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Jiang W, Sofer R, Gao X, Tkatchenko A, Kronik L, Ouyang W, Urbakh M, Hod O. Anisotropic Interlayer Force Field for Group-VI Transition Metal Dichalcogenides. J Phys Chem A 2023; 127:9820-9830. [PMID: 37938019 DOI: 10.1021/acs.jpca.3c04540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2023]
Abstract
An anisotropic interlayer force field that describes the interlayer interactions in homogeneous and heterogeneous interfaces of group-VI transition metal dichalcogenides (MX2, where M = Mo, W, and X = S, Se) is presented. The force field is benchmarked against density functional theory calculations for bilayer systems within the Heyd-Scuseria-Ernzerhof hybrid density functional approximation, augmented by a nonlocal many-body dispersion treatment of long-range correlation. The parametrization yields good agreement with the reference calculations of binding energy curves and sliding potential energy surfaces. It is found to be transferable to transition metal dichalcogenide (TMD) junctions outside of the training set that contain the same atom types. Calculated bulk moduli agree with most previous dispersion-corrected density functional theory predictions, which underestimate the available experimental values. Calculated phonon spectra of the various junctions under consideration demonstrate the importance of appropriately treating the anisotropic nature of the layered interfaces. Considering our previous parametrization for MoS2, the anisotropic interlayer potential enables accurate and efficient large-scale simulations of the dynamical, tribological, and thermal transport properties of a large set of homogeneous and heterogeneous TMD interfaces.
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Affiliation(s)
- Wenwu Jiang
- Department of Engineering Mechanics, School of Civil Engineering, Wuhan University, Wuhan, Hubei 430072, China
| | - Reut Sofer
- School of Chemistry and The Sackler Center for Computational Molecular and Materials Science, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Xiang Gao
- School of Chemistry and The Sackler Center for Computational Molecular and Materials Science, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Alexandre Tkatchenko
- Department of Physics and Materials Science, University of Luxembourg, L-1511 Luxembourg City, Luxembourg
| | - Leeor Kronik
- Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovoth 76100, Israel
| | - Wengen Ouyang
- Department of Engineering Mechanics, School of Civil Engineering, Wuhan University, Wuhan, Hubei 430072, China
- State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan 430072, China
| | - Michael Urbakh
- School of Chemistry and The Sackler Center for Computational Molecular and Materials Science, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Oded Hod
- School of Chemistry and The Sackler Center for Computational Molecular and Materials Science, Tel Aviv University, Tel Aviv 6997801, Israel
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2
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Tsuji Y, Okazawa K, Yoshizawa K. Hückel Molecular Orbital Analysis for Stability and Instability of Stacked Aromatic and Stacked Antiaromatic Systems. J Org Chem 2023; 88:14887-14898. [PMID: 37846097 DOI: 10.1021/acs.joc.3c01167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2023]
Abstract
Face-to-face stacking of aromatic compounds leads to stacked antiaromaticity, while that of antiaromatic compounds leads to stacked aromaticity. This is a prediction with a long history; in the late 2000s, the prediction was confirmed by high-precision quantum chemical calculations, and finally, in 2016, a π-conjugated system with stacked aromaticity was synthesized. Several variations have since been reported, but essentially, they are all the same molecule. To realize stacked aromaticity in a completely new and different molecular system and to trigger an extension of the concept of stacked aromaticity, it is important to understand the origin of stacked aromaticity. The Hückel method, which has been successful in giving qualitatively correct results for π-conjugated systems despite its bold assumptions, is well suited for the analysis of stacked aromaticity. We use this method to model the face-to-face stacking systems of benzene and cyclobutadiene molecules and discuss their stacked antiaromaticity and stacked aromaticity on the basis of their π-electron energies. By further developing the discussion, we search for clues to realize stacked aromaticity in synthesizable molecular systems.
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Affiliation(s)
- Yuta Tsuji
- Faculty of Engineering Sciences, Kyushu University, Kasuga, Fukuoka 816-8580, Japan
| | - Kazuki Okazawa
- Institute for Materials Chemistry and Engineering and IRCCS, Kyushu University, Nishi-ku, Fukuoka 819-0395, Japan
| | - Kazunari Yoshizawa
- Institute for Materials Chemistry and Engineering and IRCCS, Kyushu University, Nishi-ku, Fukuoka 819-0395, Japan
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3
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Evolution of the Electronic and Optical Properties of Meta-Stable Allotropic Forms of 2D Tellurium for Increasing Number of Layers. NANOMATERIALS 2022; 12:nano12142503. [PMID: 35889726 PMCID: PMC9324411 DOI: 10.3390/nano12142503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 07/15/2022] [Accepted: 07/17/2022] [Indexed: 02/05/2023]
Abstract
In this work, ab initio Density Functional Theory calculations are performed to investigate the evolution of the electronic and optical properties of 2D Tellurium—called Tellurene—for three different allotropic forms (α-, β- and γ-phase), as a function of the number of layers. We estimate the exciton binding energies and radii of the studied systems, using a 2D analytical model. Our results point out that these quantities are strongly dependent on the allotropic form, as well as on the number of layers. Remarkably, we show that the adopted method is suitable for reliably predicting, also in the case of Tellurene, the exciton binding energy, without the need of computationally demanding calculations, possibly suggesting interesting insights into the features of the system. Finally, we inspect the nature of the mechanisms ruling the interaction of neighbouring Tellurium atoms helical chains (characteristic of the bulk and α-phase crystal structures). We show that the interaction between helical chains is strong and cannot be explained by solely considering the van der Waals interaction.
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Liang N, Li Q, Pan G, Liu C, Liu Y. Carbon Material With Ordered Sub-Nanometer Hole Defects. Front Chem 2022; 10:858154. [PMID: 35386846 PMCID: PMC8979169 DOI: 10.3389/fchem.2022.858154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 03/01/2022] [Indexed: 11/13/2022] Open
Abstract
A holey carbon material with ordered sub-nanometer hole defects was synthesized from oxidative cyclodehydrogenation of a polyhexaphenylbenzene precursor. Band gap of around 2.2 eV is formed due to the narrow connection between the hexabenzocoronene subunits. It has weak interlayer interaction energy compared with graphene and shows easy dispersion in a wide range of solvents, surprisingly including water. Density functional theory calculations confirmd the excellent dispersion of this material in water. This new carbon material was then proved as effective support for various inorganic nanoparticles of small sizes. The supported iron nanoparticles showed enzyme-like catalysis behavior in nitrophenyl reduction reaction by NaBH4, exemplifying the great potential of this new material in catalysis.
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Affiliation(s)
- Nianjie Liang
- School of Chemistry, Beihang University, Beijing, China
| | - Qiaosheng Li
- School of Chemistry, Beihang University, Beijing, China
| | - Ganghuo Pan
- School of Chemistry, Beihang University, Beijing, China
| | - Chunxiang Liu
- School of Chemistry, Beihang University, Beijing, China
| | - Yuzhou Liu
- School of Chemistry, Beihang University, Beijing, China
- Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University, Beijing, China
- Beijing Shenyun Zhihe Technology Co., Ltd., Beijing, China
- *Correspondence: Yuzhou Liu,
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5
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Melekamburath A, James A, Rajeevan M, John C, Swathi RS. In pursuit of accurate interlayer potentials for twisted bilayer graphynes. Phys Chem Chem Phys 2021; 23:27031-27041. [PMID: 34846392 DOI: 10.1039/d1cp03637h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Recent explorations of twist in bilayer graphene and the discovery of superconducting phases at certain magic angles have laid the groundwork for a new branch in materials science called twistronics. However, theoretical studies on twisted layered materials are impeded due to the computational expense associated with first-principles calculations. Empirical force field approaches that include anisotropic terms to describe interlayer interactions have come to the fore as excellent alternatives to deal with such a stumbling block. Taking a cue from these formulations, herein, we describe our pursuit of capturing the interlayer interactions in bilayer graphynes with atomistic empirical potentials. The choice of the potentials, namely the improved Lennard-Jones potential and Hod's interlayer potential, is motivated by the objective of bringing out the role of anisotropy explicitly. Empirical parameters for both the potentials are calibrated against dispersion-corrected DFT calculations that are performed to incorporate the stacking, sliding and twisting features of the bilayer configurations. Although the isotropic improved Lennard-Jones potential is able to describe the interlayer stacking of graphynes, it is inadequate to account for the interlayer twist properties. The anisotropic Hod's interlayer potential portrays the interlayer twisting energy profiles of the benchmark DFT calculations with a reasonable accuracy. Our potential formulations can bestow impetus to the research on the homo- and hetero-bilayer structures of graphynes and other two-dimensional materials.
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Affiliation(s)
- Ajay Melekamburath
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram (IISER TVM), Vithura, Thiruvananthapuram, 695551, India.
| | - Anto James
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram (IISER TVM), Vithura, Thiruvananthapuram, 695551, India.
| | - Megha Rajeevan
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram (IISER TVM), Vithura, Thiruvananthapuram, 695551, India.
| | - Chris John
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram (IISER TVM), Vithura, Thiruvananthapuram, 695551, India.
| | - Rotti Srinivasamurthy Swathi
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram (IISER TVM), Vithura, Thiruvananthapuram, 695551, India.
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6
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Ruan Q, Wang L, Bets KV, Yakobson BI. Step-Edge Epitaxy for Borophene Growth on Insulators. ACS NANO 2021; 15:18347-18353. [PMID: 34766759 DOI: 10.1021/acsnano.1c07589] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Borophene─a monatomic layer of boron atoms─stands out among two-dimensional (2D) materials, with its versatile properties tantalizing for physics exploration and next-generation devices. Yet its phases are all synthesized on and stay bound to metal substrates, hampering both characterization and use. Borophene growth on an inert insulator would allow postsynthesis exfoliation, but the weak adhesion to such a substrate results in a high 2D nucleation barrier, preventing clean borophene growth. This challenge can be circumvented in a strategy devised and demonstrated here with ab initio calculations. Naturally present 1D-defects, the step-edges on an h-BN substrate surface, enable boron epitaxial assembly, reduce the nucleation dimensionality, and lower the barrier by an order of magnitude (to 1.1 eV or less), yielding a v1/9 phase. Weak borophene adhesion to the insulator makes it readily accessible for comprehensive property tests or transfer into the device setting.
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Affiliation(s)
- Qiyuan Ruan
- Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, United States
| | - Luqing Wang
- Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, United States
| | - Ksenia V Bets
- Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, United States
| | - Boris I Yakobson
- Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, United States
- Department of Chemistry, Rice University, Houston, Texas 77005, United States
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7
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Javvaji B, Vasireddi R, Zhuang X, Mahapatra DR, Rabczuk T. Laser-assisted graphene layer exfoliation from graphite slab. MOLECULAR SIMULATION 2021. [DOI: 10.1080/08927022.2021.1991920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Brahmanandam Javvaji
- Department of Aerospace Engineering, Indian Institute of Science, Bangalore, India
- Chair of Computational Science and Simulation Technology, Institute of Photonics, Faculty of Mathematics and Physics, Leibniz Universität, Hannover, Germany
| | - Ramakrishna Vasireddi
- Department of Aerospace Engineering, Indian Institute of Science, Bangalore, India
- Synchrotron SOLEIL, Gif-sur-Yvette, France
| | - Xiaoying Zhuang
- Chair of Computational Science and Simulation Technology, Institute of Photonics, Faculty of Mathematics and Physics, Leibniz Universität, Hannover, Germany
| | | | - Timon Rabczuk
- Institute of Structural Mechanics, Bauhaus University of Weimar, Weimar, Germany
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8
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Amiri S, Volkert CA, Vink RLC. Friction on incommensurate substrates: Role of anharmonicity and defects. Phys Rev E 2021; 104:014802. [PMID: 34412345 DOI: 10.1103/physreve.104.014802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 07/06/2021] [Indexed: 11/07/2022]
Abstract
We present molecular dynamics simulations of one- and two-dimensional bead-spring models sliding on incommensurate substrates after an initial kick, in the case where the coupling to the underlying substrate is weak, i.e., energy can dissipate only into the internal degrees of freedom of the sliding object, but not into the substrate below. We investigate how sliding friction is affected by structural defects and interaction anharmonicity. In their absence, we confirm earlier findings, namely, that at special resonance sliding velocities, friction is maximal. When sliding off-resonance, partially thermalized states are possible, whereby only a small number of vibrational modes becomes excited, but whose kinetic energies are already Maxwell-Boltzmann distributed. Anharmonicity and defects typically destroy partial thermalization and instead lead to full thermalization, implying much higher friction. For sliders with periodic boundaries, thermalization begins with vibrational modes whose spatial modulation is compatible with the incommensurate lattice. For a disk-shaped slider, modes corresponding to modulations compatible with the slider radius are initially the most dominant. By tuning the mechanical properties of the slider's edge, this effect can be controlled, resulting in significant changes in the sliding distance covered.
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Affiliation(s)
- S Amiri
- Institute of Materials Physics, Georg-August-Universität Göttingen, 37073 Göttingen, Germany
| | - C A Volkert
- Institute of Materials Physics, Georg-August-Universität Göttingen, 37073 Göttingen, Germany
| | - R L C Vink
- Institute of Materials Physics, Georg-August-Universität Göttingen, 37073 Göttingen, Germany
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9
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Niranjan MK, Ghosh A. Theoretical investigation of lattice dynamics, infrared reflectivity, polarized Raman spectra and nature of interlayer coupling in two-dimensional layered gallium sulfide. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:405001. [PMID: 34256354 DOI: 10.1088/1361-648x/ac13fa] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 07/13/2021] [Indexed: 06/13/2023]
Abstract
Gallium sulfide (GaS) is a highly promising two-dimensional layered semiconductor owing to its remarkable thickness dependent electronic and physical properties. In this article, we perform a comprehensiveab initiostudy of lattice dynamics, mode symmetry assignments, polarized Raman and infrared (IR) reflectivity spectra of GaS system. Polarized Raman spectra are obtained for different light polarization set-ups of incoming and scattered light. The frequencies of all allowed vibrational modes at the zone-centre are calculated and symmetry labels are assigned. Furthermore, the variation of frequencies & intensities of Raman/IR active modes of ultrathin GaS films (few layers) as function of film thickness is studied. In addition, we also explore the nature of weak interlayer coupling in GaS. The weak forces between the GaS layers are usually assumed to be due to interlayer van der Waals (vdW) interaction. However, this assumption has not been reasonably explained in reported experimental studies. Our study strongly suggests that weak interlayer interactions in GaS may be primarily electrostatic (Coulomb) in nature and therefore the contribution of vdW interactions to layer-layer coupling and lattice dynamics may be significantly lower than that of electrostatic interaction. The suggested nature of interlayer coupling in GaS and related III-VI semiconductors may have important implications in determination of their various physical properties.
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Affiliation(s)
- Manish K Niranjan
- Department of Physics, Indian Institute of Technology, Hyderabad, India
| | - Arghya Ghosh
- Department of Physics, Indian Institute of Technology, Hyderabad, India
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10
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Gao E, Wu B, Wang Y, Jia X, Ouyang W, Liu Z. Computational Prediction of Superlubric Layered Heterojunctions. ACS APPLIED MATERIALS & INTERFACES 2021; 13:33600-33608. [PMID: 34213300 DOI: 10.1021/acsami.1c04870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Structural superlubricity has attracted increasing interest in modern tribology. However, experimental identification of superlubric interfaces among the vast number of heterojunctions is a trial-and-error and time-consuming approach. In this work, based on the requirements on the in-plane stiffnesses of layered materials and the interfacial interactions at the sliding incommensurate interfaces of heterojunctions for structural superlubricity, we propose criteria for predicting structural superlubricity between heterojunctions. Based on these criteria, we identify 61 heterojunctions with potential superlubricity features from 208 candidates by screening the data of first-principles calculations. This work provides a universal route for accelerating the discovery of new superlubric heterojunctions.
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Affiliation(s)
- Enlai Gao
- Department of Engineering Mechanics, School of Civil Engineering, Wuhan University, Wuhan, Hubei 430072, China
| | - Bozhao Wu
- Department of Engineering Mechanics, School of Civil Engineering, Wuhan University, Wuhan, Hubei 430072, China
| | - Yelingyi Wang
- Department of Engineering Mechanics, School of Civil Engineering, Wuhan University, Wuhan, Hubei 430072, China
| | - Xiangzheng Jia
- Department of Engineering Mechanics, School of Civil Engineering, Wuhan University, Wuhan, Hubei 430072, China
| | - Wengen Ouyang
- Department of Engineering Mechanics, School of Civil Engineering, Wuhan University, Wuhan, Hubei 430072, China
| | - Ze Liu
- Department of Engineering Mechanics, School of Civil Engineering, Wuhan University, Wuhan, Hubei 430072, China
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11
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Liao Y, Li Z, Ghazanfari S, Croll AB, Xia W. Understanding the Role of Self-Adhesion in Crumpling Behaviors of Sheet Macromolecules. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:8627-8637. [PMID: 34227388 DOI: 10.1021/acs.langmuir.1c01545] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Understanding the crumpling behavior of two-dimensional (2D) macromolecular sheet materials is of fundamental importance in engineering and technological applications. Among the various properties of these sheets, interfacial adhesion critically contributes to the formation of crumpled structures. Here, we present a coarse-grained molecular dynamics (CG-MD) simulation study to explore the fundamental role of self-adhesion in the crumpling behaviors of macromolecular sheets having varying masses or sizes. By evaluating the potential energy evolution, our results show that the self-adhesion plays a dominant role in the crumpling behavior of the sheets compared to in-plane and out-of-plane stiffnesses. The macromolecular sheets with higher adhesion tend to form a self-folding planar structure at the quasi-equilibrium state of the crumpling and exhibit a lower packing efficiency as evaluated by the fractal dimension of the system. Notably, during the crumpling process, both the radius of gyration Rg and the hydrodynamic radius Rh of the macromolecular sheet can be quantitatively described by the power-law scaling relationships associated with adhesion. The evaluation of the shape descriptors indicates that the overall crumpling behavior of macromolecular sheets can be characterized by three regimes, i.e., the less bent, intermediate, and highly crumpled regimes, dominated by edge-bending, self-adhesion, and further compression, respectively. The internal structural analysis further reveals that the sheet transforms from the initially ordered state to the disordered glassy state upon crumpling, which can be facilitated by greater self-adhesion. Our study provides fundamental insights into the adhesion-dependent structural behavior of macromolecular sheets under crumpling, which is essential for establishing the structure-processing-property relationships for crumpled macromolecular sheets.
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Affiliation(s)
- Yangchao Liao
- Department of Civil & Environmental Engineering, North Dakota State University, 1410 14th Ave N, Fargo, North Dakota 58108, United States
| | - Zhaofan Li
- Department of Civil & Environmental Engineering, North Dakota State University, 1410 14th Ave N, Fargo, North Dakota 58108, United States
| | - Sarah Ghazanfari
- Department of Civil & Environmental Engineering, North Dakota State University, 1410 14th Ave N, Fargo, North Dakota 58108, United States
| | - Andrew B Croll
- Department of Physics, North Dakota State University, 1211 Albrecht Blvd, Fargo, North Dakota 58108, United States
- Materials and Nanotechnology, North Dakota State University, 1410 14th Ave N, Fargo, North Dakota 58108, United States
| | - Wenjie Xia
- Department of Civil & Environmental Engineering, North Dakota State University, 1410 14th Ave N, Fargo, North Dakota 58108, United States
- Materials and Nanotechnology, North Dakota State University, 1410 14th Ave N, Fargo, North Dakota 58108, United States
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12
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Hartley GO, Martsinovich N. Computational design of graphitic carbon nitride photocatalysts for water splitting. Faraday Discuss 2021; 227:341-358. [PMID: 33300894 DOI: 10.1039/c9fd00147f] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of structures based on graphitic carbon nitride (g-C3N4), a layered material composed of linked carbon-nitrogen heterocycles arranged in a plane, were investigated by density functional theory calculations. g-C3N4 is a semiconductor that absorbs UV light and visible light at the blue end of the visible spectrum, and is widely studied as a photocatalyst for water splitting; however, its photocatalytic efficiency is limited by its poor light-harvesting ability and low charge mobilities. Modifications to the g-C3N4 structure could greatly improve its optical and electronic properties and its photocatalytic efficiency. In this work, the g-C3N4 structure was modified by replacing the nitrogen linker with heteroatoms (phosphorus, boron) or aromatic groups (benzene, s-triazine and substituted benzenes). Two-dimensional (2D) sheets and three-dimensional (3D) multilayer structures with different stacking types were modelled. Several new structures were predicted to have electronic properties superior to g-C3N4 for use as water splitting photocatalysts. In particular, introduction of phosphorus, benzene and s-triazine groups led to band gaps smaller than in the standard g-C3N4 (down to 2.4 eV, corresponding to green light). Doping with boron in the linker positions dramatically reduced the band gap (to 1.6 eV, corresponding to red light); the doped material has the valence band position suitable for water oxidation. Our computational study shows that chemical modification of g-C3N4 is a powerful method to tune this material's electronic properties and improve its photocatalytic activity.
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Affiliation(s)
- Gareth O Hartley
- Department of Chemistry, University of Sheffield, Brook Hill, Sheffield, S3 7HF, UK.
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13
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Gotzias A. Binding Free Energy Calculations of Bilayer Graphenes Using Molecular Dynamics. J Chem Inf Model 2021; 61:1164-1171. [PMID: 33663215 DOI: 10.1021/acs.jcim.1c00043] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Bilayer graphenes are dimeric assemblies of single graphene layers bound together by π-complexation interactions. Controlling these assemblies can be complicated, as the layered compounds disperse in solvents or aggregate into higher columnar configurations and clusters. One way to assess the interactions that contribute to the stability of the layered compounds is to use molecular simulation. We perform pulling molecular dynamics on bilayer graphenes with different sizes and obtain the normal and shear force profiles of dissociation. We generate pathways of dissociation along the two directions and calculate the binding free energies of the structures with umbrella sampling simulations. We show that the dissociation process is direction-dependent. Along the shear direction, we compute the same free energy for the different samples, which validates the consistency of our simulations. We notice that the dissociation is less adiabatic on the normal than the shear direction, having an entropic contribution to the Gibbs energy. This contribution is more enhanced for the larger bilayer graphenes.
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Affiliation(s)
- Anastasios Gotzias
- Institute of Nanoscience and Nanotechnology, National Centre of Scientific Research Demokritos, 15310 Agia Paraskevi, Athens, Greece
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14
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Song N, Gao Z, Li X. Tailoring nanocomposite interfaces with graphene to achieve high strength and toughness. SCIENCE ADVANCES 2020; 6:6/42/eaba7016. [PMID: 33055154 PMCID: PMC7556841 DOI: 10.1126/sciadv.aba7016] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Accepted: 08/25/2020] [Indexed: 05/03/2023]
Abstract
The nanofiller reinforcing effect in nanocomposites is often far below the theoretically predicted values, largely because of the poor interfacial interaction between the nanofillers and matrix. Here, we report that graphene-wrapped B4C nanowires (B4C-NWs@graphene) empowered exceptional dispersion of nanowires in matrix and superlative nanowire-matrix bonding. The 0.2 volume % B4C-NWs@graphene reinforced epoxy composite exhibited simultaneous enhancements in strength (144.2 MPa), elastic modulus (3.5 GPa), and ductility (15%). Tailoring the composite interfaces with graphene enabled effective utilization of the nanofillers, resulting in two times increase in load transfer efficiency. Molecular dynamics simulations unlocked the shear mixing graphene/nanowire self-assembly mechanism. This low-cost yet effective technique presents unprecedented opportunities for improving nanocomposite interfaces, enabling high load transfer efficiency, and opens up a new path for developing strong and tough nanocomposites.
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Affiliation(s)
- Ningning Song
- Department of Mechanical and Aerospace Engineering, University of Virginia, 122 Engineer's Way, Charlottesville, VA 22904, USA
| | - Zan Gao
- Department of Mechanical and Aerospace Engineering, University of Virginia, 122 Engineer's Way, Charlottesville, VA 22904, USA
| | - Xiaodong Li
- Department of Mechanical and Aerospace Engineering, University of Virginia, 122 Engineer's Way, Charlottesville, VA 22904, USA.
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15
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Kizzire DG, Richter AM, Harper DP, Keffer DJ. Lithium and sodium ion binding in nanostructured carbon composites. MOLECULAR SIMULATION 2020. [DOI: 10.1080/08927022.2020.1800689] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Dayton G. Kizzire
- Materials Science & Engineering Department, University of Tennessee, Knoxville, TN, USA
| | - Alexander M. Richter
- Materials Science & Engineering Department, University of Tennessee, Knoxville, TN, USA
| | - David P. Harper
- Center for Renewable Carbon, University of Tennessee Institute of Agriculture, Knoxville, TN, USA
| | - David J. Keffer
- Materials Science & Engineering Department, University of Tennessee, Knoxville, TN, USA
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16
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King'ori GW, Ouma CNM, Mishra AK, Amolo GO, Makau NW. Two-dimensional graphene-HfS 2 van der Waals heterostructure as electrode material for alkali-ion batteries. RSC Adv 2020; 10:30127-30138. [PMID: 35518262 PMCID: PMC9056275 DOI: 10.1039/d0ra04725b] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 07/31/2020] [Indexed: 01/29/2023] Open
Abstract
Poor electrical conductivity and large volume expansion during repeated charge and discharge is what has characterized many battery electrode materials in current use. This has led to 2D materials, specifically multi-layered 2D systems, being considered as alternatives. Among these 2D multi-layered systems are the graphene-based van der Waals heterostructures with transition metal di-chalcogenides (TMDCs) as one of the layers. Thus in this study, the graphene–hafnium disulphide (Gr–HfS2) system, has been investigated as a prototype Gr–TMDC system for application as a battery electrode. Density functional theory calculations indicate that Gr–HfS2 van der Waals heterostructure formation is energetically favoured. In order to probe its battery electrode application capability, Li, Na and K intercalants were introduced between the layers of the heterostructure. Li and K were found to be good intercalants as they had low diffusion barriers as well as a positive open circuit voltage. A comparison of bilayer graphene and bilayer HfS2 indicates that Gr–HfS2 is a favourable battery electrode system. A high rate capacity, moderate volume expansion and energetically stable alkali ion graphene–HfS2 electrode material.![]()
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Affiliation(s)
- Gladys W King'ori
- University of Eldoret P.O. Box 1125 - 30100 Eldoret Kenya .,Technical University of Kenya Haile Selassie Avenue, P.O. Box 52428 - 00200 Nairobi Kenya
| | - Cecil N M Ouma
- HySA-Infrastructure, North-West University, Faculty of Engineering Private Bag X6001 Potchefstroom 2520 South Africa
| | - Abhishek K Mishra
- Department of Physics, School of Engineering, University of Petroleum and Energy Studies Bidholi via Premnagar Dehradun 248007 India
| | - George O Amolo
- Technical University of Kenya Haile Selassie Avenue, P.O. Box 52428 - 00200 Nairobi Kenya
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17
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Xu G, Hao F, Weng M, Hong J, Pan F, Fang D. Strong influence of strain gradient on lithium diffusion: flexo-diffusion effect. NANOSCALE 2020; 12:15175-15184. [PMID: 32667373 DOI: 10.1039/d0nr03746j] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Lithium ion batteries (LIBs) work under a sophisticated external force field and the electrochemical properties could be modulated by strain. Owing to electro-mechanical coupling, the change of micro local structures can greatly affect the lithium (Li) diffusion rate in solid state electrolytes and the electrode materials of LIBs. In this study, we found, through first-principles calculations, that the strain gradient in bilayer graphene (BLG) significantly affects the Li diffusion barrier, which is termed as the flexo-diffusion effect. The Li diffusion barrier substantially decreases/increases under a positive/negative strain gradient, leading to a change of Li diffusion coefficient of several orders of magnitude at 300 K. Interestingly, the regulation effect of strain gradient is much more significant than that of a uniform strain field, which can have a remarkable effect on the rate performance of batteries, with a considerable increase in the ionic conductivity and a slight change of the original material structure. Moreover, our ab initio molecular dynamics simulations (AIMD) show that the asymmetric distorted lattice structure provides a driving force for Li diffusion, resulting in oriented diffusion along the positive strain gradient direction. We predict the new phenomenon of a flexo-diffusion effect from a theoretical calculation aspect, these findings could extend present LIB technologies by introducing a novel strain gradient engineering.
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Affiliation(s)
- Gao Xu
- State Key Laboratory for Turbulence and Complex Systems & Center for Applied Physics and Technology, College of Engineering, Peking University, Beijing 100871, P.R. China.
| | - Feng Hao
- Department of Engineering Mechanics, Shandong University, Jinan 250100, P.R. China
| | - Mouyi Weng
- School of Advanced Materials, Peking University, Shenzhen Graduate School, Shenzhen 518055, P.R. China.
| | - Jiawang Hong
- School of Aerospace Engineering, Beijing Institute of Technology, Beijing 100081, P.R. China.
| | - Feng Pan
- School of Advanced Materials, Peking University, Shenzhen Graduate School, Shenzhen 518055, P.R. China.
| | - Daining Fang
- State Key Laboratory for Turbulence and Complex Systems & Center for Applied Physics and Technology, College of Engineering, Peking University, Beijing 100871, P.R. China. and Institute of Advanced Structure Technology, Beijing Institute of Technology, Beijing 100081, P.R. China
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18
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Geng WT, Wang V, Liu YC, Ohno T, Nara J. Moiré Potential, Lattice Corrugation, and Band Gap Spatial Variation in a Twist-Free MoTe 2/MoS 2 Heterobilayer. J Phys Chem Lett 2020; 11:2637-2646. [PMID: 32188242 DOI: 10.1021/acs.jpclett.0c00605] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
To have a fully first-principles description of the moiré pattern in transition-metal dichalcogenide heterobilayers, we have carried out density functional theory calculations on a MoTe2(9 × 9)/MoS2(10 × 10) stacking, which has a superlattice larger than an exciton yet not large enough to justify a continuum model treatment. Lattice corrugation is found to be significant in both monolayers, yet its effect on the electronic properties is marginal. We reveal that the variation of the average local potential near Mo atoms in both MoTe2 and MoS2 layers displays a conspicuous moiré pattern. They are the intralayer moiré potentials correlating closely with the spatial variation of the valence band maximum and conduction band minimum. The interlayer moiré potential, defined as the difference between the two intralayer moiré potentials, changes roughly in proportion to the band gap variation in the moiré cell. This finding might be instructive in chemical engineering of van der Waals bilayers.
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Affiliation(s)
- W T Geng
- National Institute for Materials Science, Tsukuba 305-0044, Japan
| | - V Wang
- Department of Applied Physics, Xi'an University of Technology, Xi'an 710054, China
| | - Y C Liu
- National Institute for Materials Science, Tsukuba 305-0044, Japan
- Department of Applied Physics, Xi'an University of Technology, Xi'an 710054, China
| | - T Ohno
- National Institute for Materials Science, Tsukuba 305-0044, Japan
| | - J Nara
- National Institute for Materials Science, Tsukuba 305-0044, Japan
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19
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Lebedeva IV, Popov AM. Two Phases with Different Domain Wall Networks and a Reentrant Phase Transition in Bilayer Graphene under Strain. PHYSICAL REVIEW LETTERS 2020; 124:116101. [PMID: 32242692 DOI: 10.1103/physrevlett.124.116101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 02/21/2020] [Indexed: 06/11/2023]
Abstract
The analytical two-chain Frenkel-Kontorova model is used to describe domain wall networks in bilayer graphene upon biaxial stretching of one of the layers. We show that the commensurate-incommensurate phase transition leading to formation of a regular triangular domain wall network at the relative biaxial elongation of 3.0×10^{-3} is followed by the transition to another incommensurate phase with a striped network at the elongation of 3.7×10^{-3}. The reentrant transition to the phase with a triangular domain wall network is predicted for the elongation ∼10^{-2}.
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Affiliation(s)
| | - Andrey M Popov
- Institute for Spectroscopy of Russian Academy of Sciences, Troitsk, Moscow 108840, Russia
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20
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Yang L, Xu H, Liu K, Gao D, Huang Y, Zhou Q, Wu Z. Molecular dynamics simulation on the formation and development of interlayer dislocations in bilayer graphene. NANOTECHNOLOGY 2020; 31:125704. [PMID: 31775124 DOI: 10.1088/1361-6528/ab5c7e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Molecular dynamics simulations are used to study the formation and development of interlayer dislocations in bilayer graphene (BLG) subjected to uniaxial tension. Two different BLGs are employed for the simulation: armchair (AC-BLG) and zigzag (ZZ-BLG). The atomic-level strains are calculated and the parameter 'dislocation intensity' is introduced to identify the dislocations. The interlayer dislocation is found to start at the edge and propagate to the center. For AC-BLG, the dislocations arise successively with the increase of applied strain, and all dislocations have the same width. For ZZ-BLG, the first dislocation arises alone. After that, two dislocations with different widths appear together every time. The simulated dislocation widths are in good agreement with existing experimental results. Across every dislocation, there is a transition from AB stacking to AC stacking, or vice versa. When temperature is taken into account, the dislocation boundaries become indistinct and the formation of dislocations is postponed due to the existence of dispersive small slippages. Due to the disturbance of temperature, dislocations present reciprocating movement. These findings contribute to the understanding of interlayer dislocations in two-dimensional materials, and will enable the exploration of many more strain related fundamental science problems and application challenges.
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Affiliation(s)
- Lei Yang
- State Key Laboratory of Structural Analysis for Industrial Equipment, School of Aeronautics and Astronautics, Dalian University of Technology, Dalian, People's Republic of China. Key Laboratory of Advanced Technology for Aerospace Vehicles, Liaoning Province, People's Republic of China
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21
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Benda R, Zucchi G, Cancès E, Lebental B. Insights into the π – π interaction driven non-covalent functionalization of carbon nanotubes of various diameters by conjugated fluorene and carbazole copolymers. J Chem Phys 2020; 152:064708. [DOI: 10.1063/1.5133634] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Affiliation(s)
- Robert Benda
- LPICM, CNRS, Ecole Polytechnique, Institut Polytechnique de Paris, Route De Saclay, 91128 Palaiseau, France
- CERMICS, Ecole des Ponts and INRIA, Université Paris-Est, 6-8 Avenue Blaise Pascal, 77455 Marne-la-Vallée, France
| | - Gaël Zucchi
- LPICM, CNRS, Ecole Polytechnique, Institut Polytechnique de Paris, Route De Saclay, 91128 Palaiseau, France
| | - Eric Cancès
- CERMICS, Ecole des Ponts and INRIA, Université Paris-Est, 6-8 Avenue Blaise Pascal, 77455 Marne-la-Vallée, France
| | - Bérengère Lebental
- LPICM, CNRS, Ecole Polytechnique, Institut Polytechnique de Paris, Route De Saclay, 91128 Palaiseau, France
- Université Paris-Est, IFSTTAR, 14-20, Boulevard Newton, 77420 Champs-sur-Marne, France
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22
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Zhou G. Effects of a graphene substrate on the structure and properties of atomically thin metal sheets. Phys Chem Chem Phys 2020; 22:667-673. [PMID: 31829359 DOI: 10.1039/c9cp05466a] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The production and use of atomically thin metal sheets are desirable but challenging. Here, density functional theory calculations indicate that the introduction of graphene as a support can play an unexpected role in the stability and function of Rh monolayer, as a representative of single-layer metal nanosheets. The graphene stabilizes the otherwise unstable Rh monolayer by the substrate interaction that not only impedes the out-of-plane movement of the Rh atoms but also decreases the surface energy. The Rh/graphene bilayer has good mechanical properties, comparable to those of emerging 2D graphene-based materials. The interfacial stress from the substrate interaction causes surface corrugations to form on the bilayer, exhibiting a degree of consistency in the direction and the area. Discrete magnetic units, compatible with the substrate interaction, are present in the corrugated Rh sheet. The visible magnetic anisotropy and spin-splitting of polarized carrier states of the corrugated Rh sheet dominate the spin-dependent transport in the bilayer film, which can be used as a building block for ultrathin electronic/spintronic devices.
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Affiliation(s)
- Gang Zhou
- School of Science, Hubei University of Technology, Wuhan 430068, People's Republic of China.
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23
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Wen Y, He P, Wang Q, Yao Y, Zhang Y, Hussain S, Wang Z, Cheng R, Yin L, Getaye Sendeku M, Wang F, Jiang C, He J. Gapless van der Waals Heterostructures for Infrared Optoelectronic Devices. ACS NANO 2019; 13:14519-14528. [PMID: 31794184 DOI: 10.1021/acsnano.9b08375] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Mixed-dimensional van der Waals (vdW) heterostructures based on two-dimensional (2D) materials exhibit immense potential in infrared optoelectronic applications. However, the weak vdW coupling results in limiting performance of infrared optoelectronic device. Here, we exploit a gapless heterostructure that S dangling bonds of nonlayered PbS are connected to the bonding sites of MoS2 (with factitious S vacancies) via strong orbital hybridization. The strong interface coupling leads to ultrahigh responsivity and photogain (G) exceeding 105, and the detectivity (D*) is greater than 1014 Jones. More importantly, the gapless heterostructure shows fast rise and decay times about 47 and 49 μs, respectively, which is 5 orders of magnitude faster than that of transferred vdW heterostructures. Furthermore, an ultrahigh photon-triggered on/off ratio of 1.6 × 106 is achieved, which is 4 orders of magnitude higher than that of transferred vdW heterostructures. This architecture can offer an effective approach for advanced infrared optoelectronic devices.
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Affiliation(s)
- Yao Wen
- School of Physics and Technology , Wuhan University , Wuhan 430072 , China
| | - Peng He
- CAS Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology , University of Chinese Academy of Sciences , Beijing 100190 , China
| | - Qisheng Wang
- CAS Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology , University of Chinese Academy of Sciences , Beijing 100190 , China
| | - Yuyu Yao
- CAS Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology , University of Chinese Academy of Sciences , Beijing 100190 , China
| | - Yu Zhang
- School of Physics and Technology , Wuhan University , Wuhan 430072 , China
| | - Sabir Hussain
- CAS Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology , University of Chinese Academy of Sciences , Beijing 100190 , China
| | - Zhenxing Wang
- CAS Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology , University of Chinese Academy of Sciences , Beijing 100190 , China
| | - Ruiqing Cheng
- CAS Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology , University of Chinese Academy of Sciences , Beijing 100190 , China
| | - Lei Yin
- CAS Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology , University of Chinese Academy of Sciences , Beijing 100190 , China
| | - Marshet Getaye Sendeku
- CAS Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology , University of Chinese Academy of Sciences , Beijing 100190 , China
| | - Feng Wang
- CAS Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology , University of Chinese Academy of Sciences , Beijing 100190 , China
| | - Chao Jiang
- CAS Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology , University of Chinese Academy of Sciences , Beijing 100190 , China
| | - Jun He
- School of Physics and Technology , Wuhan University , Wuhan 430072 , China
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24
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Li LL, Feng S. Influence of neighboring layers on interfacial energy of adjacent layers. CHINESE J CHEM PHYS 2019. [DOI: 10.1063/1674-0068/cjcp1812291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- Lei-lei Li
- CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Modern Mechanics, University of Science and Technology of China, Hefei 230027, China
| | - Shuo Feng
- Hefei National Laboratory for Physical Sciences at the Microscale, Collaborative Innovation Center of Chemistry for Energy Materials, CAS Center for Excellence in Nanoscience, School of Chemistry and Materials Science, University of Science and Technology of China, Hefei 230026, China
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25
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Zhu GL, Ye XJ, Liu CS. Graphether: a two-dimensional oxocarbon as a direct wide-band-gap semiconductor with high mechanical and electrical performances. NANOSCALE 2019; 11:22482-22492. [PMID: 31746895 DOI: 10.1039/c9nr08071f] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Although many graphene derivatives have sizable band gaps, their electrical or mechanical properties are significantly degraded due to the low degree of π-conjugation. Besides the π-π conjugation, there exist hyperconjugative interactions arising from the delocalization of σ electrons. Inspired by the structural characteristics of a hyperconjugated molecule, dimethyl ether, we design a two-dimensional oxocarbon (named graphether) by the assembly of dimethyl ether molecules. Our first-principles calculations reveal the following findings: (1) monolayer graphether possesses excellent dynamic and thermal stabilities as demonstrated by its favourable cohesive energy, the absence of soft phonon modes, and high melting point. (2) It has a direct wide-band-gap energy of 2.39 eV, indicating its potential applications in ultraviolet optoelectronic devices. Interestingly, the direct band gap feature is rather robust against the external strains (-10% to 10%) and stacking configurations. (3) Due to the hyperconjugative effect, graphether has the high intrinsic electron mobility. More importantly, its in-plane stiffness (459.8 N m-1) is even larger than that of graphene. (4) The Pt(100) surface exhibits high catalytic activity for the dehydrogenation of dimethyl ether. The electrostatic repulsion serves as a driving force for the rotation and coalescence of two dehydrogenated precursors, which is favourable for the bottom-up growth of graphether. (5) Replacement of the C-C bond with an isoelectronic B-N bond can generate a stable Pmn21-BNO monolayer. Compared with monolayer hexagonal boron nitride, Pmn21-BNO has a moderate direct band gap energy (3.32 eV) and better mechanical property along the armchair direction.
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Affiliation(s)
- Gui-Lin Zhu
- Key Laboratory of Radio Frequency and Micro-Nano Electronics of Jiangsu Province, College of Electronic and Optical Engineering, Nanjing University of Posts and Telecommunications, Nanjing 210023, China.
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26
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Zhang X, Yang S, Shan X, Li S, Tang S. Insights into the effect of the interlayer spacings of bilayer graphene on the desolvation of H +, Li +, Na +, and K + ions with water as a solvent: a first-principles study. Phys Chem Chem Phys 2019; 21:23697-23704. [PMID: 31633133 DOI: 10.1039/c9cp02922b] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The desolvation effect of ions plays an important role in adjusting the capacity of supercapacitors and has attracted considerable attention after its discovery. Here, first-principles calculations were conducted to calculate the reaction energies of ions, water, and hydrated ions in bilayer graphene (BG) with different interlayer spacings (d) and to explore the desolvation behaviors of H+, Li+, Na+, and K+ ions. The calculated results showed that H+ can only exist in the state of H3O+ in AA-stacking BG, and desolvation exists only in the case of AB-stacking BG. The complete desolvation size for H+ ions in the AB-stacking system reached 5.6 Å, which was the largest desolvation size of the four ions studied. The critical desolvation sizes of Li+, Na+, and K+ in the BG layers of AA- and AB-stacking increased sharply as a consequence of the increasing ionic radius. However, the complete desolvation sizes of all three ions were in the range of 4-5 Å and with the increase in ionic radius, the complete desolvation sizes showed a reverse tendency. The complete desolvation size of Na+ in AB-stacking BG was slightly larger than that in AA-stacking BG. Further analysis presented that the ionic radii of H+, Li+, Na+, and K+ ions make a dominant contribution to the critical size of desolvation. Our present results provide useful information for improving the capacity of supercapacitors by precisely matching the pore structure and electrolyte through the adjustment of the pore structure of carbon materials.
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Affiliation(s)
- Xu Zhang
- College of Materials Science and Engineering, Liaoning Technical University, Fuxin, Liaoning 123000, China.
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27
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Wei Y, Yang R. Nanomechanics of graphene. Natl Sci Rev 2019; 6:324-348. [PMID: 34691872 PMCID: PMC8291593 DOI: 10.1093/nsr/nwy067] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 06/12/2018] [Accepted: 06/12/2018] [Indexed: 11/12/2022] Open
Abstract
The super-high strength of single-layer graphene has attracted great interest. In practice, defects resulting from thermodynamics or introduced by fabrication, naturally or artificially, play a pivotal role in the mechanical behaviors of graphene. More importantly, high strength is just one aspect of the magnificent mechanical properties of graphene: its atomic-thin geometry not only leads to ultra-low bending rigidity, but also brings in many other unique properties of graphene in terms of mechanics in contrast to other carbon allotropes, including fullerenes and carbon nanotubes. The out-of-plane deformation is of a 'soft' nature, which gives rise to rich morphology and is crucial for morphology control. In this review article, we aim to summarize current theoretical advances in describing the mechanics of defects in graphene and the theory to capture the out-of-plane deformation. The structure-mechanical property relationship in graphene, in terms of its elasticity, strength, bending and wrinkling, with or without the influence of imperfections, is presented.
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Affiliation(s)
- Yujie Wei
- The State Key Laboratory of Nonlinear Mechanics (LNM), Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China
- School of Engineering Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ronggui Yang
- Department of Mechanical Engineering, University of Colorado, Boulder, CO 80309, USA
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28
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Hamid MAB, Kar Tim C, Bin Yaakob Y, Hazan MAB. Structural, electronic and transport properties of silicene on graphene substrate. MATERIALS RESEARCH EXPRESS 2019; 6:055803. [DOI: 10.1088/2053-1591/ab01ea] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
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29
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Yamaletdinov RD, Ivakhnenko OV, Sedelnikova OV, Shevchenko SN, Pershin YV. Snap-through transition of buckled graphene membranes for memcapacitor applications. Sci Rep 2018; 8:3566. [PMID: 29476169 PMCID: PMC5824796 DOI: 10.1038/s41598-018-21205-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 01/31/2018] [Indexed: 11/09/2022] Open
Abstract
Using computational and theoretical approaches, we investigate the snap-through transition of buckled graphene membranes. Our main interest is related to the possibility of using the buckled membrane as a plate of capacitor with memory (memcapacitor). For this purpose, we performed molecular-dynamics (MD) simulations and elasticity theory calculations of the up-to-down and down-to-up snap-through transitions for membranes of several sizes. We have obtained expressions for the threshold switching forces for both up-to-down and down-to-up transitions. Moreover, the up-to-down threshold switching force was calculated using the density functional theory (DFT). Our DFT results are in general agreement with MD and analytical theory findings. Our systematic approach can be used for the description of other structures, including nanomechanical and biological ones, experiencing the snap-through transition.
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Affiliation(s)
- Ruslan D Yamaletdinov
- Nikolaev Institute of Inorganic Chemistry SB RAS, Novosibirsk, 630090, Russia.
- Novosibirsk State University, Novosibirsk, 630090, Russia.
| | - Oleg V Ivakhnenko
- B. I. Verkin Institute for Low Temperature Physics and Engineering, Kharkov, 61103, Ukraine
- V. N. Karazin Kharkov National University, Kharkov, 61022, Ukraine
| | - Olga V Sedelnikova
- Nikolaev Institute of Inorganic Chemistry SB RAS, Novosibirsk, 630090, Russia
- Novosibirsk State University, Novosibirsk, 630090, Russia
| | - Sergey N Shevchenko
- B. I. Verkin Institute for Low Temperature Physics and Engineering, Kharkov, 61103, Ukraine
- V. N. Karazin Kharkov National University, Kharkov, 61022, Ukraine
| | - Yuriy V Pershin
- Nikolaev Institute of Inorganic Chemistry SB RAS, Novosibirsk, 630090, Russia.
- Department of Physics and Astronomy, University of South Carolina, Columbia, South Carolina, 29208, USA.
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30
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Pakhira S, Lucht KP, Mendoza-Cortes JL. Dirac cone in two dimensional bilayer graphene by intercalation with V, Nb, and Ta transition metals. J Chem Phys 2018; 148:064707. [DOI: 10.1063/1.5008996] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Affiliation(s)
- Srimanta Pakhira
- Condensed Matter Theory, National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, USA
- Scientific Computing Department, Materials Science and Engineering, Florida State University, Tallahassee, Florida 32310, USA
- Department of Chemical & Biomedical Engineering, FAMU-FSU Joint College of Engineering, Florida State University, Tallahassee, Florida 32310, USA
| | - Kevin P. Lucht
- Scientific Computing Department, Materials Science and Engineering, Florida State University, Tallahassee, Florida 32310, USA
- Department of Chemical & Biomedical Engineering, FAMU-FSU Joint College of Engineering, Florida State University, Tallahassee, Florida 32310, USA
| | - Jose L. Mendoza-Cortes
- Condensed Matter Theory, National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, USA
- Scientific Computing Department, Materials Science and Engineering, Florida State University, Tallahassee, Florida 32310, USA
- Department of Chemical & Biomedical Engineering, FAMU-FSU Joint College of Engineering, Florida State University, Tallahassee, Florida 32310, USA
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31
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Shin H, Kim J, Lee H, Heinonen O, Benali A, Kwon Y. Nature of Interlayer Binding and Stacking of sp–sp2 Hybridized Carbon Layers: A Quantum Monte Carlo Study. J Chem Theory Comput 2017; 13:5639-5646. [DOI: 10.1021/acs.jctc.7b00747] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Hyeondeok Shin
- Leadership
Computing Facility, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Jeongnim Kim
- Intel Corporation, Hillsboro, Oregon 97124, United States
| | - Hoonkyung Lee
- Department
of Physics, Konkuk University, Seoul 05029, Korea
| | - Olle Heinonen
- Material
Science Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Anouar Benali
- Leadership
Computing Facility, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Yongkyung Kwon
- Department
of Physics, Konkuk University, Seoul 05029, Korea
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32
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Yamaletdinov RD, Pershin YV. Finding Stable Graphene Conformations from Pull and Release Experiments with Molecular Dynamics. Sci Rep 2017; 7:42356. [PMID: 28195156 PMCID: PMC5307952 DOI: 10.1038/srep42356] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Accepted: 01/08/2017] [Indexed: 11/16/2022] Open
Abstract
Here, we demonstrate that stable conformations of graphene nanoribbons can be identified using pull and release experiments, when the stretching force applied to a single-layer graphene nanoribbon is suddenly removed. As it is follows from our numerical experiments performed by means of molecular dynamics simulations, in such experiments, favorable conditions for the creation of folded structures exist. Importantly, at finite temperatures, the process of folding is probabilistic. We have calculated the transition probabilities to folded conformations for a graphene nanoribbon of a selected size. Moreover, the ground state conformation has been identified and it is shown that its type is dependent on the nanoribbon length. We anticipate that the suggested pull and release approach to graphene folding may find applications in the theoretical studies and fabrication of emergent materials and their structures.
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Affiliation(s)
- Ruslan D. Yamaletdinov
- Nikolaev Institute of Inorganic Chemistry SB RAS, Novosibirsk 630090, Russia
- Novosibirsk State University, Novosibirsk 630090, Russia
| | - Yuriy V. Pershin
- Nikolaev Institute of Inorganic Chemistry SB RAS, Novosibirsk 630090, Russia
- Department of Physics and Astronomy and Smart State Center for Experimental Nanoscale Physics, University of South Carolina, Columbia, South Carolina 29208, USA
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Yao X, Zhang X, Ye X, Wang J. Structure and electronic properties of bilayer graphene functionalized with half-sandwiched transition metal-cyclopentadienyl complexes. Phys Chem Chem Phys 2016; 18:22390-8. [PMID: 27464257 DOI: 10.1039/c6cp03705d] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Tuning the electronic and magnetic properties of graphene is a crucial problem in the design of practical on-off electronic devices. Using density functional theory calculations, we explore the electronic and magnetic properties of bilayer graphene functionalized by cyclopentadienyl (Cp = cyclopentadienyl, C5H5) based half-sandwich ligands, CpTM (TM = Sc-Ni). It is found that the adsorption of CpTM ligands can introduce high magnetic moments and open the band gap of bilayer graphene, due to the electron doping as well as the asymmetric charge distribution between two graphene layers. Furthermore, the p-n doping of bilayer graphene by co-binding F/NO2 and CpTM on two external sides of BLG can further widen the band gap up to 366.1 meV. This study proposes an effective way to the modulation of the electronic and magnetic properties of graphene.
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Affiliation(s)
- Xiaojing Yao
- Department of Physics, Southeast University, Nanjing 211189, China. and Department of Physics, Yangzhou University, Yangzhou 225009, China.
| | - Xiuyun Zhang
- Department of Physics, Yangzhou University, Yangzhou 225009, China.
| | - Xiaoshan Ye
- Department of Physics, Yangzhou University, Yangzhou 225009, China.
| | - Jinlan Wang
- Department of Physics, Southeast University, Nanjing 211189, China. and Synergetic Innovation Center for Quantum Effects and Applications (SICQEA), Hunan Normal University, Changsha 410081, China
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34
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Yang S, Li S, Tang S, Dong W, Sun W, Shen D, Wang M. Sodium adsorption and intercalation in bilayer graphene from density functional theory calculations. Theor Chem Acc 2016. [DOI: 10.1007/s00214-016-1910-0] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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35
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Liao JH, Zhao YJ, Tang JJ, Yang XB, Xu H. High-coverage stable structures of 3d transition metal intercalated bilayer graphene. Phys Chem Chem Phys 2016; 18:14244-51. [PMID: 27167998 DOI: 10.1039/c6cp01841f] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Alkali-metal intercalated graphite and graphene have been intensively studied for decades, where alkali-metal atoms are found to form ordered structures at the hollow sites of hexagonal carbon rings. Using first-principles calculations, we have predicted various stable structures of high-coverage 3d transition metal (TM) intercalated bilayer graphene (BLG) stabilized by the strain. Specifically, with reference to the bulk metal, Sc and Ti can form stable TM-intercalated BLG without strain, while the stabilization of Fe, Co, and Ni intercalated BLG requires the biaxial strain of over 7%. Under the biaxial strain ranging from 0% to 10%, there are four ordered sandwich structures for Sc with the coverage of 0.25, 0.571, 0.684, and 0.75, in which the Sc atoms are all distributed homogenously instead of locating at the hollow sites. According to the phase diagram, a homogenous configuration of C8Ti3C8 with the coverage of 0.75 and another inhomogeneous structure with the coverage of 0.692 were found. The electronic and magnetic properties as a function of strain were also analyzed to indicate that the strain was important for the stabilities of the high-coverage TM-intercalated BLG.
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Affiliation(s)
- Ji-Hai Liao
- Department of Physics, South China University of Technology, Guangzhou 510640, P. R. China.
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36
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Xia W, Ruiz L, Pugno NM, Keten S. Critical length scales and strain localization govern the mechanical performance of multi-layer graphene assemblies. NANOSCALE 2016; 8:6456-6462. [PMID: 26935048 DOI: 10.1039/c5nr08488a] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Multi-layer graphene assemblies (MLGs) or fibers with a staggered architecture exhibit high toughness and failure strain that surpass those of the constituent single sheets. However, how the architectural parameters such as the sheet overlap length affect these mechanical properties remains unknown due in part to the limitations of mechanical continuum models. By exploring the mechanics of MLG assemblies under tensile deformation using our established coarse-grained molecular modeling framework, we have identified three different critical interlayer overlap lengths controlling the strength, plastic stress, and toughness of MLGs, respectively. The shortest critical length scale L(C)(S) governs the strength of the assembly as predicted by the shear-lag model. The intermediate critical length L(C)(P) is associated with a dynamic frictional process that governs the strain localization propensity of the assembly, and hence the failure strain. The largest critical length scale L(C)(T) corresponds to the overlap length necessary to achieve 90% of the maximum theoretical toughness of the material. Our analyses provide the general guidelines for tuning the constitutive properties and toughness of multilayer 2D nanomaterials using elasticity, interlayer adhesion energy and geometry as molecular design parameters.
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Affiliation(s)
- Wenjie Xia
- Department of Civil & Environmental Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208, USA.
| | - Luis Ruiz
- Department of Mechanical Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208, USA
| | - Nicola M Pugno
- Department of Civil, Environmental and Mechanical Engineering, Laboratory of Bio-inspired & Graphene Mechanics, University of Trento, Via Mesiano 77, 38123 Trento, Italy and Center for Materials and Microsystems, Fondazione Bruno Kessler, Via Sommarive 18, 38123 Trento, Italy and School of Engineering and Materials Science, Queen Mary University of London, Mile End Road, London E1 4NS, UK
| | - Sinan Keten
- Department of Civil & Environmental Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208, USA. and Department of Mechanical Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208, USA
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37
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Lebedev AV, Lebedeva IV, Knizhnik AA, Popov AM. Interlayer interaction and related properties of bilayer hexagonal boron nitride: ab initio study. RSC Adv 2016. [DOI: 10.1039/c5ra20882c] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Properties of hexagonal boron nitride bilayer related to interlayer interaction (width and formation energy of dislocations, shear mode frequency, etc.) are estimated by approximation of potential energy surface by first Fourier harmonics.
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Affiliation(s)
| | - Irina V. Lebedeva
- Nano-Bio Spectroscopy Group and ETSF Scientific Development Centre
- Departamento de Física de Materiales
- Universidad del País Vasco UPV/EHU
- San Sebastian E-20018
- Spain
| | - Andrey A. Knizhnik
- Kintech Lab Ltd
- Moscow 123182
- Russia
- National Research Centre “Kurchatov Institute”
- Moscow 123182
| | - Andrey M. Popov
- Institute for Spectroscopy of Russian Academy of Sciences
- Moscow 142190
- Russia
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38
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Mostaani E, Drummond ND, Fal'ko VI. Quantum Monte Carlo calculation of the binding energy of bilayer graphene. PHYSICAL REVIEW LETTERS 2015; 115:115501. [PMID: 26406840 DOI: 10.1103/physrevlett.115.115501] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/01/2015] [Indexed: 06/05/2023]
Abstract
We report diffusion quantum Monte Carlo calculations of the interlayer binding energy of bilayer graphene. We find the binding energies of the AA-and AB-stacked structures at the equilibrium separation to be 11.5(9) and 17.7(9) meV/atom, respectively. The out-of-plane zone-center optical phonon frequency predicted by our binding-energy curve is consistent with available experimental results. As well as assisting the modeling of interactions between graphene layers, our results will facilitate the development of van der Waals exchange-correlation functionals for density functional theory calculations.
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Affiliation(s)
- E Mostaani
- Department of Physics, Lancaster University, Lancaster LA1 4YB, United Kingdom
| | - N D Drummond
- Department of Physics, Lancaster University, Lancaster LA1 4YB, United Kingdom
| | - V I Fal'ko
- Department of Physics, Lancaster University, Lancaster LA1 4YB, United Kingdom and National Graphene Institute, University of Manchester, Booth Street East, Manchester M13 9PL, United Kingdom
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39
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Tian YH, Huang J, Sheng X, Sumpter BG, Yoon M, Kertesz M. Nitrogen Doping Enables Covalent-Like π-π Bonding between Graphenes. NANO LETTERS 2015; 15:5482-91. [PMID: 26151153 DOI: 10.1021/acs.nanolett.5b01940] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The neighboring layers in bilayer (and few-layer) graphenes of both AA and AB stacking motifs are known to be separated at a distance corresponding to van der Waals (vdW) interactions. In this Letter, we present for the first time a new aspect of graphene chemistry in terms of a special chemical bonding between the giant graphene "molecules". Through rigorous theoretical calculations, we demonstrate that the N-doped graphenes (NGPs) with various doping levels can form an unusual two-dimensional (2D) π-π bonding in bilayer NGPs bringing the neighboring NGPs to significantly reduced interlayer separations. The interlayer binding energies can be enhanced by up to 50% compared to the pristine graphene bilayers that are characterized by only vdW interactions. Such an unusual chemical bonding arises from the π-π overlap across the vdW gap while the individual layers maintain their in-plane π-conjugation and are accordingly planar. The existence of the resulting interlayer covalent-like bonding is corroborated by electronic structure calculations and crystal orbital overlap population (COOP) analyses. In NGP-based graphite with the optimal doping level, the NGP layers are uniformly stacked and the 3D bulk exhibits metallic characteristics both in the in-plane and along the stacking directions.
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Affiliation(s)
- Yong-Hui Tian
- †College of Life Sciences, Research Center of Analytical Instrumentation, Sichuan University, Chengdu, Sichuan 610064, P. R. China
| | - Jingsong Huang
- ‡Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Xiaolan Sheng
- †College of Life Sciences, Research Center of Analytical Instrumentation, Sichuan University, Chengdu, Sichuan 610064, P. R. China
| | - Bobby G Sumpter
- ‡Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Mina Yoon
- ‡Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Miklos Kertesz
- §Department of Chemistry, Georgetown University, 37th and O Streets, NW, Washington, D.C. 20057, United States
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40
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Ye Z, Otero-de-la-Roza A, Johnson ER, Martini A. Oscillatory motion in layered materials: graphene, boron nitride, and molybdenum disulfide. NANOTECHNOLOGY 2015; 26:165701. [PMID: 25815685 DOI: 10.1088/0957-4484/26/16/165701] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Offset-driven self-retraction and oscillatory motion of bilayer graphene has been observed experimentally and is potentially relevant for nanoscale technological applications. In a previous article, we showed that friction between laterally offset graphene layers is controlled by roughness and proposed a simple reduced-order model based on density-functional theory (DFT) and molecular dynamics (MD) data, with which predictions on the experimental size-scale could be made. In this article, we extend our study to other layered materials, with emphasis on boron nitride (BN) and molybdenum disulfide (MoS2). Using MD and DFT simulations of these systems and a generalized version of the reduced-order model, we predict that BN will exhibit behavior similar to graphene (heavily-damped oscillation with a decay rate that increases with roughness) and that MoS2 shows no oscillatory behavior even in the absence of roughness. This is attributed to the higher energy barrier for sliding in MoS2 as well as the surface structure. Our generalized reduced-order model provides a guide to predicting and tuning experimental oscillation behavior using a few parameters that can be derived from simulation data.
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Affiliation(s)
- Zhijiang Ye
- School of Engineering, University of California Merced, 5200 N. Lake Road, Merced, CA, 95343, USA
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41
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Wang W, Zhang Y, Sun T, Wang YB. On the nature of the stacking interaction between two graphene layers. Chem Phys Lett 2015. [DOI: 10.1016/j.cplett.2014.12.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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42
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43
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Paci JT, Furmanchuk A, Espinosa HD, Schatz GC. Shear and friction between carbon nanotubes in bundles and yarns. NANO LETTERS 2014; 14:6138-6147. [PMID: 25279773 DOI: 10.1021/nl502210r] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We perform a detailed density functional theory assessment of the factors that determine shear interactions between carbon nanotubes (CNTs) within bundles and in related CNT and graphene structures including yarns, providing an explanation for the shear force measured in recent experiments (Filleter, T. etal. Nano Lett. 2012, 12, 73). The potential energy barriers separating AB stacked structures are found to be irrelevant to the shear analysis for bundles and yarns due to turbostratic stacking, and as a result, the tube-tube shear strength for pristine CNTs is estimated to be <0.24 MPa, that is, extremely small. Instead, it is pinning due to the presence of defects and functional groups at the tube ends that primarily cause resistance to shear when bundles are fractured in weak vacuum (∼10(-5) Torr). Such defects and groups are estimated to involve 0.55 eV interaction energies on average, which is much larger than single-atom vacancy defects (approximately 0.039 eV). Furthermore, because graphitic materials are stiff they have large coherence lengths, and this means that push-pull effects result in force cancellation for vacancy and other defects that are internal to the CNTs. Another important factor is the softness of cantilever structures relative to the stiff CNTs in the experiments, as this contributes to elastic instability transitions that account for significant dissipation during shear that has been observed. The application of these results to the mechanical behavior of yarns is discussed, providing general guidelines for the manufacture of strong yarns composed of CNTs.
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Affiliation(s)
- Jeffrey T Paci
- Department of Chemistry and ‡Department of Mechanical Engineering, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
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44
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Ye Z, Otero-de-la-Roza A, Johnson ER, Martini A. The role of roughness-induced damping in the oscillatory motion of bilayer graphene. NANOTECHNOLOGY 2014; 25:425703. [PMID: 25274535 DOI: 10.1088/0957-4484/25/42/425703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
A multi-scale theoretical model is presented that is the first to offer quantitative agreement with experimental measurements of self-retraction and oscillation of bilayer graphene. The model integrates density-functional theory calculations of the energetics driving flake retraction and molecular-dynamics simulations capturing the dynamic response of laterally-offset rough surfaces. We demonstrate that nanoscale roughness explains self-retraction motion and propose a recipe for tuning that motion by controlling friction.
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Affiliation(s)
- Zhijiang Ye
- School of Engineering, University of California, Merced, 5200 N. Lake Road, Merced, CA 95343, USA
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45
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Leven I, Azuri I, Kronik L, Hod O. Inter-layer potential for hexagonal boron nitride. J Chem Phys 2014; 140:104106. [DOI: 10.1063/1.4867272] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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46
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Kim MH, Kim D, Choi JB, Kim MK. Vibrational characteristics of graphene sheets elucidated using an elastic network model. Phys Chem Chem Phys 2014; 16:15263-71. [DOI: 10.1039/c4cp00732h] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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47
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Popov AM, Lebedeva IV, Knizhnik AA, Lozovik YE, Potapkin BV, Poklonski NA, Siahlo AI, Vyrko SA. AA stacking, tribological and electronic properties of double-layer graphene with krypton spacer. J Chem Phys 2013; 139:154705. [DOI: 10.1063/1.4824298] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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48
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Xu Z, Li X, Yakobson BI, Ding F. Interaction between graphene layers and the mechanisms of graphite's superlubricity and self-retraction. NANOSCALE 2013; 5:6736-6741. [PMID: 23793933 DOI: 10.1039/c3nr01854g] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Graphene layer-layer interaction is explored as a function of the misorientation angle. A stepwise potential energy surface (PES), where the optimized commensurate configuration (AB stacking) corresponds to the global minimum and all incommensurate configurations correspond to nearly equal energies, is shown. The stepwise behavior is attributed to the alternating appearance of AB and AA stacking-like areas and the transition areas between them. Further, the PES of most incommensurate configurations is found to be ultra-smooth. Based on this, the puzzling experimental observation of graphite flake self-retraction is successfully explained.
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Affiliation(s)
- Ziwei Xu
- Institute of Textiles and Clothing, Hong Kong Polytechnic University, Hung Hom, Hong Kong
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49
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Jing L, Huang P, Zhu H, Gao X. Spin-polarized semiconductors: tuning the electronic structure of graphene by introducing a regular pattern of sp3 carbons on the graphene plane. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2013; 9:306-311. [PMID: 23027424 DOI: 10.1002/smll.201201100] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Indexed: 06/01/2023]
Abstract
First-principles calculations (generalized gradient approximation, density functional therory (DFT) with dispersion corrections, and DFT plus local atomic potential) are carried out on the stability and electronic structures of superlattice configurations of nitrophenyl diazonium functionalized graphene with different coverage. In the calculations, the stabilities of these structures are strengthened significantly since van der Waals interactions between nitrophenyl groups are taken into account. Furthermore, spin-polarized and wider-bandgap electronic structures are obtained when the nitrophenyl groups break the sublattice symmetry of the graphene. The unpaired quasi-localized p electrons are responsible for this itinerant magnetism. The results provide a novel approach to tune graphene's electronic structures as well as to form ferromagnetic semiconductive graphene.
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Affiliation(s)
- Long Jing
- CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, PR China
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50
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Popov AM, Lebedeva IV, Knizhnik AA, Lozovik YE, Potapkin BV. Ab initio study of edge effect on relative motion of walls in carbon nanotubes. J Chem Phys 2013; 138:024703. [PMID: 23320709 DOI: 10.1063/1.4774083] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Andrey M Popov
- Institute of Spectroscopy, Russian Academy of Science, Fizicheskaya Street 5, Troitsk, Moscow Region 142190, Russia.
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