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- Nature-inspired materials help humans live longer
- Nature-inspired materials help humans live longer By seeking inspiration from pizza toppings and the suction cups of octopi, material scientists at Sungkyunkwan University are improving biomedicine and solar cells Sang-Woo Kim (left), Nam-Gyu Park (centre) and Nae-Eung Lee (right) are all seeking to use materials to benefit society. In their quest to develop materials that can greatly enhance human health and longevity, researchers at Sungkyunkwan University (SKKU) in South Korea are seeking inspiration from some surprising sources. “To come up with new ideas for biologically inspired biomaterials, our researchers often visit museums, talk to zoologists and watch nature documentaries,” says Nae-Eung Lee, the dean of Engineering at SKKU. The results include technology based on octopus suction cups, beetle hairs and spider organs. One key has been interdisciplinary initiatives such as the Biomedical Institute for Convergence at SKKU (BICS), which bring together researchers working on diverse topics such as integrated theragnostic approaches, nanomaterials, drug-delivery systems, nerve sensors and bioimaging systems. Inspiration from nature Taking inspiration from biopolymers, such as cellulose, collagen and exosomes — small packages of biomolecules that are released by cells — SKKU researchers are developing a technology that can directly sense parameters such as pH and temperature in the body. And it can deliver therapy based on the measurement results. “Nanomedicine promises to provide better treatment options for diseases such as cancer, rheumatoid arthritis and diabetes,” Lee says. Larger scale internal medical technology includes integrated bioelectronics that can attach to organs, tissue engineering for effective drug delivery, and neuroprosthetics that can connect machines directly into the brain. Integrating technology with humans is a revolution that Sang-Woo Kim believes could push human longevity above 100. Using static electricity to charge devices Kim’s group is trying to harness triboelectricity to charge biomedical devices. A phenomenon known to the ancient Greeks, triboelectricity is the static electricity generated by friction between dissimilar materials; it is behind the crackles and sparks that occur when removing synthetic clothing. Kim plans to use this static electricity to charge batteries in implanted devices. Tiny devices with layers of different materials that move back and forth with body movements, breathing or pulse can harvest energy, thereby eliminating the need for surgery to replace batteries. Characterizing the electrical output and biodegradability of an ultrasound-driven triboelectric nanogenerator based on transient materials. It is in a bovine serum solution, since it provides a similar composition to biological tissue. Kim initially hoped to use natural body movements, but they don’t provide enough energy. So to supplement this charging, his team is using ultrasound, which passes through tissue harmlessly and stimulates the triboelectric components to move back and forth. His group has painstakingly explored the best materials to use, including both existing materials such as Teflon and perovskites whose triboelectric properties had never been tested and new, more efficient materials. They have also improved the efficiency of the devices by using nanostructuring and porous structures to increase the surface area, to maximize the charge, and to funnel it into batteries before it discharges. Adding a topping to a pizza The variability of triboelectric pulses is not ideal for the slow, constant charging that batteries require, and so SKKU researchers began exploring supercapacitors for incorporating into triboelectric nanogenerators. They found that a better option was to build capacitance into the electrodes of the batteries. One example is black phosphorus, which is already used in batteries, despite its sluggish kinetics. The team improved its performance with an approach inspired by pizza. Instead of topping their black phosphorus with pepperoni, they added oxide molecules to the surface, which can quickly store charge like a capacitor. “Pristine black phosphorus is like mediocre plain pizza,” says Kim. “By adding toppings of oxygen atoms, we have developed a pseudo-capacitive device with a fast, reversible charge-storage mechanism.” Dissolving implanted devices safely Thanks to SKKU researchers’ impressive control of material properties, they are employing ultrasound to solve another problem: how to dispose of implanted devices that are no longer needed. Kim’s group is developing devices that can be dissolved at will using focused ultrasound. “The fact that we can choose the time to be absorbed would provide high practicality of transient implanted medical devices and eliminate inflammation or side effects from material residue,” Kim says. Making perovskites more competitive SKKU researchers are also addressing planetary health, by developing high-efficiency solar cells based on perovskites. Perovskites are organic–inorganic lead or tin halide-based crystalline materials that are challenging silicon-based cells in the efficiency stakes. “Because perovskites have high efficiency and are low cost they will play an important role,” says Nam-Gyu Park. An encapsulated perovskite solar-cell module. Nam-Gyu Park and his team are seeking to make such perovskite-based solar cells superior to conventional silicon-based ones. Park says perovskites’ early problems with instability caused by humidity can be overcome by encasing the cells in watertight layers. However, other challenges still need to be addressed, he says, citing Nobel Laureate Herbert Kroemer’s quote “the interface is the device.” Perovskites are currently used with silicon cells in tandem cells, which increases the number of interfaces. But Park and his group believe they can improve the efficiency of perovskite cells beyond 30% and make them viable stand-alone cells. Already, by creating a wrinkly surface they have improved the electrical properties, and now they are exploring the effect of defects in the crystals. Cracking that problem will need a fundamental shift in understanding, Park says. “Perovskites are mysterious materials that behave differently to conventional semiconductors. It’s an interesting journey to understand this intrinsic material.”
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- 작성일 2021-09-27
- 조회수 4263
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- Atomic-scale disorder enabled ever-smaller and ever-more-efficient microlasers
- Atomic-scale disorder enabled ever-smaller and ever-more-efficient microlasers Liquid-quenching breaks down the lattice structure of crystalline materials to minimize the energy loss during laser process. The research team of Prof. Dong-Hwan Kim (1st author: Dr. Byeong-Seok Moon) develop an ever-smaller and ever-more-efficient microlaser using a new upconversion material that has atomic-scale microstructural disorder through the collaboration with Prof. Young-Jin Kim (KAIST) and Prof. Sang Kyu Kwak (UNIST). Microlasers are the optical device that can generate laser emission while it is smaller than a few tenths of the thickness of a human hair. Microlasers have attracted a great attention because it can be used as a light source for photonic integrated circuits, for example, an optical communication chip (Intel® Silicon Photonics) for massive data transport. To bring the microlasers in our daily life, the researchers around the world have dedicated their efforts to further miniaturize the microlasers and improve their efficiency. However, as we miniaturize the microlasers, they lose their ability to confine and amplify the light. Therefore, the realization of both miniaturization and high laser efficiency has been considered as a challenging task. The research team of Prof. Dong-Hwan Kim has overcome this challenge by minimizing the energy loss of gain medium during laser process. The developed microlaser in this study has the great potential in next-generation biomedical technologies such like ‘sinlge-molecular biodetection’ and ‘real-time biosensing in live-cells’. Furthermore, since it is feasible for a light source of photonic integrated circuits, it will pave the way for highly-valued industrial applications. Prof. Kim said “We for the first time exploited the atomically disordered material for developing microlasers to overcome the conventional limitations of miniaturization and laser efficiency. By automating the fabrication and integrating systems, we are planing to utilize our microlaser as a solution for future technologies.” Continuous-wave upconversion lasing with a sub-10 W cm-2 threshold enabled by atomic disorder in the host matrix. Nature Communications, 12, Article number: 4437 (2021), (1st authors: Dr. Byeong-Seok Moon). Published July 21 2021 (IF: 14.919) https://www.nature.com/articles/s41467-021-24751-z
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- 작성일 2021-07-28
- 조회수 4344
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- A diagnostic patch that can be applied to disease treatment and provide therapeutic feedback was developed
- A diagnostic patch that can be applied to disease treatment and provide therapeutic feedback was developed The research team of Prof. Changhyun Pang (1st authors: Jihyun Lee, Jin Ho Song, and Dr. Sangyul Baik) revealed the structure and principle of the adhesive cup existing on the foreleg of a male diving beetle. A diagnostic patch that can be applied to disease treatment and provide therapeutic feedback was developed for the first time. [1] Science Advances June 16 (IF: 14.136); Diving beetle–like miniaturized plungers with reversible, rapid biofluid capturing for machine learning–based care of skin disease, 7(25), eabf5695 (2021), (1st authors: Jihyun Lee and Dr. Sangyul Baik) [2] Chemical Engineering Journal May 7 (IF: 13.273); “Wet soft bio-adhesion of insect-inspired polymeric oil-loadable perforated microcylinders; 423, 130194 (2021) (1st authors: Jin Ho Song) The diving beetle, an aquatic insect, has a unique characteristic that distinguishes males and females, namely, the round sticky cups on its foreleg. This adhesive cup adheres well to the surface of the female's curved and rough back during mating in the water, and serves to detect chemicals required during mating. It is a unique evolutionary product of the male diving beetle species. Prof. Changhyun Pang in the Department of Chemical Engineering at Sungkyunkwan University (SKKU) report the new approach for the diagnosis and treatment of skin in advanced biomedical technologies. Related research papers are published in Science Advances (Impact Factor 14.136) journal and Chemical Engineering Journal (Impact Factor 13.273). Inspired by the male diving beetle, the microscale suction cups achieve repeatable, enhanced, and multidirectional adhesion to human skin in dry/wet environments, revealing the role of the cavities in these architectures. The hydrogels within the suction cups instantaneously absorb liquids from the epidermis for enhanced adhesiveness and reversibly change color for visual indication of skin pH levels. To realize advanced biomedical technologies for the diagnosis and treatment of skin, our suction-mediated device is integrated with a machine learning framework for accurate and automated colorimetric analysis of pH levels. Furthermore, the research team of Changhyun Pang developed omni-directional non-slip and damage-free soft surgical gripper. For this research outcome, the research team of Prof. Changhyun Pang try to mimic the complex adhesion mechanism of underwater insect creatures, which are composed by suction force and mucus (oil) adhesion. This kind of new approach (oil-assisted suction adhesion inspired adhesive) make the adhesive possible to attach on wet, soft organ surface comparing the previous study. Prof. Pang said that the skin diagnosis patch with non-powered body fluid capture system can be used in medical data-based disease diagnosis and self-diagnosis medical devices and services. [Fig 1] The diving beetle–like reversible microplungers with biofluid-capturing hydrogel [Fig 2] Adhesion of the DIAs via structural deformation in dry and wet conditions
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- 작성일 2021-07-20
- 조회수 4397
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- Prof. Sangwoo Kim Won the Prime Minister’s Award at Nano Korea 2021
- Prof. Sangwoo Kim, School of Advanced Materials Science & Engineering, Won the Prime Minister’s Award at Nano Korea 2021 Sangwoo Kim, a professor of Advanced Materials Science & Engineering, received the 2021 Prime Minister’s Award for developing new materials for triboelectric nanogenerator and applying energy harvesting technology to smart wearable devices, IoT sensors, and implantable medical devices. Prof. Sang-woo Kim’s research team developed energy harvesting technology driven by ultrasound that enables powering biomedical implants in safe and convenience manner for the first time. This study theoretically identified the mechanical deformation and deformation of triboelectric energy under the skin layer with ultrasound, and induces continues triboelectrification through harmless ultrasound. Additionally, Prof. Sangwoo Kim’s research team suggested the triboelectric energy harvesting technology driven by transcutaneous ultrasound for powering medical implants. The energy harvesting technology driven by ultrasound is expected to contribute significantly to the future development of implantable medical device by addressing the limitations of battery replacement in implantable medical devices. Original Article: https://www.etnews.com/20210707000115
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- 작성일 2021-07-16
- 조회수 4172
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- Research Lab of Prof. Jang Am, Selected as “Healthy Lab” by Ministry of Science and ICT
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Research Lab of Prof. Jang Am, Selected as “Healthy Lab” by Ministry of Science and ICT A research lab of Prof. Jang Am (School of Civil, Architectural Engineering and Landscape Architecture) was selected for the “Health Lab” as an example of domestic laboratories. The selection of Healthy Laboratory was established by the Ministry of Science and ICT to create a research environment that supports the growth of young scientists by discovering and awarding laboratories with excellent research culture, management and performance. This year, a total of 10 healthy laboratories were selected after written and presentation evaluations among 89 registered laboratories (20 universities). ※ Selection Criteria: Laboratory culture (innovation, organizational culture), management (management of performance and safety), research performance (cultivating professionals) Prof. Jang Am’s research lab,
, was highly evaluated as their harmonious laboratory cultural atmosphere, including pursuing mutual respect, exploring research topics with mentor-mentee systems, helping school and laboratory life, etc. In addition, the laboratory was recognized for supporting and managing lab students such as giving each student opportunity to take charge of one project, providing incentives for writing papers, and providing tuition reduction for students. -
- 작성일 2021-07-09
- 조회수 4155
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- Gwang-Bum Im (Prof. Suk Ho Bhang’ group) in School of Chemical Engineering, Sungkyunkwan University reports a new platfo
- Gwang-Bum Im (Prof. Suk Ho Bhang’ group) in School of Chemical Engineering, Sungkyunkwan University reports anew platform which used both 2D and 3D keratinocytes’ performance to enhance wound closure. Journal: Chemical Engineering Journal Paper Title: 2D and 3D co-spatial compartmentalized patch to enhance the therapeutic efficacy of keratinocytes for wound closure Contents: We report the fabrication of a 2D and 3D co-spatial compartmentalized patch (CSCP) for a microscale keratinocyte-engineering platform and a novel method for delivering keratinocytes to enhance wound closure compared to that achieved by the conventional keratinocyte delivery method. Micro-sized cylinders engraved within a polydimethylsiloxane (PDMS) substrate were fabricated to induce and trap 3D keratinocyte clusters. Simultaneously, the outer surface of the PDMS substrate was used as an area for 2D keratinocyte culture. As a result, the CSCPs could be simultaneously applied for both 2D and 3D in vitro keratinocyte culture and in vivo cell delivery. The 3D keratinocytes increased the cell density for delivery and angiogenic factor expression but decreased the cell proliferation, which was complemented by the high proliferation of 2D keratinocytes. Our in vivo results confirmed that the therapeutic efficacy of keratinocytes for wound closure was significantly enhanced when the cells were delivered in a 2D and 3D co-spatial manner. DOI: https://doi.org/10.1016/j.cej.2020.128130 Gwang-Bum Im is a unified master's and doctor's course student under the supervision of Prof. Suk Ho Bhang in School of Chemical Engineering, Sungkyunkwan University (SKKU). His main research interests include the biomedical engineering, tissue engineering, and their applications. The recent work is based on the co-delivery of 2D and 3D keratinocytes through the PDMS patch and its therapeutic effect. Scheme figure of 2D and 3D co-spatial compartmentalized patch (CSCP), co-delivery of 2D and 3D keratinocytes enhanced the wound healing effect
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- 작성일 2021-07-06
- 조회수 4150
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- Jeong Seok Yeon (Prof. Ho Seok Park’s group) in School of Advanced Materials Science & Engineering, Sungkyunkwan Univers
- Jeong Seok Yeon (Prof. Ho Seok Park’s group) in School of Advanced Materials Science & Engineering, Sungkyunkwan University (SKKU) reports a radially oriented open-porous structure and overall microspherical morphology of the as-designed host material, a uniform distribution and high loading of rod-like nano sulfur (nS), and a proper composition and strong bonding of host and nS. Thus, we could greatly improve the rate and cyclic capabilities of Li-S battery cathodes by optimizing redox kinetics of multi-electron conversion reaction. Journal: ACS Nano, 2016, (5), 5163-5171 Paper Title:Surface-modified sulfur nanorods immobilized on radially assembled open-porous graphene microspheres for lithium–sulfur batteries Contents: Hierarchical complex architectures of 2D conductive nanomaterials such as graphene and MXene, precisely controlling internal open porosity and orientation, external morphology, composition, and interaction are expected to provide promising hosts for high-capacity active materials. Moreover, the assembly of 2D nanomaterials into a specific direction leads to the achievement of unexpected transport properties exceeding the limitation of conventional randomly assembled ones. Thus, we first demonstrate the combined chemistry of a spray-frozen assembly and ozonation for the design of surface-modified rod-like nanosulfur (nS) immobilized onto radially oriented open-porous microspherical reduced graphene oxide (rGO) architectures. Our concept is featured with a radially oriented open-porous structure and overall microspherical morphology of the as-designed host material, a uniform distribution and high loading of rod-like nS, and a proper composition and strong bonding of host and nS. Thus, we could greatly improve the rate and cyclic capabilities of Li-S battery cathodes by optimizing redox kinetics of multi-electron conversion reaction. DOI:https://doi.org/10.1021/acsnano.8b08822 Jeong Seok Yeon is a unified master's and doctor's course student under the supervision of Prof. Ho Seok Park in School of Advanced Materials Science & Engineering, Sungkyunkwan University (SKKU). His main research interests include the advanced energy storage materials and devices, including nanocarbon materials, modified polyoxometalate, advanced Li-ion batteries, Li-S batteries, Zn-ion batteries. Chronoamperometry data of photo-assisted electrochemical oxidation process, open-circuit potential (OCP) enhanced by stacked structure.
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- 작성일 2021-07-05
- 조회수 4239
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- The joint research team led by ChemE’s professor Nam Gyu Park and AMSE’s professor Sang-Woo Kim developed the world’s fi
- The joint research team led by ChemE’s professor Nam Gyu Park and AMSE’s professor Sang-Woo Kim developed the world’s first perovskite-based direct current triboelectric nanogenerator AMSE Prof. Sang-woo Kim, as the corresponding author, and a M.S./Ph.D. combined course student Bosung Kim (co-lead author) developed the world’s first perovskite-based direct current (DC) triboelectric nanogenerator (TENG) in collaboration with Prof.Park Nam Gyu (corresponding author) of ChemE, Dr. Chunqing Ma (lead author). The TENG converts mechanical energy from external sources into electrical energy through the contact-separation processes. Using micro-movement techniques in which generates electrical output, the TENG can be employed as an energy source for portable electronic devices and as a technology to treat skin wounds leveraging human body movements. Conventional triboelectrification entailed AC (alternating current) signals, which demands an external circuit that leads to the reduction of energy conversion efficiency with bulk system size. Free electrons and holes generated by triboelectrification from the sliding motion can be transferred by the heterojunction, forming DC power output. The phenomenon was first identified by the joint research team led by Prof. Sang-Woo Kim and Prof. Nam Gyu Park. Upon the contact and separating (Sliding) processes, the spiro’s organic hole conductor film placed on the perovskite semiconductor film produces negative and positive charges on the mutual interfaces. The charges migrate to form stable energy levels thermodynamically, resulting in electric current. [Figure] Schematic device structure and output analysis. (a) Schematic illustration of the dynamic perovskite/hole transport layer (HTL) heterojunction device. (b) IV curves obtained from the dynamic sliding contact between the FAPbI3 perovskite and the spiro layers, along with static (no sliding movement) condition, measured in the dar (c) voltage and (d) current output of the dynamic perovskite/spiro heterojunction device under continuous sliding movements. Conventional triboelectricity generates AC as the electric current changes along with the contact-separation direction. On the contrary, this triboelectricity follows the principle of charge separation in P/N junction; DC can be generated regardless of the direction of the contact-separation process. Furthermore, the research team demonstrated that light illumination and physical pressure act as stimuli to current output to a large extent. “Dynamic halide perovskite heterojunction that generates DC doesn’t require rectifier to convert AC to DC; thus it can reduce the device size”, said Prof. Nam Gyu Park. “The dynamic halide perovskite heterojunction will perform better than conventional AC triboelectricity when applied to wound treatment that requires micro-electric fields.”, Prof. Sang-woo Kim noted. This work was supported by the National Research Foundation of Korea (NRF) grants funded by the Ministry of Science and ICT (MSIT) of Korea under contracts NRF-2016M3D1A1027663 and NRF-2016M3D1A1027664 (Future Materials Discovery Program) and NRF-2018R1A2A1A19021947 (the Basic Science Research Program). This research was in part supported by Energy Technology Program of the Korea Institute of Energy Technology Evaluation and Planning (KETEP), funded by the Ministry of Trade, Industry & Energy (No. 20193091010310). ※ Paper title: Dynamic halide perovskite heterojunction generates direct current
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- 작성일 2021-07-01
- 조회수 4284
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- AMSE research team led by Prof. Hyung Koun Cho (Young-Been Kim Ph.D.) suggests photocurrent generation enhancement and p
- AMSE research team led by Prof. Hyung Koun Cho (Young-Been Kim Ph.D.) suggests photocurrent generation enhancement and pulse-driven system by developing water-splitting Hydrogen producing-purpose Interleaved biphasic p–n blended copper indium selenide (Cu-In-Se) photoelectrode material AMSE Young-Been Kim under the Ph.D. program in Prof. Hyung Koun Cho‘s research team fabricated a high-efficient solar energy water splitting system that operates in alternating current (AC) voltage. By designing an electrochemical deposition-based precursor synthesis process in order to micro-control based on thermodynamic morphology of Cu-In-Se (CIS), the research team developed a semiconductor structure where secondary phases coexist through the selenization process. Based on that, the team built the pulse-driven system in which enables high hydrogen evolution. The multiphasic structure has improved the charge transport efficiency due to the expansion of the depletion region formed inside and on the surface of semiconductor electrodes. It can also generate photocurrent at reduction under negative (-) voltage and oxidation under positive (+) voltage due to the presence of multiphase. Consequently, the pulse-driven system is the new mechanism that can fully leverage the entire photocurrent generated out of AC output. Pulse-driven photoelectrochemical (PEC) water splitting has been introduced to improve Hydrogen evolution efficiency by destroying the charge accumulation and electrical double layer (ionic layer) of the electrode surface causing the loss. Herein, the research team demonstrated first significant performance in the field of photoelectrochemical water-splitting employing semiconductor electrodes. Furthermore, efficient hydrogen evolution was confirmed by suppressing the formation of large-size cluster bubbles and facilitating hydrogen ion adsorption. Specifically, Through a 156% improvement in hydrogen evolution over the DC voltage system, Researcher Kim attested the superior performance of pulse-driven PEC water splitting system. Along with public attention on hydrogen energy in which shows high efficiency as renewable energy to replace petroleum, water-splitting research using light to generate hydrogen is increasingly being active. Thus, research has been conducted on photoactive materials that can generate high current under sunlight. However, it was limited to single conductivity types in which shows very low efficiency of photo-generated charge transport due to the neutrality of the inner area of absorbers. Consequently, the researchers, by focusing on the development of multi-phase chalcogenide materials that enhance charge transport efficiency, enabled utilizing both photocathode and photoanode by controlling the precursor synthesis and selenization process. This research was supported by Samsung Research Funding &Incubation Center of Samsung Electronics [grant number SRFC-MA170206]. The paper was published online in January 2021 in Applied Catalogis B: Environmental (IF 16.683), a SCI journal within the top 1.94% in materials and environmental engineering category. [Figure 1] The photo-generated minority carriers effectively flow into interleaved depletion regions and transport along the externally induced built-in field at 0 V vs RHE. [Figure 2] (a) Sequential steps illustrating one-cycle of current behavior in chronoamperometry result under pulse bias of 0 and 0.8 V vs RHE under light illumination (b) schematic diagrams for charge transport mechanism under constant light illumination from p-n interleaved CIS photoelectrode, where (Steps 1 and 3 ) the high-density charge transport through interleaved depletion regions; and (Steps 2 and 4 ) charge accumulation at the surface region and equilibrium state indicating a saturated steady state. (c) CA results and hydrogen evolution rate of the CIS/AZO/TiO2/Pt photoelectrode at pulse bias of 0 and 0.8 V vs RHE with alternating frequency of 150 cpm (1 M Na2SO4 electrolyte buffered at pH 5 with potassium borate solution) under constant 1 sun light illumination. [Figure 3] (a) Electrical double layer (EDL) formation under negative biased electrode (b) Hydrogen generation mechanisms through the reduction reaction in the electrolyte (c) Active area loss due to gas agglomeration produced when DC power has driven
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- 작성일 2021-06-25
- 조회수 4512
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- Prof. Hyoungsub Kim’ s research team in collaboration with Samsung Advanced Institute of Technology (SAIT) revealed dime
- Prof. Hyoungsub Kim’ s research team in collaboration with Samsung Advanced Institute of Technology (SAIT) revealed dimension-breaking reconstruction process during conversion of MoO2 to MoS2 [Figure 1] Professor Hyoungsub Kim (AMSE, co-corresponding author), Dr. Eunha Lee (SAIT, co-corresponding author) The joint research team led by Prof. Hyoungsub Kim (AMSE) and Dr. Eunha Lee (SAIT) first discovered the appearance of highly ordered arrays of 1D intermediate crystals during the chemical transformation of MoO2 to 2D layer-structured MoS2. Recently, for application to next-generation semiconductor and energy devices, numerous researches have been actively conducted to synthesize various 2D layer-structured materials (transition-metal dichalcogenides) via a thermal sulfidation- or selenization-based conversion process of metal oxides. Ideally, such a synthesis process follows sequential layer-by-layer phase transformation characteristics of an atomic layer-level thickness. During the sulfidation process of MoO2, the joint research team directly observed the appearance of highly ordered arrays of 1D intermediate crystals at the MoO2/MoS2 interface using STEM with an atomic-scale resolution. They also developed a comprehensive structural model and energetics of the intermediate crystals during the dimension-breaking transformation process (3D→1D→2D) based on the first-principles DFT calculations. [Figure 2] (left) Schematic illustration of chemical phase transformation, (right) STEM images Furthermore, by collaborating with a Prof. Mann-Ho Cho’s team (department of physics at Yonsei University), they proved possible modulation of the metal-contact type (from p- to n-type) with the number of atomic MoS2 layers via X-ray photoelectron spectroscopy, which can be used for innovative device applications. In this paper, Dr. Hyangsook Lee (SAIT) and Dr. Yeonchoo Cho (SAIT) contributed as co-first authors, and the results were published online in ‘Materials Today (Impact Factor = 26.416, JCR Ranking Top 2.7%)' on March 17, 2021. ※ Title : “3D-to-2D phase transformation through highly ordered 1D crystals from transition-metal oxides to dichalcogenides” ※ Source : https://www.sciencedirect.com/science/article/abs/pii/S1369702121000560
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- 작성일 2021-06-25
- 조회수 4192