Department of Chemistry

Abstract Perovskite/organic tandem solar cells (POTSCs) are promising candidates for surpassing the Shockley-Queisser limit through reduction of thermalization losses. However, wide bandgap perovskite solar cells (WBG PSCs), which function as top cells of POTSCs, still suffer from significant open-circuit voltage (VOC) losses, limiting efficiency improvement of POTSCs. Here, a multi-functional hole-selective layer (mHSL) is reported via blending two functionalized self-assembled monolayer (SAM) molecules: (4-(3,6-diiodo-9H-carbazol-9-yl)butyl)phosphonic acid (36ICzC4PA) and (4-(3,6-dimethoxy-9H-carbazol-9-yl)butyl)phosphonic acid (36MeOCzC4PA). The blending of the two molecules plays multiple roles: i) Suppressing micelle formation of SAM molecules, ii) optimizing energy level alignment with homogeneous and highly covered SAMs, iii) enhancing crystallinity and orientation of perovskite through interaction with SAM materials, and iv) suppressing both lattice strain and phase segregation. Implementing mHSL on WBG PSCs enables a power conversion efficiency (PCE) of 18.85% with a notable VOC of 1.366 V. When integrated into POTSCs, the PCE reached 24.73% (certified 24.19%) with record-high VOC and fill factor (FF) of 2.216 V and 84.07%, respectively. Furthermore, POTSCs exhibit excellent photo- and thermal stabilities, retaining ≈80% of their initial PCEs after maximum power point (MPP) tracking under 1-sun illumination in ambient conditions for 305 h or exposure to 65 °C in N2 conditions for 500 h. A novel thin-film material, capable of simultaneously enhancing the efficiency and durability of tandem solar cells has been developed. Led by Professor BongSoo Kim from the Department of Chemistry at UNIST, in collaboration with Professors Jin Young Kim and Dong Suk Kim from the Graduate School of Carbon Neutrality at UNIST, the team announced the development of a multi-functional hole-selective layer (mHSL) designed to significantly improve the performance of perovskite/organic tandem solar cells (POTSCs). Tandem solar cells are advanced photovoltaic devices that stack two different types of cells to absorb a broader spectrum of sunlight, thereby increasing overall energy conversion efficiency. Among these, combinations of perovskite and organic materials are particularly promising for producing thin, flexible solar panels suitable for wearable devices and building-integrated photovoltaics, positioning them as next-generation energy sources. The research team successfully developed a hole-transport layer (HTL) by blending two self-assembled molecules, achieving a record open-circuit voltage (VOC) of 2.216 V and a power conversion efficiency (PCE) of 24.73%. The VOC, which reflects the maximum voltage the cell can produce without current flow, is a critical indicator of device performance. This efficiency level is among the highest ever recorded for perovskite-organic tandem solar cells globally. Moreover, the device maintained over 80% of its initial efficiency after prolonged exposure to high temperatures of 65°C and continuous illumination, demonstrating excellent long-term stability. The newly developed HTL is carefully engineered to align its energy levels with the perovskite active layer, selectively extracting holes while blocking electrons, thereby reducing charge recombination losses. Efficient charge extraction is essential because, after light absorption, electrons and holes must reach their respective electrodes to generate current; misaligned energy levels cause charge loss and reduced efficiency. Additionally, this HTL reduces interface defects that hinder charge transport and stabilizes the crystal structure, thanks to the strong chemical bonds formed between the substituents of the self-assembled molecules—36ICzC4PA and 36MeOCzC4PA—and the metal ions within the perovskite layer. The self-assembly property of these molecules ensures a uniform, ultra-thin coating over large areas, simplifying manufacturing processes and facilitating scalable production for commercialization. Professor Kim commented, "By developing a self-assembled hole transport layer that improves charge extraction, interface stability, and structural durability, we have made a significant leap forward in enhancing the performance of tandem solar cells. This development brings us closer to realizing thin, flexible, and high-efficiency next-generation solar panels for practical applications." This research involved first authors Jung Geon Son and Shahid Ameen and was published in Advanced Energy Materials on April 8, 2025. The study was supported by the National Research Foundation of Korea (NRF) through the Ministry of Science and ICT (MSIT). Journal Reference Jung Geon Son, Shahid Ameen, Jina Roe, et al., "Exceeding 2.2 V Open-Circuit Voltage in Perovskite/Organic Tandem Solar Cells via Multi-Functional Hole-Selective Layer," Adv. Energy Mater., (2025).

Abstract Zeolitic imidazolate frameworks (ZIFs), metal–organic analogues of zeolites, hold great potential for carbon-neutral applications due to their exceptional stability and porosity. However, ZIF discovery has been hindered by the limited topologies resulting from a mismatch between numerous predicted and few synthesized zeolitic networks. To address this, we propose a data-driven search algorithm using structural descriptors of known materials as a screening tool. From over 4 million zeolite structures, we identified potential ZIF candidates based on O–T–O angle differences, vertex symbols, and T–O–T angles. Energy calculations facilitated the ranking of ZIFs by their synthesizability, leading to the successful synthesis of three ZIFs with two novel topologies: UZIF-31 (uft1) and UZIF-32, -33 (uft2). Notably, UZIF-33 exhibited remarkable CO2 selective adsorption. This study highlights the synergistic potential of combining structural predictions with chemical intuition to advance material discovery. A collaborative research effort between UNIST and the Korea Institute of Science and Technology (KIST) has led to the successful synthesis of three novel porous materials by leveraging a data-driven structure prediction algorithm. These newly developed materials, modeled after zeolites, represent metal-organic frameworks (MOFs) with exceptional selectivity in gas separation, particularly for carbon dioxide (CO₂). Led by Professor Wonyoung Choe of the Department of Chemistry at UNIST, in collaboration with Professor Hyunchul Oh and Dr. Jung-Hoon Lee from KIST, the team has reported the first-ever synthesis of UZIF-31, UZIF-32, and UZIF-33—three unprecedented zeolitic imidazolate frameworks (ZIFs). MOFs are crystalline materials composed of metal ions and organic ligands that form highly porous structures. ZIFs, in particular, are known for their chemical stability and tunable pore architectures, making them ideal candidates for applications in catalysis, gas storage, and separation. Despite the theoretical potential for millions of ZIF structures, only about 50 have been synthesized since their discovery in 2006, a limitation often referred to as the "zeolite conundrum." To address this challenge, the research team developed a novel algorithm that integrates chemical intuition with structural analysis, evaluating key parameters such as bond angles, ring connectivity, and network regularity. By applying this methodology to a virtual dataset of over 4.45 million candidates, the team shortlisted 420 structures and identified 90 top-tier candidates based on energy stability. The structure of the ZIF predicted by the algorithm has been featured on the cover of the March 2025 issue of JACS Au. The experimental validation of the selected candidates resulted in the successful synthesis of three high-performance ZIFs, all of which demonstrated superior gas separation capabilities. Notably, UZIF-33 exhibited more than tenfold selectivity for CO₂ over methane, underscoring its significant potential for greenhouse gas separation and purification applications. "This study exemplifies how digital prediction can directly translate into experimental success," said Professor Choe. "By combining our algorithm with automated synthesis technologies, we could dramatically accelerate the development of next-generation ZIF materials with tailored properties." The findings were published on March 24 in JACS Au, a prestigious journal of the American Chemical Society (ACS). This research was supported by the Ministry of Science and ICT (MSIT), the Institute of Information & communications Technology Planning & Evaluation (IITP), the National Research Foundation of Korea (NRF), KIST, and the Carbon Neutral Institute Research Fund of UNIST. Journal Reference Soochan Lee, Hyein Jeong, Sungyeop Jung, et al., "Data-Driven Search Algorithm for Discovery of Synthesizable Zeolitic Imidazolate Frameworks," JACS Au, (2025).

Abstract Recently, targeted protein degradation (TPD) strategies have emerged as a promising solution to tackle undruggable proteins. While most TPD strategies target intracellular proteins, limited options exist for targeting extracellular or membrane proteins. Herein, cancer specific carbonic anhydrase IX (CAIX)-targeting supramolecular nanofibrous lysosome-targeting chimeras (Supra-LYTAC) is reported. Two self-assembling amphiphilic peptides are synthesized: one that interacts with the protein of interest (POI), and another that mediates lysosomal endocytosis by targeting a cancer-specific enzyme. Notably, these two peptides co-assemble into nanofibers capable of targeting cancer cells in a spatiotemporal manner. Through dynamic and multivalent binding, a ternary complex form (supramolecular chimeric nanostructure; CAIX-nanofiber-POI), which undergoes internalization into lysosomes where the POI is degraded through lysosomal catalytic activity. This study demonstrates the potential of supramolecular approaches to expand the scope of LYTAC technology, offering new opportunities for designing TPD strategies in the future. A research team, affiliated with UNIST has introduced a novel approach that targets and destroys proteins used by cancer cells to escape immune detection, potentially opening new avenues for effective cancer therapies. Led by Professor Ja-Hyoung Ryu in the Department of Chemistry at UNIST, the team has pioneered a groundbreaking composite assembly technology capable of degrading immune-evasion proteins on cancer cells. This innovative method involves encapsulating these proteins within a complex that directs them to lysosomes—cellular structures dedicated to breaking down proteins. By creating an environment conducive to immune recognition and attack, this technology promises to enhance the efficacy of immunotherapies. Cancer cells often overexpress the protein PD-L1 on their surfaces, which transmits inhibitory signals to immune cells, effectively 'turning off' immune responses and allowing tumors to proliferate unchecked. Overcoming this immune suppression is critical for advancing cancer treatments. The research team developed a technology based on acetazolamide that selectively degrades PD-L1 on cancer cells. Acetazolamide binds specifically to CAIX, an enzyme predominantly expressed on the surface of cancer cells, forming nano-sized protein complexes. These complexes simultaneously carry immune-evasion proteins like PD-L1 into the cell’s interior. Once inside, the nanocomplexes are recognized as abnormal proteins and are degraded within lysosomes—the cell’s 'waste disposal' organelles. Since CAIX is scarcely present in normal cells, this reaction is highly selective for cancer cells, minimizing potential side effects. In animal experiments involving mice, administration of this complex resulted in more than a 50% reduction in tumor size and a significant decrease in PD-L1 levels on cancer cells. These findings demonstrate the potential of this technology to restore immune system recognition and facilitate tumor elimination. Scheme 1. a,b) Monomer design for Supra-LYTAC; c,d) Illustration demonstrating co-assembly to yield nanofiber and nanosphere. The nanofiber structure could be constructed in FFK-based peptides due to the high self-assembly propensity, while GGK-based peptides generate nanosphere structure; e) Supra-LYTAC constructed in the cancerous membrane by targeting CAIX. It can further interact with POI, as followed by internalization into lysosome via CAIX-induced endocytosis; f) Nanosphere showing weak ability for the internalization into lysosome due to low self-assembly propensity; g) POI internalizing into lysosome with Supra-LYTAC could be degraded in the lysosome. Dohyun Kim, the first author of the study, stated, "We aim to further explore additional pathways through which the immune system can directly target and eliminate cancer." While existing protein-degrading technologies such as PROTACs and LYTACs have shown promise, they often face limitations related to molecule size and cellular entry due to their complex structures. To overcome these hurdles, the research introduces a new approach where the molecules self-assemble within the body, enabling more efficient and targeted protein degradation. Professor Ryu commented, "This represents a new form of targeted protein degradation technology that surpasses the limitations of conventional polymer-based chimeras. It has significant potential for combination therapy with immunotherapies and for treating various refractory solid tumors." The study was published in Advanced Science on April 3 and was supported by the Ministry of Science and ICT and the National Research Foundation of Korea. Journal Reference Dohyun Kim, Gyeongseok Yang, Chaelyeong Lim, et al., "Cancer Specific CAIX-Targeting Supramolecular Lysosome-Targeting Chimeras (Supra-LYTAC) for Targeted Protein Degradation," Adv. Sci., (2025).

Abstract Irreproducible wrinkling, characterized by randomly arranged ridges or creases on material surfaces, has significant potential for application in entity identification and anti-counterfeiting. However, active research in this field is hindered because the existing wrinkling methods face challenges in realizing discernible patterns and potential applications of submillimeter-scale wavelength wrinkles are yet to be identified. Herein, we propose a strategy to create unique and irreproducible styrene–ethylene–butylene–styrene (SEBS) wrinkles using “spin evaporation”, a technique that rapidly removes the solvent by spinning. We demonstrate the realization of SEBS wrinkles with wavelengths of hundreds of micrometers with high randomness, irreproducibility, and resistance to external stimuli. Importantly, to demonstrate the potential application of the wrinkle, we suggest and fabricate a human-finger-like fully soft identifiable artificial finger pad electronics and integrate it with a soft bimodal sensing system. The artificial finger pad mimics human finger pad features such as identification, object recognition, and effective grasping. Further integration of this pad into soft robots, cephalopods, and prosthetic skin offers insightful potential for the proposed wrinkling method in various fields. The likelihood of two human fingerprints being identical is extremely low—about 1 in 640 billion. Even identical twins, despite sharing the same genetic information, have unique fingerprints. A new technology now allows us to engrave these unique fingerprint patterns onto electronic skin, with the probability of matching an artificial fingerprint being 10²³² times lower than that of human fingerprints. A research team, led by Professor Kyoseung Sim from the Department of Chemistry at UNIST has developed advanced electronic skin that features unique wrinkling patterns, surpassing even those of human fingerprints. This innovation may pave the way for a new era in which physical AI robots can possess unique fingerprint identification capabilities. To be effective, electronic skin must incorporate sensors for tactile sensation while also maintaining flexibility. Thus, flexible organic materials are more suitable than rigid inorganic ones. Moreover, electronic skin meant for fingers must be capable of distinguishing between objects, making it challenging to create skin that possesses both functionality and unique fingerprint-like patterns. Professor Sim's team has designed a method to easily engrave random wrinkling patterns on styrene–ethylene–butylene–styrene (SEBS) electronic skin. The technique involves chemically treating a flexible polymer to initially create the skin and then applying toluene solvent before spinning it rapidly. As the toluene evaporates, the skin’s surface contracts to form these random wrinkles. Figure 1: SEBS wrinkling enabling identifiable artificial finger pad electronics. (a) Optical image and schematic of SEBS structure. (b) Schematic of spin evaporation. (c)–(e) Representative optical microscopy (c), confocal laser scan microscopy (d), and cross-sectional profile (e) of SEBS wrinkle. (f) Optical image of the human hand and identifiable artificial finger pad electronics. The probability of this artificial fingerprint being reproduced in the exact same shape is merely 10⁻⁴³ based on a 1mm² area—an astounding figure that is 10²³² times lower than the probability for human fingerprints. When scaled up to the size of a human fingerprint, the likelihood of producing the same pattern approaches zero. Additionally, this electronic skin is resilient to physical impacts, heat, and humidity, allowing for the preservation of its fingerprint-like structure. When implanted into a robotic hand, the developed electronic skin enables the robot to grasp objects similarly to humans, recognize surface textures, and differentiate between living beings. The research team has demonstrated a physical interaction where a robot equipped with temperature-sensing electronic skin avoids hot objects, mimicking human responses. Figure 2. Soft artificial finger pad. (a) Optical images of the soft artificial finger pad on robotic hand (left), freestanding artificial finger pad (middle), and optical microscopy image of artificial fingerprint (right). (b) Schematic exploded view of the fully soft artificial finger pad. c Stress-strain curves of components used. "By employing a straightforward process, we have achieved a lower probability of creating identical patterns compared to actual fingerprints," noted Professor Sim. "This technology has broad potential applications in security and unique identification for future technologies, such as personalized electronic skin, soft robots with life-cycle management, and next-generation human-machine interfaces." The study involved first authors Juyeong Lee and Haechan Park from the UNIST Department of Chemistry and was conducted in collaboration with Professor Zhengwei Li's team from the Department of Biomedical Engineering at the University of Houston in the United States of America. This research was supported through the UBSI Research Fund of UNIST and the Young Researcher Support Program by the Ministry of Science and ICT (MSIT) and the National Research Foundation of Korea (NRF). The findings were published in the prestigious international journal, Nature Communications on March 5, 2025. Journal Reference Juyeong Lee, Haechan Park, Sehyun Kim, et al., "Irreproducible SEBS wrinkling based on spin evaporation enabling identifiable artificial finger pad electronics," Nat. Commun., (2025).

Abstract The photovoltaic performance of inverted perovskite solar cells (PSCs) relies on effectively managing the interface between the hole extraction layer and the light-absorbing perovskite layer. In this study, we have synthesised (4-(3,6-bis(methylthio)-9H-carbazol-9-yl)butyl)phosphonic acid (MeS-4PACz), which forms a self-assembled monolayer (SAM) on the fluorine-doped tin oxide (FTO) electrode. The molecule‘s methylthio substituents generate a favourable interfacial dipole moment and interact with the perovskite layer. This interaction results in well-aligned energy levels among the FTO/SAM/perovskite layers, promoting efficient hole extraction and significantly reducing carrier recombination losses. Additionally, the methylthio groups passivate iodide vacancies and interact with Pb2+ ions of the perovskite, reducing defect-induced trap states and enhancing the crystalline growth of the perovskite layer. Consequently, inverted PSCs incorporating MeS-4PACz achieve a power conversion efficiency of 25.13 %, along with outstanding photostability. A research team, affiliated with UNIST has announced a significant advancement in the efficiency and stability of perovskite solar cells (PSCs), known as next-generation photovoltaic technology, through the development of a self-assembled hole transport material. On March 19, Professor BongSoo Kim and his research team from the Department of Chemistry at UNIST, in collaboration with Professor Dong Suk Kim and Professor Jin Young Kim from the Graduate School of Carbon Neutrality at UNIST, as well as Professor Kyung-Koo Lee from Kunsan National University (KSNU), revealed their new self-assembling monolayer (SAM) material that enhances the performance of PSCs. PSCs are highly competitive in price due to their use of inexpensive materials and low manufacturing costs. The self-assembled monolayer serves as the material that transports holes (positively charged carriers) generated by the light-absorbing perovskite layer to the electrode. Because the SAM forms through the self-assembly of molecules on the substrate, it provides a cost advantage over traditional polymer-based hole transport layers. Figure 1. Schematic representation illustrating a methylthiocarbazole-based phosphonic acid, MeS-4PACz, forms a self-assembled monolayer (SAM) on fluorine-doped tin oxide, inducing an interfacial dipole and passivating iodide vacancies in FAPbI3 perovskite. Inverted perovskite solar cells with MeS-4PACz as a hole-selective layer achieved a power conversion efficiency of 25.134%. The research team designed a new molecule, MeS-4PACz, to improve hole transport performance beyond that of its predecessor, 4PACz. The application of MeS-4PACz in PSCs resulted in a power conversion efficiency of 25.16%, an increase of over 13% compared to previous SAMs. High efficiency in solar cells arises when both electrons (negatively charged carriers) and holes efficiently reach the electrodes. The hysteresis value—the indicator of solar cell output and long-term stability—also showed significant improvement. The developed material demonstrated excellent photostability, maintaining 93% of its initial efficiency after exposure to strong sunlight for 500 hours, while the solar cells utilizing 4PACz saw a reduction in efficiency of over 20% after the same duration. The MeS-4PACz molecule incorporates a methylthio (-SCH₃) functional group that aligns well with the energy levels of the perovskite layer, facilitating the smooth transport of holes generated in the perovskite layer to the electrode. Additionally, the sulfur in the methylthio group forms a strong chemical bond with the cations in the perovskite, effectively preserving the initial optimized state of the perovskite layer under solar exposure and significantly enhancing interfacial stability. Professor Kim noted, "The developed SAM maximizes the cost advantages of PSCs while simultaneously improving their stability and efficiency, greatly enhancing the prospects for market entry of perovskite solar technologies." This research involved joint first authors Dr. Shahid Ameen, researchers Dongmin Lee and Jung Geon Son from UNIST, along with Abdullah Bin Faheem from Kunsan National University. The findings have been made available online in Angewandte Chemie International Edition ahead of its formal publication. The research was conducted with support from the Ministry of Science and ICT (MSIT) and the National Research Foundation of Korea (NRF). Journal Reference Dr. Shahid Ameen, Dongmin Lee, Abdullah Bin Faheem, et al., "3,6-Bis(methylthio)-9H-carbazole Based Self-Assembled Monolayer for Highly Efficient and Stable Inverted Perovskite Solar Cells," Angew. Chem., Int. Ed., (2025).

Abstract Understanding efficiency–durability relationships and related mitigation strategies is an important step toward the commercialization of organic photovoltaics (OPVs). Here, we report that a photoactivated 6-bridged azide cross-linker (6Bx) improves the morphological stability by suppressing the thermally activated diffusion of (Y6) acceptor molecules in PM6:Y6 bulk-heterojunction (BHJ)-based OPVs. Cross-linked PM6:Y6 (0.05 wt % 6Bx) BHJ OPVs retain 93.4% of the initial power conversion efficiency upon thermal aging at 85 °C for 1680 h (T80 = 3290 h). Molecular origins of enhanced thermal stability are corroborated by optical spectroscopy, surface imaging, 2D solid-state nuclear magnetic resonance (ssNMR), Raman spectroscopy, scanning electron diffraction (SED) measurements, and analysis of the BHJ thin films. The facile single-step cross-linking strategy in conjugation with advanced characterization methods presented in the study paves the way toward developing durable OPVs based on non-fullerene acceptors (NFAs). An international team of researchers, affiliated with UNIST, has unveiled a novel cross-linker additives that significantly address the longstanding stability issues associated with organic solar cells, also known as organic photovoltaics (OPVs). With the incorporation of just 0.05% of this cross-linking agent, the lifespan of OPVs can be improved by over 59%. Industry analysts suggest this breakthrough brings the commercialization of OPVs—regarded as next-generation solar cells—closer to reality. Led by Professor BongSoo Kim in the Department of Chemistry at UNIST, the research team, in collaboration with researchers from the University of California, Santa Barbara (UCSB), the University of Lille in France, and the French National Center for Scientific Research (CNRS), identified the operational principles of this innovative cross-linker using a variety of advanced analytical techniques. OPVs are emerging as promising next-generation solar cells due to their ease of manufacturing and flexibility, allowing them to be applied as films. However, the inherent nature of organic materials poses challenges for long-term stability, particularly under heat exposure. While previous strategies have explored the addition of cross-linkers to enhance stability, excessive amounts often led to a decrease in battery efficiency. The research team developed a 6-bridged azide cross-linker (6Bx), a highly efficient photo-crosslinker that demonstrates superior stabilizing effects with minimal additives quantities. As illustrated in Figure 1, 6Bx is composed of six azide cross-linkable units, which enables an impressive theoretical cross-linking efficiency of 96%. This efficiency significantly surpasses that of conventional cross-linkers, with four azide units yielding an efficiency of 82% (4Bx) and two azide units resulting in only 36% (2Bx). Figure 1. (Top) Chemical structures of PM6, Y6, and 6Bx cross-linker. (Bottom) Power conversion efficiency (PCE) of OPVs fabricated with the new cross-linker. The reported OPVs fabricated with the new cross-linker demonstrated an impressive efficiency of 11.70% even after 1,680 hours (70 days) at 85°C, retaining 93.4% of their initial efficiency. In contrast, OPVs produced without the cross-linker experienced a decline in efficiency to 8.17%, representing only 58.7% of the initial efficiency of 13.92%. This signifies a more than 59% improvement in performance longevity. The research team also discovered that the elevated performance can be attributed to the effective suppression of molecular movement of the Y6 acceptor molecule in the photoactive layer of OPV devices, enabled by cross-linking reactions. Professor Kim stated, "We have successfully addressed the chronic stability issues in organic solar cells through the development of high-efficiency photo-crosslinking agents and comprehensive investigations into their mechanisms." He further added, "This research will significantly contribute to the development of stability enhancement technologies for the commercialization of OPVs." This study also involved contributions from Professor Thuc-Quyen Nguyen of UC Santa Barbara, as well as Professor G. N. Manjunatha Reddy from the University of Lille and CNRS in France. At UNIST, researchers Myongjae Lee and Seongju Yoo from the Department of Chemistry participated in the project. The research has been supported by the Samsung Future Technology Promotion Foundation, and the findings were published in ACS Energy Letters on January 10, 2025. Journal Reference Sangcheol YoonBraulio Reyes-SuárezSang T. Pham, et al., "Molecular Cross-Linking Enhances Stability of Non-Fullerene Acceptor Organic Photovoltaics," ACS Energy Lett., (2025).

Abstract Efficient separation of hydrogen isotopes, especially deuterium (D2), is pivotal for advancing industries such as nuclear fusion, semiconductor processing, and metabolic imaging. Current technologies, including cryogenic distillation and Girdler sulfide processes, suffer from significant limitations in selectivity and cost-effectiveness. Herein, we introduce a novel approach utilizing an imidazolium-based Metal–Organic Framework (MOF), JCM-1, designed to enhance D2/H2 separation through temperature-dependent gate-opening controlled by ion exchange. By substituting NO3− ions in JCM-1(NO3−) with Cl− ions to form JCM-1(Cl−), we precisely modulate the gate-opening threshold, achieving a significant enhancement in isotope selectivity. JCM-1(NO3−) exhibited a D2/H2 selectivity (SD2/H2) of 14.4 at 30 K and 1 bar, while JCM-1(Cl−) achieved an exceptional selectivity of 27.7 at 50 K and 1 mbar. This heightened performance is attributed to the reduced pore aperture and higher gate-opening temperature resulting from the Cl− exchange, which optimizes the selective adsorption of D2. Our findings reveal that JCM-1 frameworks, with their finely tunable gate-opening properties, offer a highly efficient and adaptable platform for hydrogen isotope separation. This work not only advances the understanding of ion-exchanged MOFs but also opens new pathways for targeted applications in isotope separation and other gas separation processes. A research team, jointly led by Professor Hyunchul Oh in the Department of Chemistry at UNIST and Professor Eunsung Lee at Seoul National University, has introduced a novel approach, capable of adjusting the pore size of porous materials in increments of 0.01 nm (10-9 m). This innovative technology efficiently separates deuterium, an isotope of hydrogen that constitutes only 0.015% of the total hydrogen found in nature and shares similar properties with ordinary hydrogen. Deuterium is a crucial resource for applications in nuclear fusion power generation and semiconductor manufacturing, making its efficient separation highly valuable. The research team demonstrated that the pore sizes of metal-organic frameworks (MOFs) can be fine-tuned through ion exchange, achieving unprecedented control and significantly enhancing the separation efficiency of deuterium in these materials. To optimize separation efficiency, the researchers illustrated that deuterium and hydrogen can effectively be separated using the precisely adjusted pores of a newly developed MOF. It is essential to finely calibrate the pore size, which acts as a molecular sieve. Given that both hydrogen and deuterium are approximately 0.3 nm in size, achieving precise modifications at the 0.01 nm scale is critical. Figure 1. A schematic diagram representing the summary of the study. Gate-opening control via anion exchange in JCM-1 enables enhanced hydrogen isotope separation through precise tuning of pore aperture and diffusion barriers. The dynamic interplay between structural flexibility and adsorption energetics maximizes D2/H2 selectivity, establishing a robust platform for cryogenic gas separation applications. The researchers successfully reduced the pore inlet size of the JCM-1 MOF from about 0.39 nanometers to 0.36 nanometers by replacing nitrate ions (NO₃⁻) with chloride ions (Cl⁻). Their analysis revealed that Cl⁻ induces a stronger inward pull on the outer framework connected to the pore, resulting in a smaller pore size. As a result of this modification, the selectivity for deuterium separation in JCM-1 (Cl⁻) increased significantly from 14.4 to 27.7, effectively doubling the efficiency compared to JCM-1 (NO₃⁻). Notably, JCM-1 (NO₃⁻) exhibited selectivity nine times greater than the conventional cryogenic distillation method at 24K (-249.15°C), while JCM-1 (Cl⁻) demonstrated over 18 times higher selectivity than that method. Professor Oh, the lead investigator, stated, "This achievement offers a novel approach to precisely controlling the nanopore sizes of porous materials, with potential applications not only in isotope separation but also in various gas separation processes." Their findings have been published in Angewandte Chemie International Edition (Impact Factor: 16.1) on February 12, 2025. This research was funded by the National Research Foundation of Korea (NRF) and the Ministry of Science and ICT (MSIT). Journal Reference Hyunlim Kim, Younggyu Seo, Jaewoo Park, et al., "A Gate-Opening Control Strategy via Nitrate–Chloride Anion Exchange for Enhanced Hydrogen Isotope Separation in Metal–Organic Frameworks," Angew. Chem. Int. Ed., (2025).

Abstract Anion–π interactions are crucial in various biological processes, such as enzyme catalysis and ion transport. Despite their significance, the exploitation of anion–π interactions in synthetic polymer systems remains underexplored. This study investigates anion–π interactions using chemically well-defined peptidomimetics guided by the composition of mussel foot proteins. Specifically, polyether-based polymers were designed utilizing two functional epoxide monomers—catechol acetonide glycidyl ether and 4,4-dimethyl-2-oxazoline glycidyl ether—to mimic the key amino acids 3,4-dihydroxyphenylalanine and aspartic acid, respectively. A surface forces apparatus was employed to study the anion–π interaction between the polymers, considering the effects of relative monomer composition and pH conditions. The maximum cohesion energy of 15.0 mJ/m2 was observed at an equimolar monomer composition at pH 7. Incorporating a phenyl group instead of the catechol group and introducing competing anions confirmed the dominant role of anion–π interactions. This study highlights the significance of anion–π interactions, posing a high potential in the design and synthesis of functional materials. A research team, led by Professor Dong Woog Lee from the Department of Chemistry at UNIST, in collaboration with Professor Byeong-Su Kim from the Department of Chemistry at Yonsei University, has discovered that the synergistic anion–π interactions serves as a key principle in enhancing the cohesion of synthetic polymers. In this groundbreaking study, the researchers developed an epoxy monomer-based polymer that mimics the structural features of mussel foot proteins and experimentally demonstrated that anion–π interactions are pivotal in strengthening polymer cohesion. Figure 1. (Top) Representative examples of anion–π interactions exploited in natural and synthetic systems and (Bottom) the peptidomimetic system explored in this study. l Image Credit: Department of Chemistry, Yonsei University Anion–π interactions are non-covalent bonds formed between negatively charged molecules (anions) and the π electron systems of aromatic rings. While these interactions are known to play critical roles in biological processes such as enzyme catalysis and ion transport, research exploring their application in synthetic polymers remains scarce. Inspired by mussels, which exhibit remarkable adhesive properties in natural environments, the research team focused on the plantar proteins of these organisms. Through an analysis of the key components contributing to their strong binding capabilities, the scientists found that the structural characteristics of 3,4-dihydroxyphenylalanine (DOPA) and aspartic acid are particularly significant. To advance their findings, the research team designed functional monomers that replicate these structural features, leading to the synthesis of a novel polymer. This work proposes a new design methodology for polymers, taking into account the complex intermolecular interactions present in biological systems. Specifically, the monomer that emulates the DOPA structure provides the π-electronic field of the aromatic ring, while the monomer representing aspartic acid introduces the anion necessary for anion–π interactions within the polymer framework. Furthermore, the team employed a surface force apparatus (SFA) to quantitatively analyze the cohesiveness of the polymer under various conditions. The team compared the cohesion of the polymer in neutral environments, where its functional groups are ionized, against acidic conditions, where they remain non-ionized. Their findings revealed that in neutral environments, anion–π interactions serve as the principal binding force, significantly enhancing polymer cohesion. In contrast, under acidic conditions, hydrogen bonding dominates, resulting in comparatively weaker cohesion. This study marks the first experimental evidence highlighting the decisive role of anion–π interactions in reinforcing cohesion among synthetic polymers. The implications of these findings open avenues for innovative polymer design strategies applicable in diverse fields, including adhesives, self-assembly systems, catalysts, and drug delivery. This research was supported by the National Research Foundation of Korea (NRF) and the Ministry of Science and ICT (MSIT). The findings of this study were published in the online version of Proceedings of the National Academy of Sciences (PNAS) on February 6, 2025. Journal Reference Seunghyun Lee, Aram Shin, Jinwoo Park, et al., "Synergistic anion–π interactions in peptidomimetic polyethers," PNAS, (2025).

Abstract Entropy-driven strategy enables the systematic design of complex systems by using entropy as a quantifiable design parameter for the degree of mixing. In this study, we present mixed-linker zeolitic imidazolate frameworks (ZIFs), sod-ZIF-1 series, that features two types of six-membered rings (6MRs) with aperture sizes of 3.4 Å and 1.7 Å. By adjusting the configurational entropy, the ratio of these 6MRs can be systematically controlled, which significantly influences adsorptive properties, particularly improving the H2 affinity about 3 times throughout the series. This results in the significant enhancement of retention times in dynamic separation of hydrogen isotopes (D2/H2), even over LNG liquefaction temperature. This approach to entropy-driven pore engineering provides new opportunities for enhancing gas adsorption and separation processes. A research team, affiliated with UNIST has successfully developed a new porous material for the efficient separation of deuterium, a primary fuel for nuclear fusion. The team, jointly led by Professors Wonyoung Cho and Hyunchul Oh in the Department of Chemistry at UNIST, announced this breakthrough online in the January 2025 issue of Angewandte Chemie International Edition, a leading chemistry journal. Metal-organic frameworks (MOFs) are a form of porous and crystalline materials constructed by the formation of chemical bonds between metal ions and organic ligands. A MOF separates the heavy hydrogen isotope deuterium from ordinary hydrogen, just like grain sieves that detect millet and other grains for screening and grading. The newly-developed MOF exhibits remarkable efficiency in deuterium separation, even at temperatures above the liquefied natural gas (LNG) liquefaction temperature (111K, -162.15°C). This is a significant improvement over the traditional method, which requires much colder cryogenic temperatures below 20K (-253.15°C). Figure 1. Entropy-based porous material design strategy. As entropy increases, the proportion of narrow pore entrances increases. The team employed an entropy-driven design strategy to create this new material. By mixing different organic ligands, similar to creating a cocktail, they increased the structural disorder, or entropy, within the MOF. This high-entropy state optimized the process of quantum sieving, which separates hydrogen and deuterium based on their differing diffusion rates. Quantum sieving exploits the differences in diffusion rates between hydrogen and deuterium. This results in a higher proportion of narrow pores in the framework, thereby improving the efficiency of the quantum sieving. The team confirmed this through X-ray diffraction and hydrogen isotope breakthrough experiments. According to Professor Cho, "This study marks the first application of high-entropy porous materials for gas separation and adsorption, confirming the potential of entropy-based design." He adds, "We hope this technology will contribute to the use of clean energy resources and the development of future energy technologies." The research team included Joohan Nam as the first author, alongside contributions from Changheon Cho, Yeongjin Kim, Yejin Hong, Sohyeon Lee, Sungyeop Jung, and Minji Jung. This study has been supported by the Ministry of Science and ICT (MSIT), the National Research Foundation of Korea (NRF), the Information and Communication Planning and Evaluation Institute (IITP), and UNIST. Journal Reference Joohan Nam, Changhyeon Cho, Sungyeop Jung, et al., "High-Entropy Zeolitic Imidazolate Frameworks for Dynamic Hydrogen Isotope Separation," Angew. Chem. Int. Ed.,(2024).

The '2025 Korean Chemistry Olympiad Winter School,' hosted by the Department of Chemistry at UNIST, concluded successfully, fostering a new generation of talented young chemists. About 52 first- and second-year high school students from across the country participated in the program, demonstrating exceptional enthusiasm and dedication to the study of chemistry. The winter school was a crucial step in selecting the Korean representative for the prestigious International Chemistry Olympiad (IChO). The 2025 Winter School consisted of two stages, providing a comprehensive learning experience for the students. The first stage, held from Janurary 6 to 10, offered in-depth chemistry theory lectures for first-year high school students. The second stage, which took place from January 12 to 18, brought all participating students together on the UNIST campus for an immersive six-day program, featuring hands-on experiments and lectures in various fields, including physical chemistry, analytical chemistry, organic chemistry, and inorganic chemistry. A notable highlight of the winter school was the rigorous evaluation process, which assessed students' knowledge and skills through interim, final, and experimental evaluations. Outstanding sophomore students who excelled in these assessments were awarded the opportunity to represent Korea at the International Chemistry Olympiad. The completion ceremony, held on January 18, was attended by distinguished guests, including President Phil Ho Lee of the Korean Chemical Society (KCS) and Chairman Hyeon Jeong of the Chemical Olympiad Committee, who offered words of encouragement and inspiration to the students. "We hope that our students will continue to challenge themselves and explore new knowledge, building on the foundation they established during the winter school," said Department Head Jaeheung Cho of the Department of Chemistry at UNIST, who also serves as the President of the 2025 Winter School. "Looking forward, we hope to cultivate a future generation of scientists who will harness the power of science to make a positive impact on society." The 2025 Korean Chemistry Olympiad Winter School was made possible through the generous support of the Korean Chemical Society (KCS), the Korea Foundation for Science and Creativity (KOSAC), and LG Chem Ltd. The UNIST faculty and the Korean Chemistry Olympiad Committee played a crucial role in designing and delivering a high-quality educational program, providing students with a unique opportunity to grow and develop their skills in a supportive and stimulating environment.