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Jiang M, Yang X, Qu S, Wang C, Ohya S, Tanaka M. Field-Free Spin-Orbit Torque Magnetization Switching in a Perpendicularly Magnetized Semiconductor (Ga,Mn)As Single Layer. ACS Appl Mater Interfaces 2024. [PMID: 38661041 DOI: 10.1021/acsami.3c19468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
Current-induced spin-orbit torque (SOT) in a perpendicularly magnetized single layer has a strong potential to switch the magnetization using an extremely low current density, which is generally 2-3 orders of magnitude smaller than that required for conventional metal bilayer systems. However, an in-plane external magnetic field has to be applied to break the symmetry and achieve deterministic switching. To further enhance the high-density integration and accelerate the practical application of highly efficient SOT magnetic random-access memory (SOT-MRAM) devices, field-free SOT magnetization switching in a ferromagnetic single layer is strongly needed. In a spin-orbit ferromagnet (a ferromagnet with strong spin-orbit interaction) with crystal inversion asymmetry and a multi-domain structure, the internal Dzyaloshinskii-Moriya effective fields are considered to induce field-free switching. Here, combined with strong spin-orbit coupling and a tilted anisotropy axis induced by a nonuniform Mn distribution and a possible magnetocrystalline anisotropy resulting from a slight substrate tilting, we successfully achieve magnetization switching in a spin-orbit ferromagnet (Ga,Mn)As single layer by utilizing SOT without applying any external magnetic field. Our findings help to deeply elucidate the SOT switching mechanism and can advance the development of a highly efficient MRAM with better scalability.
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Affiliation(s)
- Miao Jiang
- School of Materials Science and Engineering, Beijing Institute of Technology, Haidian, Beijing 100081, P. R. China
- National Key Laboratory of Science and Technology on Materials under Shock and Impact, Beijing Institute of Technology, Haidian, Beijing 100081, P. R. China
| | - Xinyuan Yang
- Department of Electrical Engineering and Information Systems, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Shengyuan Qu
- School of Materials Science and Engineering, Beijing Institute of Technology, Haidian, Beijing 100081, P. R. China
| | - Chenda Wang
- Department of Electrical Engineering and Information Systems, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Shinobu Ohya
- Department of Electrical Engineering and Information Systems, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan
- Center for Spintronics Research Network (CSRN), Graduate School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan
- Institute for Nano Quantum Information Electronics, The University of Tokyo, Meguro-ku, Tokyo 153-8505, Japan
| | - Masaaki Tanaka
- Department of Electrical Engineering and Information Systems, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan
- Center for Spintronics Research Network (CSRN), Graduate School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan
- Institute for Nano Quantum Information Electronics, The University of Tokyo, Meguro-ku, Tokyo 153-8505, Japan
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2
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Lefevre E, Dupont S, Liguoro D, Chasseloup F, Kamenicky P, Roblot P. Anatomy of the medial wall of the cavernous sinus: A systematic review of the literature. Clin Anat 2024. [PMID: 38468565 DOI: 10.1002/ca.24152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 02/13/2024] [Accepted: 02/22/2024] [Indexed: 03/13/2024]
Abstract
The existence, composition, and continuity of the medial wall of the cavernous sinus (MWCS) have been extensively studied and debated. However, the precise nature of this membrane remains unknown. Understanding the anatomical characteristics of the MWCS is crucial, notably in relation to pituitary adenomas, which often invade the cavernous sinus. Indeed, surgical treatment of those tumors is frequently incomplete because of such invasion. The anatomical and molecular basis of the peculiar and often lateralized tropism of adenomatous cells to the cavernous sinus is not yet understood and it has been suggested repeatedly that the MWCS is physiologically frail. During the past three decades, there have been several conflicting accounts of the existence, composition, and continuity of this medial wall, but methodological differences and varying definitions could have contributed to the current lack of consensus regarding it. The aim of this systematic review was to summarize previously published data concerning the existence, anatomy, composition, and continuity of the MWCS.
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Affiliation(s)
- Etienne Lefevre
- Physiologie et Physiopathologie Endocriniennes, Paris-Saclay University, INSERM U1185, Le Kremlin-Bicêtre, France
- Department of Neurosurgery, APHP, Groupe Hospitalier Pitié-Salpêtrière, Paris, France
- Laboratory of Anatomy, Sorbonne Université, Paris, France
| | - Sophie Dupont
- Laboratory of Anatomy, Sorbonne Université, Paris, France
- Department of Neurology, APHP, Groupe Hospitalier Pitié-Salpêtrière, Paris, France
| | - Dominique Liguoro
- Neurosurgery Department A, University Hospital of Bordeaux, Bordeaux, France
- Laboratory of Anatomy, Université de Bordeaux, Bordeaux, France
| | - Fanny Chasseloup
- Physiologie et Physiopathologie Endocriniennes, Paris-Saclay University, INSERM U1185, Le Kremlin-Bicêtre, France
- Service d'Endocrinologie et des Maladies de la Reproduction, Centre de Référence des maladies Rares de l'Hypophyse, Hôpital de Bicêtre, Le Kremlin-Bicêtre, France
| | - Peter Kamenicky
- Physiologie et Physiopathologie Endocriniennes, Paris-Saclay University, INSERM U1185, Le Kremlin-Bicêtre, France
- Service d'Endocrinologie et des Maladies de la Reproduction, Centre de Référence des maladies Rares de l'Hypophyse, Hôpital de Bicêtre, Le Kremlin-Bicêtre, France
| | - Paul Roblot
- Neurosurgery Department A, University Hospital of Bordeaux, Bordeaux, France
- Laboratory of Anatomy, Université de Bordeaux, Bordeaux, France
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Kumar R, Jenjeti RN, Vankayala K, Sampath S. Quaternary, layered, 2D chalcogenide, Mo 1-xW xSSe: thickness dependent transport properties. Nanotechnology 2023; 35:045202. [PMID: 37816337 DOI: 10.1088/1361-6528/ad01c1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 10/09/2023] [Indexed: 10/12/2023]
Abstract
Highly oriented, single crystalline, quaternary alloy chalcogenide crystal, MoxW1-xS2ySe2(1-y), is synthesized using a high temperature chemical vapor transport technique and its transport properties studied over a wide temperature range. Field effect transistors (FET) with bottom gated configuration are fabricated using Mo0.5W0.5SSe flakes of different thicknesses, from a single layer to bulk. The FET characteristics are thickness tunable, with thin flakes (1-4 layers) exhibiting n-type transport behaviour while ambipolar transfer characteristics are observed for thicker flakes (>90 layers). Ambipolar behavior with the dominance of n-type over p-type transport is noted for devices fabricated with layers between 9 and 90. The devices with flake thickness ∼9 layers exhibit a maximum electron mobility 63 ± 4 cm2V-1s-1and anION/IOFFratio >108. A maximum hole mobility 10.3 ± 0.4 cm2V-1s-1is observed for the devices with flake thickness ∼94 layers withION/IOFFratio >102-103observed for the hole conduction. A maximumION/IOFFfor hole conduction, 104is obtained for the devices fabricated with flakes of thickness ∼7-19 layers. The electron Schottky barrier height values are determined to be ∼23.3 meV and ∼74 meV for 2 layer and 94 layers flakes respectively, as measured using low temperature measurements. This indicates that an increase in hole current with thickness is likely to be due to lowering of the band gap as a function of thickness. Furthermore, the contact resistance (Rct) is evaluated using transmission line model (TLM) and is found to be 14 kohm.μm. These results suggest that quaternary alloys of Mo0.5W0.5SSe are potential candidates for various electronic/optoelectronic devices where properties and performance can be tuned within a single composition.
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Affiliation(s)
- Rajat Kumar
- Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore, India
| | - Ramesh Naidu Jenjeti
- Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore, India
| | - Kiran Vankayala
- Department of Chemistry, Birla Institute of Technology and Science, Pilani, K. K. Birla Goa Campus, Goa, India
| | - S Sampath
- Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore, India
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Jiang M, Asahara H, Ohya S, Tanaka M. Electric Field Control of Spin-Orbit Torque Magnetization Switching in a Spin-Orbit Ferromagnet Single Layer. Adv Sci (Weinh) 2023; 10:e2301540. [PMID: 37329321 PMCID: PMC10460875 DOI: 10.1002/advs.202301540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 04/29/2023] [Indexed: 06/19/2023]
Abstract
To achieve a desirable magnitude of spin-orbit torque (SOT) for magnetization switching and realize multifunctional spin logic and memory devices utilizing SOT, controlling the SOT manipulation is vitally important. In conventional SOT bilayer systems, researchers have tried to control the magnetization switching behavior via interfacial oxidization, modulation of spin-orbit effective field, and effective spin Hall angle; however, the switching efficiency is limited by the interface quality. A current-induced effective magnetic field in a single layer of a ferromagnet with strong spin-orbit interactions, the so-called spin-orbit ferromagnet, can be utilized to induce SOT. In spin-orbit ferromagnet systems, electric field application has the potential for manipulating the spin-orbit interactions via carrier concentration modulation. In this work, it is demonstrated that SOT magnetization switching can be successfully controlled via an external electric field using a (Ga, Mn)As single layer. By applying a gate voltage, the switching current density can be solidly and reversibly manipulated with a large ratio of 14.5%, which is ascribed to the successful modulation of the interfacial electric field. The findings of this work help further the understanding of the magnetization switching mechanism and advance the development of gate-controlled SOT devices.
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Affiliation(s)
- Miao Jiang
- School of Materials Science and EngineeringBeijing Institute of TechnologyZhongguancun South Street No.5, HaidianBeijing100081China
- Department of Electrical Engineering and Information SystemsThe University of Tokyo7‐3‐1 Hongo, Bunkyo‐kuTokyo113‐8656Japan
| | - Hirokatsu Asahara
- Department of Electrical Engineering and Information SystemsThe University of Tokyo7‐3‐1 Hongo, Bunkyo‐kuTokyo113‐8656Japan
| | - Shinobu Ohya
- Department of Electrical Engineering and Information SystemsThe University of Tokyo7‐3‐1 Hongo, Bunkyo‐kuTokyo113‐8656Japan
- Center for Spintronics Research Network (CSRN)Graduate School of EngineeringThe University of Tokyo7‐3‐1 Hongo, Bunkyo‐kuTokyo113‐8656Japan
| | - Masaaki Tanaka
- Department of Electrical Engineering and Information SystemsThe University of Tokyo7‐3‐1 Hongo, Bunkyo‐kuTokyo113‐8656Japan
- Center for Spintronics Research Network (CSRN)Graduate School of EngineeringThe University of Tokyo7‐3‐1 Hongo, Bunkyo‐kuTokyo113‐8656Japan
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Raghavan D, Kannan D, Sekaran PG, Thangarasu M, J SP, Paul R, Taur P. A Novel Technique of Renorrhaphy in Difficult Partial Nephrectomies by Single-Layered Parenchymal Imbrication. Cureus 2023; 15:e42702. [PMID: 37654940 PMCID: PMC10465805 DOI: 10.7759/cureus.42702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/30/2023] [Indexed: 09/02/2023] Open
Abstract
Background In partial nephrectomies, achieving the trifecta outcome of negative tumor margins, no surgical complications, and minimal decline in renal function depends on various factors, with the complexity of the tumor described by the nephrometry score being chief among them. These factors often motivate surgeons toward a minimally invasive route even if the preferred route is an open approach. We describe an innovative renorrhaphy technique that overcomes the commonly encountered difficulty in reconstructing the renal parenchyma after resecting a complex tumor with a single-layered parenchymal imbrication (SLPI) technique. Methodology We conducted a retrospective review of case records of the patients who had undergone partial nephrectomies in our center from March 2017 to March 2021. The patients who underwent the SLPI technique were chosen, and data were extracted. Data collected included patients' preoperative imaging findings; intraoperative parameters such as ischemia time, blood loss, and number of renal arteries; and postoperative factors such as margin positivity rate, urine leak, secondary bleeding, follow-up imaging, and recurrence rates. Results A total of 28 patients were included in our study. The estimated blood loss was 234 mL (standard deviation [SD] = 55 mL), warm ischemia time was 31 minutes (SD 4 minutes), a hospital stay of 3 days (SD 2 days), two minor complications, two intraoperative complications, and one margin positivity. There were no major complications or recurrences. Conclusions The novel technique of SLPI renorrhaphy can help deal with complex renal masses and is an easily reproducible technique both in open and minimally invasive approaches.
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Ohlin H, Frisk T, Vogt U. Single Layer Lift-Off of CSAR62 for Dense Nanostructured Patterns. Micromachines (Basel) 2023; 14:766. [PMID: 37420999 DOI: 10.3390/mi14040766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 03/17/2023] [Accepted: 03/28/2023] [Indexed: 07/09/2023]
Abstract
Lift-off processing is a common method of pattern transfer for different nanofabrication applications. With the emergence of chemically amplified and semi-amplified resist systems, the possibilities for pattern definition via electron beam lithography has been widened. We report a reliable and simple lift-off process for dense nanostructured pattern in CSAR62. The pattern is defined in a single layer CSAR62 resist mask for gold nanostructures on silicon. The process offers a slimmed down pathway for pattern definition of dense nanostructures with varied feature size and an up to 10 nm thick gold layer. The resulting patterns from this process have been successfully used in metal assisted chemical etching applications.
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Affiliation(s)
- Hanna Ohlin
- Department of Applied Physics, Biomedical and X-ray Physics, KTH Royal Institute of Technology, Albanova University Center, 106 91 Stockholm, Sweden
| | - Thomas Frisk
- Department of Applied Physics, Biomedical and X-ray Physics, KTH Royal Institute of Technology, Albanova University Center, 106 91 Stockholm, Sweden
| | - Ulrich Vogt
- Department of Applied Physics, Biomedical and X-ray Physics, KTH Royal Institute of Technology, Albanova University Center, 106 91 Stockholm, Sweden
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Canton-Vitoria R, Hotta T, Xue M, Zhang S, Kitaura R. Synthesis and Characterization of Transition Metal Dichalcogenide Nanoribbons Based on a Controllable O 2 Etching. JACS Au 2023; 3:775-784. [PMID: 37006761 PMCID: PMC10052231 DOI: 10.1021/jacsau.2c00536] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 12/17/2022] [Accepted: 12/19/2022] [Indexed: 06/18/2023]
Abstract
Although the synthesis of monolayer transition metal dichalcogenides has been established in the last decade, synthesizing nanoribbons remains challenging. In this study, we have developed a straightforward method to obtain nanoribbons with controllable widths (25-8000 nm) and lengths (1-50 μm) by O2 etching of the metallic phase in metallic/semiconducting in-plane heterostructures of monolayer MoS2. We also successfully applied this process for synthesizing WS2, MoSe2, and WSe2 nanoribbons. Furthermore, field-effect transistors of the nanoribbons show an on/off ratio of larger than 1000, photoresponses of 1000%, and time responses of 5 s. The nanoribbons were compared with monolayer MoS2, highlighting a substantial difference in the photoluminescence emission and photoresponses. Additionally, the nanoribbons were used as a template to build one-dimensional (1D)-1D or 1D-2D heterostructures with various transition metal dichalcogenides. The process developed in this study offers simple production of nanoribbons with applications in several fields of nanotechnology and chemistry.
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Affiliation(s)
- Ruben Canton-Vitoria
- Department
of Chemistry, Nagoya University, Furo-Cho, Nagoya, Aichi 464-8602, Japan
- Theoretical
and Physical Chemistry Institute, National
Hellenic Research Foundation, 48 Vassileos Constantinou Avenue, Athens 116 35, Greece
| | - Takato Hotta
- Department
of Chemistry, Nagoya University, Furo-Cho, Nagoya, Aichi 464-8602, Japan
| | - Mengsong Xue
- Department
of Chemistry, Nagoya University, Furo-Cho, Nagoya, Aichi 464-8602, Japan
| | - Shaochun Zhang
- Department
of Chemistry, Nagoya University, Furo-Cho, Nagoya, Aichi 464-8602, Japan
| | - Ryo Kitaura
- Department
of Chemistry, Nagoya University, Furo-Cho, Nagoya, Aichi 464-8602, Japan
- International
Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
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8
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Zhang Z, Nie J, Zhang Z, Yuan Y, Fu YS, Zhang W. Atomic Visualization and Switching of Ferroelectric Order in β-In 2 Se 3 Films at the Single Layer Limit. Adv Mater 2022; 34:e2106951. [PMID: 34755394 DOI: 10.1002/adma.202106951] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 10/24/2021] [Indexed: 06/13/2023]
Abstract
2D ferroelectrics have received wide interest due to the remarkable quantum states of emerging physics at reduced dimensionality, associated with their exotic properties in high-performance and nonvolatile functional devices. Here, by combing molecular beam epitaxy synthesis and scanning tunneling microscopy characterization, two metastable phases of layered In2 Se3 films: β'- and β*-In2 Se3 are reported, which develop different types of in-plane spontaneous polarizations, thus resulting in different striped morphologies. The anti-ferroelectric order in β'-In2 Se3 and ferroelectric order of β*-In2 Se3 are identified, respectively, down to the 2D limit by comprehensive investigations of structural and spectroscopic signatures, including the lattice distortion, the spatial profile of images, the formation of domain structure, and the electronic band-bending by polarization charges at edges. The ferroelectric switching between those two phases are further controlled via applying an electric field generated from the scanning tunneling microscopy tip in a reversible manner. The intriguing tunability between the (anti-)ferroelectric orders in the 2D limit provides a promising platform for studying the interplay between electronic structure and ferroelectricity in van der Waals materials, and promotes potential development of miniaturized transistors and memory devices based on electric polarizations.
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Affiliation(s)
- Zhimo Zhang
- School of Physics and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Jinhua Nie
- School of Physics and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Zhihao Zhang
- School of Physics and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Yuan Yuan
- School of Physics and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Ying-Shuang Fu
- School of Physics and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Wenhao Zhang
- School of Physics and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan, 430074, China
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Gao Y, Luo Y, Lu J. High-Reflective Templated Cholesteric Liquid Crystal Filters. Molecules 2021; 26:molecules26226889. [PMID: 34833978 PMCID: PMC8619078 DOI: 10.3390/molecules26226889] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 11/05/2021] [Accepted: 11/13/2021] [Indexed: 11/16/2022] Open
Abstract
Cholesteric liquid crystals (CLCs) have been widely applied in optical filters due to Bragg reflection caused by their helical structure. However, the reflectivity of CLC filters is relatively low, commonly less than 50%, as the filters can only reflect light polarized circularly either left- or right-handedly. Therefore, a high-reflective CLC filter with a single-layer template was proposed which may reflect both right- and left-handed polarized light. The CLC filters of the red, green, blue color were fabricated by the templating technology, which show good wavelength consistency. Additionally, a multi-phase liquid crystal filter with high reflectance was demonstrated by the single-layer templating technology. The templated CLC or multi-phase liquid crystal filters show great potential applications in the optical community, reflective display, and lasing.
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Zhu Z, Gao Y, Lu J. Multi-Pitch Liquid Crystal Filters with Single Layer Polymer Template. Polymers (Basel) 2021; 13:2521. [PMID: 34372123 DOI: 10.3390/polym13152521] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 07/21/2021] [Accepted: 07/28/2021] [Indexed: 11/17/2022] Open
Abstract
Multi-reflective peak and bandwidth scalable liquid crystal (LC) filters were investigated. By refilling a cholesteric LC (CLC) whose chiral pitch is different to the target template into a blue phase LC (BPLC) template, a multi-reflective peak single layer LC filter can be fabricated. With multiple templating and refilling processes, the number of reflective peaks can be further increased. Moreover, by refilling the CLCs of designed chiral pitch into a CLC template sequentially, a bandwidth scalable single layer CLC filter can be fabricated. The LC filters show great potential applications in optical communication, display, and LC lasing.
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Lv Q, Yang YH, Zhou SG, Shao C, Zhou D, Sim CY. Design of a Single-Layer ±45° Dual-Polarized Directional Array Antenna for Millimeter Wave Applications. Sensors (Basel) 2021; 21:4326. [PMID: 34202672 DOI: 10.3390/s21134326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 06/14/2021] [Accepted: 06/21/2021] [Indexed: 11/24/2022]
Abstract
A single-layer ±45° dual-polarized directional array antenna for millimeter wave (mm-wave) applications is designed in this communication. Based on the theory of orthogonal circularly polarized (CP) wave multiplexing, two ports of a series-fed dual CP array are fed with equal amplitudes, and the array can radiate a linearly polarized wave with ±45° polarization orientations through the adjustment of the feeding phase difference. As the two ports of the series-fed array are simultaneously excited, the antenna can achieve directional radiation. In addition, the cross-polarization level of the array can be effectively suppressed by placing two series-fed arrays side by side. A prototype of the designed array antenna operating at 30 GHz is fabricated and measured; the working bandwidth of the proposed antenna is approximately 3.5%. Owing to its simple structure and directional radiation, the proposed antenna array is a competitive candidate for mm-wave applications.
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Han C, Zhong R, Liang Z, Yang L, Fang Z, Wang Y, Ma A, Wu Z, Hu M, Liu D, Liu S. Independently Tunable Multipurpose Absorber with Single Layer of Metal-Graphene Metamaterials. Materials (Basel) 2021; 14:E284. [PMID: 33429875 DOI: 10.3390/ma14020284] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 12/22/2020] [Accepted: 01/04/2021] [Indexed: 12/02/2022]
Abstract
This paper reports an independently tunable graphene-based metamaterial absorber (GMA) designed by etching two cascaded resonators with dissimilar sizes in the unit cell. Two perfect absorption peaks were obtained at 6.94 and 10.68 μm with simple single-layer metal-graphene metamaterials; the peaks show absorption values higher than 99%. The mechanism of absorption was analyzed theoretically. The independent tunability of the metamaterial absorber (MA) was realized by varying the Fermi level of graphene under a set of resonators. Furthermore, multi-band and wide-band absorption were observed by the proposed structure upon increasing the number of resonators and resizing them in the unit cell. The obtained results demonstrate the multipurpose performance of this type of absorber and indicate its potential application in diverse applications, such as solar energy harvesting and thermal absorbing.
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13
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Stegwee SI, van der Voet LF, Ben AJ, de Leeuw RA, van de Ven PM, Duijnhoven RG, Bongers MY, Lambalk CB, de Groot C, Huirne J. Effect of single- versus double-layer uterine closure during caesarean section on postmenstrual spotting (2Close): multicentre, double-blind, randomised controlled superiority trial. BJOG 2020; 128:866-878. [PMID: 32892392 PMCID: PMC7983985 DOI: 10.1111/1471-0528.16472] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/07/2020] [Indexed: 12/01/2022]
Abstract
OBJECTIVE To evaluate whether double-layer uterine closure after a first caesarean section (CS) is superior compared with single-layer uterine closure in terms of postmenstrual spotting and niche development in the uterine caesarean scar. DESIGN Multicentre, double-blind, randomised controlled superiority trial. SETTING Thirty-two hospitals in the Netherlands. POPULATION A total of 2292 women aged ≥18 years undergoing a first CS were randomly assigned to each procedure (1:1): 1144 women were assigned to single-layer uterine closure and 1148 women were assigned to double-layer uterine closure. METHODS Single-layer unlocked closure and double-layer unlocked closure, with the second layer imbricating the first. MAIN OUTCOME MEASURES Number of days with postmenstrual spotting during one menstrual cycle 9 months after CS. SECONDARY OUTCOMES perioperative and menstrual characteristics; transvaginal ultrasound measurements. RESULTS A total of 774 (67.7%) women from the single-layer group and 770 (67.1%) women from the double-layer group were evaluable for the primary outcome, as a result of drop-out and amenorrhoea. The mean number of postmenstrual spotting days was 1.33 (bootstrapped 95% CI 1.12-1.54) after single-layer closure and 1.26 (bootstrapped 95% CI 1.07-1.45) after double-layer closure (adjusted mean difference -0.07, 95% CI -0.37 to 0.22, P = 0.810). The operative time was 3.9 minutes longer (95% CI 3.0-4.9 minutes, P < 0.001) and niche prevalence was 4.7% higher (95% CI 0.7-8.7%, P = 0.022) after double-layer closure. CONCLUSIONS The superiority of double-layer closure compared with single-layer closure in terms of postmenstrual spotting after a first CS was not shown. Long-term obstetric follow-up of our trial is needed to assess whether uterine caesarean closure guidelines should be adapted. TWEETABLE ABSTRACT Double-layer uterine closure is not superior for postmenstrual spotting after a first caesarean; single-layer closure performs slightly better on other outcomes.
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Affiliation(s)
- S I Stegwee
- Department of Obstetrics and Gynaecology, Amsterdam Reproduction & Development, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - L F van der Voet
- Department of Obstetrics and Gynaecology, Deventer Hospital, Deventer, the Netherlands
| | - A J Ben
- Department of Health Sciences, Amsterdam Public Health, Faculty of Science, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - R A de Leeuw
- Department of Obstetrics and Gynaecology, Amsterdam Reproduction & Development, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands.,Department of Obstetrics and Gynaecology, Amsterdam Reproduction & Development, Amsterdam UMC, Universiteit van Amsterdam, Amsterdam, the Netherlands
| | - P M van de Ven
- Department of Epidemiology and Biostatistics, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - R G Duijnhoven
- Department of Obstetrics and Gynaecology, Amsterdam Reproduction & Development, Amsterdam UMC, Universiteit van Amsterdam, Amsterdam, the Netherlands
| | - M Y Bongers
- Department of Obstetrics and Gynaecology, Máxima Medical Centre, Research School Grow Maastricht University, Veldhoven, the Netherlands
| | - C B Lambalk
- Department of Obstetrics and Gynaecology, Amsterdam Reproduction & Development, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Cjm de Groot
- Department of Obstetrics and Gynaecology, Amsterdam Reproduction & Development, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands.,Department of Obstetrics and Gynaecology, Amsterdam Reproduction & Development, Amsterdam UMC, Universiteit van Amsterdam, Amsterdam, the Netherlands
| | - Jaf Huirne
- Department of Obstetrics and Gynaecology, Amsterdam Reproduction & Development, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands.,Department of Obstetrics and Gynaecology, Amsterdam Reproduction & Development, Amsterdam UMC, Universiteit van Amsterdam, Amsterdam, the Netherlands
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14
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Cheng N, Chen Y, Zhang Y, Liu Y. Cucurbit[7]uril-Mediated 2D Single-Layer Hybrid Frameworks Assembled by Tetraphenylethene and Polyoxometalate toward Modulation of the α-Chymotrypsin Activity. ACS Appl Mater Interfaces 2020; 12:15615-15621. [PMID: 32134235 DOI: 10.1021/acsami.0c02976] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Construction of large-scale single-layer two-dimensional (2D) frameworks in water is significant due to their utilities in various fields. Utilizing macrocycle-mediated supramolecular self-assembly represents a promising approach; however, challenges still remain in their practical preparation. Here, we exploited a two-step supramolecular strategy to build 2D organic-inorganic hybrid frameworks at a micrometer scale in water. Taking advantage of the high binding affinity to cucurbit[7]uril (CB[7]), mono-quaternary ammonium tetraphenylethene (MQATPE) derivatives were first included with CB[7] to form a 1:1 complex (MQATPE@CB[7]). Then, just mixing the complex with anionic polyoxometalate Na9[EuW10O36]·32H2O (denoted as Eu-POM) in a 3:1 molar ratio leads to the formation of single-layer 2D films with tens of micrometers via electrostatic and π-π stacking interactions. The most unique feature of this strategy is that the steric effect imposed by CB[7] would not only lead the modules to adopt a periodic hexagonal assembly but also forbid stacking between layers through comparison with the merely multilayered 2D nanosheets self-assembled by MQATPE/Eu-POM. Interestingly, the charge interactions between MQATPE and Eu-POM would lead to the aggregation-induced emission (AIE) fluorescence of MQATPE, and white light emission could be obtained through the simple regulation of the contents of Eu-POM and MQATPE. Furthermore, due to the high surface areas and more accessible active sites, the single-layer films can act as an effective enzyme inhibitor to modulate the activity of α-chymotrypsin (ChT). These findings suggest a simple but universal approach for single-layer hybrid materials, which may hold promise for practical applications in photophysical and biomedical fields.
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Affiliation(s)
- Ni Cheng
- College of Pharmacy, Weifang Medical University, Weifang, Shandong 261053, P. R. China
- College of Chemistry, State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, P. R. China
| | - Yong Chen
- College of Chemistry, State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, P. R. China
| | - Yi Zhang
- College of Chemistry, State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, P. R. China
| | - Yu Liu
- College of Chemistry, State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, P. R. China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300071, P. R. China
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15
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Hamilton ES, Ganjalizadeh V, Wright JG, Schmidt H, Hawkins AR. 3D Hydrodynamic Focusing in Microscale Optofluidic Channels Formed with a Single Sacrificial Layer. Micromachines (Basel) 2020; 11:E349. [PMID: 32230783 PMCID: PMC7230747 DOI: 10.3390/mi11040349] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 03/25/2020] [Accepted: 03/26/2020] [Indexed: 12/20/2022]
Abstract
Optofluidic devices are capable of detecting single molecules, but greater sensitivity and specificity is desired through hydrodynamic focusing (HDF). Three-dimensional (3D) hydrodynamic focusing was implemented in 10-μm scale microchannel cross-sections made with a single sacrificial layer. HDF is achieved using buffer fluid to sheath the sample fluid, requiring four fluid ports to operate by pressure driven flow. A low-pressure chamber, or pit, formed by etching into a substrate, enables volumetric flow ratio-induced focusing at a low flow velocity. The single layer design simplifies surface micromachining and improves device yield by 1.56 times over previous work. The focusing design was integrated with optical waveguides and used in order to analyze fluorescent signals from beads in fluid flow. The implementation of the focusing scheme was found to narrow the distribution of bead velocity and fluorescent signal, giving rise to 33% more consistent signal. Reservoir effects were observed at low operational vacuum pressures and a balance between optofluidic signal variance and intensity was achieved. The implementation of the design in optofluidic sensors will enable higher detection sensitivity and sample specificity.
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Affiliation(s)
- Erik S. Hamilton
- Electrical and Computer Engineering, Brigham Young University, Provo, UT 84602, USA; (J.G.W.); (A.R.H.)
| | - Vahid Ganjalizadeh
- Electrical and Computer Engineering, University of California, Santa Cruz, Santa Cruz, CA 95064, USA; (V.G.); (H.S.)
| | - Joel G. Wright
- Electrical and Computer Engineering, Brigham Young University, Provo, UT 84602, USA; (J.G.W.); (A.R.H.)
| | - Holger Schmidt
- Electrical and Computer Engineering, University of California, Santa Cruz, Santa Cruz, CA 95064, USA; (V.G.); (H.S.)
| | - Aaron R. Hawkins
- Electrical and Computer Engineering, Brigham Young University, Provo, UT 84602, USA; (J.G.W.); (A.R.H.)
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16
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Beeharry T, Yahiaoui R, Selemani K, Ouslimani HH. A Co-Polarization Broadband Radar Absorber for RCS Reduction. Materials (Basel) 2018; 11:E1668. [PMID: 30205609 DOI: 10.3390/ma11091668] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Revised: 09/03/2018] [Accepted: 09/07/2018] [Indexed: 11/16/2022]
Abstract
In this article, a single layer co-polarization broadband radar absorber is presented. Under normal incidence, it achieves at least 90% of absorption from 5.6 GHz to 9.1 GHz for both Transverse Electric (TE) and Transverse Magnetic (TM) polarizations. Our contribution and the challenge of this work is to achieve broadband absorption using a very thin single layer dielectric and it is achieved by rotating the resonating element by 45 ∘ . An original optimized Underlined U shape has been developed for the resonating element which provides a broadband co-polarization absorption. The structure is 12.7 times thinner than the wavelength at the center frequency. To understand the absorption mechanism, the transmission line model of an absorber and the three near unity absorption peaks at 5.87 GHz, 7.16 GHz and 8.82 GHz have been used to study the electric and magnetic fields. The physical insight of how the three near unity absorption peaks are achieved has also been discussed. After fabricating the structure, the measurements were found to be in good agreement with the simulation results. Furthermore, with the proposed original UUSR resonating element, the operational bandwidth to thickness ratio of 6.43 is obtained making the proposed UUSR very competitive.
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Abstract
Two-dimensional, graphene-based materials have attracted great attention as a new membrane building block, primarily owing to their potential to make the thinnest possible membranes and thus provide the highest permeance for effective sieving, assuming comparable porosity to conventional membranes and uniform molecular-sized pores. However, a great challenge exists to fabricate large-area, single-layered graphene or graphene oxide (GO) membranes that have negligible undesired transport pathways, such as grain boundaries, tears, and cracks. Therefore, model systems, such as a single flake or nanochannels between graphene or GO flakes, have been studied via both simulations and experiments to explore the transport mechanisms and separation potential of graphene-based membranes. This article critically reviews literature related to single- to few-layered graphene and GO membranes, from material synthesis and characteristics, fundamental membrane structures, and transport mechanisms to potential separation applications. Knowledge gaps between science and engineering in this new field and future opportunities for practical separation applications are also discussed.
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Affiliation(s)
- Fanglei Zhou
- Department of Chemical & Biological Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, USA; ,
| | - Mahdi Fathizadeh
- Department of Chemical Engineering, University of South Carolina, Columbia, South Carolina 29208, USA;
| | - Miao Yu
- Department of Chemical & Biological Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, USA; ,
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18
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Li H, Tran TN, Lee BJ, Zhang C, Park JD, Kang TH, Yu JS. Synthesis of Water-Dispersible Single-Layer CoAl-Carbonate Layered Double Hydroxide. ACS Appl Mater Interfaces 2017; 9:20294-20298. [PMID: 28590111 DOI: 10.1021/acsami.7b02912] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Despite extensive study on single-layer layered double hydroxides (SL-LDHs) with NO3- counterions, SL-LDHs with CO32- counterions (CO32- SL-LDHs) have never been prepared before. Herein, a CoAl-CO32- SL-LDH which stays stable in water and powdery state is first synthesized using ethylene glycol as a reaction medium. The SL-LDH, with thickness of ∼0.85 nm, is composed of one Co(Al)O6 layer sandwiched between two CO32- layers. The SL-LDH powder shows high specific surface area (∼289 m2/g) and excellent electrocatalytic oxygen evolution efficiency. This work provides the first simple way to prepare CO32- SL-LDHs and will open an avenue for synthesizing other SL-LDHs.
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Affiliation(s)
- Haiping Li
- Department of Energy Systems Engineering, DGIST , Daegu 42988, South of Korea
- National Engineering Research Center for Colloidal Materials, Shandong University , Jinan 250100, P.R. China
| | - Thanh-Nhan Tran
- Department of Energy Systems Engineering, DGIST , Daegu 42988, South of Korea
| | - Byong-Jun Lee
- Department of Energy Systems Engineering, DGIST , Daegu 42988, South of Korea
| | - Chunfei Zhang
- Department of Energy Systems Engineering, DGIST , Daegu 42988, South of Korea
| | - Jong-Deok Park
- Department of Energy Systems Engineering, DGIST , Daegu 42988, South of Korea
| | - Tong-Hyun Kang
- Department of Energy Systems Engineering, DGIST , Daegu 42988, South of Korea
| | - Jong-Sung Yu
- Department of Energy Systems Engineering, DGIST , Daegu 42988, South of Korea
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19
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Bennich G, Rudnicki M, Wilken-Jensen C, Lousen T, Lassen PD, Wøjdemann K. Impact of adding a second layer to a single unlocked closure of a Cesarean uterine incision: randomized controlled trial. Ultrasound Obstet Gynecol 2016; 47:417-422. [PMID: 26489989 DOI: 10.1002/uog.15792] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Revised: 10/06/2015] [Accepted: 10/11/2015] [Indexed: 06/05/2023]
Abstract
OBJECTIVE To investigate short- and long-term effects on residual myometrial thickness (RMT) of adding a second layer to a single unlocked closure of a Cesarean uterine incision. METHODS This was a randomized double-blind controlled trial. Healthy nulliparous women scheduled for first-time elective Cesarean delivery were operated on using a modified version of the Misgav Ladach surgical technique. The women were examined by transabdominal ultrasound before discharge from the maternity ward and by transvaginal saline contrast sonohysterography at a minimum of 5 months postpartum. RESULTS Seventy-six nulliparae met the criteria and agreed to participate in the study. Thirty-five women were assigned to the single-layer technique and 38 to the double-layer unlocked closure technique. Groups were comparable regarding gestational age at delivery, duration of surgery and perioperative blood loss. There was no difference in RMT between the two groups, both at time of discharge (mean ± SD, 20.2 ± 8.0 mm vs 21.0 ± 9.7 mm) and after 5 months postpartum (mean, 5.7 ± 2.9 mm vs 5.7 ± 2.2 mm). RMT was approximately half that of the normal myometrium at both examinations. CONCLUSION The results of this study suggest that double-layer closure of a Cesarean uterine incision does not increase RMT compared with single-layer closure when an unlocked technique is used.
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Affiliation(s)
- G Bennich
- Department of Obstetrics and Gynecology, Roskilde University Hospital, Roskilde, Denmark
| | - M Rudnicki
- Department of Obstetrics and Gynecology, Odense University Hospital, Odense, Denmark
| | - C Wilken-Jensen
- Department of Obstetrics and Gynecology, Hvidovre University Hospital, Hvidovre, Denmark
| | - T Lousen
- Department of Obstetrics and Gynecology, Roskilde University Hospital, Roskilde, Denmark
| | - P D Lassen
- Department of Obstetrics and Gynecology, Roskilde University Hospital, Roskilde, Denmark
| | - K Wøjdemann
- Department of Surgery, Bornholms Hospital, Roenne, Denmark
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20
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Yu S, Kim J, Yoon KR, Jung JW, Oh J, Kim ID. Rational Design of Efficient Electrocatalysts for Hydrogen Evolution Reaction: Single Layers of WS2 Nanoplates Anchored to Hollow Nitrogen-Doped Carbon Nanofibers. ACS Appl Mater Interfaces 2015; 7:28116-21. [PMID: 26654256 DOI: 10.1021/acsami.5b09447] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
To exploit the benefits of nanostructuring for enhanced hydrogen evolution reaction (HER), we employed coaxial electrospinning to synthesize single-layered WS2 nanoplates anchored to hollow nitrogen-doped carbon nanofibers (WS2@HNCNFs) as efficient electrocatalysts. For comparison, bulk WS2 powder and single layers of WS2 embedded in nitrogen-doped carbon nanofibers (WS2@NCNFs) were synthesized and electrochemically tested. The distinctive design of the WS2@HNCNFs enables remarkable electrochemical performances showing a low overpotential with reduced charge transfer resistance, a small Tafel slope, and excellent durability. The experimental results highlight the importance of nanostructure engineering in electrocatalysts for enhanced HER.
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Affiliation(s)
- Sunmoon Yu
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST) , 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Jaehoon Kim
- Graduate School of Energy, Environment, Water and Sustainability (EEWS), Korea Advanced Institute of Science and Technology (KAIST) , 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Ki Ro Yoon
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST) , 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Ji-Won Jung
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST) , 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Jihun Oh
- Graduate School of Energy, Environment, Water and Sustainability (EEWS), Korea Advanced Institute of Science and Technology (KAIST) , 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Il-Doo Kim
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST) , 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
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