Friday, March 21, 2025

 

SNU researchers develop an electrochemical catalyst for high-efficiency, low-cost, and eco-friendly hydrogen production



- Designed a ‘core-shell structure catalyst’ using cost-effective ruthenium to enhance commercialization potential / - Selected as a cover paper in the prestigious catalysis journal Energy & Environmental Science



Seoul National University College of Engineering

Figure 1. Schematic diagram of the core-shell nanocluster 

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Figure 1. Schematic diagram of the core-shell nanocluster

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Credit: © Seoul National University College of Engineering




Seoul National University’s College of Engineering has announced a major breakthrough in eco-friendly hydrogen production. A research team led by Professor Jin Young Kim from the Department of Materials Science and Engineering, in collaboration with Professor Chan Woo Lee from Kookmin University and Dr. Sung Jong Yoo from the Korea Institute of Science and Technology (KIST), has successfully developed an advanced electrochemical catalyst. This innovation is expected to lead the next generation of sustainable hydrogen production.

 

The newly developed catalyst features a ruthenium (Ru)-based nanocluster with a core-shell structure. Despite using only a minimal amount of precious metal, it delivers world-class performance and exceptional stability. Moreover, when applied to industrial-scale water electrolysis equipment, it demonstrated remarkable efficiency, highlighting its potential for commercial applications.

 

This groundbreaking research was published in Energy & Environmental Science (Impact Factor: 32.4, Top 0.5% in JCR), one of the most prestigious journals in the field of catalysis. Notably, the study was selected as the cover paper, further underscoring its innovation and academic significance.

 

Hydrogen is widely regarded as a clean energy source because it does not emit carbon dioxide when burned, making it a promising alternative to fossil fuels. One of the most efficient ways to produce eco-friendly hydrogen is through water electrolysis, which splits water into hydrogen and oxygen using electricity. Among various electrolysis methods, Anion Exchange Membrane Water Electrolysis (AEMWE) is gaining attention as a next-generation technology due to its ability to produce high-purity hydrogen. However, for AEMWE to be commercially viable, it requires catalysts that offer both high efficiency and long-term stability.

 

Currently, platinum (Pt) is the most widely used catalyst for hydrogen production, but its high cost and rapid degradation present significant challenges. While researchers have explored non-precious metal alternatives, these materials typically suffer from low efficiency and poor stability, making them unsuitable for industrial use.

 

To overcome these limitations, the research team developed a novel core-shell nanocluster catalyst based on ruthenium (Ru), which is more than twice as cost-effective as platinum. By reducing the catalyst size to below 2 nanometers (nm) and minimizing the amount of precious metal to just one-third of what is used in conventional platinum-based electrodes, the team achieved superior performance surpassing that of existing platinum catalysts.

 

The newly developed catalyst demonstrated 4.4 times higher performance than platinum catalysts with the same precious metal content, setting a new benchmark in hydrogen evolution reaction efficiency. Additionally, it recorded the highest performance ever reported among hydrogen evolution catalysts. Its unique foam electrode structure optimizes the supply of reaction materials, ensuring outstanding stability even under high current densities.

 

In industrial-scale AEMWE testing, the new catalyst required significantly less power compared to commercial platinum catalysts. This result solidifies its potential as a game-changing solution for next-generation water electrolysis technology.

 

The development process involved several key innovations. First, the research team treated a titanium foam substrate with hydrogen peroxide to form a thin titanium oxide layer. This was followed by doping with the transition metal molybdenum (Mo). Next, ruthenium oxide nanoparticles, measuring just 1–2 nm in size, were uniformly deposited on the modified substrate.

 

A precise low-temperature thermal treatment induced atomic-level diffusion, forming the core-shell structure. During the hydrogen evolution reaction, an electrochemical reduction process further enhanced the material’s properties, resulting in a ruthenium metal core encapsulated by a porous reduced titania monolayer, with metallic molybdenum atoms positioned at the interface.

 

Looking ahead, the core-shell nanocluster catalyst is expected to significantly improve the efficiency of hydrogen production while drastically reducing the amount of precious metal required, ultimately lowering production costs. Its combination of high performance and economic feasibility makes it a strong candidate for use in hydrogen fuel cells for vehicles, eco-friendly transportation systems, hydrogen power plants, and various industrial applications.

 

Beyond its practical applications, this breakthrough represents a major technological advancement that could accelerate the transition from fossil fuel-based energy systems to a hydrogen-driven economy.

 

Professor Jin Young Kim emphasized the impact of the research, stating, “The core-shell catalyst, despite being smaller than 2 nanometers, demonstrates remarkable performance and stability. This breakthrough will contribute significantly to the development of nano core-shell device fabrication technology and hydrogen production, bringing us closer to a carbon-neutral future.”

 

Meanwhile, Dr. Hyun Woo Lim, the study’s first author, has been selected for the government’s Sejong Fellowship Program and continues his research as a postdoctoral fellow in Professor Kim’s lab at Seoul National University. His current focus is on further developing and commercializing the core-shell catalyst technology.

 

□ Introduction to the SNU College of Engineering

 

Seoul National University (SNU) founded in 1946 is the first national university in South Korea. The College of Engineering at SNU has worked tirelessly to achieve its goal of ‘fostering leaders for global industry and society. In 12 departments, 323 internationally recognized full-time professors lead the development of cutting-edge technology in South Korea and serving as a driving force for international development.

Nano-sized particles exhibit high activity but low stability, whereas bulk materials demonstrate high stability but low activity. By leveraging the advantages of both materials, a core-shell nanocluster material with both high activity and stability was synthesized.


First, titanium dioxide (TiO₂) is doped with molybdenum (Mo) through initial hydrothermal synthesis. Next, additional hydrothermal synthesis is performed to deposit ruthenium oxide (RuO₂) onto the molybdenum-doped titanium dioxide substrate. A subsequent low-temperature thermal treatment (200°C) in air facilitates diffusion between titanium, molybdenum, and ruthenium oxide, forming the core-shell structure. Finally, electrochemical reduction during the hydrogen evolution reaction results in the synthesis of a unique core-shell nanocluster material.

Credit

© Energy & Environmental Science, originally published in Energy & Environmental Science

 

Nanotech-induced cooling improves crop yields in arid climates



Scientists find crop yields of Chinese cabbage inside miniature greenhouses increased by almost 200% using their hybrid technology




King Abdullah University of Science & Technology (KAUST)




Scientists at King Abdullah University of Science and Technology (KAUST) have developed and combined a new nanoplastic and biodegradable mulch to passively cool greenhouses in hot, arid climates like those in the Middle East. Applying their technology, they lowered temperatures of miniature greenhouses by 25 degrees Celsius and increased crop yields of Chinese cabbage by nearly 200%. The study can be read in Nexus.  

The nanoplastic consists of polyethylene, the most widely produced plastic in the world, infused with nanoparticles consisting of the molecule cesium tungsten oxide. These nanoparticles absorb infrared light, which greatly contributes to heating the greenhouse, preventing this light from entering with minimal effects on visible light, which is the light that drives photosynthesis and plant growth.  

"Most greenhouse covers, whether they are made of glass, polycarbonate or polyethylene, transmit more than 90% of light, including infrared light, which has no benefit to crop yield but generates heat. Our goal was to create a cover that lets good light in and keeps bad light out," said KAUST Professor Qiaoqiang Gan, who developed the nanoplastic and is an expert in passive cooling systems.  

Even with the infrared light reduced, solar radiance caused by any light still heats the soil. Mulch is commonly used to reflect sunlight, keeping the soil cooler than otherwise. Cooler soil promotes more photosynthesis and thus more growth and better crop yields. The new mulch designed by Gan's postdoctoral researcher, Yanpei Tian, is made of biodegradable cellulose paper. As the plants grow leaves that offer shade to the soil, this mulch vanishes from the soil, providing a more sustainable solution to greenhouse cooling and better human health.  

"Most commercial mulch is plastic and extremely wasteful. It results in about 1.5 million tons of waste, and more than 40% goes unrecycled. Plus, this leaves microplastics in our soil that can enter the food chain," said Tian. 

Testing the two technologies in miniature greenhouses in Saudi Arabia to grow Chinese cabbage, the researchers found excellent water retention in the soil and a crop yield that was 200% that of crops grown with commercial covers and mulch. In addition, using public weather data, the KAUST team estimates that adopting their new system could reduce energy consumption in hot cities around the world, like Riyadh and Houston, by more than 40%.   

The researchers are now investigating the benefits of their dual technology on larger scale greenhouses and other crops. 

"The cooling of greenhouses can be extremely expensive. Our approach can make a number of crops available to arid regions, increasing their food security while at the same time helping meet carbon emission targets," said Gan. 

Relax, I'm cool


Uncovering the mysteries of the Mpemba effect



Kyoto University

Relax, I'm cool 

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Developing a universal criterion for measuring the Mpemba effect

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Credit: Vu/KyotoU




Kyoto, Japan -- The Mpemba effect, in which hot systems cool faster than cold ones under the same conditions, was first described by Aristotle more than 2,000 years ago. In 1963 it was rediscovered by Tanzanian student Erasto Mpemba, who observed it when preparing ice cream in a cooking class at school. Mpemba later collaborated with British physicist Denis Osborne on a paper that described its effect on water.

Since Mpemba and Osborne's influential research, further studies have demonstrated that the effect extends beyond simple liquids and can be observed in a variety of physical systems --even microscopic ones. Yet one fundamental challenge has persisted; the detection of the Mpemba effect depends on the choice of a specific distance measure.

An infinite number of distance measures exist, so observing the effect using one distance measure may not materialize within a finite time when evaluated with another. Conventional methods typically assess relaxation speed, which is the rate of return to equilibrium after a change in temperature -- by using a single monotone measure -- but this often leads to inconsistent results.

These pitfalls motivated a team of researchers at Kyoto University to develop a universal criterion for determining the presence of the Mpemba effect: one that does not rely on a single measure. Their approach uses thermomajorization theory, a mathematical framework that unifies different distance measures.

"Our study proves that the use of thermomajorization is equivalent to considering all monotone measures simultaneously," says corresponding author Tan Van Vu.

By employing this theory, Vu and his colleague Hisao Hayakawa were able to provide a rigorous criterion for evaluating thermal relaxation speed, eliminating ambiguities in previous studies and establishing an unambiguous framework for measuring the Mpemba effect.

The team's research also led to the intriguing discovery that the effect is not restricted to a specific temperature range, but can emerge across a wide spectrum of thermal conditions.

"This surprising result suggests that the Mpemba effect reflects a more universal underlying mechanism than previously thought," continues Vu.

In uncovering these mysteries, the group's findings offer new insights into the fundamental principles governing thermal relaxation dynamics, as well as having potential application in enhancing the efficiency of heat engines and cooling technologies. The fields of quantum computing and biophysics stand to benefit as well.

According to Vu and Hayakawa, however, one important question remains: what is the minimum timescale at which the thermomajorization Mpemba effect can occur? Investigating this aspect through the lens of speed limits could help establish fundamental constraints on relaxation dynamics.

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The paper "Thermomajorization Mpemba Effect" appeared on 10 March 2025 in Physical Review Letters, with doi: 10.1103/PhysRevLett.134.107101

About Kyoto University

Kyoto University is one of Japan and Asia's premier research institutions, founded in 1897 and responsible for producing numerous Nobel laureates and winners of other prestigious international prizes. A broad curriculum across the arts and sciences at undergraduate and graduate levels complements several research centers, facilities, and offices around Japan and the world. For more information, please see: http://www.kyoto-u.ac.jp/en

 

Home sweet home: some great hammerhead sharks stick to the perfect neighborhood in the Bahamas instead of migrating



Scientists tracking endangered great hammerhead sharks show that Andros Island, in the Bahamas, is a year-round refuge for some individuals that choose not to migrate




Frontiers

A great hammerhead shark circles beneath the water 

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A great hammerhead shark circles beneath the water, surrounded by smaller fish. Image by Annie Guttridge.

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Credit: Image by Annie Guttridge.





New research shows that some great hammerhead sharks are homebodies. Scientists studying great hammerheads around Andros in the Bahamas shark sanctuary have found that while some individuals migrate, others prefer to stay at home — potentially because their environment provides them with everything they need. This information could help protect the critically endangered species. 

“The global population of great hammerheads is thought to have reduced by more than 80% over the last three generations, and genomic analysis revealed low genetic variation and inbreeding,” said Dr Tristan Guttridge of Saving the Blue, lead author of the article in Frontiers in Marine Science. “Understanding the movement patterns of great hammerheads is important for improving conservation efforts. We find that some great hammerheads show residency in the Bahamas, protecting them year-round from fishing pressures.” 

Fishing for information 

Great hammerhead sharks have been recorded making journeys of 3,000km. However, they have also been recorded staying in areas that are particularly favorable, including Bimini in the Bahamas, where great hammerheads overwinter but leave in the summer. But the potential importance of other Bahamian islands to the sharks, their role in local food webs, and whether they stay there long-term is much less well-known. The scientists set out to investigate this, focusing on Andros Island, the largest in the country.  

“When we started this study there was little to no information about great hammerheads in the central Bahamas and no information about their habitat use at Andros, which has one of the largest fringing reefs in the world and arguably has the most pristine flats habitats in the wider Caribbean,” explained Guttridge. “We had no answers to simple questions like, what do these sharks eat?” 

Using tags and support from Discovery's Shark Week, the team captured 22 sharks between March 2020 and June 2024. They chose sites that reflected great hammerheads’ usual habitat preferences, and placed baited block rigs there. They measured, sexed, and took small muscle biopsies from each shark, and attached satellite trackers to seven sharks. As the stress of capture affects great hammerheads severely, they assessed the health of each shark before deciding whether to tag them. 

Data from captured sharks was combined with records of opportunistic sightings, to provide a total of 78 shark encounters between 2018 and 2024, mainly large juveniles and adults. Half of the sightings occurred between January and March, although a significant number were spotted between June and July. Two sightings provided evidence of recent mating, indicating the area could be important for reproduction. Several sharks were re-sighted in the same locations, and some were captured in the same locations several years apart.  

Sharks favored eastern waters just off north and central Andros for long-term use, particularly preferring a comparatively small 400km2 area of water. However, there were also patches of increased use elsewhere around the island: edge habitats near the reef drop-off, rich in prey species, were particularly popular.  

If the sharks swam south, or past the northern tip of the island, they were much more likely to continue in transit. Sharks which left the Bahamas traveled to the east coast of the US, suggesting they could be part of the west Atlantic population of great hammerheads.  

A great hammerhead menu 

Isotope analysis of the biopsies indicated that barracuda and stingrays made up about two-thirds of the sharks’ diet, while the rest was comprised of smaller sharks. However, different sharks had different preferences. One individual had a diet that was almost two-thirds silky sharks. Plentiful prey, combined with access to deep waters that remain cool during the summer wet season, might enable these sharks to reside in the Bahamas year-round, unlike hammerheads near Bimini.  

“Resource availability is a key driver of space use, but why don’t all of them stay if food is so abundant?” said Guttridge. “We found evidence of individual variation in their diets, so deciding whether to stay or go might depend on what they feed on.” 

“For other species, why or if migration has been linked to environmental conditions, body size, food availability, competition, and predation,” added Guttridge. “Perhaps, like salmon, there is a genetic component to it? We need to explore this phenomenon further.” 

“Our research showcases the importance of Bahamian waters and their protective measures,” concluded Guttridge. “It also shows that although some individuals reside year-round in protected waters, others do not, emphasizing the need for international collaboration on conservation efforts for these mobile species. A key next step is seeing how these hammerheads fit in with the broader north-west Atlantic population.” 

The team work with another great hammerhead shark. Image by Annie Guttridge.

The team capture a great hammerhead shark. Image by Gabby Lozada.

 

Revolutionizing cassava breeding: CRISPR-Cas9 unlocks potential for disease resistance and enhanced yield




Maximum Academic Press




By successfully applying CRISPR-Cas9 to enhance disease resistance, drought tolerance, and starch content, the study paves the way for more efficient cassava breeding programs.

Cassava (Manihot esculenta Crantz, 2n = 36) is one of the most important root crops globally, particularly in tropical regions of Africa, Asia, and Latin America. It is a major source of food, livestock feed, and industrial products. However, cassava cultivation faces numerous challenges, such as low yields, vulnerability to pests and diseases, and poor nutritional quality. While traditional breeding methods have been employed to address some of these issues, progress has been slow, and they often fail to produce significant improvements.

study (DOI: 10.48130/tp-0024-0046) published in Tropical Plants on 11 February 2025 by Qiuxiang Ma and Peng Zhang’s team, Chinese Academy of Sciences, represents a breakthrough in crop biotechnology and offers a promising pathway for future applications of genome editing in cassava and other important crops.

The research uses the CRISPR-Cas9 genome-editing tool to enhance cassava’s resistance to diseases, tolerance to drought, and starch content. The study identifies and targets critical genes associated with cassava mosaic disease (CMD), cassava brown streak disease (CBSD), drought stress response, and starch biosynthesis. By introducing precise edits into these genes, the researchers were able to develop cassava plants with enhanced resistance to both CMD and CBSD, which are two of the most destructive diseases affecting cassava crops globally. Additionally, edited cassava plants exhibited improved drought tolerance, an essential trait in light of the growing challenges posed by climate change. The study also reports that genome-edited cassava plants showed increased starch content, which is beneficial both for food security and industrial applications such as bioethanol production. The application of CRISPR-Cas9 technology in this context offers several advantages, including increased precision, faster breeding cycles, and the creation of genetically improved varieties without the introduction of foreign DNA, which may address concerns in regions with stringent regulatory policies.

In conclusion, the research highlights the potential of genome editing to transform cassava breeding and contribute to the improvement of this vital crop. These advancements could lead to increased cassava yields, improved nutritional quality, and greater resilience to climate change and disease. The findings of this research have significant implications for global food security, particularly in developing regions where cassava is a key staple.

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References

DOI

10.48130/tp-0024-0046

Original Source URL

https://doi.org/10.48130/tp-0024-0046

Funding information

This work was supported by the National Natural Science Foundation of China (32072118, 32160398), Central Public-interest Scientific Institution Basal Research Fund (NO. 1630052024001), and the Earmarked Fund for China Agriculture Research System (CARS-11).

About Tropical Plants

Tropical Plants (e-ISSN 2833-9851) is the official journal of Hainan University and published by Maximum Academic Press. Tropical Plants undergoes rigorous peer review and is published in open-access format to enable swift dissemination of research findings, facilitate exchange of academic knowledge and encourage academic discourse on innovative technologies and issues emerging in tropical plant research.