waste.

“Our technology has the potential to significantly reduce plastic pollution, lower the environmental footprint of plastics and contribute to a circular economy where materials are reused rather than discarded,” Malik said. “It’s a tangible step toward a cleaner, greener future, and it demonstrates how innovative chemistry can address global challenges in a way that aligns with nature.”

More information: Naveen Malik et al, Thermodynamically leveraged solventless aerobic deconstruction of polyethylene-terephthalate plastics over a single-site molybdenum-dioxo catalyst, Green Chemistry (2025). DOI: 10.1039/D4GC05916F

Journal information: Green Chemistry 

Provided by Northwestern University 

by Amanda Morris

For the first time, Northwestern University scientists have watched water molecules in real-time as they prepared to give up electrons to form oxygen.

In the crucial moment before producing oxygen, the water molecules performed an unexpected trick: They flipped.

Because these acrobatics are energy intensive, the observations help explain why water splitting uses more energy than theoretical calculations suggest. The findings also could lead to new insights into increasing the efficiency of water splitting, a process that holds promise for generating clean hydrogen fuel and for producing breathable oxygen during future missions to Mars.

The study was published in the journal Science Advances.

“When you split water, two half-reactions occur,” said Northwestern’s Franz Geiger, who led the study.

“One half-reaction produces hydrogen and the other produces oxygen. The half-reaction that produces oxygen is really difficult to perform because everything has to be aligned just right. It ends up taking more energy than theoretically calculated. If you do the math, it should require 1.23 volts. But, in reality, it requires more like 1.5 or 1.6 volts.

“Providing that extra voltage costs money, and that’s why water splitting hasn’t been implemented at a large scale. We argue that the energy required to flip the water is a significant contributor to needing this extra energy. By designing new catalysts that make water flipping easier, we could make water splitting more practical and cost-effective.”

Geiger is the Charles E. and Emma H. Morrison Professor of Chemistry at Northwestern’s Weinberg College of Arts and Sciences and member of the International Institute for Nanotechnology and the Paula M. Trienens Institute for Energy and Sustainability. The study’s co-authors are Northwestern’s Raiden Speelman and Ezra J. Marker, who are both members of Geiger’s lab.

Water splitting’s promise and challenges

As the climate continues to warm, researchers have become increasingly interested in water splitting as a way to produce clean hydrogen fuels as an alternative to fossil fuels. To perform the process, scientists add water to a metallic electrode and then apply a voltage.

This electricity splits water molecules into two components—hydrogen and oxygen—without any unwanted byproducts. From there, researchers can collect hydrogen for fuel or repurpose the hydrogen and oxygen into energy-efficient fuel cells.

While water splitting could play a significant role in a future clean-energy economy, it faces several challenges. The main issue is that the oxygen part of the reaction, called the oxygen evolution reaction (OER), can be difficult and inefficient. Although it’s most efficient when iridium is used as the electrode, Geiger said scientists need more affordable alternatives.

“Iridium only comes to Earth from meteoric impacts, so there’s a limited amount,” he said. “It’s very expensive and certainly not going to help solve the energy crisis any time soon. Researchers are looking at alternatives, like nickel and iron, and we’re hoping to find ways to make these materials just as efficient—if not more efficient—than iridium.”

‘Optical equivalent to noise-canceling headphones’

To understand why some catalysts are better than others, Geiger’s team wanted to watch the OER process in action. To gain this unprecedented glimpse, his team developed a sophisticated new technique to observe how water molecules interact with the metallic electrode in real time.

First, they added an electrode and the water to a special container. Then, they shined a laser onto the electrode’s surface and measured the light intensity at half the wavelength.

Called second harmonic generation, the process is like listening for the first overtone of a tuning fork when hitting it a bit harder than usual. But, using multiple optical components—lenses, mirrors and crystals—the researchers manipulated the laser beam to gain more information.

“Our technique is the optical equivalent to noise-canceling headphones,” Geiger said. “We can essentially control constructive and deconstructive interference—the photon’s phase—and, from that, we can precisely quantify how many water molecules are pointing to the surface and how many rearrange to point in away from it.”

By analyzing the amplitude and phase of the signal photons, Geiger’s team gained information about how the water molecules were arranged. Before applying the voltage, the researchers noticed the water molecules were randomly positioned.

As they applied a precise voltage to the electrode, however, they watched the water molecules reorient themselves.

Flipping water on its ‘head’

Water molecules look like a simplified drawing of Mickey Mouse—with a large oxygen atom as the “head” and two smaller hydrogen atoms as the “ears.”

Initially, the hydrogen “ears” touch the nickel electrode. But the applied voltage caused the molecules to flip, so the oxygen “head” touched the electrode, ready to give up its electrons.

“Electrodes are negatively charged, so the water molecule wants to put its positively charged hydrogen atoms toward the electrode’s surface,” Geiger said.

“In that position, electron transfer from water’s oxygen atom to the electrode’s active site is blocked. When the electric field becomes strong enough, it causes the molecules to flip, so the oxygen atoms point toward the electrode’s surface. Then, the hydrogen atoms are out of the way, and the electrons can move from water’s oxygen to the electrode.”

By directly observing the water molecules flip, the researchers were able to measure how many water molecules flipped as well as the energy associated with that flipping. They found the flipping happens immediately before OER starts, indicating this is a necessary, non-negotiable step in the process.

They also found the water’s pH level influences the orientation of water molecules. Higher pH levels, for example, made the process more efficient.

While this new window into the behavior of water molecules could lead to more efficient catalysts for water splitting, it could also help researchers better understand other electrochemical processes for energy storage and energy-conversion technologies.

Geiger said his team’s new technique also could help shed new insights into the mysterious nature of water.

“Our work underscores how little we know about water at interfaces,” he said.

“A classic curiosity is the melting anomaly. When you freeze a liquid, it becomes denser, meaning the frozen matter should fall to the bottom of a container. Almost all liquids do this. But when water freezes, its density actually decreases. That’s why we see ice floating on top of Lake Michigan. Water is tricky, and our new technology could help us understand it a bit better.”

More information: Raiden Speelman et al, Quantifying Stern Layer Water Alignment Prior to and During the Oxygen Evolution Reaction, Science Advances (2025). DOI: 10.1126/sciadv.ado8536. www.science.org/doi/10.1126/sciadv.ado8536

Journal information: Science Advances 

Provided by Northwestern University 

Iodine is a crucial element in various industries, but it is one of the least abundant nonmetallic elements on Earth. Although seawater holds around 70% of the world’s iodine reserves, its low concentrations—approximately 60 ppb—make extraction challenging. Additionally, radioactive iodine, which is released during nuclear accidents, presents significant long-term risks to marine ecosystems and human health. Therefore, there is an urgent need for effective strategies to both extract iodine from seawater and address radioactive iodine pollution.

Now, a team at Hainan University has developed a supramolecular organic framework (SOF) for iodine capture from seawater. This framework has demonstrated the ability to remove 79% of iodine pollution in a simulated contaminated environment. In natural seawater, it achieves an ultrahigh iodine adsorption capacity of 46 mg g⁻¹ within a 20-day extraction period. The research is published in the journal Research.

“The sustainable extraction of iodine from seawater is not only vital to meet the increasing global demand but also essential for mitigating the ecological risks posed by radioactive iodine pollution,” said senior author Ning Wang. “Innovative materials can contribute to the field by enhancing the selectivity and capacity for iodine extraction from seawater. Our findings showcase an effective strategy for fabricating multi-dimensional 3D SOF materials and also present a promising material for iodine capture from seawater.”

Wang is a professor in State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University.

Multi-dimensional space for iodine storage

Supramolecular organic frameworks (SOFs) are crystalline porous frameworks materials formed through weak noncovalent interactions, such as hydrogen bonding and π-π stacking. Compared to the other crystalline porous frameworks, SOFs possess abundant active sites, flexible storage space, and enhanced reversibility, making them ideal for storing target substances.

In the study, the researchers developed a novel 3D SOF through the self-assembly of two adjustable compounds for highly efficient iodine recovery from seawater. This 3D SOF contains interconnected 1D channels and 2D interlayer spaces, providing ample iodine storage space for iodine, which enables it to achieve a high iodine adsorption capacity.

Selective adsorption of iodine

The researchers discovered that the 3D SOF exhibits an outstanding adsorption capacity for triiodide, one of the highest reported iodine adsorption capacities for non-covalent organic framework in aqueous conditions. The material also demonstrates impressive reusability, retaining over 88% of its initial adsorption capacity after six reuse cycles. Additionally, it achieved an ultrahigh iodine adsorption capacity in natural seawater.

The 3D SOF exhibits selective adsorption ability of triiodide in simulated nuclear-polluted seawater and iodide in natural seawater. This selectivity is attributed to the charge interactions of amine and pyridyl groups, as well as the binding affinity of aromatic rings.

“The extraction of iodine from marine resources and the management of iodine pollution requires a comprehensive understanding of both chemical and environmental processes,” Professor Wang said.

“The various iodine species, such as iodides and iodates, and their complex interactions with other interfering ions in seawater, highlight the need for highly selective and efficient extraction methods. These methods are crucial for ensuring sustainable iodine recovery and the long-term mitigation of iodine pollution.”

More information: Lijuan Feng et al, Supramolecular Organic Framework with Multidimensional Storage Spaces for Ultrahigh-Capacity Iodine Capture from Seawater, Research (2025). DOI: 10.34133/research.0608

Journal information: Research 

Provided by Research

Producing clean hydrogen energy usually involves the oxygen evolution reaction (OER), which has the unfortunate drawback of being sluggish and inefficient. Catalysts can fast-track this process, but it is no easy task finding the ideal candidate for the job.

However, researchers at Tohoku University found that incorporating gadolinium (Gd) into iron (Fe)-doped nickel oxide (NiO) markedly enhances OER activity. In addition, this catalyst is naturally abundant, relatively inexpensive, nontoxic, and stable.

The study is published in Advanced Functional Materials.

Density functional theory (DFT) calculations were used to provide an in-depth analysis of the reaction mechanisms. They found that Gd-doping improves performance by opening up oxygen vacancies that facilitate the lattice oxygen oxidation mechanism.

Gd-doping reduces the theoretical overpotentials for the Fe and Ni sites, which improves performance. The overpotential was 40mV lower than Fe-doped NiO (without Gd). It also demonstrates favorable kinematics (Tafel slope: 43.1 mV dec^-1).

In addition, Gd and Fe co-doped NiO exhibits a remarkable long-term stability exceeding 150 hours and robust performance in an anion exchange membrane water electrolysis system, operating continuously for more than 120 hours.

“This research plays a crucial role in advancing green energy solutions by improving water electrolysis, a key technology for producing green hydrogen from renewable sources like wind and solar power,” says Hao Li, associate professor at Tohoku University’s Advanced Institute for Materials Research (WPI-AIMR).

Green hydrogen is essential for clean energy systems, with applications in fuel cell vehicles, industrial processes, and other energy-intensive sectors. By enhancing electrolysis efficiency, this study supports large-scale hydrogen production—thus reducing our reliance on fossil fuels and lowering greenhouse gas emissions.

“We plan to scale up the synthesis process to ensure consistent production for industrial applications, and conduct extended stability tests under realistic conditions,” says Li.

More information: Yong Wang et al, Gd-Induced Oxygen Vacancy Creation Activates Lattice Oxygen Oxidation for Water Electrolysis, Advanced Functional Materials (2025). DOI: 10.1002/adfm.202500118. advanced.onlinelibrary.wiley.c … .1002/adfm.202500118

Journal information: Advanced Functional Materials 

Provided by Tohoku University