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Energy & Environmental Materials 2024年第4期7卷 285-294页

作者： Yan Zhang Huandi Zhang Xiaoxiao Wang Xiaowei Shi Zehua Zhao Yaling Wang Jiamei Liu Cheng Tang Guolong Wang Lei Li State Key Laboratory for Mechanical Behavior of Materials School of Materials Science and EngineeringXi’an Jiaotong UniversityNo.28Xianning West RoadXi’an 710049China Center for Materials Chemistry Frontier Institute of Science and TechnologyXi’an Jiaotong UniversityXi’an 710054China Instrument Analysis Center of Xi’an Jiaotong University Xi’an Jiaotong UniversityNo.28Xianning West RoadXi’an 710049China

The electrochemical performance of microsupercapacitors with graphene electrodes is reduced by the issue of graphene sheets aggregation,which limits electrolyte ions penetration into *** the space between graphene sheets in electrodes facilitates the electrolyte ions penetration,but sacrifices its electronic conductivity which also influences the charge storage *** challenging task is to improve the electrodes’electronic conductivity and ionic diffusion simultaneously,boosting the device’s electrochemical ***,we experimentally realize the enhancement of both electronic conductivity and ionic diffusion from 2D graphene nanoribbons assisted graphene electrode with porous layer-uponlayer structure,which is tailored by graphene nanoribbons and self-sacrificial templates ethyl *** designed electrode-based device delivers a high areal capacitance of 71 mF cm^(-2)and areal energy density of 9.83μWh cm^(-2),promising rate performance,outstanding cycling stability with 97%capacitance retention after 20000 cycles,and good mechanical *** strategy paves the way for fabricating high-performance graphene-based MSCs.

关键词： areal energy density graphene graphene nanoribbons microsupercapacitors structure engineering

Sandwich structured graphene-wrapped FeS-graphene nanoribbons with improved cycling stability for lithium ion batteries

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Nano Research 2016年第10期9卷 2904-2911页

作者： Lei Li Caitian Gao Anton Kovalchuk Zhiwei Peng Gedeng Ruan Yang Yang Huilong Fei Qifeng Zhong Yilun Li James M. Tour Department of Chemistry Rice University 5100 Main Street Houston Texas 77005 USA School of Physical Science and Technology Lanzhou University Lanzhou 730000 China NanoCarbon Center Rice University 6100 Main Street Houston Texas 77005 USA State Key Laboratory of Bioelectronics School of Biological Science and Medical Engineering Southeast University Nanjing 210096 China Department of Materials Science and NanoEngineering Rice University 6100 Main Street Houston Texas 77005 USA

Sandwich structured graphene-wrapped FeS-graphene nanoribbons （G@FeS-GNIKs） were developed. In this composite, FeS nanoparticles were sandwiched between graphene and graphene nanoribbons. When used as anodes in lithium ion batteries （L1Bs）, the G@FeS-GNR composite demonstrated an outstanding electrochemical performance. This composite showed high reversible capacity, good rate performance, and enhanced cycling stability owing to the synergy between the electrically conductive graphene, graphene nanoribbons, and FeS. The design concept developed here opens up a new avenue for constructing anodes with improved electrochemical stability for LIBs.

关键词： lithium ion battery iron sulfide graphene nanoribbons graphene energy storage

Modulating magnetism of nitrogen-doped zigzag graphene nanoribbons

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Chinese Physics B 2014年第6期23卷 507-513页

作者：赵尚骞吕燕吕文刚梁文杰王恩哥 Institute of Physics Chinese Academy of Sciences and Beijing National Laboratory for Condensed Matter Physics International Center for Quantum Materials School of Physics Peking University

We present a study of electronic properties of zigzag graphene nanoribbons （ZGNRs） substitutionally doped with nitrogen atoms at a single edge by first principle calculations. We find that the two edge states near the Fermi level sepa- rate due to the asymmetric nitrogen-doping. The ground states of these systems become ferromagnetic because the local magnetic moments along the undoped edges remain and those along the doped edges are suppressed. By controlling the charge-doping level, the magnetic moments of the whole ribbons are modulated. Proper charge doping leads to interest- ing half-metallic and single-edge conducting ribbons which would be helpful for designing graphene-nanoribbon-based spintronic devices in the future.

关键词： graphene nanoribbons charge doping spin-polarization spatial localization

Effects of Monovacancy on Thermal Properties of Bilayer graphene nanoribbons by Molecular Dynamics Simulations

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Journal of Thermal Science 2021年第6期30卷 1917-1924页

作者： YANG Ming ZHANG Xingli ZHANG Hang Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100190China College of Mechanical and Electrical Engineering Northeast Forestry UniversityHarbin 150040China Department of Mechanical Engineering University of ColoradoBoulderCO80309USA

The monovacancy defect effect on thermal conductivity of bilayer graphene nanoribbons(BGNs)was investigated using non-equilibrium molecular dynamics(NEMD)simulations in this *** results demonstrate that the presence of monovacancy defect in BGNs reduces their thermal transport properties *** major finding of this work shows that the calculated thermal conductivity reduces approximately linearly with the raise of monovacancy *** contrast to the temperature-dependent thermal conductivity in perfect BGNs,the thermal conductivity of defected BGNs first increases and then decreases with the increasing *** addition,when the difference in the monovacancy density between two layers is larger,the thermal conductivity of BGNs is *** also calculated the phonon density of states,phonon relaxation time and participation ratio to provide a deeper understanding of the simulation *** investigation confirms that the BGNs-based nano-devices could be applied in thermal management by defect engineering.

关键词： monovacancy thermal conductivity molecular dynamics graphene nanoribbons

First principle study of edge topological defect-modulated electronic and magnetic properties in zigzag graphene nanoribbons

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Chinese Physics B 2017年第10期26卷 169-174页

作者：黄露婷陈铮王永欣卢艳丽 State Key Laboratory of Solidification Processing School of Materials Science and EngineeringNorthwestern Polytechnical University

Zigzag graphene nanoribbon （ZGNR） is a promising candidate for next-generation spintronic devices. Development of the field requires potential systems with variable and adjustable electromagnetic properties. Here we show a detailed investigation of ZGNR decorated with edge topological defects （ED-ZGNR） synthesized in laboratory by Ruffieux in 2015 [Pascal Ruffieux, Shiyong Wang, Bo Yang, et al. 2015 Nature 531 489]. The pristine ED-ZGNR in the ground state is an antiferromagnetic semiconductor, and the acquired band structure is significantly changed compared with that of perfect ZGNR. After doping heteroatoms on the edge, the breaking of degeneration of band structure makes the doped ribbon a half-semi-metal, and nonzero magnetic moments are induced. Our results indicate the tunable electronic and magnetic properties of ZGNR by deriving unique edge state from topological defect, which opens a new route to practical nano devices based on ZGNR.

关键词： graphene nanoribbons topological defect spin edge

Polarization Raman spectra of graphene nanoribbons

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Chinese Physics B 2023年第4期32卷 568-573页

作者：许望伟孙诗杰杨慕紫郝振亮高蕾卢建臣朱嘉森陈建蔡金明 Faculty of Materials Science and Engineering Kunming University of Science and TechnologyKunming 650000China School of Materials Science and Engineering Instrumental Analysis and Research CenterSun Yat-sen UniversityGuangzhou 510275China Faculty of Science Kunming University of Science and TechnologyKunming 650000China

The on-surface synthesis method allows the fabrication of atomically precise narrow graphene nanoribbons(GNRs),which bears great potential in electronic ***,we synthesize armchair graphene nanoribbons(AGNRs)and chevron-type graphene nanoribbons(CGNRs)array on a vicinal Au(111112)surface using 10,10′-dibromo-9,9′-bianthracene(DBBA)and 6,12-dibromochrysene(DBCh)as precursors,*** process creates spatially wellaligned GNRs,as characterized by scanning tunneling *** show strong Raman linear polarizability for application in optical modulation *** from the distinct polarization of AGNRs,only weak polarization exists in CGNRs polarized Raman spectrum,which suggests that the presence of the zigzag boundary in the nanoribbon attenuates the polarization rate as an important factor affecting the *** analyze the Raman activation mode of CGNRs using the peak polarization to expand the application of the polarization Raman spectroscopy in nanoarray analysis.

关键词： graphene nanoribbons polarization Raman spectroscopy scanning tunneling microscopy

Enhanced CO2 electroreduction on armchair graphene nanoribbons edge-decorated with copper

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Nano Research 2017年第5期10卷 1641-1650页

作者： Guizhi Zhu Singapore-Peking University Research Centre Campus for Research Excellence & Technological Enterprise (CREATE) Singapore 138602 Singapore Department of Materials Science and Engineering Peking University Beijing 100871 China Institute of Modern Physics Shaanxi Key Laboratory for Theoretical Physics Frontiers Northwest University Xi'an 710069 China School of Materials Science and Engineering Nanyang Technological University Singapore 639798 Singapore School of Mechanical and Aerospace Engineering Nanyang Technological University Singapore 639798 Singapore

Inspired by the recent experimental synthesis of graphene nanoribbons （GNKs） and theoretical research on their edge-decoration, we comprehensively studied the electrocatalytic performance of GNRs edge-decorated with Cu for CO2 reduction. Compared to zigzag GNRs, the Cu-terminated armchair GNRs with a width of n = 3p ＋ 2 were more efficient catalysts for producing methanol from CO2 with a free energy barrier of less than 0.5 eV, offering the advantages of a lower overpotential and higher selectivity than bulk Cu and other graphene-supported Cu structures. On the other hand, the competing hydrogen evolution reaction could be effectively suppressed by Cu-terminated armchair GNRs. Hence, the edge-decorated GNRs offer great flexibility for tuning the catalytic efficiency and selectivity for CO2 electroreduction.

关键词： carbon dioxide density functionalcalculations edge effects electrocatalysis graphene nanoribbons

Chevron-type graphene nanoribbons with a reduced energy band gap:Solution synthesis,scanning tunneling microscopy and electrical characterization

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Nano Research 2020年第6期13卷 1713-1722页

作者： Ximeng Liu Gang Li Alexey Lipatov Tao Sun Mohammad Mehdi Pour Narayana R.Aluru Joseph W.Lyding Alexander Sinitskii Beckman Institute for Advanced Science and Technology University of Illinois at Urbana-ChampaignUrbanaIL61801USA Department of Electrical and Computer Engineering University of Illinois at Urbana-ChampaignUrbanaIL61801USA Department of Chemistry University of Nebraska-LincolnLincolnNE68588USA Department of Mechanical Science and Engineering University of Illinois at Urbana-ChampaignUrbanaIL61801USA Nebraska Center for Materials and Nanoscience University of Nebraska-LincolnLincolnNE68588USA

graphene nanoribbons(GNRs)attract a growing interest due to their tunable physical properties and promise for device applications.A variety of atomically precise GNRs have recently been synthesized by on-surface and solution *** on-surface GNRs can be conveniently visualized by scanning tunneling microscopy(STM),and their electronic structure can be probed by scanning tunneling spectroscopy(STS),such characterization remains a great challenge for the solution-synthesized ***,we report solution synthesis and detailed STM/STS characterization of atomically precise GNRs with a meandering shape that are structurally related to chevron GNRs but have a reduced energy band *** ribbons were synthesized by Ni0-mediated Yamamoto polymerization of specially designed molecular precursors using triflates as the leaving groups and oxidative cyclodehydrogenation of the resulting polymers using Scholl *** ribbons were deposited onto III-V semiconducting InAs(110)substrates by a dry contact transfer ***-resolution STM/STS characterization not only confirmed the GNR geometry,but also revealed details of electronic structure including energy states,electronic band gap,as well as the spatial distribution of the local density of *** experimental STS band gap of GNRs is about 2 eV,which is very close to 2.35 eV predicted by the density functional theory simulations with GW correction,indicating a weak screening effect of InAs(110)***,several aspects of GNR-InAs(110)substrate interactions were also probed and analyzed,including GNR tunable transparency,alignment to the substrate,and manipulations of GNR position by the STM *** weak interaction between the GNRs and the InAs(110)surface makes InAs(110)an ideal substrate for investigating the intrinsic properties of *** of the reduced energy band gap of these ribbons,the GNR thin films exhibit appreciably high electrical conductivity and on/off ratios of about 1

关键词： graphene nanoribbons bottom-up synthesis electronic structure dry contact transfer scanning tunneling microscopy scanning tunneling spectroscopy

Effect of electron injection in copper-contacted graphene nanoribbons

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Nano Research 2016年第9期9卷 2735-2746页

作者： Konstantin A.Simonov Nikolay A.Vinogradov Alexander S.Vinogradov Alexander V.Generalov Gleb I.Svirskiy Attilio A.Cafolla Nils Martensson Alexei B. Preobrajenski Department of Physics and Astronomy Uppsala UniversityUppsala Box 51675120Sweden MAX Ⅳ Laboratory Lund UniversityLund Box 11822100Sweden V.A.Fock Institute of Physics St.Petersburg State UniversitySt.Petersburg 198504Russia School of Physical Sciences Dublin City UniversityDublin 9Ireland

For practical electronic device applications of graphene nanoribbons (GNRs), it is essential to have abrupt and well-defined contacts between the ribbon and the adjacent metal lead. By analogy with graphene, these contacts can induce electron or hole doping, which may significantly affect the I/V characteristics of the device. Cu is among the most popular metals of choice for contact materials. In this study, we investigate the effect of in situ intercalation of Cu on the electronic structure of atomically precise, spatially aligned armchair GNRs of width N = 7 (7-AGNRs) fabricated via a bottom-up method on the Au(788) surface. Scanning tunneling microscopy data reveal that the complete intercalation of about one monolayer of Cu under 7-AGNRs can be facilitated by gentle annealing of the sample at 80 °C. Angle-resolved photoemission spectroscopy (ARPES) data clearly reflect the one-dimensional character of the 7-AGNR band dispersion before and after intercalation. Moreover, ARPES and core-level photoemission results show that intercalation of Cu leads to significant electron injection into the nanoribbons, which causes a pronounced downshift of the valence and conduction bands of the GNR with respect to the Fermi energy (ΔE ~ 0.5 eV). As demonstrated by ARPES and X-ray absorption spectroscopy measurements, the effect of Cu intercalation is restricted to n-doping only, without considerable modification of the band structure of the GNRs. Post-annealing of the 7-AGNRs/Cu/Au(788) system at 200 °C activates the diffusion of Cu into Au and the formation of a Cu-rich surface Au layer. Alloying of intercalated Cu leads to the recovery of the initial position of GNR-related bands with respect to the Fermi energy (E F), thus, proving the tunability of the induced n-doping.

关键词： graphene nanoribbons bottom-up method copper intercalation charge injection angle-resolved photoemission spectroscopy (ARPES) scanning tunneling microscopy

Numerical Analysis of Alternating-Current Small-Signal Response in graphene nanoribbons

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Chinese Physics Letters 2010年第8期27卷 172-175页

作者：陈志东张进宇余志平 Institute of Microelectronics Tsinghua University Beijing 100084

Alternating-current small-signal admittances of armchair graphene nanoribbons are investigated using the method of non-equilibrium Green＇s function. The calculated ac admittances show an oscillatory response between inductive and capacitive behaviors, which is a result of the finite length of the graphene nanoribbon. The effects of hydrogen-passivated edges on ac response are demonstrated. At low frequency, the edge effects transform the inductive behavior in a metallic graphene nanoribbon into a capacitive one. Finally, the effects of variations in the width and bandgap of a graphene nanoribbon on its dynamic response are investigated.

关键词： Numerical Analysis graphene nanoribbons Small-Signal