Pub Date : 2024-09-18DOI: 10.1088/2053-1583/ad6884
Xuesong Yang, Yuao Wang, Zhuo Li, Zhuoying Cheng, Yinyi Gao, Kai Zhu and Dianxue Cao
Graphene oxide (GO) can serve as cathode material for a viable primary lithium metal battery due to its richness in oxygen-containing functional groups. However, its application is hindered by non-conductivity of GO. Herein, a proposed electrode structure design strategy is carried to regulate the electron and ion conductivity of the graphene oxide aerogel (GO/CNT@NMP) electrode while retaining the original energy density. GO/CNT@NMP exhibits a discharge specific capacity of 703 mAh g−1 and an ultra-high energy density of 1655.76 Wh kg−1 at a low rate of 0.02 A g−1. Additionally, it achieves a maximum discharge rate of 1.4 A g−1, five times higher than the initial maximum discharge rate of GO. Characterization and electrochemical tests reveal that the excellent performance of GO/CNT@NMP can be attributed to its porous structure, high electrical conductivity, and large layer spacing. This study presents a potent strategy for the advancement of ultra-fast primary batteries, aiming to integrate ultra-high energy density and high-rate discharge capabilities.
氧化石墨烯（GO）含有丰富的含氧官能团，可作为可行的一次锂金属电池的阴极材料。然而，GO 的非导电性阻碍了它的应用。本文提出了一种电极结构设计策略，以调节氧化石墨烯气凝胶（GO/CNT@NMP）电极的电子和离子导电性，同时保持原有的能量密度。在 0.02 A g-1 的低速率下，GO/CNT@NMP 显示出 703 mAh g-1 的放电比容量和 1655.76 Wh kg-1 的超高能量密度。此外，它还实现了 1.4 A g-1 的最大放电速率，是 GO 初始最大放电速率的五倍。表征和电化学测试表明，GO/CNT@NMP 的优异性能可归因于其多孔结构、高导电性和大层间距。这项研究为超快一次电池的发展提供了一种有效的策略，旨在将超高能量密度和高速放电能力结合起来。
{"title":"Constructing three-dimensional GO/CNT@NMP aerogels towards primary lithium metal batteries","authors":"Xuesong Yang, Yuao Wang, Zhuo Li, Zhuoying Cheng, Yinyi Gao, Kai Zhu and Dianxue Cao","doi":"10.1088/2053-1583/ad6884","DOIUrl":"https://doi.org/10.1088/2053-1583/ad6884","url":null,"abstract":"Graphene oxide (GO) can serve as cathode material for a viable primary lithium metal battery due to its richness in oxygen-containing functional groups. However, its application is hindered by non-conductivity of GO. Herein, a proposed electrode structure design strategy is carried to regulate the electron and ion conductivity of the graphene oxide aerogel (GO/CNT@NMP) electrode while retaining the original energy density. GO/CNT@NMP exhibits a discharge specific capacity of 703 mAh g−1 and an ultra-high energy density of 1655.76 Wh kg−1 at a low rate of 0.02 A g−1. Additionally, it achieves a maximum discharge rate of 1.4 A g−1, five times higher than the initial maximum discharge rate of GO. Characterization and electrochemical tests reveal that the excellent performance of GO/CNT@NMP can be attributed to its porous structure, high electrical conductivity, and large layer spacing. This study presents a potent strategy for the advancement of ultra-fast primary batteries, aiming to integrate ultra-high energy density and high-rate discharge capabilities.","PeriodicalId":6812,"journal":{"name":"2D Materials","volume":"32 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142254943","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-18DOI: 10.1088/2053-1583/ad71dd
Hermina Lizzette C Lim, Ela T Tobias, Guan-Yu Chen, Yen-Lin Lu, Alexandra B Santos-Putungan, Allan Abraham B Padama, Shi-Hsin Lin and Darwin Barayang Putungan
We computationally investigated potential piezoelectrocatalysts, two-dimensional (2D) Janus MXTe (M = Hf, Zr; X = S, Se). The structural and electronic properties, synthesis feasibility, piezoelectric properties, and hydrogen evolution reaction were calculated. Our results showed that these 2D Janus MXTe are narrow-gap semiconductors, indicating great conductivity for electrocatalysis. The feasibility of synthesis was comparable to the already synthesized Janus materials. To exhibit a piezoelectrocatalytic effect, the material has to be piezoelectric and catalytically effective simultaneously. As the Janus structure breaks the centrosymmetry, the considered MXTe are intrinsically piezoelectric. We therefore calculated the dipole moments and the variation of out-of-plane polarization upon strain. The computed piezoelectric coefficient e31 is within the same order of magnitude as that of other Janus 2D materials. Finally, although pristine 2D Janus MXTe were inert to hydrogen evolution reaction, incorporation of single-atom defects was found to boost hydrogen adsorption significantly. The catalytic efficacy can be further tuned by biaxial tensile strain, effectively controlling the Gibbs free energy of adsorption to be close to the thermoneutral value that is indicative of an excellent hydrogen evolution reaction activity, at least for ZrSTe Janus monolayer. In summary, this work proposed and comprehensively investigated a new class of possible piezoelectrocatalysts, 2D Janus materials, which is feasible to be synthesized, catalytically effective, and has great conductivity.
{"title":"Two-dimensional Janus MXTe (M = Hf, Zr; X = S, Se) piezoelectrocatalysts: a comprehensive investigation of its electronic, synthesis feasibility, electric polarization, and hydrogen evolution reaction activity","authors":"Hermina Lizzette C Lim, Ela T Tobias, Guan-Yu Chen, Yen-Lin Lu, Alexandra B Santos-Putungan, Allan Abraham B Padama, Shi-Hsin Lin and Darwin Barayang Putungan","doi":"10.1088/2053-1583/ad71dd","DOIUrl":"https://doi.org/10.1088/2053-1583/ad71dd","url":null,"abstract":"We computationally investigated potential piezoelectrocatalysts, two-dimensional (2D) Janus MXTe (M = Hf, Zr; X = S, Se). The structural and electronic properties, synthesis feasibility, piezoelectric properties, and hydrogen evolution reaction were calculated. Our results showed that these 2D Janus MXTe are narrow-gap semiconductors, indicating great conductivity for electrocatalysis. The feasibility of synthesis was comparable to the already synthesized Janus materials. To exhibit a piezoelectrocatalytic effect, the material has to be piezoelectric and catalytically effective simultaneously. As the Janus structure breaks the centrosymmetry, the considered MXTe are intrinsically piezoelectric. We therefore calculated the dipole moments and the variation of out-of-plane polarization upon strain. The computed piezoelectric coefficient e31 is within the same order of magnitude as that of other Janus 2D materials. Finally, although pristine 2D Janus MXTe were inert to hydrogen evolution reaction, incorporation of single-atom defects was found to boost hydrogen adsorption significantly. The catalytic efficacy can be further tuned by biaxial tensile strain, effectively controlling the Gibbs free energy of adsorption to be close to the thermoneutral value that is indicative of an excellent hydrogen evolution reaction activity, at least for ZrSTe Janus monolayer. In summary, this work proposed and comprehensively investigated a new class of possible piezoelectrocatalysts, 2D Janus materials, which is feasible to be synthesized, catalytically effective, and has great conductivity.","PeriodicalId":6812,"journal":{"name":"2D Materials","volume":"194 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142254944","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-16DOI: 10.1088/2053-1583/ad77e0
Carlo Grazianetti, Alessandro Molle and Christian Martella
After more than ten years since the silicene discovery, many Xenes, the class of elemental graphene-like lattices, have now enriched the two-dimensional periodic table of elements. Here, we provide a perspective on the future of the Xenes by briefly summarizing their properties and devices reported thus far. Two main challenges are expected to focus the scientists’ attention to bring the Xenes to the next level. To step over the current scenario the Xenes need standardization either in the growth or in the fabrication of devices, aiming at the wafer-scale and the reliability and stability, respectively. The benefits arising from these challenges will enable the concept of hybrid Xenes and hybrid Xenes-based devices, that is a combination of different Xenes with new properties and multifunctional Xenes-based devices, respectively, with potential unexpected fascinating properties to continue the journey.
{"title":"The future of Xenes beyond graphene: challenges and perspective","authors":"Carlo Grazianetti, Alessandro Molle and Christian Martella","doi":"10.1088/2053-1583/ad77e0","DOIUrl":"https://doi.org/10.1088/2053-1583/ad77e0","url":null,"abstract":"After more than ten years since the silicene discovery, many Xenes, the class of elemental graphene-like lattices, have now enriched the two-dimensional periodic table of elements. Here, we provide a perspective on the future of the Xenes by briefly summarizing their properties and devices reported thus far. Two main challenges are expected to focus the scientists’ attention to bring the Xenes to the next level. To step over the current scenario the Xenes need standardization either in the growth or in the fabrication of devices, aiming at the wafer-scale and the reliability and stability, respectively. The benefits arising from these challenges will enable the concept of hybrid Xenes and hybrid Xenes-based devices, that is a combination of different Xenes with new properties and multifunctional Xenes-based devices, respectively, with potential unexpected fascinating properties to continue the journey.","PeriodicalId":6812,"journal":{"name":"2D Materials","volume":"42 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142254945","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-12DOI: 10.1088/2053-1583/ad77e1
Hongjin Dai, Yufang Cao and Jingyu Sun
High-rate hard carbon anode is critical for achieving fast-charging sodium-ion batteries, whereas the limited ion/electron kinetics caused by unexpected surface defects and unsatisfactory conductivity greatly limits rate capability. Herein, a coconut shell-derived soft-carbon-tuned hard carbon (SHC) with low surface area (4.7 m2 g−1) was prepared. With SHCs as bricks, a high conductivity single-walled carbon nanotube (SWNT)-bonded hard carbon film was constructed. The pitch-derived soft carbon formed on SHCs can effectively decrease the surface defects and simultaneously induce optimized disordered graphite domains into carbon matrix, enabling high Na+ reversibility and ionic/electronic conductivity. The crosslinked SWNTs in-between can provide continuous ion/charge transport ‘highways’, thus ensuring rapid ion/electron kinetics. As a result, such a self-supporting carbon anode exhibits remarkable rate performance (330 mAh g−1 at 0.1 C and 272 mAh g−1 at 5 C), superior initial Coulombic efficiency of 95.2% and outstanding cycling stability.
高倍率硬碳阳极是实现钠离子电池快速充电的关键，而意外的表面缺陷和不理想的导电性导致的离子/电子动力学限制极大地限制了倍率能力。本文制备了一种低表面积（4.7 m2 g-1）的椰壳衍生软碳调谐硬碳（SHC）。以 SHC 为砖，构建了高导电率的单壁碳纳米管（SWNT）结合硬碳薄膜。在 SHC 上形成的沥青衍生软碳可有效减少表面缺陷，同时将优化的无序石墨畴诱导到碳基体中，从而实现高 Na+ 可逆性和离子/电子导电性。中间交联的 SWNT 可提供连续的离子/电荷传输 "高速公路"，从而确保快速的离子/电子动力学。因此，这种自支撑碳阳极具有卓越的速率性能（0.1 C 时为 330 mAh g-1，5 C 时为 272 mAh g-1）、95.2% 的出色初始库仑效率和出色的循环稳定性。
{"title":"Soft-carbon-tuned hard carbon anode for ultrahigh-rate sodium storage","authors":"Hongjin Dai, Yufang Cao and Jingyu Sun","doi":"10.1088/2053-1583/ad77e1","DOIUrl":"https://doi.org/10.1088/2053-1583/ad77e1","url":null,"abstract":"High-rate hard carbon anode is critical for achieving fast-charging sodium-ion batteries, whereas the limited ion/electron kinetics caused by unexpected surface defects and unsatisfactory conductivity greatly limits rate capability. Herein, a coconut shell-derived soft-carbon-tuned hard carbon (SHC) with low surface area (4.7 m2 g−1) was prepared. With SHCs as bricks, a high conductivity single-walled carbon nanotube (SWNT)-bonded hard carbon film was constructed. The pitch-derived soft carbon formed on SHCs can effectively decrease the surface defects and simultaneously induce optimized disordered graphite domains into carbon matrix, enabling high Na+ reversibility and ionic/electronic conductivity. The crosslinked SWNTs in-between can provide continuous ion/charge transport ‘highways’, thus ensuring rapid ion/electron kinetics. As a result, such a self-supporting carbon anode exhibits remarkable rate performance (330 mAh g−1 at 0.1 C and 272 mAh g−1 at 5 C), superior initial Coulombic efficiency of 95.2% and outstanding cycling stability.","PeriodicalId":6812,"journal":{"name":"2D Materials","volume":"69 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142198532","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This article provides an overview of recent advances, challenges, and opportunities in multiscale computational modeling techniques for study and design of two-dimensional (2D) materials. We discuss the role of computational modeling in understanding the structures and properties of 2D materials, followed by a review of various length-scale models aiding in their synthesis. We present an integration of multiscale computational techniques for study and design of 2D materials, including density functional theory, molecular dynamics, phase-field modeling, continuum-based molecular mechanics, and machine learning. The study focuses on recent advancements, challenges, and future prospects in modeling techniques tailored for emerging 2D materials. Key challenges include accurately capturing intricate behaviors across various scales and environments. Conversely, opportunities lie in enhancing predictive capabilities to accelerate materials discovery for applications spanning from electronics, photonics, energy storage, catalysis, and nanomechanical devices. Through this comprehensive review, our aim is to provide a roadmap for future research in multiscale computational modeling and simulation of 2D materials.
{"title":"Multiscale computational modeling techniques in study and design of 2D materials: recent advances, challenges, and opportunities","authors":"Mohsen Asle Zaeem, Siby Thomas, Sepideh Kavousi, Ning Zhang, Tanmoy Mukhopadhyay, Avik Mahata","doi":"10.1088/2053-1583/ad63b6","DOIUrl":"https://doi.org/10.1088/2053-1583/ad63b6","url":null,"abstract":"This article provides an overview of recent advances, challenges, and opportunities in multiscale computational modeling techniques for study and design of two-dimensional (2D) materials. We discuss the role of computational modeling in understanding the structures and properties of 2D materials, followed by a review of various length-scale models aiding in their synthesis. We present an integration of multiscale computational techniques for study and design of 2D materials, including density functional theory, molecular dynamics, phase-field modeling, continuum-based molecular mechanics, and machine learning. The study focuses on recent advancements, challenges, and future prospects in modeling techniques tailored for emerging 2D materials. Key challenges include accurately capturing intricate behaviors across various scales and environments. Conversely, opportunities lie in enhancing predictive capabilities to accelerate materials discovery for applications spanning from electronics, photonics, energy storage, catalysis, and nanomechanical devices. Through this comprehensive review, our aim is to provide a roadmap for future research in multiscale computational modeling and simulation of 2D materials.","PeriodicalId":6812,"journal":{"name":"2D Materials","volume":"14 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142198533","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-05DOI: 10.1088/2053-1583/ad70c6
Na Luo, Hao Ma, Tao Zhang, Jiajing Wu, Zheng-Jie Chen, Minwei Xu, Yuanmiao Sun, Jing Peng
Designing two-dimensional (2D) ferromagnetic materials with high Curie temperature is urgent for the development of spintronic technology. The exploration of non-van der Waals (vdW) ferromagnetic nanosheets play a vital role in enriching the 2D ferromagnetic materials family on account of the scarcity of vdW materials in nature. Herein, we report a non-vdW AgCrS2 material with antiferro-to-ferro-magnetism transition when it thinned down to monolayer. Based on it, a universal ion-exchange strategy was employed to replace Ag+ by the M (M = Li+, Na+, K+) cations, acquiring a series of 2D non-vdW MxAg0.5−xCrS2 materials with tunable ferromagnetism. The Curie temperature is higher than the AgCrS2 nanosheet, and reaches up to 160 K when M is K+. The theoretical calculations verify the ferromagnetism of AgCrS2 and MxAg0.5−xCrS2 nanosheet originated from CrS2 layer. The disorderly arranged M and Ag ions increase the asymmetry of the lattice structure of MxAg0.5−xCrS2, thereby strengthening the interlayer ferromagnetic coupling and raising the Curie temperature of the nanosheets. This work provides ideas for discovering more 2D ferromagnetic materials with high Curie temperature.
设计具有高居里温度的二维（2D）铁磁材料是发展自旋电子技术的当务之急。非范德华（vdW）铁磁纳米片的探索对于丰富二维铁磁材料家族起着至关重要的作用，因为自然界中的vdW材料非常稀缺。在此，我们报告了一种非 vdW AgCrS2 材料，当它变薄到单层时，具有反铁磁性到铁磁性的转变。在此基础上，我们采用通用离子交换策略，用 M（M = Li+、Na+、K+）阳离子取代 Ag+，获得了一系列具有可调铁磁性的二维非vdW MxAg0.5-xCrS2 材料。其居里温度高于 AgCrS2 纳米片，当 M 为 K+ 时，居里温度高达 160 K。理论计算验证了源于 CrS2 层的 AgCrS2 和 MxAg0.5-xCrS2 纳米片的铁磁性。无序排列的 M 离子和 Ag 离子增加了 MxAg0.5-xCrS2 晶格结构的不对称性，从而加强了层间铁磁耦合，提高了纳米片的居里温度。这项工作为发现更多具有高居里温度的二维铁磁材料提供了思路。
{"title":"Non-van der Waals MCrS2 nanosheets with tunable two-dimensional ferromagnetism","authors":"Na Luo, Hao Ma, Tao Zhang, Jiajing Wu, Zheng-Jie Chen, Minwei Xu, Yuanmiao Sun, Jing Peng","doi":"10.1088/2053-1583/ad70c6","DOIUrl":"https://doi.org/10.1088/2053-1583/ad70c6","url":null,"abstract":"Designing two-dimensional (2D) ferromagnetic materials with high Curie temperature is urgent for the development of spintronic technology. The exploration of non-van der Waals (vdW) ferromagnetic nanosheets play a vital role in enriching the 2D ferromagnetic materials family on account of the scarcity of vdW materials in nature. Herein, we report a non-vdW AgCrS<sub>2</sub> material with antiferro-to-ferro-magnetism transition when it thinned down to monolayer. Based on it, a universal ion-exchange strategy was employed to replace Ag<sup>+</sup> by the M (M = Li<sup>+</sup>, Na<sup>+</sup>, K<sup>+</sup>) cations, acquiring a series of 2D non-vdW M<italic toggle=\"yes\"><sub>x</sub></italic>Ag<sub>0.5−<italic toggle=\"yes\">x</italic></sub>CrS<sub>2</sub> materials with tunable ferromagnetism. The Curie temperature is higher than the AgCrS<sub>2</sub> nanosheet, and reaches up to 160 K when M is K<sup>+</sup>. The theoretical calculations verify the ferromagnetism of AgCrS<sub>2</sub> and M<italic toggle=\"yes\"><sub>x</sub></italic>Ag<sub>0.5−<italic toggle=\"yes\">x</italic></sub>CrS<sub>2</sub> nanosheet originated from CrS<sub>2</sub> layer. The disorderly arranged M and Ag ions increase the asymmetry of the lattice structure of M<italic toggle=\"yes\"><sub>x</sub></italic>Ag<sub>0.5−<italic toggle=\"yes\">x</italic></sub>CrS<sub>2</sub>, thereby strengthening the interlayer ferromagnetic coupling and raising the Curie temperature of the nanosheets. This work provides ideas for discovering more 2D ferromagnetic materials with high Curie temperature.","PeriodicalId":6812,"journal":{"name":"2D Materials","volume":"101 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142198535","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-05DOI: 10.1088/2053-1583/ad690f
Marc Vila
Resistance switching in multilayer structures are typically based on materials possessing ferroic orders. Here we predict an extremely large resistance switching based on the relative spin–orbit splitting in twisted transition metal dichalcogenide (TMD) monolayers tunnel junctions. Because of the valence band spin splitting which depends on the valley index in the Brillouin zone, the perpendicular electronic transport through the junction depends on the relative reciprocal space overlap of the spin-dependent Fermi surfaces of both layers, which can be tuned by twisting one layer. Our quantum transport calculations reveal a switching resistance larger than 106% when the relative alignment of TMDs goes from 0∘ to 60∘ and when the angle is kept fixed at 60∘ and the Fermi level is varied. By creating vacancies, we evaluate how inter-valley scattering affects the efficiency and find that the resistance switching remains large (104%) for typical values of vacancy concentration. Not only should this resistance switching be observed at room temperature due to the large spin splitting, but our results also show how twist angle engineering and control of van der Waals heterostructures could be used for next-generation memory and electronic applications.
{"title":"Giant resistance switch in twisted transition metal dichalcogenide tunnel junctions","authors":"Marc Vila","doi":"10.1088/2053-1583/ad690f","DOIUrl":"https://doi.org/10.1088/2053-1583/ad690f","url":null,"abstract":"Resistance switching in multilayer structures are typically based on materials possessing ferroic orders. Here we predict an extremely large resistance switching based on the relative spin–orbit splitting in twisted transition metal dichalcogenide (TMD) monolayers tunnel junctions. Because of the valence band spin splitting which depends on the valley index in the Brillouin zone, the perpendicular electronic transport through the junction depends on the relative reciprocal space overlap of the spin-dependent Fermi surfaces of both layers, which can be tuned by twisting one layer. Our quantum transport calculations reveal a switching resistance larger than <inline-formula>\u0000<tex-math><?CDATA $10^6 %$?></tex-math><mml:math overflow=\"scroll\"><mml:mrow><mml:msup><mml:mn>10</mml:mn><mml:mn>6</mml:mn></mml:msup><mml:mi mathvariant=\"normal\">%</mml:mi></mml:mrow></mml:math><inline-graphic xlink:href=\"tdmad690fieqn1.gif\"></inline-graphic></inline-formula> when the relative alignment of TMDs goes from 0<sup>∘</sup> to 60<sup>∘</sup> and when the angle is kept fixed at 60<sup>∘</sup> and the Fermi level is varied. By creating vacancies, we evaluate how inter-valley scattering affects the efficiency and find that the resistance switching remains large (<inline-formula>\u0000<tex-math><?CDATA $10^4 %$?></tex-math><mml:math overflow=\"scroll\"><mml:mrow><mml:msup><mml:mn>10</mml:mn><mml:mn>4</mml:mn></mml:msup><mml:mi mathvariant=\"normal\">%</mml:mi></mml:mrow></mml:math><inline-graphic xlink:href=\"tdmad690fieqn2.gif\"></inline-graphic></inline-formula>) for typical values of vacancy concentration. Not only should this resistance switching be observed at room temperature due to the large spin splitting, but our results also show how twist angle engineering and control of van der Waals heterostructures could be used for next-generation memory and electronic applications.","PeriodicalId":6812,"journal":{"name":"2D Materials","volume":"51 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142198534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-05DOI: 10.1088/2053-1583/ad7271
Ziyu Li, Xuefeng Liu, Ke Xu, Qiao Xie, Yage Li, Haijun Zhang, Shaowei Zhang, Wen Lei
With the increasing need for energy and the swift advancement of the electric vehicle industry, the field of energy storage has garnered significant attention. Especially, lithium-ion batteries (LIBs) serve as crucial energy storage devices and have received particular attention. As an emerging class of electrode materials, two-dimensional (2D) materials have become promising candidates for solving the challenges of LIBs owing to their high theoretical capacity, high specific surface area, high ionic conductivity, and long cycle life. The research progress on 2D materials, especially those prepared through liquid-phase exfoliation (LPE), has shown great potential in improving the performance of LIBs. LPE is a powerful and efficient method for preparing 2D materials with various sizes and properties, which is suitable for practical applications. Given these, this paper underscores the great potential of 2D materials prepared via LPE as anode materials for LIBs. Meanwhile, the existence of challenges that need to be overcome in relation to the scalability of the LPE method and the use of 2D materials in practical applications are also proposed.
{"title":"Liquid-phase exfoliated 2D materials for lithium-ion battery anode: current status and future direction","authors":"Ziyu Li, Xuefeng Liu, Ke Xu, Qiao Xie, Yage Li, Haijun Zhang, Shaowei Zhang, Wen Lei","doi":"10.1088/2053-1583/ad7271","DOIUrl":"https://doi.org/10.1088/2053-1583/ad7271","url":null,"abstract":"With the increasing need for energy and the swift advancement of the electric vehicle industry, the field of energy storage has garnered significant attention. Especially, lithium-ion batteries (LIBs) serve as crucial energy storage devices and have received particular attention. As an emerging class of electrode materials, two-dimensional (2D) materials have become promising candidates for solving the challenges of LIBs owing to their high theoretical capacity, high specific surface area, high ionic conductivity, and long cycle life. The research progress on 2D materials, especially those prepared through liquid-phase exfoliation (LPE), has shown great potential in improving the performance of LIBs. LPE is a powerful and efficient method for preparing 2D materials with various sizes and properties, which is suitable for practical applications. Given these, this paper underscores the great potential of 2D materials prepared via LPE as anode materials for LIBs. Meanwhile, the existence of challenges that need to be overcome in relation to the scalability of the LPE method and the use of 2D materials in practical applications are also proposed.","PeriodicalId":6812,"journal":{"name":"2D Materials","volume":"10 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142198538","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-30DOI: 10.1088/2053-1583/ad6ba4
Ina Turcan, Tudor Alexandru Filip, Tăchiță Vlad-Bubulac, Daniela Rusu, Marius Andrei Olariu
Controlling, orientating, and assembling 2D materials is critical for their successful exploitation as active elements in various applications, particularly for sensors. Despite the increased interest in exploiting the properties of MXenes, to date, the direct dielectrophoretic assembly of this category of materials has not been reported. Thus, this work presents an experimental study on dielectrophoretic assembly of pristine MXene flakes at the level of screen-printed interdigitated microelectrodes. The development of MXene uniaxial ‘bridges’ across electrode micro-gaps can be controlled by convenient dielectrophoretic parameters such as voltage and frequency, which are thoroughly discussed. Moreover, appropriate frequencies for avoiding parasitic electrokinetic phenomena (AC electro-osmosis, electrothermal effect) that hamper the application of dielectrophoresis were identified. Finally, the proposed methodology for assembling MXene flakes demonstrates its feasibility of being used for development of chemiresistors as of satisfactory response of pristine MXene ‘bridges’ to ethanol atmosphere.
{"title":"Dielectrophoretic direct assembling of Mxene flakes at the level of screen-printed interdigitated microelectrodes and their evaluation in gas sensing applications","authors":"Ina Turcan, Tudor Alexandru Filip, Tăchiță Vlad-Bubulac, Daniela Rusu, Marius Andrei Olariu","doi":"10.1088/2053-1583/ad6ba4","DOIUrl":"https://doi.org/10.1088/2053-1583/ad6ba4","url":null,"abstract":"Controlling, orientating, and assembling 2D materials is critical for their successful exploitation as active elements in various applications, particularly for sensors. Despite the increased interest in exploiting the properties of MXenes, to date, the direct dielectrophoretic assembly of this category of materials has not been reported. Thus, this work presents an experimental study on dielectrophoretic assembly of pristine MXene flakes at the level of screen-printed interdigitated microelectrodes. The development of MXene uniaxial ‘bridges’ across electrode micro-gaps can be controlled by convenient dielectrophoretic parameters such as voltage and frequency, which are thoroughly discussed. Moreover, appropriate frequencies for avoiding parasitic electrokinetic phenomena (AC electro-osmosis, electrothermal effect) that hamper the application of dielectrophoresis were identified. Finally, the proposed methodology for assembling MXene flakes demonstrates its feasibility of being used for development of chemiresistors as of satisfactory response of pristine MXene ‘bridges’ to ethanol atmosphere.","PeriodicalId":6812,"journal":{"name":"2D Materials","volume":"13 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142198539","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-30DOI: 10.1088/2053-1583/ad70c8
Chhor Yi Ly, Chenda Vong, Tharith Sriv, Hyeonsik Cheong
We investigated interlayer modes of few-layer HfX2 (X = S, Se) by using low-frequency micro-Raman spectroscopy with three excitation energies (1.96 eV, 2.33 eV, 2.54 eV) under vacuum condition (∼10−6Torr). We observed interlayer modes in HfSe2 when the 2.54 eV excitation energy was used. The low-frequency Raman spectra reveal a series of shear and breathing modes (<50 cm−1) that are helpful for identifying the number of layers. The in-plane Eg and out-of-plane A1g modes of HfSe2 are located at ∼150 cm−1 and ∼200 cm−1, respectively. In HfS2, in-plane Eg and out-of-plane A1g optical phonons are observed at ∼260 cm−1 and ∼337 cm−1, respectively. The in-plane and out-of-plane force constants of atomically thin HfSe2 are obtained to be 1.87 × 1019N m−3 and 6.55 × 1019N m−3, respectively, by fitting the observed interlayer modes using the linear chain model. These results provide valuable information on materials parameters for device designs using atomically-thin layered HfX2 (X = S, Se).
{"title":"Raman spectroscopy of atomically thin HfX2 (X=S, Se)","authors":"Chhor Yi Ly, Chenda Vong, Tharith Sriv, Hyeonsik Cheong","doi":"10.1088/2053-1583/ad70c8","DOIUrl":"https://doi.org/10.1088/2053-1583/ad70c8","url":null,"abstract":"We investigated interlayer modes of few-layer HfX<sub>2</sub> (X = S, Se) by using low-frequency micro-Raman spectroscopy with three excitation energies (1.96 eV, 2.33 eV, 2.54 eV) under vacuum condition (∼10<sup>−6</sup>Torr). We observed interlayer modes in HfSe<sub>2</sub> when the 2.54 eV excitation energy was used. The low-frequency Raman spectra reveal a series of shear and breathing modes (<50 cm<sup>−1</sup>) that are helpful for identifying the number of layers. The in-plane <italic toggle=\"yes\">E</italic><sub>g</sub> and out-of-plane <italic toggle=\"yes\">A</italic><sub>1g</sub> modes of HfSe<sub>2</sub> are located at ∼150 cm<sup>−1</sup> and ∼200 cm<sup>−1</sup>, respectively. In HfS<sub>2</sub>, in-plane <italic toggle=\"yes\">E</italic><sub>g</sub> and out-of-plane <italic toggle=\"yes\">A</italic><sub>1g</sub> optical phonons are observed at ∼260 cm<sup>−1</sup> and ∼337 cm<sup>−1,</sup> respectively. The in-plane and out-of-plane force constants of atomically thin HfSe<sub>2</sub> are obtained to be 1.87 × 10<sup>19</sup>N m<sup>−3</sup> and 6.55 × 10<sup>19</sup>N m<sup>−3</sup>, respectively, by fitting the observed interlayer modes using the linear chain model. These results provide valuable information on materials parameters for device designs using atomically-thin layered HfX<sub>2</sub> (X = S, Se).","PeriodicalId":6812,"journal":{"name":"2D Materials","volume":"45 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142198540","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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