- Developing high-performance single-atom catalysts through chemical-free dry processes and computational science. - Rapid removal of bisphenol, an endocrine disruptor, in water treatment process Bisphenols are widely used as the main raw material for plastics such as receipts, water bottles, water containers, and vinyl due to their heat-resistant and mechanochemical properties. Among bisphenols, bisphenol A (BPA) that we often refer to as an "endocrine-disrupting chemicals" has been linked to adverse effects on reproduction, development, intelligence, and various metabolic diseases. Bisphenol F (BPF), a recently developed alternative to BPA Bisphenol A has also been reported in the literature to cause neurological disruption and various health risks. Dr. Jong Min Kim of the Materials Architecturing Research Center, Dr. Sang Soo Han of the Computational Science Research Center, Dr. Sang Hoon Kim of the Extreme Materials Research Center at Korea Institute of Science and Technology (KIST), and Professor Byeong-Kwon Ju of the School of Electrical Engineering at Korea University have fabricated high-performance cobalt single-atom catalysts through a chemical-free and environmentally friendly dry-based arc plasma deposition process. The team applied it to an electro-Fenton process based on electrochemical hydrogen peroxide synthesis to remove harmful bisphenols from aqueous solutions in a short time. The arc plasma process vaporizes metals or ceramics with repeated pulsed voltages in a vacuum, depositing them as a thin film on the surface of the substrates, and the number of pulses can be controlled to create a deposited layer with the desired thickness or properties. The cobalt single-atom catalyst fabricated by the arc plasma process exhibited the world's highest metal single-atom loading (2.24 wt%) compared to previously reported single-atom loading of dry processes (around 1 wt%). The coordination structure and active sites of the prepared Co single-atom catalyst were characterized by various material analyses including computational science, and electrochemical measurements confirmed that it is an excellent single-atom catalyst for electrochemical hydrogen peroxide production. The researchers applied the Co single-atom catalyst as an electrode to supply hydrogen peroxide in real time in the electro-Fenton water treatment process, and found that it could rapidly degrade 100% of BPF at a targeted concentration of 20 ppm in aqueous solution within 5 minutes. Through repeated experiments and wastewater treatment tests, the stability of the catalyst and the removal of bisphenol compounds were verified, and based on this, it is expected to be applied to the removal of emerging pollutants in wastewater treatment plants in large cities or specific industrial wastewater treatment facilities. "This achievement is significant in that we have produced high-performance single-atom catalysts in a dry process that does not use harmful chemicals and applied them to the water treatment field," said Dr. Jong Min Kim of KIST, while Dr. Sang Hoon Kim of KIST said, "Research on the production of metal nanoparticles by arc plasma deposition is widely known, but this is the first study to show that single-atom deposition is possible.“ [Figure 1] Schematic illustration of the synthetic process of Co single-atom catalyst using arc plasma deposition. [Figure 2] Images of a Co single-atom catalyst prepared using arc plasma deposition (APD) and comparison of loading amount of single atoms using a conventional dry process. [Figure 3] Identification of the active sites of electrochemical hydrogen peroxide production reaction on Co single-atom catalyst using computational science and its application to the rapid removal of bisphenol F (BPF), an organic pollutant, using electro-Fenton. [Figure 4] High-performance Co single-atom catalyst supported on carbon nanofibers developed by KIST researchers through a dry-based arc plasma deposition process. ### KIST was established in 1966 as the first government-funded research institute in Korea. KIST now strives to solve national and social challenges and secure growth engines through leading and innovative research. For more information, please visit KIST’s website at https://eng.kist.re.kr/ The research was supported by the Ministry of Science and ICT (Minister Lee Jong-ho) through the KIST Major Project and Nanomaterial Technology Development Project (NRF-2022M3H4A7046278) and the Ministry of Environment. This research was published online on July 5 in the SCI journal Carbon Energy (IF: 19.5, JCR: 3.8%).

- KIST develops next-generation cooling material to increase summer cooling efficiency without electricity - Coloring materials for both design and energy savings Dr. Jin Gu, Kang and his team at the Nanophotonics Research Center at the Korea Institute of Science and Technology (KIST) have developed a colorful radiation-cooling liquid crystal material that can cool without external power while simultaneously emitting color. Radiative cooling is a powerless cooling technology that releases infrared radiation as heat through the atmospheric window to reduce temperatures. It is attracting attention as a next-generation eco-friendly cooling technology that can supplement power-hungry air conditioners. Radiative cooling materials for daytime use are colored white to reduce sunlight absorption. This provides excellent cooling performance but has the disadvantage that it cannot be used in buildings or vehicles that require aesthetics because it is difficult to implement multiple colors. Therefore, the development of colored radiative cooling materials that meet cooling and aesthetics at the same time has recently attracted attention. Previously known colored radiative cooling materials use light absorption to produce color, resulting in low temperature reduction. Alternative colored materials in the form of photonic crystals that use light reflection had excellent cooling performance but were limited in realizing distinct colors. The team solved this problem by fabricating bent spiral liquid crystal photonic crystals. The commercial liquid crystal (LC242) used in this study is not only a material that reduces its temperature through radiation cooling, but also forms colored photonic crystals through its periodic structure when aligned into a spiral using an inducer. The researchers used a spin coating process to bend these colored photonic crystals, resulting in vivid colors unlike conventional photonic crystals, which have different colors depending on the angle. By combining the fabricated colored radiation-cooling liquid crystal material with an upper transparent film and a lower metallic thin film, the team was able to achieve a temperature of about 30.8 °C lower than the same colored commercial paint and about 3.1 °C lower than ambient air in the middle of the day, the researchers said. The material could be used to reduce air conditioning consumption on the exterior of buildings and vehicles where aesthetics is a consideration, as well as to provide power-free cooling for outdoor leisure items and military tents. "The colored radiation-cooling liquid crystal material developed in this study can be quickly fabricated through a low-cost and simple spin coating process," said Dr. Jin Gu Kang, a professor at KIST. "If the large-scale commercialization of this technology is successful, it will be used for cooling a wide range of fields such as electronics and mobility in the future." [Figure 1] Schematic and real-world photos of colorful radiation-cooling liquid crystal material [Figure 2] Cooling performance of colorful radiative cooling liquid crystal materials [Figure 3] Fabrication schematic of the colorful radiation-cooled liquid crystal material [Figure 4] Postdoctoral researcher Minjeong Kim (left) and principal investigator Jin Gu Kang (right) show the colorful radiative cooling material they created in the process lab. [Figure 5] A research team prepares to measure radiative cooling performance in the outdoor experimental space on the roof of the research building. ### KIST was established in 1966 as the first government-funded research institute in Korea. KIST now strives to solve national and social challenges and secure growth engines through leading and innovative research. For more information, please visit KIST’s website at https://eng.kist.re.kr/ The research was supported by the Ministry of Science and ICT (Minister Lee Jong-ho) through KIST Institutional Program and the Ministry of Trade, Industry and Energy (Minister Ahn Duk-geun) (20213091010020). The research results were published* in the latest issue of the international journal Chemical Engineering Journal (IF: 13.3, top 3.1% in JCR).

- KIST researchers develop atomically controlled MXenes as water electrolysis catalyst support - Molybdenum-based MXene electrocatalyst support reduces the cost of green hydrogen production 137 countries around the world have signed a "net-zero" climate change agreement to end fossil fuel use and achieve zero carbon emissions by 2050. Hydrogen is being touted as the next green energy source because it emits only water and oxygen when utilized as an energy source. Hydrogen production methods are divided into gray hydrogen, blue hydrogen, and green hydrogen depending on the energy source and carbon emissions. Among them, green hydrogen production method is the most eco-friendly method that produces hydrogen without carbon emissions by electrolyzing water using green energy. A research team led by Dr. Albert Sung Soo Lee of the Convergence Research Center for Solutions to Electromagnetic Interference in Future-Mobility and Materials Architecturing Research Center at Korea Institute of Science and Technology (KIST) with collaboration with Professor Chong Min Koo’s group at Sungkyunkwan University has developed an oxidatively stable molybdenum-based MXene as electrocatalyst support in anion exchange membrane water electrolyzers. As it is stable against oxidative high voltage conditions, if it is applied as a carrier for electrolysis catalysts, it can be used as an oxygen evolution reaction electrode material for green hydrogen production to reduce the cost of green hydrogen production. The breakdown of water into hydrogen and oxygen molecules requires a high amount of energy. To reduce this initial reaction energy, a catalyst is used, and the smaller size of the catalyst, which is made up of tiny nanoscale particles, the larger the surface area, which allows the reaction to take place. However, over time, small catalyst particles can agglomerate, reducing the surface area and reducing the efficiency of hydrogen production. To prevent this, catalysts and supports are used together, and carbon is mainly used for the cathode, where hydrogen is produced, but when carbon is used in an oxidation reaction at the anode, it is oxidized to carbon dioxide. Thus a support with high oxidation resistance is required. One material that can be used as a support is MXene. MXenes are nanomaterials composed of metal atoms (Ti, Mo, Hf, Ta, etc.) and carbon or nitrogen atoms, which show electrically conductive properties and have a 2D nanostructure suitable for catalyst support, making them favorable for hydrogen production. Titanium-based MXenes have been the most widely studied due to their high electrical conductivity. However, due to the atomic nature of titanium, which is easily oxidized in water, has led to the inherent disadvantage that the catalyst cannot maintain high electrical conductivity. To overcome this, the team designed a new anode catalyst that uses molybdenum-carbide based MXene as a support. When the molybdenum-based MXene is utilized as a support, strong chemical bonds are created between the molybdenum atoms on the surface of the MXene and the active materials cobalt. The resulting chemical bonds increased the hydrogen production efficiency by about 2.45 times. In particular, the durability of the unit cell was improved by more than 10 times compared to the results of a recent titanium-based MXene, which lasted less than 40 hours. This is expected to reduce the cost of green hydrogen production and will be applied to large-scale hydrogen production plants and large-scale green hydrogen power stations in the future. "By controlling the elements that make up MXene, we were able to find suitable candidates for green hydrogen production environments, and through this, we secured a stable MXene support in an oxidizing environment," said Dr. Albert Sung Soo Lee of KIST. "In the future, we will contribute to the revitalization of hydrogen-based economy by developing oxygen-generating electrode catalysts with catalytic efficiency and durability." [Figure 1] Overall concept of catalyst design using MXene as an electrocatalyt support and its utilization as an electrode for an anion exchange membrane water electrolyzer. [Figure 2] Water electrolyzer device performance and durability as a function of catalyst utilizing various MXene supports [Figure 3] An electrode with a molybdenum MXene catalyst transferred onto an electrolyzer device. The cathode element, one of the key components of a hydrogen production device, is being held. [Figure 4] (Standing from left) Senior Research Scientist Dr. Albert Sung Soo Lee, Postdoctoral Researcher Gwan-Hyun Choi, and (Sitting) Student Researcher Young Sang Park at KIST. ### KIST was established in 1966 as the first government-funded research institute in Korea. KIST now strives to solve national and social challenges and secure growth engines through leading and innovative research. For more information, please visit KIST’s website at https://eng.kist.re.kr/ This research was supported by the National Research Council of Science and Technology (NST) grant by the Korea Government (MSIT) (CRC22031-000), Ministry of Science and ICT (Minister Lee Jong-Ho) under the Basic Science Research Program, as well as and KIST Young Fellow Program. These findings were published in the latest issue of the international journal Applied Catalysis B: Environment and Energy (IF: 20.2, top 0.6% in JCR).

- Smart labs powered by AI robots are 500x more efficient in material development than simple automation - Expect a new R&D paradigm to address the aging research workforce In the early 20th century, the development of a catalyst for ammonia synthesis by the Haber-Bosch method took more than 10,000 experiments before it was successful. The development of new materials is a time-consuming and costly process from design to commercialization. However, in recent years, researchers have been working to shorten the development period by using artificial intelligence (AI). When combined with robots, it is possible to conduct material development research 24 hours a day, 365 days a year without human intervention. The Korea Institute of Science and Technology (KIST) announced that Dr. Sang Soo, Han and Dr. Donghun, Kim of the Computational Science Research Center and Professor Kwan-Young Lee of the Department of Chemical Engineering and Biotechnology at Korea University (President Kim Dong-won) have developed a bespoke synthesis platform of nanomaterials using AI and robotics, called Smart Lab. The KIST-Korea University joint research team first developed an automated device that synthesizes nanoparticles based on a robotic arm and measures the optical properties of the synthesized nanoparticles. By combining AI technology with this, a smart laboratory for bespoke synthesis of nanomaterials was developed, with which researchers can readily synthesize nanomaterials that meet their requirements just by inputting the desired material properties. The AI technology applied to the Smart Lab platform combines a Bayesian optimization method with the early stopping technology to increase the efficiency for material discovery by more than 500 times compared to simple automated devices. Human experiments are often difficult to obtain reproducible results because the results are very sensitively dependent on the research environment and the proficiency of researchers; however, the developed smart lab has the advantage of producing consistent, high-quality data in large quantities. The researchers also developed an AI technology to ensure the safety of smart labs. Although there is no risk of injury to researchers in unmanned smart labs, it is difficult to prevent safety accidents such as malfunctions due to robot overload. The researchers developed an AI vision technology (DenseSSD) to detect and prevent such safety accidents in advance and installed it in the smart lab. DenseSSD detects various objects in the lab, including research equipment and materials, and notifies users of any abnormalities so that they can take appropriate measures. "The smart lab platform, which enables material development without human intervention, will be a new R&D paradigm that can solve the problem of declining research manpower due to aging," said Dr. Sang Soo, Han of KIST. "In the future, we plan to incorporate interactive language models such as ChatGPT to make it easier for non-experts to use the smart lab," said Dr. Donghun, Kim. The research team plans to expand the Smart Lab platform to various material fields such as catalysts, batteries, and displays. [Figure 1] KIST Computational Science Research Center Smart Lab development staff photo [Figure 2] Conceptualization of a closed-loop experimentation phase with AI robots [Figure 3] Illustration of quantitative efficiency of AI-powered experimental design versus traditional methodologies ### KIST was established in 1966 as the first government-funded research institute in Korea. KIST now strives to solve national and social challenges and secure growth engines through leading and innovative research. For more information, please visit KIST’s website at https://eng.kist.re.kr/ The research was supported by the Ministry of Science and ICT (Minister Lee Jong-ho) through the Korea Research Foundation's Nano and Materials Technology Development Project, and the results were published online March 6 and February 22 in the international journals Advanced Functional Materials and npj Computational Materials, respectively.

- Unlike conventional refractory conductimaterials, it not oxidizeand maintains performance at temperatures up to 1,000°C in air - Expected to be used in a wide range of extreme environments, including space, aerospace and thermophotovoltaic(TPV) system. Thermal radiation is electromagnetic radiation emitted by all objects with temperature and most representatively, there is the solar radiation spectrum that enters the Earth and causes the greenhouse effect. Controlling and utilizing the thermal radiation energy emitted from solar power, thermal power generation, and residual heat in industrial sites can reduce the cost of electricity production. Therefore, interest in radiation spectrum controlling technology is increasing in areas such as cooling, heat dissipation, and energy production. Until now, radiation spectrum control technology has been mainly used in general environmental conditions, but recently, materials that can withstand extreme environments such as space, aviation and TPV system are needed. Korea Institute of Science and Technology (KIST) announced that a team led by senior researcher Jongbum Kim at the Nanophotonics Research Center has developed a refractory material for controlling thermal radiation spectrum that maintains optical properties even at high temperatures of 1,000°C in air atmosphere and strong ultraviolet illumination. The team fabricated lanthanum-doped barium stannate oxide ("LBSO") as a nanoscale thin film with no lattice strain by pulsed laser deposition. Unlike conventional refractory conducting materials such as tungsten, nickel, and titanium nitride, which are easily oxidized at high temperatures, the LBSO material maintained its performance even when exposed to high temperatures of 1,000°C and intense ultraviolet light of 9 MW/cm2. The researchers then fabricated a thermal emitter based on a multilayer structure with high spectral selectivity in the infrared band using LBSO, and found that the multilayer structure was stable to heat and light as with the single layer thin film, confirming its applicability to TPV power generation technology. The LBSO material allows thermal radiation to be transferred to the PV cell without any additional methods to prevent it from oxidizing in contact with air. "As an alternative to solar and wind renewable energy, whose electricity production varies depending on the weather, eco-friendly thermoelectric power generation technology that uses radiant energy emitted by the Sun and high-temperature environments to generate electricity is gaining attention," said KIST senior researcher Jongbum Kim. "LBSO will contribute to addressing to climate change and the energy crisis by accelerating the commercialization of thermoelectric power generation." The researchers expect that LBSO can be applied not only to thermoelectric power generation technology and recycling of waste heat from industrial equipment, but also to technology for managing heat generated by exposure to and absorption of strong sunlight in extreme environments such as space and aviation, as it is highly resistant to UV exposure. [Fig 1] Schematic diagram of the application of LBSO thermal emitter in TPV energy conversion technology This diagram illustrates the effects of applying LBSO thermal emitter to TPV technology. In the case of a typical blackbody, when it absorbs heat, it emits radiant energy over a very broad wavelength range. However, this results in the emission of radiation energy at wavelengths that cannot be utilized by TPV cells, leading to reduced efficiency. By applying LBSO thermal emitters, it can selectively emit heat in the wavelength range where the TPV cells have the highest efficiency, increasing the overall energy generation efficiency. [Fig 2] Thermal durability of LBSO thin film and LBSO thermal emitter (Above) Changes in the crystal structure and optical properties of LBSO thin films before and after heat exposure. Metal oxides like ITO and AZO, which have similar properties with LBSO, exhibit changes in optical properties such as plasma frequency and damping coefficient when exposed to temperatures below 400 degrees. In contrast, LBSO maintains stable performance even up to 1000 degrees. (Below) Scanning electron microscope image and crystal structure of a multilayer structure including LBSO. The thermal emitter shows minimal changes in its characteristics when exposed to high temperatures and intense ultraviolet laser illumination in the air, as with the single layer. [Fig 3] Surface changes of LBSO thin films before and after heat treatment Surface changes of the thin film at various temperatures and laser intensities during heat exposure. It was observed that fine nanostructures formed on the surface; however, it was experimentally confirmed that these particles did not affect the material's linear optical properties. Semiconductor materials absorb light with higher energy than their bandgap, and exposure to intense ultraviolet light can induce changes in material properties. However, experimental evidence shows that LBSO material remains unchanged in its characteristics even when exposed to intense UV excimer laser, strong enough for the thin film to be etched. ### KIST was established in 1966 as the first government-funded research institute in Korea. KIST now strives to solve national and social challenges and secure growth engines through leading and innovative research. For more information, please visit KIST’s website at https://eng.kist.re.kr/ The research, which was supported by the Ministry of Science and ICT (Minister Jong-ho Lee) through the Information and Communication Technology Development Project and Standard Development Support Project (RS-2023-00223082) and the KIST Future Source Research Project, was published in the international journal Advanced Science (IF: 15.1, JCR(%): 6.2) was published on Nov. 23. Journal : Nature Communications Title : Perovskite Lanthanum-Doped Barium Stannate: A Refractory Near-Zero-Index Material for High-Temperature Energy Harvesting Systems Publication Date : 2023.11.23. DOI : https://doi.org/10.1002/advs.202302410

- Novel approach for real-time detection of ultra-low levels of hydrogen gas leakageusing palladium materials embedded in Terahertz Metamaterials. - Successfully elucidation of underlying mechanism of metal-light interaction during a genesis of nano-water film Hydrogen gas is the smallest and lightest of all known molecules, and its colorless and odorless nature makes it easy to leak. Also when concentrated above 4% in a confined space, it poses a risk of ignition or explosion. In order for hydrogen to become a major player in the future energy industry, it is essential to ensure the safety issues via ultra-sensitive gas detection technology over the entire gas-dealing processes such as gas production, storage, and transportation. However, conventional gas-leakage sensors using electric signals are prone to yield electrical sparks, which can cause an explosion of leaked hydrogen gas. In addition, the mainstream electrode-based contact sensors affect the effective signal stability depending on the device's contact state showing weak signal fidelity. Thus, it is desirable for achieving stable, non-explosive via non-contact mode detection for removing any possible dangers have been spiring to develop a secure device that does not lead to disaster situations. The Korea Institute of Science and Technology (KIST) announced that a team led by Dr. Minah Seo of the Sensor Systems Research Center & KU-KIST Graduate School and Prof. Yong-Sang Ryu of School of Biomedical Engineering, College of Health Sciences, Korea University, has developed a non-contact terahertz light sensor. This can detect hydrogen gas leaks as small as 0.25% in real-world environments at room temperature and pressure, which is the world-top level of limit-of-detection performance via optical detection methods. Spectroscopy is the non-contact observation method measuring changes in the value of optical constants of an analytic sample. In this method, changes in the reacting substance are observed non-invasively, by measuring variations in the optical properties when the reacting substance encounters hydrogen gas. Terahertz electromagnetic waves have a very wide frequency band, which makes them sensitive to the natural vibrations of gas molecules, and can be utilized in spectroscopy to resolve minute unique information and differences in molecules such as various gases, DNA, and amino acids. However, due to the low probability of interaction with trace amounts of hydrogen gas and the lack of technology to amplify the signal of terahertz waves, it has been difficult to utilize in practice. The research team focused on the property of hydrogen permeating into palladium metal, and devised a research strategy to address this through the interaction of light and matter. The researchers developed a gas-detection sensing platform that can sensitively measure changes in terahertz optical signals caused by trace amounts of gas using metamaterials that have the ability to amplify signals in specific bands of electromagnetic waves. The team first developed a terahertz metamaterial that can amplify signals in the gas-sensitive terahertz band, and then uniformly applied palladium to the metamaterial to create an extremely narrow 14 nm space to maximize the sensitivity of the terahertz signal. The palladium plays bifunctional roles in not only the catalytic reaction of adsorbed hydrogen and oxygen to produce water molecules on the surface, but also in the hydrogen storage. For mimicry of real-world environments (80 % of Nitrogen, 20 % of Oxygen), Hydrogen and oxygen gases were then injected into the developed sensing chamber and exposed to the terahertz sensing platform. The results showed great responsibility with respect to exposed hydrogen gas via significant optical signal variation, and these were scientifically analyzed in a real-time fashion. The usage of ultra-thin palladium together with ultra-sensitive optical band width (the terahertz) provided synergetic performance enabling to detect under 1% of hydrogen gas leakage to the real-time detection level. Not only for the superior detection performance, but also the reusability of the detection platforms was considered during platform designing process. In general, metal hydrides such as palladium are difficult to reuse because they are irreversible, meaning they cannot return to their original state after a phase change, but the KIST-Korea University research team secured the reusability of the sample through special processing technology. They also succeeded in developing a technology to contactlessly track the mechanism of hydrogen desorption at the nanometer scale in real time through optical signals. "Existing light sensors have very limited reliability in normal temperature, pressure, and humidity environments, but this is a promising technology that can detect and screen not only gases but also various biochemical substances in extremely small amounts by dramatically increasing sensitivity," said Dr. Minah Seo, lead author of the study. "It is expected to be used to develop a system that can immediately respond to various harmful factors, gases, and diseases through mobile, on-site, and real-time inspections." "In addition to the terahertz measurement technology, it has opened up the possibility of visually checking various gas adsorption and desorption processes and molecular-level chemical reaction mechanisms occurring on metal surfaces," said Professor Ryu Yong-sang of Korea University, lead author of the study. [Fig 1] Observe the metastructure and optical constants of the palladium-catalyzed reaction as a function of the concentration ratio of hydrogen and oxygen, the thickness of the resulting water layer, and the resulting terahertz signal changes. ### KIST was established in 1966 as the first government-funded research institute in Korea. KIST now strives to solve national and social challenges and secure growth engines through leading and innovative research. For more information, please visit KIST’s website at https://eng.kist.re.kr/ The research was supported by the KIST Major Project, the National Research Foundation of Korea (No. 2023R1A2C2003898 , and 2021R1A2C2009236) from the Ministry of Science and ICT (Minister Lee Jong-ho), the KIST Major Project, the KU-KIST School Program of Korea University, and the Korea University Intramural Project, and the results were published online on November 23 in the international journal Advanced Materials (IF 29.4, JCR 2.2%). Journal : Advanced Materials Title : Advancements in intense terahertz field focusing over metallic nanoarchitectures for monitoring hidden interatomic gas-matter interactions Publication Date : 2023.11.23. DOI : https://doi.org/10.1002/adma.202308975

- Developing a hybrid energy harvester that goes beyond simple coupling of thermoelectric and piezoelectric devices to generate higher power - Commercial GPS positioning sensor runs successfully, showing promise for real-world applications Harvesting energy sources such as heat, vibration, light, and electromagnetic waves from everyday environments such as industrial sites and automobiles and converting them into electrical energy is known as energy harvesting. Energy harvesting makes it easier to power today's popular IoT sensors and wireless devices that are located in environments where battery replacement is difficult. Dr. Hyun-Cheol Song and Dr. Sunghoon Hur of Electronic Materials Research Center at the Korea Institute of Science and Technology (KIST) have developed a hybrid energy harvesting system that increases power production by more than 50% by combining thermoelectric and piezoelectric effects. The thermoelectric effect, which converts thermal energy from both ends of the device into electrical energy, has a low energy conversion efficiency, and the piezoelectric effect, which converts mechanical vibration into electrical energy, has a high impedance, so energy cannot be reliably harvested. To overcome the limitations of single-mode energy harvesters, hybrid energy harvesters have been proposed in the past, but they are mainly based on simply combining the energy generated by each mechanism. In response, the KIST research team developed a thermoelectric-piezoelectric hybrid energy harvester that complements the shortcomings of thermoelectric and piezoelectric devices to create a synergistic effect in environments with heat sources and vibrations. First, instead of a heat sink, which is a static shape with a large cross-sectional area that is bulky and in contact with air, a cantilever was fabricated to improve the heat dissipation effect in a vibration environment, resulting in a thermoelectric device output that was improved by more than 25%. The researchers also proposed a hybrid energy harvesting structure in which a polymer-type piezoelectric device (MFC) was attached to the cantilever to generate additional power by generating tensile and compressive deformation of the piezoelectric device as the cantilever shakes. The research team successfully applied this hybrid energy harvester to stably drive a commercial IoT sensor (GPS positioning sensor, 3 V, 20 mW), demonstrating the potential for future IoT sensors to run continuously without battery power supply. "This study confirms that the hybrid energy harvesting system can be reliably applied to our real life," said Dr. Sunghoon Hur of KIST, who led the research. "We have confirmed its effectiveness in places where heat and vibration exist together, such as automobile engines, and are currently planning to build a system that can be applied to factory facilities or construction machinery engines that are difficult to supply power and diagnose their condition wirelessly." [Fig 1] Thermoelectric-voltaic hybrid harvester utilizing a cantilevered dynamic heat sink developed by KIST researchers [Fig 2] Graph showing the characteristics of a thermoelectric-voltaic hybrid harvester utilizing a cantilevered dynamic heat sink. [Fig 3] Illustration and graph showing that the output of a thermoelectric-piezoelectric hybrid harvester can be used to reduce IoT sensor drive time, increasing hybrid power due to the synergy of the thermoelectric-piezoelectric mechanism. ### KIST was established in 1966 as the first government-funded research institute in Korea. KIST now strives to solve national and social challenges and secure growth engines through leading and innovative research. For more information, please visit KIST’s website at https://eng.kist.re.kr/ The research was supported by the Ministry of Science and ICT (Minister Jong-ho Lee) as Institutional Program of KIST and was published in the latest issue of Energy Conversion and Management (IF: 10.4, top 1.8% in JCR), an international journal in the energy field. Journal : Energy Conversion and Management Title : A synergetic effect of piezoelectric energy harvester to enhance thermoelectric Power: An effective hybrid energy harvesting method Publication Date : 2023.10.30. DOI : https://doi.org/10.1016/j.enconman.2023.117774

- Development of a new ternary alloy (Cu-Au-Pt) catalyst that is cheaper and more efficient than traditional platinum (Pt) catalysts Proton exchange membrane hydrogen fuel cells (PEMFCs) used in hydrogen vehicles use expensive platinum catalysts to facilitate the oxygen reduction reaction at the anode. There are a vast number of elemental combinations and compositions that need to be explored to develop more efficient and cost-effective catalyst materials than platinum, and researchers are still doing a lot of trial and error in the lab. The Korea Institute of Science and Technology (KIST, President Seok Jin Yoon) announced that Dr. Donghun Kim and Dr. Sang Soo Han of the Computational Science Research Center, Dr. Jong Min Kim of the Materials Architecturing Research Center, and Prof. Hyuck Mo Lee of the Department of Materials Science and Engineering at the Korea Advanced Institute of Science and Technology (KAIST, President Kwang Hyung Lee) have presented a new artificial intelligence-based catalyst screening methodology and succeeded in developing a new catalytic material based on a ternary element-based alloy (Cu-Au-Pt) that is cheaper and performs more than twice as well as pure platinum catalysts. [Figure 1] GRAPHICAL ABSTRACT OF MACHINE LEARNING-DRIVEN HYDROGEN FUEL CELL CATALYST DESIGN The team developed Slab Graph Convolutional Neural Network (SGCNN) artificial intelligence model to accurately predict the binding energy of adsorbates on the catalyst surface. This is not the first application of AI to materials discovery. The SGCNN model was developed by evolving the CGCNN model, which is specialized in predicting bulk properties of solid materials, to predict surface properties of catalytic materials. However, there is a big difference between predicting bulk properties and surface properties. When you can quickly and accurately predict the surface properties of a catalyst, you can more efficiently screen for catalysts that meet the triple bottom line of material stability, performance, and cost. In fact, when developing fuel cell anode reaction catalysts using this methodology, we were able to explore the potential of nearly 3,200 ternary candidate materials in just one day, a scale that would have taken years using the density functional theory (DFT) adsorption energy simulation calculations traditionally used to predict catalyst properties. [Figure 2] Machine learning-driven material screening workflow for each anode and cathode of fuel cell The researchers developed a novel ternary (Cu-Au-Pt) alloy catalyst through experimental validation of 10 catalysts with the potential to outperform platinum catalysts out of approximately 3,200 candidate materials. The catalyst uses only 37% of the element platinum compared to pure platinum catalysts, but the kinetic current density is more than twice as high as that of pure platinum catalysts. The catalyst also exhibits excellent durability, with little degradation after 5,000 stability tests. "In the future, we plan to continue to build high-quality adsorption energy data and perform more sophisticated AI modeling, which will further improve the success rate of catalytic material development," said Dr. Kim of KIST. The new methodology has the advantage of being immediately applicable not only to catalysts for hydrogen fuel cells, but also to various catalytic reactions such as water electrolysis-based hydrogen production, which is essential for the realization of the hydrogen economy. The team plans to further reduce the unit cost and improve the performance of the developed catalysts through material and system optimization. ### KIST was established in 1966 as the first government-funded research institute in Korea. KIST now strives to solve national and social challenges and secure growth engines through leading and innovative research. For more information, please visit KIST’s website at https://eng.kist.re.kr/ The research was supported by the Samsung Future Technology Fostering Project (SRFC-MA1801-03) of Samsung Electronics (CEO Kye-hyun Kyung) and the Materials Research Data Platform Project of the Ministry of Science and ICT (Minister Jong-ho Lee), and was published in the international journal Applied Catalysis B: Environmental. Journal : Applied Catalysis B: Environmental Title : Machine learning filters out efficient electrocatalysts in the massive ternary alloy space for fuel cells Publication Date : 24-July-2023 DOI :https://doi.org/10.1016/j.apcatb.2023.123128

- A novel membrane using a combination of a water filteration membrane and conductive polymer - Water quality improvement and continuous electricity generation using a simple operation method The purification of various water resources, such as rain, seawater, groundwater, river water, sewage, and wastewater, into potable or usable water is a high-energy process. So, what if electricity could be generated during the water purification process? In the spotlight, a domestic research team has developed a multifunctional membrane that can simultaneously generate electricity while purifying wastewater into drinking water. The Korea Institute of Science and Technology (KIST, President Seok Jin Yoon) has announced that Dr. Ji-Soo Jang's team from the Electronic Materials Research Center and Prof. Tae-Gwang Yoon's team from the Department of Materials Science and Engineering, Myongji University (President Byeong-Jin Yoo) have jointly developed an advanced membrane that can simultaneously provide drinking water and generate continuous electricity from various water resources, such as sewage/wastewater, seawater, and groundwater. The developed "sandwich-like" membrane is composed of a porous membrane that filters water at the bottom and a conductive polymer that generates electricity at the top. The membrane is designed to purify wastewater by controlling the direction of the water flow. Water flowing perpendicularly to the membrane generates direct current by the movement of ions along the horizontal direction. The membrane can reject more than 95% of the contaminants of sizes less than 10 nm (one hundred-millionth of a meter). Hence, microplastics and heavy metal particles in wastewater can be removed, and continuous electricity can be generated for more than 3 h with only 10 µl (microliter) of water. Since the membrane can be manufactured using a simple printing process without size restrictions, it has a high potential to be commercialized due to low manufacturing costs and processing time. The research team is currently conducting follow-up research to generate electricity while improving the water quality of wastewater to the level of drinking water by developing the membrane for an actual factory. Dr. Ji-Soo Jang from KIST expressed his opinion on the research saying that, "As a novel technology that can solve water shortage problem and produce ecofriendly energy simultaneously, it also has great potential applications in the water quality management system and emergency power system." This research was conducted as a major project of KIST with the support of the Ministry of Science and ICT (Minister Jong-Ho Lee). These research findings were published in the latest issue of 'Advanced Materials', an international journal of materials (IF: 32.086, top 2.17% in the JCR field), and were selected to be on the front cover of the issue. Journal: Advanced Materials Title: Bidirectional water-stream behavior on multifunctional membrane for simultaneous energy generation and water purification Publication Date: 9-Dec-2022 DOI: https://doi.org/10.1002/adma.202209076 Electricity generation and water purification membrane developed by the KIST-Myongji University joint research team Schematic illustration for the operation of the electricity generation and water purification membrane developed by KIST-Myongji University joint research team

- Compact 'Energy Harvesting' technology equipped with an autonomous resonance-tuning mechanism - Realization of stable power supply for small electronic devices (IOT sensors) through demonstration The Internet of Things (IoT) requires the installation free of time and space, therefore, needs independent power sources that are not restricted by batteries or power lines. Energy harvesting technology harvests wasted energy such as vibration, heat, light, and electromagnetic waves from everyday settings, such as automobiles, buildings, and home appliances, and converts it into electrical energy. Energy harvesters can generate sufficient electricity to run small electronic devices by harvesting ambient energy sources without an external power supply. The Korea Institute of Science and Technology (KIST, President Seok Jin Yoon) announced that Dr. Hyun-Cheol Song's research team at the Electronic Materials Research Center developed an autonomous resonance tuning (ART) piezoelectric energy harvester that autonomously adjusts its resonance according to the surrounding environment. The developed energy harvester can tune its own resonance over a broad bandwidth of more than 30 Hz, and convert the absorbed vibration energy into electrical energy. The energy harvesting process that converts vibration into electrical energy inevitably causes a mechanical energy loss, which leads to low energy conversion efficiency. This problem can be solved by using the resonance phenomenon in which the vibration amplifies when the natural frequency of an object and the frequency of the vibration match. However, while the natural frequency of the energy harvester is fixed, the various vibrations we experience in our everyday settings have different ranges of frequency. For this reason, the natural frequency of the harvester must be adjusted to the usage environment every time in order to induce resonance, making it difficult to put into practical use. Accordingly, the KIST research team developed a specially designed energy harvester that can tune itself to the surrounding frequency without a separate electrical device. When the energy harvester senses the vibration of the surroundings, an adaptive clamping system (tuning system) attached to the harvester modulates its frequency to the same frequency as the external vibration, thus enabling resonance. As a result, it was possible to quickly achieve resonant frequency tuning within 2 seconds, continuously generating electricity in a broad bandwidth of more than 30Hz. For the real-world validation of the ART function, this energy harvester equipped with a tuning system was mounted on a driving vehicle. Unlike piezoelectric energy harvesters that have been introduced in preceding studies, it successfully drove a wireless positioning device without a battery in an environment where the vibration frequency continuously changed. Dr. Song (KIST), who led this study, said, "This result suggests that energy harvesters using vibrations can be applied to our real life soon. It is expected to be applicable as an independent power source for wireless sensors, including the IOT, in the future." This research was carried out as a KIST major project supported by the Ministry of Science and ICT (Minister Jong-ho Lee), and as an energy technology development project of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) supported by the Ministry of Trade, Industry and Energy (Minister Chang-yang Lee). The results of this study were published as a front cover in the issue of Advanced Science, an international journal in the energy field. Journal: Advanced Science Title: Autonomous Resonance-Tuning Mechanism for Environmental Adaptive Energy Harvesting Publication Date: 28-Nov-2022 DOI: https://doi.org/10.1002/advs.202205179 Schematics for energy harvester structure and adaptive clamping system (above) Graphs showing the characteristics of an ART energy harvester Diagrams showing the potential for practical use of an ART energy harvester that successfully drives a positioning device by utilizing the vibration energy of an automobile engine.