Sungkyunkwan University Research Team Led by Prof. Jeong Su Oh Identifies a Key Mechanism for Genome Stability in Mammal
New Insights into Efficient Chromosome Repair During Oocyte Meiosis
Integrative Biotechnology OH, JEONG SU Prof. · Crystal Lee
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Sungkyunkwan University Research Team Led by Prof. Jeong Su Oh Identifies a Key Mechanism for Genome Stability in Mammal
A research team led by Professor Jeong Su Oh from the Department of Integrative Biotechnology at Sungkyunkwan University has revealed a novel mechanism critical for maintaining genome stability in mammalian oocytes. The team identified the novel BRCA1-PLK1-CIP2A axis, a pathway regulated by homologous recombination (HR), a pivotal DNA repair mechanism. This pathway ensures efficient repair of damaged chromosomes during oocyte meiosis, preventing chromosomal breaks and safeguarding genome integrity. This discovery underscores the importance of maintaining genome stability to enhance oocyte quality. “This research uncovers a new pathway for maintaining genomic stability in mammalian oocytes, with promising implications for advancing infertility treatments and germ cell research,” said Professor Oh. The team also highlighted the potential of this discovery to provide critical insights into diseases associated with oocyte health. The findings significantly contribute to our understanding of genome stability mechanisms in mammalian oocytes, offering potential applications in reproductive medicine and genetics. This study supported by the National Research Foundation of Korea was published online on December 9 in Nucleic Acids Research. Journal Details: Title: Novel BRCA1-PLK1-CIP2A Axis Orchestrates Homologous Recombination-Mediated DNA Repair to Maintain Chromosome Integrity During Oocyte Meiosis Journal: Nucleic Acids Research (IF: 16.6; Top 2% in Biochemistry and Molecular Biology) DOI: 10.1093/nar/gkae1207 Authors: Crystal Lee (First Author), Jeong Su Oh (Corresponding Author)
- No. 283
- 2025-01-09
- 396
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Bioorthogonal Activation of Deep Red Photoredox Catalysis Inducing Pyroptosis
The research team led by Prof. Jin Yong Lee of the Department of Chemistry (co-first author Ph. D. Jong Hyeon Lim) has developed a novel photoredox catalytic system, PC-Tz, based on bioorthogonally activatable photoredox catalysis through collaborative research with research teams led by Prof. Mingle Li (Shenzhen University), Prof. Joseph Fox (University of Delaware), Marc Vendrell (University of Edinburgh), and Prof. Jong Seung Kim (Korea University). The research was published in Journal of the American Chemical Society (IF: 14.4) in December 2024 under the title "Bioorthogonal Activation of Deep Red Photoredox Catalysis Inducing Pyroptosis." Traditional photodynamic therapy (PDT) has been established as an important technique in cancer treatment, but its therapeutic efficacy has been limited by low activation efficiency and biocompatibility issues in hypoxic environments. To address these challenges, this study introduces an innovative bioorthogonal photoredox catalytic technology. The PC-Tz system employs a unique design where its catalytic activity is suppressed by the 1,2,4,5-tetrazine structure and restored through selective reactions with trans-cyclooctene (TCO) within cells. The developed PC-Tz system promotes the oxidation of nicotinamide adenine dinucleotide (NADH) in a selective activation mechanism, effectively manipulating the mitochondrial electron transport chain (ETC) under hypoxic conditions in cancer cells. Professor Lee’s team utilized density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations to investigate the effects of TCO binding on the activation of the photoredox catalysis of PC-Tz. Moreover, the team employed a conductor-like polarizable continuum model (CPCM) to optimize the structural changes of PC-Tz before and after TCO binding, elucidating the energy state transitions and reaction mechanisms induced by light irradiation. This novel photoredox catalytic system is expected to contribute significantly to advancements in light-controlled therapeutic strategies for cancer, paving the way for the precise design of bioorthogonal photoredox catalysts for future medical applications. *Title: Bioorthogonal Activation of Deep Red Photoredox Catalysis Inducing Pyroptosis.
- No. 282
- 2025-01-03
- 432
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Professor Jin-Hong Park's team at SKKU, in collaboration with MIT and Samsung Advanced Institute of Technology
Professor Jin-Hong Park's research team at Sungkyunkwan University (President Yoo Ji-Beom), in collaboration with Professor Ji-Hwan Kim’s team at MIT and Dr. Sang-Won Kim’s team at the Samsung Advanced Institute of Technology (SAIT), has developed a 3D C-FET** semiconductor device technology based on single-crystal 2D semiconductor* channels, targeted for sub-10-angstrom (1 nanometer) technology nodes. Following their publication last year in Nature, which introduced a novel method for growing single-crystal 2D materials using a non-epitaxial approach, the team has now unveiled a new 3D C-FET semiconductor device technology. This latest advancement overcomes the integration density limitations of conventional 2D planar semiconductors through a low-temperature integration process. Both technologies are based on next-generation 2D semiconductors and are being recognized as a groundbreaking leap forward in foundry semiconductor integration technology. * 2D Semiconductor: A two-dimensional semiconductor material with an atomically thin structure. Due to its exceptional electrical properties and ultra-thin design, it is particularly advantageous for realizing high-performance and high-density integrated devices at sub-1-nanometer scales. ** 3D C-FET: A transistor structure where n-FET and p-FET are electrically connected in a three-dimensional stacked configuration. This technology significantly enhances integration density and power efficiency compared to conventional 2D planar devices. It is anticipated to be a key technology for sub-10-angstrom technology nodes by 2031. The existing 3D semiconductor technology mainly used the Through-Silicon Via (TSV) method, which involves penetrating the silicon wafer. However, the TSV method faced several issues, including wafer alignment errors, high processing costs, and chip area loss due to the TSVs. To address these challenges, the research team approached the problem using a 'Monolithic 3D Integration Method,' which directly grows single-crystal transition metal dichalcogenide (TMD) channels without the need for physical connections between wafers. This approach maximizes device performance while minimizing physical connections, thus improving both process efficiency and integration density. In this study, a low-temperature process below 385°C was applied for the fabrication of the upper single-crystal 2D semiconductor device, instead of the conventional high-temperature process above 700°C. This low-temperature process prevented damage to already fabricated devices or wiring while providing an environment for fabricating the upper device using the 3D monolithic method. Through this approach, the research team successfully integrated a single-crystal n-FET device directly on top of a pre-existing single-crystal p-FET. The developed vertical CMOS device demonstrated more than double the integration density compared to conventional 2D planar CMOS devices, offering a new approach that could replace TSV technology. Professor Jin-Hong Park stated, "This study represents an example of achieving innovative technological progress beyond existing TSV technology," and added, "The realization of 3D C-FET semiconductor integration technology by directly growing single-crystal devices in a low-temperature process using the monolithic 3D integration method is a significant technological leap in the semiconductor industry." He further mentioned, "This technology is expected to contribute not only to the improvement of integration density in next-generation semiconductor devices but also to maximizing energy efficiency," and added, "In the future, this technology is expected to play an important role in various advanced technology fields, such as artificial intelligence, data centers, and the Internet of Things (IoTs).” The results of this study were published in Nature on the 18th, and the technology is expected to be a key to overcoming the limitations of Moore's Law through improvements in semiconductor device integration density and innovations in manufacturing processes. This research (2024-12) ※ Title: Growth-based monolithic 3D integration of single-crystal 2D semiconductors ※ Journal: Nature (IF: 50.5) ※ Link: https://doi.org/10.1038/s41586-024-08236-9 Previous research (2023-2) ※ Title: Non-epitaxial single-crystal 2D material growth by geometric confinement ※ Journal: Nature (IF: 50.5) ※ Link: https://doi.org/10.1038/s41586-022-05524-0 ▲ Comparison of Existing 3D Semiconductor Integration Technology and the 3D Semiconductor Integration Technology ▲Diagram of Low-Temperature Growth Technology for Single-Crystal 2D TMD and Single-Crystal 3D C-FET Semiconductor Devices
- No. 281
- 2024-12-27
- 564
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Professor Yong Taik Lim’s Research Team at SAINT Develops a Novel Cancer Immunotherapy Inspired by Pathogen Kinetics
Professor Yong Taek Lim's research team at the Sungkyunkwan Advanced Institute of Nano Technology (SAINT) has developed a next-generation cancer immunotherapy inspired by the antiviral immune responses triggered during infection. The study mimics the dynamic behavior of pathogens, leveraging the synergistic effects of sequential Toll-like receptor (TLR) signaling and the self-replication-driven sustained immune response observed in pathogens. This innovative approach significantly enhances the efficacy of traditional immunotherapies. The findings were published online in two renowned journals in the fields of nanobiotechnology and materials science: Advanced Materials (IF=27.4) on October 9, 2024, and Advanced Functional Materials (IF=18.5) on November 3, 2024. Bioadhesive Immune Niche Domain (BIND) to overcome the limitations of conventional Toll-like receptor 7/8 agonist-based therapies. Utilizing bioadhesive tannic acid, BIND is designed to adhere to and penetrate lymph nodes, enabling localized and sustained immune activation. This vaccine mimics the kinetics of pathogen self-replication, allowing gradual and sustained antigen delivery within lymph nodes for 7–14 days. Moreover, it replicates the viral mechanism of lymph node penetration by leveraging collagen interactions to efficiently infiltrate lymph nodes and induce the effective generation of antigen-specific T cells. In melanoma models, this vaccine demonstrated significantly higher anticancer efficacy than traditional mRNA-based cancer vaccines. Professor Lim’s team also addressed the side effects of the BCG vaccine, commonly used for pediatric tuberculosis and bladder cancer. Despite its widespread use, the BCG vaccine is often associated with adverse effects like inflammation and secondary infections, as well as limited long-term efficacy. To overcome these issues, the team extracted a cell-wall skeleton capable of stimulating Toll-like receptor 2 (TLR-2) from the Microbacterium strain. They formulated this component with a TLR-7/8 agonist (t-TLR-7/8a) to create a "Reconstituted Synthetic Nanopathogen (RSnP)." The RSnP showed remarkable therapeutic efficacy in bladder cancer models, even when used alone. When combined with the Treg-depleting anti-CCR8 antibody, it demonstrated exceptional results, achieving complete remission in large, previously difficult-to-treat tumors. Furthermore, systemic toxicity analysis revealed that RSnP exhibited low toxicity comparable to the control group, highlighting its potential for clinical application as a virulence-free treatment option. Research article: Transformable Gel-to-Nanovaccine Enhances Cancer Immunotherapy via Metronomic-Like Immunomodulation and Collagen-Mediated Paracortex Delivery (Advanced Materials; IF=27.4, Oct 09, 2024) Author: Seung Mo Jin (First author, Post-doctoral researcher), Ju Hee Cho (Co-author, Researcher), Yejin Gwak (Co-author, PhD-MS student), Sei Hyun Park (Co-author, PhD student), Jin-Ho Choi (Co-author, PhD student), Hong Sik Shin (Co-author, PhD student), Yong Taik Lim (Corresponding author, SKKU professor) Research article: Virulence-Free Reconstituted Synthetic Nanopathogen Empowered by Timely-Activating TLR Agonist Promotes Heterologous Cancer Immunotherapy with Depletion of Tumor-Specific Treg Cells (Advanced Functional Materials; IF=18.5, Nov 03, 2024) Author: Sang Nam Lee (First author, Post-doctoral researcher), Sei Hyun Park (Co-author, PhD student), Jin-Ho Choi (Co-author, PhD student), Jang Hun Heo (Co-author, PhD-MS student), Yong Taik Lim (Corresponding author, SKKU professor)
- No. 280
- 2024-12-23
- 531
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Advancing the Era of Biodegradable Plastics Through the Use of Cork
Prof. Jonghwan Suhr's (School of mechanical engineering) research team at Sungkyunkwan University has pioneered an innovative approach to overcoming the limitations of biodegradable plastic (PLA) by utilizing suberin derivatives extracted from cork and potato peels, paving the way for new advancements in sustainable material research. PLA, a prominent eco-friendly polymer material, is derived from glucose extracted from crops like corn, sugarcane, and potatoes through a fermentation process. It is widely used in various forms, including films, fibers, packaging materials, and 3D printing. However, PLA's inherent brittleness makes it vulnerable to impact, and its high shear viscosity and low glass transition temperature (Tg) pose challenges in achieving uniform molding and producing high-quality products during processing. In this study, depolymerized suberin derivatives (DSD) extracted from cork and potato peels were repolymerized into a plasticizer (pDSD) to alleviate the intermolecular interactions between PLA polymer chains. This modification significantly enhanced PLA’s flexibility and increased its tensile toughness by 1148%. PLA with pDSD additives exhibited reduced viscosity and over a threefold increase in melt flow index (MFI), dramatically improving efficiency and quality in various processing methods, including injection molding, film manufacturing, and additive manufacturing (3D printing). Furthermore, improved crystallization speed and uniformity expanded its potential applications to structural components. This research goes beyond merely enhancing PLA’s mechanical properties by developing an environmentally friendly material that retains over 90% biodegradability within 12 weeks. This study is being further developed in collaboration with Chiang Mai University in Thailand, aiming for industrial commercialization of plastic alternatives. Notably, the material has demonstrated potential for diverse applications in 3D printing, eco-friendly disposable products, medical materials, and structural components in various fields of daily life and engineering. Professor Seo remarked, "We are committed to developing innovative and practical solutions for a sustainable future. Through global research collaboration, we anticipate continuously achieving breakthroughs that transcend technological limitations." Related Journal: Yoon, Hyejung, et al. "Plasticizing effect of depolymerized suberin derivatives from natural cork and potato periderm in poly (lactic acid)(PLA) for improved toughness and processability." Industrial Crops and Products 209 (2024): 117990. Fig.1 (a) Suberin composition from exodermis of the cork tree, (b) suberin domain between primary cell wall and cell membrane, and (c) schematic illustrations of the DSDs polycondensation Fig. 2 (a) stress-train curves determined from tensile tests for the neat PLA and pDSDs/PLA blends, (b) melt flow index for the neat PLA and pDSDs/PLA blends, and (c) degree of disintegration for the neat PLA and 5 wt% pDSDs/PLA blends determined from biodisintegration test over a span of 14 weeks inset photographs of the specimen taken at intervals of 0, 4, 8, and 12 weeks.
- No. 279
- 2024-12-13
- 574
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Deep Learning-Based ESG Research
Professor Doojin Ryu co-authored this paper with Jeongseok Bang (Korea Institute of Finance) and Jinyoung Yu (Xi’an Jiaotong-Liverpool University). The research bridges social science (ESG and financial markets) and engineering methods (machine learning, deep learning) to analyze how ESG controversies influence investor behavior using big data. The study employed deep learning-based natural language processing to systematically analyze news articles, classifying them by specific ESG controversy types. ESG controversies generally increase trading activity, though responses vary by ESG factor. Domestic institutional investors, unlike foreign or individual investors, showed a distinct tendency to sell stocks tied to controversies. Highlighting the Korean market, it was published in Finance Research Letters, a high-ranking SSCI journal in the Business/Finance category. Publication Details: Bang, J., Ryu, D., & Yu, J. (2023). ESG controversies and investor trading behavior in the Korean market. Finance Research Letters, 54 (Jun.), 103750.
- No. 278
- 2024-12-09
- 531
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How to Distribute benefits Fairly Even When External Factors Interfere?
If LG's battery competitor, Northvolt, collaborates with BMW's competitor, Mercedes-Benz, how should LG and BMW share their profits? Professor Frank Huettner of Sungkyunkwan University’s SKK GSB has published a paper in the prestigious journal Games and Economic Behavior on a method for plausibly distributing benefits, even when outsiders can exert externalities. Professor Huettner, along with Professor André Casajus of HHL Leipzig Graduate School of Management and Professor Yukihiko Funaki of Waseda University, conducted research on the Shapley value and its extensions. The Shapley value is a concept that provides a fair method for distributing the benefits gained by multiple participants working together. It calculates the contribution of each participant to the overall value of the project and proposes a fair distribution of rewards. The traditional Shapley value is difficult to apply in situations where external factors can exert externalities. In this paper, Professor Huettner and his co-authors address how to plausibly distribute benefits even when external factors interfere. To illustrate the impact of externalities, consider a scenario where LG and BMW are negotiating a deal to divide the benefits of 100 billion KRW from using LG's batteries in BMW vehicles. The traditional Shapley value might suggest dividing these benefits 50-50. However, the benefit might depend on whether LG's Swedish competitor Northvolt reaches an agreement with BMW's competitor Mercedes-Benz. If Northvolt and Mercedes-Benz collaborate, the estimated benefit between LG and BMW could drop to 80 billion KRW. In this case, Northvolt and Mercedes-Benz exert external effects on BMW and LG, making the traditional Shapley value inapplicable. The scenario might be even more complex, involving potential collaborations between BMW and Northvolt, Mercedes-Benz and LG, or even technological partnerships between Northvolt and LG, further complicating the value distribution problem. The authors refine and extend a previous approach to better account for these complex scenarios, offering a more comprehensive and conclusive way to distribute value. Their generalization of the Shapley value can be employed in situations like the above example, providing a fair allocation method that takes into account the potential actions of external entities. Journal: http://doi.org/10.1016/j.geb.2024.06.004
- No. 277
- 2024-12-04
- 500
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Development of High-Performance Tungsten Disulfide-Graphene Electrode Material Using Polarization-Field-Embedded 2D mat.
A collaborative research team led by Professor Taesung Kim (Departments of Mechanical Engineering, Nanoscience and Technology, and Semiconductor Convergence Engineering) and Professor Pil J. Yoo (Departments of Chemical Engineering, Nanoscience and Technology, and SKKU Institute of Energy Science and Technology) at Sungkyunkwan University, together with Dr. Hyeong-U Kim from the Korea Institute of Machinery and Materials, has successfully developed a high-efficiency, stable hydrogen production electrode material utilizing a low-temperature plasma polarization-field-embedded two-dimensional (2D) heterojunction structure. In recent years, transition metal dichalcogenide (TMD) thin films have gained attention for their tunable hydrogen ion adsorption energies, which vary with crystal structure, providing a basis for designing hydrogen evolution reaction (HER) electrodes with controllable morphologies. The 2H phase, characterized by semiconducting properties, exhibits lower charge transfer capacity compared to the metallic 1T phase. Although efforts to produce 1T-phase TMDs have been ongoing, the strong adsorption in the 1T phase has resulted in desorption-related challenges. Thus, research focused on tuning material properties to address these limitations has become essential. To overcome these obstacles, the research team devised a novel approach that leverages a heterojunction interface with embedded polarization fields, introducing interfacial vacancies that liberate electrons previously constrained by sulfur. This structural innovation facilitates enhanced charge transfer to the electrode surface, ultimately enabling a system capable of rapidly reducing adsorbed hydrogen ions to molecular hydrogen. The team demonstrated that a polarization field formed at the tungsten-graphene interface due to differences in work functions, acting as an internal barrier that prevents the penetration of ionized hydrogen sulfide ions, achieved under low-temperature plasma conditions. This configuration induces sulfur vacancies at the bottom layer, thereby generating free electrons that enhance charge transfer to the surface, surpassing the performance of conventional 2D thin-film-based hydrogen production electrodes. The team demonstrated that a polarization field formed at the tungsten-graphene interface due to differences in work functions, acting as an internal barrier that prevents the penetration of ionized hydrogen sulfide ions, achieved under low-temperature plasma conditions. This configuration induces sulfur vacancies at the bottom layer, thereby generating free electrons that enhance charge transfer to the surface, surpassing the performance of conventional 2D thin-film-based hydrogen production electrodes. Experimental validation, conducted via spherical aberration-corrected transmission electron microscopy, revealed the formation of nanocrystalline atomic layers under hydrogen sulfide ion penetration resulting from ion collision reactions in low-temperature plasma. Additionally, X-ray photoelectron spectroscopy and X-ray diffraction analyses elucidated the mechanism by which hydrogen sulfide ions infiltrate the lattice structure to facilitate the crystallization of amorphous WS₂, enabling in-situ synthesis of 1T-phase lattice through excessive ion injection at the lattice interface. The significance of this work is underscored by its publication in Advanced Materials, a leading journal in multidisciplinary materials science, on September 9, 2024. Publication Details Journal: Advanced Materials Article Title: Electron Release via Internal Polarization Fields for Optimal S-H Bonding States DOI: 10.1002/adma.202411211 ※Authors Corresponding Authors: Professor Taesung Kim (Sungkyunkwan University, Departments of Mechanical Engineering, Nanoscience and Technology, and Semiconductor Convergence Engineering), Professor Pil J. Yoo (Sungkyunkwan University, Departments of Chemical Engineering, Nanoscience and Technology, and SKKU Institute of Energy Science and Technology), Dr. Hyeong-U Kim (Korea Institute of Machinery and Materials) First Authors: Hyunho Seok (Integrated Master-PhD Program, Department of Nanoscience and Technology, Sungkyunkwan University), Minjun Kim (Integrated Master-PhD Program, Department of Nanoscience and Technology, Sungkyunkwan University), Jinil Cho (Department of Mechanical Engineering, Sungkyunkwan University)
- No. 276
- 2024-11-29
- 456
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Sungkyunkwan University Study Reveals the Hidden Genomic Evolution of Brown Algae
A groundbreaking study from South Korea has revealed the evolutionary journey of brown algae through genomic analysis. The research highlights key milestones, including the transition to multicellularity and species diversification, and uncovers viral integrations in brown algae genomes that influenced their evolution. It also explores practical applications in aquaculture, biotechnology, and climate change mitigation, emphasizing brown algae's potential for carbon capture and ecosystem restoration, while offering valuable insights into enhancing ecological resilience amid climatic challenges. Covering over 70% of Earth’s surface, the oceans are home to countless life forms that maintain ecological balance and support human well-being. Among these, brown algae (Phaeophyceae) play a crucial role in sustaining coastal habitats, supporting marine biodiversity, and combating climate change through carbon capture. While they have long captured interest of the scientific world, the genomic and evolutionary history of these organisms have remained largely unexplored. A groundbreaking study by researchers from Sungkyunkwan University has unveiled the evolutionary journey of brown algae through a comprehensive genomic analysis of 44 species. The study was available online on November 20, 2024 and published on November 27, 2024 in Volume 187, Issue 24 of Cell. It created the Phaeoexplorer database, a valuable tool for comparative genomics. The researchers explored key evolutionary milestones, including the transition from unicellular to multicellular forms and the integration of viral sequences into brown algae genomes—an area previously unexplored. The study revealed two major evolutionary milestones in the history of brown algae. Lead author Professor Hwan Su Yoon explains, "Approximately 450 million years ago, brown algae transitioned from unicellular organisms to simple multicellular forms. This shift was driven by horizontal gene transfer from bacteria, enabling the synthesis of vital cell wall components like alginate and phlorotannin. These adaptations the algae aggregate, improved cell-to-cell communication, and defend against predators, marking a crucial step in their evolution." Around 200 million years ago, following the breakup of the supercontinent Pangaea, brown algae underwent significant species diversification. Prof. Yoon explains, "This diversification led to the development of complex life cycles, structural innovations, and specialized metabolic pathways, shaping the ecological roles of various species. The study also revealed widespread viral integration in brown algal genomes, with Phaeovirus sequences found in 67 out of 69 genomes analyzed." These viral integrations likely played a key role in shaping the evolution and diversity of brown algae. The study offers valuable insights into practical applications of brown algae. In aquaculture, it supports selective breeding programs of commercially important species like Undaria pinnatifida and Saccharina japonica, boosting productivity and disease resistance. In biotechnology, the biosynthesis of compounds like alginate opens doors to health supplements, bioactive substances, and sustainable biomaterials. The study also highlights brown algae’s potential in climate change mitigation, particularly in carbon capture and ecosystem restoration, highlighting their ecological and economic benefits. This study also offers valuable insights on how climate change could impact marine ecosystems. Prof. Yoon states, “By analyzing how past environmental changes shaped the evolution of brown algae, we can better predict how future climate shifts might affect marine biodiversity. The genomic resources established from this research help identify traits that enhance ecological resilience, guiding efforts to develop brown algae resistant to climate stresses such as rising temperatures and sea-level changes.” Additionally, promoting kelp forests as "blue carbon" reservoirs offers a natural solution to sequester carbon, mitigating climate change effects while fostering ecological sustainability in marine environments. By decoding the genetic makeup of brown algae, this study enhances our understanding of marine ecosystems and provides insights into how we can use their ecological and economic potential for a more sustainable future. The oceans hold the keys to our planet’s resilience, and this study offers a roadmap for a sustainable future rooted in the nature’s wisdom.
- No. 275
- 2024-11-25
- 1127
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Development of a groundbreaking strategy to significantly enhance oxygen evolution reaction (OER) catalyst performance
The research team led by Prof. Sang Uck Lee from the School of Chemical Engineering, Sungkyunkwan University, in collaboration with Prof. Hyung-Sang Kim and Prof. Hyun-Sik Im from Dongguk University, has developed a groundbreaking strategy to significantly enhance oxygen evolution reaction (OER) catalyst performance. OER is a critical step in the water-splitting process to produce hydrogen and requires the highest energy input, particularly due to its high overpotentials. State-of-the-art commercial catalysts, such as IrO₂ and RuO₂, are noble-metal-based and exhibit excellent performance but are economically impractical for large-scale hydrogen production due to their scarcity. Hence, there is an urgent need to develop alternative catalysts using abundant metal-based materials for large-scale green hydrogen production. Metal-organic frameworks (MOFs) have gained attention as effective and low-cost catalysts for OER, particularly due to their structural versatility and potential to expose active metal nodes. To maximize the catalytic performance of MOF-based catalysts, it is necessary to increase the exposure of active metal node sites and optimize the structural disorder within the framework. In this regard, the research team introduced a novel strategy by doping cerium (Ce) into MOFs, selectively inducing structural disorder and enhancing the exposure of catalytic sites, thus greatly improving OER electrochemical performance. The research successfully demonstrated the synthesis of a crystalline/amorphous heterostructure in nickel-based MOFs via Ce doping. X-ray diffraction (XRD) and electron microscopy revealed that while flat sheets retained a crystalline structure, Ce-rich regions formed amorphous spherical domains. The optimized NiCe-0.2 MOF/NF catalyst exhibited significantly lower overpotentials (η) of 205, 290, 410 and 450 mV to drive the OER under current densities of 10, 100, 1000 and 2000 mAcm−2, respectively with a superior kinetic of 46.09 mVdec− 1 and a larger turnover frequency (TOF@η = 330 mV) of 0.36 s−1, outperforming both Ni-MOF/NF and commercial IrO₂/NF catalysts in high-current-density applications. Additionally, it demonstrated outstanding stability, maintaining performance for over 146 hours at a current density of 1000 mA/cm². Prof. Sang Uck Lee and Ph.D Course Jun Ho Seok used density functional theory (DFT) calculations to elucidate the mechanism by which Ce3+ doping enhances OER catalytic performance. The DFT analysis revealed that Ce³⁺ ions reduce defect formation energy, facilitating the transformation of the MOF structure from crystalline to amorphous, exposing more active metal nodes. Ce³⁺ ions also promote electron transfer and enhance reactivity with OH⁻ ions, accelerating the OER process. The study provided valuable insights into the geometric and electronic structure synergies that contribute to improved catalytic performance, offering a guideline for future MOF-based catalyst designs. Title: Cerium guided site-selective crystal disorder engineering of MIL-88B(Ni) frameworks for electrocatalysis offering high-performance water oxidation Author Information: Nabeen K. Shrestha (First author, Dongguk University), Supriya A. Patil (Sejong University), Jun Ho Seok (Sungkyunkwan University), Amol S. Salunke (Dongguk University), Sangeun Cho (Dongguk University), Akbar I. Inamdar (Dongguk University), Youngsin Park (Dongguk University), The corresponding authors are Prof. Sang Uck Lee (Sungkyunkwan University), Prof. Hyungsang Kim (Dongguk University), and Prof. Hyunsik Im (Dongguk University). (A total of 10 authors participated.) Journal: Materials Today Physics(IF: 10.0) Paper Link: DOI: 10.1016/j.mtphys.2023.101252 Figure 1. Comparative electrocatalytic OER performances of various anodes. (A) Linear sweep polarization curves measured at 1 mVs− 1 in 1.0 M aqueous KOH solution and corresponding (B) OER overpotential vs. current density profiles, (C) Tafel slopes and (D) Nyquist plots exhibited by the anodes. The inset image in (d) is the equivalent circuit used to fit the impedance data. Figure 2. Theoretical evaluation on the oxygen evolution reaction (OER) catalytic activities of Ni-MOF and NiCe-0.2 MOF. (A) Differences in crystal structure metal-oxygen bond length and distortion index between Ni-MOF and NiCe-0.2 MOF, (B) Ce3+ ion induced charge transfer in NiCe-0.2 MOF, and (C) Proposed adsorbate evolution mechanism (AEM) pathway for the NiCe-0.2 MOF catalysts. Free energy diagrams (FEDs) of OER according to the active sites of (D) Ni-MOF and (E) NiCe-0.2 MOF at U = 0 V, U = 0.402 V, and U = 0.402 V+ ηOER in alkaline media. The pink shading indicates the potential determining step (PDS).
- No. 274
- 2024-11-20
- 540
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Development of Self-Evolving Virtual Sensing Technology in Digital Twin Environments
Dr. Sungmin Yoon’s research team from the School of Civil Architectural Engineering and Landscape Architecture has developed a virtual sensing technology for building operational phases that autonomously evolves and self-calibrates within a digital twin environment. Conventional virtual sensor technology has primarily focused on products in the manufacturing industry, utilizing controlled laboratory settings for research and development. However, in the building sector, where “every building is different,” the architectural uniqueness and complex systems make it challenging to establish laboratory environments and develop high-performance virtual sensors. Particularly, there is a technical contradiction when physical sensors are required to develop virtual sensors for specific variables. This study overcomes these limitations by creating an innovative modeling technique and algorithm that enables virtual sensors to be autonomously generated, expanded, and continuously self-calibrated within actual building digital twin environments beyond the lab. This technology implements the concept of in-situ virtual sensing through nonintrusive indirect modeling, which integrates physical theories of building systems with surrounding sensor data without relying on direct measurements of physical variables. <Digital Twin Living Lab and Winter District Heating System Validation Results> Validation results demonstrated the performance of this technology, achieving an RMSE of 0.27°C for hot water temperature in district heating systems in residential complexes and an annual MAPE of less than 1.5% for flow rates in centralized HVAC systems over a three-month winter period. <In-situ Virtual Sensing in Building Digital Twins: Autonomous Sensor Creation, Expansion, and Continuous Calibration in Building Operations> Dr. Yoon stated, "This field-based virtual sensing technology can potentially replace all thermometers and flow meters commonly used in the return lines of HVAC systems, significantly reducing sensor installation and maintenance costs in large-scale HVAC systems for plants, semiconductor clusters, communities, and campuses." He also mentioned ongoing development of virtual sensing-based AI operational management technology using GPT agents within the SKKU-SSIT program to explore its applicability in semiconductor clusters. <Urban Building Operational Management Platform with Virtual Sensing: T-ranno> This research was supported by the National Research Foundation of Korea’s Basic Research Program and published in Journal of Industrial Information Integration (Top JCR category, December 2023). - Title: In situ virtual sensors in building digital twins: framework and methodology - Authors:Sungmin Yoon, Jaebum Koo, Youngwoong Choi (Sungkyunkwan University) - Journal: Journal of Industrial Information Integration (IF 15.7, as of publication year) - DOI: https://doi.org/10.1016/j.jii.2023.100532
- No. 273
- 2024-11-15
- 540
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Innovative Design of Stretchable Pressure Sensors with Enhanced Sensitivity and Linearity
Professor Jong-Woong Kim's research team has proposed a new structure to enhance linearity and sensitivity in pressure sensor design, unveiling two types of stretchable sensors. This research is expected to expand the application range significantly by dramatically improving the properties of the device through a simple approach. Reliable pressure sensors must possess both high sensitivity and excellent linearity within their detection range. The research team designed the sensor structure to ensure that the initial voltage and current values remain low while allowing for linear changes in response to pressure, considering that the sensitivity is calculated based on the ratio of electrical characteristics during initial deformation. Additionally, to enhance the longevity of the device in light of continuous friction and contact, self-healing materials were introduced, enabling all components of the manufactured sensors to be self-healable repeatedly. To address potential noise issues in the sensor's operating environment, a one-dimensional convolutional neural network (1D CNN) model was incorporated to differentiate subtle signals. Furthermore, the frictional electric pressure sensor equipped with an artificial intelligence model was attached to a glove, successfully detecting electrical signals that vary based on the user's grip strength and timing when holding a baseball, thereby demonstrating its potential as an intelligent sensor. These two pressure sensors have been published in the international journals Nano Energy (Impact Factor: 16.8) and Advanced Science (Impact Factor: 14.3) in September 2024, acknowledging the credibility of the research results. The main idea of this research, regarding the nonlinear increase in contact area between sensor materials under pressure, was proposed by Su Bin Choi, a doctoral student and first author of the paper. This concept was validated through experiments and simulations, leading to its publication. Professor Jong-Woong Kim's research team continues to conduct studies that strategically enhance properties through structural design and material selection, actively incorporating artificial intelligence models to further expand the functionality of the devices. This is expected to broaden the possibilities for intelligent sensor applications.
- No. 272
- 2024-11-12
- 714
