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Journal of Materials Science & Technology 2021年第35期94卷 90-98页

作者： Zhong Huang Yangfan Zheng Haijun Zhang Faliang Li Yuan Zeng Quanli Jia Jun Zhang Junyi Li Shaowei Zhang The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081China Henan Key Laboratory of High Temperature Functional Ceramics Zhengzhou UniversityZhengzhou 450052China College of Engineering Mathematics and Physical SciencesUniversity of ExeterExeter EX44QFUnited Kingdom

Waste plastics recycling and oil/organics remediation are environmental issues of global concern.In this work,a protectant was introduced,for the first time,to make highly efficient catalysts for pyrolysis of waste plastics into carbon nanotubes(CNTs)with high yield.By using waste polyethylene,Co(NO_(3))_(2) and oleylamine respectively as carbon source,catalyst precursor and protectant,a yield as high as 59.0%was achieved.The CNTs exhibited a high adsorption capacity for methylene blue(up to 107.1 mg/g).Furthermore,by combining the CNTs with graphene oxide,a graphene-CNT aerogel with a low density of8.2 mg/cm^(3)and high porosity of 96.0%was successfully prepared.It showed excellent hydrophobicity and mechanical stability,as well as high adsorption capacity of 289-410 g/g oil/organic solvent,which was much higher than most of these achieved by carbon-based three-dimensional materials reported previously,making the as-prepared aerogel a very promising adsorbent for oil/water separation.

关键词： Waste plastics carbon nanotubes Pyrolysis Oleylamine Aerogel Oil/organics remediation

Large magnetic moment at sheared ends of single-walled carbon nanotubes

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Chinese Physics B 2018年第12期27卷 510-516页

作者：张健邓娅郝婷婷胡潇刘雅芸彭志盛 Jean Pierre Nshimiyimana 池宪念武佩刘思雨张忠李俊杰王公堂褚卫国顾长志孙连峰 CAS Key Laboratory of Nanosystem and Hierarchical Fabrication CAS Center for Excellence in NanoscienceNational Center for Nanoscience and Technology University of Chinese Academy of Sciences Institute of Physics Chinese Academy of Sciences (CAS) School of Physics and Electronics Shandong Normal University

In this work we report that after single-walled carbon nanotubes(SWNTs) are sheared with a pair of titanium scissors,the magnetization becomes larger than that of the corresponding pristine ones. The magnetization increases proportionally with the number of SWNTs with sheared ends, suggesting that there exist magnetic moments at the sheared ends of SWNTs.By using the coefficient of this linear relation, the average magnetic moment is estimated to be 41.5 ± 9.8 μB(Bohr magneton) per carbon atom in the edge state at temperature of 300.0 K, suggesting that ultrahigh magnetic fields can be produced. The dangling sigma and pi bonds of the carbon atoms at sheared ends play important roles in determining the unexpectedly high magnetic moments, which may have great potential applications.

关键词： carbon nanotubes shear open ends magnetic moments

Ultralow-temperature assisted synthesis of single platinum atoms anchored on carbon nanotubes for efficiently electrocatalytic acidic hydrogen evolution

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Journal of Energy Chemistry 2020年第12期29卷 280-292页

作者： Wenwu Zhong Wenguang Tu Zongpeng Wang Zhiping Lin Aijiao Xu Xiufang Ye Dongchu Chen Beibei Xiao Department of Materials Taizhou UniversityTaizhou 318000ZhejiangChina School of Energy and Power Engineering Jiangsu University of Science and TechnologyZhenjiang 212003JiangsuChina School of Material Science and Energy Engineering Foshan UniversityFoshan 528001GuangdongChina School of Mechanical df Aerospace Engineering Nanyang Technological UniversitySingapore637459Singapore

Although platinum(Pt) is highly active for hydrogen evolution reaction(HER)[1], it is crucial to explore the effective approach for minimizing the Pt loading amount in the practical application. Herein, one ultralow-temperature solution reduction approach is developed to anchor atomically dispersed Pt atoms on carbon nanotubes(Pt-CNTs), which decelerates the diffusion rate of Pt Cl2-6 ion reached onto the carbon nanotubes and lowers the free energy of Pt atoms in the solution to reduce the probability of the Pt aggregation. The obtained Pt-CNTs exhibits a low overpotential of 41 mV@10 mA cm^(-2) for HER in acidic media. The calculation results revealed that the improvement of the electrocatalytic activity is contributed by the interaction between CNTs and Pt atoms, which descreases the the Pt d band cneter referred to the Fermi level and lowers the Gibbs free energy of H*adsorption. This work may provide one easy and convenient strategy for the large-scale use of Pt catalysts in practical applications.

关键词： Hydrogen evolution reaction Single-atom catalysts Ultralow-temperature Platinum carbon nanotubes

Effect of Longitudinal Magnetic Field on Vibration Response of Double-Walled carbon nanotubes Embedded in Viscoelastic Medium

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Acta Mechanica Solida Sinica 2018年第2期31卷 187-206页

作者： Dapeng Zhang Yongjun Lei Zhibin Shen College of Aerospace Science and Engineering National University of Defense Technology

This paper aims to study the effect of externally applied longitudinal magnetic field on the transverse vibration of viscoelastic double-walled carbon nanotubes （visco-DWCNTs） embedded in a viscoelastic medium. The analyses are carried out based on the nonlocal viscoelastic model and Euler-Bernoulli beam theory. Governing equations are derived for the vibration of the embedded visco-DWCNT subjected to a magnetic field, where the Lorentz magnetic force, the surrounding viscoelastic medium, the intertube van der Waals forces and viscoelasticity of the DWCNT are taken into consideration. In this study, the transfer function method is employed to solve the governing equations, which enables one to obtain the natural frequencies and the corresponding mode shapes in closed form for the DWCNTs with arbitrary boundary conditions. Here the developed mechanics model is first compared with the existing techniques available in the literature in a few particular cases, where excellent agreement is achieved. The validation of the model is followed by a detailed parametric study of the effects of longitudinal magnetic field, nonlocal parameter, boundary conditions, structural damping coefficient and aspect ratio of the DWCNTs on their vibration. The study demonstrates the efficiency of the present technique designed for vibration analysis of a complicated multi-physics system comprising DWCNTs, the viscoelastic medium and a magnetic field in longitudinal direction.

关键词： carbon nanotubes Nonlocal continuum theory Free vibration Magnetic field Viscoelastic medium

Performance of a combined capacitor based on ultrafine nickel oxide/carbon nanotubes composite electrodes

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Journal of University of Science and Technology Beijing 2004年第6期11卷 533-538页

作者： XiaofengWang YanqiuCao YiqiangLu QiqianSha JiLiang AppliedScienceSchool UniversityofScienceandTechnologyBeijingBeijing100083China DepartmentofMechanicalEngineering TsinghuaUniversityBeijing100084China

A new sol-gel process for the preparation of ultrafine nickel hydroxideelectrode materials was developed. The composite electrodes consisting of carbon nanotubes andNi(OH)_2 were developed by mixing the hydroxide and carbon nanotubes together in different massratios. In order to enhance energy density, a combined type pseudocapacitor/electric double layercapacitor was considered and its electrochemical properties were characterized by cyclic voltammetryand dc charge/discharge test. The combined capacitor shows excellent capacitor behavior with anoperating voltage up to 1.6 V in KOH aqueous electrolyte. Stable charge/discharge behaviors wereobserved with much higher specific capacitance values of 24 F/g compared with that of EDLC (12 F/g)by introducing 60 percent Ni(0H)_2 in the anode material. By using the modified anode of aNi(OH)_2/carbon nanotubes composite electrode, the specific capacitance of the cell was lesssensitive to discharge current density compared with that of the capacitor employing pure nickelhydroxide as anode. The combined capacitor in this study exhibits high energy density and stablepower characteristics.

关键词： nickel oxide carbon nanotubes combined capacitor supercapacitor

High energy density performance of hydrothermally produced hydrous ruthenium oxide/multiwalled carbon nanotubes composite: Design of an asymmetric supercapacitor with excellent cycle life

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Journal of Energy Chemistry 2016年第4期25卷 627-635页

作者： K.Chaitra P.Sivaraman R.T.Vinny Umananda M.Bhatta N.Nagaraju N.Kathyayini Department of Nanobiosciences Centre for Emerging TechnologiesJain Global CampusJain UniversityJakkasandra postKanakapura TalukRamanagara District Naval Materials Research Laboratory Department of Chemistry St.Joseph's College

Hydrous ruthenium oxide(h-Ru O) nanoparticles and its composite with multiwalled carbon nanotubes(h-Ru O/MWCNT) were synthesized by a simple hydrothermal method and proved to have potential application as hybrid supercapacitor material.The h-Ru Oand h-Ru O/MWCNT were characterized for their physico-chemical properties by PXRD,BET surface area,Raman,SEM-EDS and TEM techniques.The electrochemical performance of the materials were investigated,specific capacitance(Cs) of h-Ru Oand hRu O/MWCNT estimated by their cyclic voltammetric studies were found to be 604 and 1585 F/g respectively at a scan rate of 2 m V/s in the potential range 0–1.2 V.Further,this value was found to be nearly three times higher than that of pure h-Ru O.An asymmetric supercapacitor(AS) device was fabricated by employing h-Ru O/MWCNT as the positive electrode and activated carbon as the negative electrode.The device exhibited Cs of 61.8 F/g at a scan rate of 2 m V/s.Further,the device showed excellent long term stability for 20,000 cycles with 88% capacitance retention at a high current density of 25 A/g.

关键词： carbon nanotubes Hybrid composites Asymmetric supercapacitors Cycle life

Performance of a 60 F carbon nanotubes-based supercapacitor for hybrid power sources

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Journal of University of Science and Technology Beijing 2005年第3期12卷 267-273页

作者： XiaofengWang DianboRuan ZhengYou YiqiangLu QiqianSha DepartmentofPrecisionInstrumentsandMechanics TsinghuaUniversityBeijing100084China Departmentofchemistry UniversityofscienceandtechnologyBeijingBeijing100084China

A supercapacitor based on charge storage at the interface between a high surface area carbon nanotube electrode and a Li-ClO4/PC electrolyte was assembled. The performance of the capacitor depends on not only the material used in the cell but also the construction of the cell. From a constant charge-discharge test, the capacitance of 60 F was obtained. The performance of the power capacitor for pulse power sources was described. The specific energy (0.8 W·h·kg-1) and the specific power (0.75 kW·kg-1) of the power supercapacitor were demonstrated with a cell of the maximum operating voltage of 2.5 V. A hybrid power source consisting of a lithium ionic battery and the 60 F supercapacitor was demonstrated to power successfully a simulated power load encountered in GSM portable communication equipment. The addition of the supercapacitor to the power train of a cellular phone results in significantly more energy from the battery being used by the load. The experiments indicate that more than 33.8% energy is utilized by load and less stored energy is dissipated within the battery for each charge-discharge cycle.

关键词： carbon nanotubes supercapacitor lithium-ion battery GSM portable communication

Enhancing Dielectric and Mechanical Behaviors of Hybrid Polymer Nanocomposites Based on Polystyrene,Polyaniline and carbon nanotubes Coated with Polyaniline

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Chinese Journal of Polymer Science 2016年第12期34卷 1500-1509页

作者： Tanveer ul Haq Zia Ahmad Nawaz Khan Majid Hussain Ibrar Hassan Iftikhar Hussain Gul Department of Materials Engineering School of Chemical and Materials EngineeringNational University of Sciences and Technology

The dielectric and mechanical properties of hybrid polymer nanocomposites of polystyrene/polyaniline/carbon nanotubes coated with polyaniline （pCNTs） have been investigated using impedance analyzer and extensometer. The blends of PS/PANI formed the heterogeneous phase separated morphology in which pCNTs are dispersed uniformly. The incorporation of a small amount of pCNTs into the blend of PS/PANI has remarkably increased the dielectric properties. Similarly, the AC conductivity of PS/PANI is also increased five orders of magnitude from 1.6 × 10^-10 to 2.0×10^-5 S.cm-1 in the hybrid nanocomposites. Such behavior of hybrid nanocomposites is owing to the interfacial polarization occurring due to the presence of multicomponent domains with varying conductivity character of the phases from insulative PS to poor conductor PANI to highly conductive CNTs. Meanwhile, the tensile modulus and tensile strength are also enhanced significantly up to 55% and 160%, respectively, without much loss of ductility for three phase hybrid nanocomposites as compared to the neat PS. Thereby, the hybrid nanocomposites of PS/PANI/pCNTs become stiffer, stronger and tougher as compared to the neat systems.

关键词： Nanocomposites carbon nanotubes Dielectric behavior Mechanical properties Polystyrene.

Structure of Lennard–Jones nanowires encapsulated by carbon nanotubes

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Chinese Physics B 2014年第1期23卷 318-323页

作者：吴雯倩田明丽陈航燕袁清红孙得彦 Department of Physics East China Normal University Shanghai 200062 China College of Electric and Information Engineering Pingdingshan University Pingdingshan 467000 China

Molecular dynamics simulations have been performed to investigate the structures of Lennard-Jones （LJ） nanowires （NWs） encapsulated in carbon nanotubes （CNTs）. We find that the structures of NWs in a small CNT only adopt multi-shell motifs, while the structures of NWs in a larger CNT tend to adopt various motifs. Among these structures, three of them have not been reported previously. The phase boundaries among these structures are obtained regarding filling fractions, as well as the interaction between NWs and CNTs.

关键词： structure of nanowires carbon nanotubes molecular dynamics simulation

Fabrication and thermal conductivity of copper matrix composites reinforced by tungsten-coated carbon nanotubes

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International Journal of Minerals,Metallurgy and Materials 2012年第5期19卷 446-452页

作者： Jun-hui Nie Cheng-chang Jia XianJia Yi Li Ya-feng Zhang Xue-bing Liang School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China China Iron ＆ Steel Research Institute Group Beijing 100081 China

carbon nanotubes （CNTs） were coated by tungsten using metal organic chemical vapor deposition. Magnetic stirring was employed to disperse the W-coated CNTs （W-CNTs） in a Cu matrix, and then, the mixed powders were consolidated by spark plasma sintering. The W-CNTs obtained a uniform dispersion within the Cu matrix when the W-CNT content was less than 5.0vo1%, but high content of W-CNTs （10vol%） resulted in the presence of clusters. The W-CNT/Cu composites containing low content of W-CNTs （〈5.0vol%） exhibited a higher thermal conductivity than the sintered pure Cu, while the CNT/Cu composites exhibited no increase in thermal conductivity after the incorporation of uncoated CNTs. The W-CNT content was found to play a crucial role in determining the thermal conductivity of the W-CNT/Cu composites. The thermal conductivity of the W-CNT/Cu composites increased first and then decreased with the W-CNT content increasing. When the W-CNT content was 2.5vo1%, the W-CNT/Cu composite obtained the maximum value of thermal conductivity. The thermal resistance of the （W-CNT）-Cu interface was predicted in terms of Maxwell-Gamett effective medium approximation, and its calculated value was about 3.0× 10-9 m2.K.W-l.

关键词： metallic matrix composites （MMCs） carbon nanotubes tungsten copper spark plasma sintering thermal conductivity