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  Subjects -> CHEMISTRY (Total: 876 journals)
    - ANALYTICAL CHEMISTRY (54 journals)
    - CHEMISTRY (614 journals)
    - CRYSTALLOGRAPHY (21 journals)
    - ELECTROCHEMISTRY (26 journals)
    - INORGANIC CHEMISTRY (43 journals)
    - ORGANIC CHEMISTRY (48 journals)
    - PHYSICAL CHEMISTRY (70 journals)

CHEMISTRY (614 journals)                  1 2 3 4 | Last

Showing 1 - 200 of 735 Journals sorted alphabetically
2D Materials     Hybrid Journal   (Followers: 13)
Accreditation and Quality Assurance: Journal for Quality, Comparability and Reliability in Chemical Measurement     Hybrid Journal   (Followers: 26)
ACS Catalysis     Full-text available via subscription   (Followers: 42)
ACS Chemical Neuroscience     Full-text available via subscription   (Followers: 20)
ACS Combinatorial Science     Full-text available via subscription   (Followers: 20)
ACS Macro Letters     Full-text available via subscription   (Followers: 25)
ACS Medicinal Chemistry Letters     Full-text available via subscription   (Followers: 40)
ACS Nano     Full-text available via subscription   (Followers: 265)
ACS Photonics     Full-text available via subscription   (Followers: 13)
ACS Synthetic Biology     Full-text available via subscription   (Followers: 23)
Acta Chemica Iasi     Open Access   (Followers: 2)
Acta Chimica Sinica     Full-text available via subscription   (Followers: 1)
Acta Chimica Slovaca     Open Access   (Followers: 1)
Acta Chimica Slovenica     Open Access  
Acta Chromatographica     Full-text available via subscription   (Followers: 8)
Acta Facultatis Medicae Naissensis     Open Access  
Acta Metallurgica Sinica (English Letters)     Hybrid Journal   (Followers: 6)
Acta Scientifica Naturalis     Open Access   (Followers: 2)
adhäsion KLEBEN & DICHTEN     Hybrid Journal   (Followers: 5)
Adhesion Adhesives & Sealants     Hybrid Journal   (Followers: 8)
Adsorption Science & Technology     Full-text available via subscription   (Followers: 5)
Advanced Functional Materials     Hybrid Journal   (Followers: 54)
Advanced Science Focus     Free   (Followers: 5)
Advances in Chemical Engineering and Science     Open Access   (Followers: 65)
Advances in Chemical Science     Open Access   (Followers: 16)
Advances in Chemistry     Open Access   (Followers: 20)
Advances in Colloid and Interface Science     Full-text available via subscription   (Followers: 19)
Advances in Drug Research     Full-text available via subscription   (Followers: 21)
Advances in Enzyme Research     Open Access   (Followers: 9)
Advances in Fluorine Science     Full-text available via subscription   (Followers: 7)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 15)
Advances in Heterocyclic Chemistry     Full-text available via subscription   (Followers: 9)
Advances in Materials Physics and Chemistry     Open Access   (Followers: 25)
Advances in Nanoparticles     Open Access   (Followers: 15)
Advances in Organometallic Chemistry     Full-text available via subscription   (Followers: 15)
Advances in Polymer Science     Hybrid Journal   (Followers: 43)
Advances in Protein Chemistry     Full-text available via subscription   (Followers: 17)
Advances in Protein Chemistry and Structural Biology     Full-text available via subscription   (Followers: 18)
Advances in Quantum Chemistry     Full-text available via subscription   (Followers: 6)
Advances in Science and Technology     Full-text available via subscription   (Followers: 12)
African Journal of Bacteriology Research     Open Access  
African Journal of Chemical Education     Open Access   (Followers: 3)
African Journal of Pure and Applied Chemistry     Open Access   (Followers: 7)
Agrokémia és Talajtan     Full-text available via subscription   (Followers: 2)
Al-Kimia : Jurnal Penelitian Sains Kimia     Open Access  
Alkaloids: Chemical and Biological Perspectives     Full-text available via subscription   (Followers: 2)
AMB Express     Open Access   (Followers: 1)
Ambix     Hybrid Journal   (Followers: 3)
American Journal of Biochemistry and Biotechnology     Open Access   (Followers: 61)
American Journal of Biochemistry and Molecular Biology     Open Access   (Followers: 15)
American Journal of Chemistry     Open Access   (Followers: 29)
American Journal of Plant Physiology     Open Access   (Followers: 11)
American Mineralogist     Hybrid Journal   (Followers: 15)
Analyst     Full-text available via subscription   (Followers: 38)
Angewandte Chemie     Hybrid Journal   (Followers: 164)
Angewandte Chemie International Edition     Hybrid Journal   (Followers: 236)
Annales UMCS, Chemia     Open Access  
Annals of Clinical Chemistry and Laboratory Medicine     Open Access   (Followers: 5)
Annual Reports in Computational Chemistry     Full-text available via subscription   (Followers: 3)
Annual Reports Section A (Inorganic Chemistry)     Full-text available via subscription   (Followers: 4)
Annual Reports Section B (Organic Chemistry)     Full-text available via subscription   (Followers: 9)
Annual Review of Chemical and Biomolecular Engineering     Full-text available via subscription   (Followers: 12)
Annual Review of Food Science and Technology     Full-text available via subscription   (Followers: 13)
Anti-Infective Agents     Hybrid Journal   (Followers: 3)
Antiviral Chemistry and Chemotherapy     Hybrid Journal   (Followers: 1)
Applied Organometallic Chemistry     Hybrid Journal   (Followers: 8)
Applied Spectroscopy     Full-text available via subscription   (Followers: 22)
Applied Surface Science     Hybrid Journal   (Followers: 31)
Arabian Journal of Chemistry     Open Access   (Followers: 5)
ARKIVOC     Open Access   (Followers: 1)
Asian Journal of Biochemistry     Open Access   (Followers: 1)
Atomization and Sprays     Full-text available via subscription   (Followers: 4)
Australian Journal of Chemistry     Hybrid Journal   (Followers: 7)
Autophagy     Hybrid Journal   (Followers: 2)
Avances en Quimica     Open Access  
Biochemical Pharmacology     Hybrid Journal   (Followers: 10)
Biochemistry     Full-text available via subscription   (Followers: 337)
Biochemistry Insights     Open Access   (Followers: 6)
Biochemistry Research International     Open Access   (Followers: 6)
BioChip Journal     Hybrid Journal  
Bioinorganic Chemistry and Applications     Open Access   (Followers: 9)
Bioinspired Materials     Open Access   (Followers: 5)
Biointerface Research in Applied Chemistry     Open Access   (Followers: 2)
Biointerphases     Open Access   (Followers: 1)
Biology, Medicine, & Natural Product Chemistry     Open Access   (Followers: 1)
Biomacromolecules     Full-text available via subscription   (Followers: 20)
Biomass Conversion and Biorefinery     Partially Free   (Followers: 10)
Biomedical Chromatography     Hybrid Journal   (Followers: 7)
Biomolecular NMR Assignments     Hybrid Journal   (Followers: 3)
BioNanoScience     Partially Free   (Followers: 5)
Bioorganic & Medicinal Chemistry     Hybrid Journal   (Followers: 119)
Bioorganic & Medicinal Chemistry Letters     Hybrid Journal   (Followers: 84)
Bioorganic Chemistry     Hybrid Journal   (Followers: 10)
Biopolymers     Hybrid Journal   (Followers: 18)
Biosensors     Open Access   (Followers: 2)
Biotechnic and Histochemistry     Hybrid Journal   (Followers: 2)
Bitácora Digital     Open Access  
Boletin de la Sociedad Chilena de Quimica     Open Access  
Bulletin of the Chemical Society of Ethiopia     Open Access   (Followers: 2)
Bulletin of the Chemical Society of Japan     Full-text available via subscription   (Followers: 24)
Bulletin of the Korean Chemical Society     Hybrid Journal   (Followers: 1)
C - Journal of Carbon Research     Open Access   (Followers: 3)
Cakra Kimia (Indonesian E-Journal of Applied Chemistry)     Open Access  
Canadian Association of Radiologists Journal     Full-text available via subscription   (Followers: 2)
Canadian Journal of Chemistry     Hybrid Journal   (Followers: 10)
Canadian Mineralogist     Full-text available via subscription   (Followers: 6)
Carbohydrate Research     Hybrid Journal   (Followers: 26)
Carbon     Hybrid Journal   (Followers: 71)
Catalysis for Sustainable Energy     Open Access   (Followers: 7)
Catalysis Reviews: Science and Engineering     Hybrid Journal   (Followers: 7)
Catalysis Science and Technology     Free   (Followers: 8)
Catalysis Surveys from Asia     Hybrid Journal   (Followers: 3)
Catalysts     Open Access   (Followers: 9)
Cellulose     Hybrid Journal   (Followers: 7)
Cereal Chemistry     Full-text available via subscription   (Followers: 4)
ChemBioEng Reviews     Full-text available via subscription   (Followers: 1)
ChemCatChem     Hybrid Journal   (Followers: 8)
Chemical and Engineering News     Free   (Followers: 18)
Chemical Bulletin of Kazakh National University     Open Access  
Chemical Communications     Full-text available via subscription   (Followers: 73)
Chemical Engineering Research and Design     Hybrid Journal   (Followers: 26)
Chemical Research in Chinese Universities     Hybrid Journal   (Followers: 3)
Chemical Research in Toxicology     Full-text available via subscription   (Followers: 22)
Chemical Reviews     Full-text available via subscription   (Followers: 181)
Chemical Science     Open Access   (Followers: 23)
Chemical Technology     Open Access   (Followers: 22)
Chemical Vapor Deposition     Hybrid Journal   (Followers: 5)
Chemical Week     Full-text available via subscription   (Followers: 7)
Chemie in Unserer Zeit     Hybrid Journal   (Followers: 56)
Chemie-Ingenieur-Technik (Cit)     Hybrid Journal   (Followers: 24)
ChemInform     Hybrid Journal   (Followers: 8)
Chemistry & Biodiversity     Hybrid Journal   (Followers: 7)
Chemistry & Biology     Full-text available via subscription   (Followers: 32)
Chemistry & Industry     Hybrid Journal   (Followers: 6)
Chemistry - A European Journal     Hybrid Journal   (Followers: 151)
Chemistry - An Asian Journal     Hybrid Journal   (Followers: 16)
Chemistry and Materials Research     Open Access   (Followers: 20)
Chemistry Central Journal     Open Access   (Followers: 4)
Chemistry Education Research and Practice     Free   (Followers: 5)
Chemistry in Education     Open Access   (Followers: 9)
Chemistry International     Hybrid Journal   (Followers: 2)
Chemistry Letters     Full-text available via subscription   (Followers: 44)
Chemistry of Materials     Full-text available via subscription   (Followers: 245)
Chemistry of Natural Compounds     Hybrid Journal   (Followers: 9)
Chemistry World     Full-text available via subscription   (Followers: 19)
Chemistry-Didactics-Ecology-Metrology     Open Access   (Followers: 1)
ChemistryOpen     Open Access   (Followers: 1)
Chemkon - Chemie Konkret, Forum Fuer Unterricht Und Didaktik     Hybrid Journal  
Chemoecology     Hybrid Journal   (Followers: 4)
Chemometrics and Intelligent Laboratory Systems     Hybrid Journal   (Followers: 14)
Chemosensors     Open Access  
ChemPhysChem     Hybrid Journal   (Followers: 11)
ChemPlusChem     Hybrid Journal   (Followers: 2)
ChemTexts     Hybrid Journal  
CHIMIA International Journal for Chemistry     Full-text available via subscription   (Followers: 2)
Chinese Journal of Chemistry     Hybrid Journal   (Followers: 6)
Chinese Journal of Polymer Science     Hybrid Journal   (Followers: 11)
Chromatographia     Hybrid Journal   (Followers: 24)
Chromatography     Open Access   (Followers: 2)
Chromatography Research International     Open Access   (Followers: 6)
Clay Minerals     Full-text available via subscription   (Followers: 10)
Cogent Chemistry     Open Access  
Colloid and Interface Science Communications     Open Access  
Colloid and Polymer Science     Hybrid Journal   (Followers: 11)
Colloids and Interfaces     Open Access  
Colloids and Surfaces B: Biointerfaces     Hybrid Journal   (Followers: 6)
Combinatorial Chemistry & High Throughput Screening     Hybrid Journal   (Followers: 5)
Combustion Science and Technology     Hybrid Journal   (Followers: 22)
Comments on Inorganic Chemistry: A Journal of Critical Discussion of the Current Literature     Hybrid Journal   (Followers: 2)
Composite Interfaces     Hybrid Journal   (Followers: 7)
Comprehensive Chemical Kinetics     Full-text available via subscription   (Followers: 1)
Comptes Rendus Chimie     Full-text available via subscription  
Comptes Rendus Physique     Full-text available via subscription   (Followers: 1)
Computational and Theoretical Chemistry     Hybrid Journal   (Followers: 9)
Computational Biology and Chemistry     Hybrid Journal   (Followers: 11)
Computational Chemistry     Open Access   (Followers: 2)
Computers & Chemical Engineering     Hybrid Journal   (Followers: 10)
Coordination Chemistry Reviews     Full-text available via subscription   (Followers: 3)
Copernican Letters     Open Access   (Followers: 1)
Corrosion Series     Full-text available via subscription   (Followers: 6)
Critical Reviews in Biochemistry and Molecular Biology     Hybrid Journal   (Followers: 5)
Croatica Chemica Acta     Open Access  
Crystal Structure Theory and Applications     Open Access   (Followers: 4)
CrystEngComm     Full-text available via subscription   (Followers: 13)
Current Catalysis     Hybrid Journal   (Followers: 2)
Current Chromatography     Hybrid Journal  
Current Green Chemistry     Hybrid Journal  
Current Metabolomics     Hybrid Journal   (Followers: 5)
Current Microwave Chemistry     Hybrid Journal  
Current Opinion in Colloid & Interface Science     Hybrid Journal   (Followers: 9)
Current Opinion in Molecular Therapeutics     Full-text available via subscription   (Followers: 14)
Current Research in Chemistry     Open Access   (Followers: 8)
Current Science     Open Access   (Followers: 70)
Current Trends in Biotechnology and Chemical Research     Open Access   (Followers: 3)
Dalton Transactions     Full-text available via subscription   (Followers: 23)
Detection     Open Access   (Followers: 2)
Developments in Geochemistry     Full-text available via subscription   (Followers: 2)
Diamond and Related Materials     Hybrid Journal   (Followers: 12)
Dislocations in Solids     Full-text available via subscription  
Doklady Chemistry     Hybrid Journal  

        1 2 3 4 | Last

Journal Cover Carbon
  [SJR: 2.109]   [H-I: 194]   [71 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0008-6223
   Published by Elsevier Homepage  [3177 journals]
  • Microwave-based preparation and characterization of Fe-cored carbon
           nanocapsules with novel stability and super electromagnetic wave
           absorption performance
    • Authors: Yican Wang; Wenlong Wang; Jing Sun; Chenggong Sun; Yukun Feng; Zhe Li
      Pages: 1 - 11
      Abstract: Publication date: August 2018
      Source:Carbon, Volume 135
      Author(s): Yican Wang, Wenlong Wang, Jing Sun, Chenggong Sun, Yukun Feng, Zhe Li
      Microwave-metal discharge was proposed as a facile methodology to prepare unique Fe-cored carbon nanocapsules (Fe@CNCs) with high purity, novel stability and extraordinary electromagnetic wave (EMW) absorption performance. The effect of microwave power, irradiation time and cyclohexane/ferrocene ratio on the production of Fe@CNCs was examined and the properties of the nanocapsules, such as their Fe content, phase, yield, degree of graphitization and associated microstructures were investigated in detail. It was found that the prepared Fe@CNCs, which can easily be separated from the reaction system, displayed exceedingly high electromagnetic wave (EMW) absorption performance over the 2–18 GHz range. At the minimal reflection loss (RL) values over −10 dB, the EMW absorption bandwidth can reach up to 13.8 GHz with an absorber thickness of 1.5–5 mm. In addition, novel thermo-oxidative stability and super anti-corrosion property were also obtained for the Fe@CNCs as no signs of any corrosion or oxidative degradation loss were observed from the accelerated degradation tests in air and acid at temperatures up to 420 °C. The exceedingly high EMW absorption performance coupled with the superior anti-degradation and anti-corrosion properties of the prepared nanocomposite microcapsules highlights the novel capability of microwave-metal discharge in synthesizing advanced metal-cored nanocarbon microcapsules with promising application potentials in diverse fields, such as but not limited to microwave absorption, EM shielding and advanced separations etc.
      Graphical abstract image

      PubDate: 2018-04-23T08:22:29Z
      DOI: 10.1016/j.carbon.2018.04.026
      Issue No: Vol. 135 (2018)
       
  • Super-sieving effect in phenol adsorption from aqueous solutions on
           nanoporous carbon beads
    • Authors: Piotr Kowalczyk; Artur Deditius; Wendell P. Ela; Marek Wiśniewski; Piotr A. Gauden; Artur P. Terzyk; Sylwester Furmaniak; Jerzy Włoch; Katsumi Kaneko; Alexander V. Neimark
      Pages: 12 - 20
      Abstract: Publication date: August 2018
      Source:Carbon, Volume 135
      Author(s): Piotr Kowalczyk, Artur Deditius, Wendell P. Ela, Marek Wiśniewski, Piotr A. Gauden, Artur P. Terzyk, Sylwester Furmaniak, Jerzy Włoch, Katsumi Kaneko, Alexander V. Neimark
      Removal of aromatic contaminants, like phenol, from water can be efficiently achieved by preferential adsorption on porous carbons which exhibit molecular sieving properties. Here, we present nanoporous carbon beads exhibiting an outstanding sieving effect in phenol adsorption from aqueous solution at neutral pH, which is evidenced experimentally and theoretically. The molecular sieving with pure phenol adsorbed phase is achieved by tuning the pore size and surface chemistry of the adsorbent. This study elucidates the essential role of hydrophobic interactions in narrow carbon micropores in removal and clean-up of water from organic pollutants. Furthermore, we suggest a new theoretical approach for evaluation of phenol adsorption capacity that is based on the Monte Carlo simulation of phenol adsorption with the relevance to the pore size distribution function determined by the density functional theory method from low temperature nitrogen adsorption.
      Graphical abstract image

      PubDate: 2018-04-23T08:22:29Z
      DOI: 10.1016/j.carbon.2018.03.063
      Issue No: Vol. 135 (2018)
       
  • Planar metallic carbon allotrope from graphene-like nanoribbons
    • Authors: Ju Rong; Huicong Dong; Jing Feng; Xiao Wang; Yannan Zhang; Xiaohua Yu; Zhaolin Zhan
      Pages: 21 - 28
      Abstract: Publication date: August 2018
      Source:Carbon, Volume 135
      Author(s): Ju Rong, Huicong Dong, Jing Feng, Xiao Wang, Yannan Zhang, Xiaohua Yu, Zhaolin Zhan
      The net-Y, a novel two-dimensional carbon allotrope with four-, six- and eight-membered rings, is investigated by performing first-principles calculations. The calculations on structural stability unambiguously prove that net-Y is an energetically metastable, dynamically and thermally stable phase, and it can also be buckled about 0.4 Å. We find that the net-Y exhibits strong mechanical anisotropy, and the in-plane Young's modulus of net-Y along a and b directions is found smaller than graphene but comparable with that of ψ-graphene and penta-graphene. Meanwhile, the net-Y possesses intrinsic metallicity with high carrier velocities comparable to that of graphene (∼106 m/s). Excitedly, a possible synthetic route towards net-Y from graphene-like nanoribbons embedded four- and eight-membered rings is achieved by first-principles molecular dynamics simulations, indicating that the realization of net-Y is not impossible. Moreover, two three-dimensional (3D) stable close-packed net-Y carbon allotropes are also proposed. Unlike the metallic 3D planar net-Y, the 3D buckled net-Y is a superhard indirect bandgap semiconductor, which further broadens the application potential of net-Y.
      Graphical abstract image

      PubDate: 2018-04-23T08:22:29Z
      DOI: 10.1016/j.carbon.2018.04.033
      Issue No: Vol. 135 (2018)
       
  • Realization of tunable Goos-Hänchen effect with magneto-optical
           effect in graphene
    • Authors: Tingting Tang; Jie Li; Ming Zhu; Li Luo; Jianquan Yao; Nengxi Li; Pengyu Zhang
      Pages: 29 - 34
      Abstract: Publication date: August 2018
      Source:Carbon, Volume 135
      Author(s): Tingting Tang, Jie Li, Ming Zhu, Li Luo, Jianquan Yao, Nengxi Li, Pengyu Zhang
      Tunable Goos-Hänchen (GH) effect with magneto-optical (MO) effect in a prism-graphene coupling structure is proposed. Based on MO effect of graphene in terahertz region, GH effect can be modulated by applied magnetic fields. The GH shift is calculated by stationary phase method and verified by finite-element method (FEM). The physical mechanism of MO modulation for GH effect in the prism-graphene coupling structure is also analyzed based on the interaction between graphene and incident light. GH effect based on Kerr rotation may have great potential in the application of optical rotation displacement modulation and sensing. Meanwhile tunable GH effect in graphene shows a big potential in the measurement of Fermi energy or relaxation time of graphene. It provides us an effective method to facilitate its design and applications in terahertz devices and systems.
      Graphical abstract image

      PubDate: 2018-04-23T08:22:29Z
      DOI: 10.1016/j.carbon.2018.04.028
      Issue No: Vol. 135 (2018)
       
  • Development of 3D interconnected carbon materials derived from
           Zn-MOF-74@carbon nanofiber web as an efficient metal-free electrocatalyst
           for oxygen reduction
    • Authors: Il To Kim; Seoyoon Shin; Moo Whan Shin
      Pages: 35 - 43
      Abstract: Publication date: August 2018
      Source:Carbon, Volume 135
      Author(s): Il To Kim, Seoyoon Shin, Moo Whan Shin
      A novel 3D interconnected web-like carbon material with high electrocatalytic activities toward oxygen reduction reaction (ORR) has been developed for the first time via direct carbonization of a composite (Zn-MOF-74@CNFs) comprising Zn-MOF-74s grown on carbon nanofibers (CNFs) web. The hexagonal pillar shaped Zn-MOF-74s with a diameter which ranges from 300 to 600 nm grow along the CNFs web by solvothermal method. After carbonization of Zn-MOF-74@CNFs, effective interconnections promoting electron transfer are successfully formed between carbonized Zn-MOF-74 (C-Zn-MOF-74) and on CNFs as well as C-Zn-MOF-74 themselves. The extraordinary 3D structure thus fabricated significantly improves the electrocatalytic activity toward ORR. The calculated electron transfers number (n) values for carbonized Zn-MOF-74@CNFs (C-Zn-MOF-74@CNFs) are nearly 4 at potentials ranging from 0.4 to 0.6 V (vs. reversible hydrogen electrode), demonstrating that the ORR process occurs dominantly through a direct four-electron pathway. Tafel slope of C-Zn-MOF-74@CNFs at low over-potential are lower than those from C-Zn-MOF-74 and even commercial Pt/C. Durability is also found to exceed that of commercial Pt/C. This study provides a novel 3D interconnected carbon material as a non-metal ORR electrocatalyst and design strategy for a large-area, self-standing and binder-free carbon-based electrochemical electrode.
      Graphical abstract image

      PubDate: 2018-04-23T08:22:29Z
      DOI: 10.1016/j.carbon.2018.04.019
      Issue No: Vol. 135 (2018)
       
  • Graphene aerogel films with expansion enhancement effect of
           high-performance electromagnetic interference shielding
    • Authors: Jiabin Xi; Youliang Li; Erzhen Zhou; Yingjun Liu; Weiwei Gao; Yan Guo; Ji Ying; Zichen Chen; Guogui Chen; Chao Gao
      Pages: 44 - 51
      Abstract: Publication date: August 2018
      Source:Carbon, Volume 135
      Author(s): Jiabin Xi, Youliang Li, Erzhen Zhou, Yingjun Liu, Weiwei Gao, Yan Guo, Ji Ying, Zichen Chen, Guogui Chen, Chao Gao
      Lightweight and flexible materials with high electromagnetic interference (EMI) shielding performance are highly desirable in numerous occasions to prevent interference between electronic devices. Here, we designed graphene aerogel films (GAF) with multilayer structure, which showed low density (0.02 g cm−3), high flexibility and excellent shielding effectiveness (SE). SE reaches ∼135 dB in 0.1–3 GHz at thickness of 1.4 mm, and shows an uptrend from 65 to 105 dB in 2–18 GHz at thickness of 120 μm. In depth study reveal the excellent shielding performance is attributed to expansion enhancement effect, that shielding effectiveness can be significantly improved by expansion in an individual identical substance. The design of GAFs and the discovery of EEE open the avenue to lightweight materials with high EMI shielding performance.
      Graphical abstract image

      PubDate: 2018-04-23T08:22:29Z
      DOI: 10.1016/j.carbon.2018.04.041
      Issue No: Vol. 135 (2018)
       
  • 3D graphene foam-reinforced polymer composites – A review
    • Authors: Adeyinka Idowu; Benjamin Boesl; Arvind Agarwal
      Pages: 52 - 71
      Abstract: Publication date: August 2018
      Source:Carbon, Volume 135
      Author(s): Adeyinka Idowu, Benjamin Boesl, Arvind Agarwal
      This review summarizes the present state and advances of three-dimensional (3D) graphene foam-reinforced polymer matrix composites (GrF-PMC). Graphene foam as a filler is being considered to address challenging issues of graphene dispersion and restacking in composite materials because of its three-dimensional interconnected hierarchical structure and its physio-chemical attributes. Synthesis approaches to prepare 3D graphene-based frameworks, node-branch behavior and intrinsic material properties of free-standing graphene foam are highlighted. The review discusses different processing techniques to fabricate graphene foam-based polymer composites which can be employed in structural and thermal applications. Influence of graphene foam addition on the mechanical behavior of GrF-PMC has been critically examined. Additionally, the electrical, thermal and other material properties vested in graphene foam to enhance the multifunctional behavior of GrF-PMC are summarized. Current challenges associated with GrF-PMC are discussed, and research pathway into the future for progress in GrF-PMC are introduced.
      Graphical abstract image

      PubDate: 2018-04-23T08:22:29Z
      DOI: 10.1016/j.carbon.2018.04.024
      Issue No: Vol. 135 (2018)
       
  • Development and properties of high thermal conductivity molybdenum carbide
           - graphite composites
    • Authors: Jorge Guardia-Valenzuela; Alessandro Bertarelli; Federico Carra; Nicola Mariani; Stefano Bizzaro; Raul Arenal
      Pages: 72 - 84
      Abstract: Publication date: August 2018
      Source:Carbon, Volume 135
      Author(s): Jorge Guardia-Valenzuela, Alessandro Bertarelli, Federico Carra, Nicola Mariani, Stefano Bizzaro, Raul Arenal
      A family of novel graphite-based composites reinforced with a dispersion of molybdenum carbide particles, with very high thermal and electrical properties, has been recently developed at CERN, in collaboration with Brevetti Bizz (IT), for applications in particle accelerators. These materials, produced by spark plasma sintering, assisted by liquid phase, have been extensively investigated and characterized. The influence of the initial constituents, together with the sintering parameters, have been studied in view of optimizing the thermo-physical and mechanical properties as well as ultra-high vacuum compatibility. The carbide phases and the microstructures have been analysed. Their excellent thermal conductivity (approaching 800 W m − 1 K − 1 ), low thermal expansion and low density make these materials appealing for high-end thermal management applications.
      Graphical abstract image

      PubDate: 2018-04-23T08:22:29Z
      DOI: 10.1016/j.carbon.2018.04.010
      Issue No: Vol. 135 (2018)
       
  • Kinetics of the catalytic polymerization of pyrene with AlCl3
    • Authors: W. Cabell Lamie; David A. Bruce; Wesley P. Hoffman; Mark C. Thies
      Pages: 1 - 8
      Abstract: Publication date: August 2018
      Source:Carbon, Volume 134
      Author(s): W. Cabell Lamie, David A. Bruce, Wesley P. Hoffman, Mark C. Thies
      The kinetics of the catalytic polymerization of pyrene monomer to pyrene pitch in the presence of aluminum trichloride (AlCl3) were studied at temperatures between 330 and 370 °C in a 1-L batch reactor. Both reactants and reaction products were isolated from the bulk pitch using supercritical extraction (SCE), so that they could be quantified. Concentrations of monomer, dimer, and trimer were measured at discrete reaction times, and each was found to exhibit first-order reaction behavior. Analysis of the oligomerization reaction behavior at differing temperatures enabled the calculation of apparent activation energies and pre-exponential factors for each reaction. Relatively low activation energies that decreased with increasing oligomer size were obtained, suggesting that the reactions are mass-transfer-limited. The microkinetic model that was developed can be used to estimate the reaction time for which the formation of liquid crystalline, mesophase-forming pyrene trimer is maximized. Other groups have developed models for bulk mesophase formation, but this is the first time that reaction kinetics have been measured for individual oligomers in a carbonaceous pitch formed from pure polycyclic aromatic hydrocarbons (PAHs) or mixtures thereof.
      Graphical abstract image

      PubDate: 2018-04-15T08:44:17Z
      DOI: 10.1016/j.carbon.2018.03.073
      Issue No: Vol. 134 (2018)
       
  • Elongated graphitic hollow nanofibers from vegetable oil as prospective
           insertion host for constructing advanced high energy Li-Ion capacitor and
           battery
    • Authors: Sundaramurthy Jayaraman; Gurdev Singh; Srinivasan Madhavi; Vanchiappan Aravindan
      Pages: 9 - 14
      Abstract: Publication date: August 2018
      Source:Carbon, Volume 134
      Author(s): Sundaramurthy Jayaraman, Gurdev Singh, Srinivasan Madhavi, Vanchiappan Aravindan
      We report the facile and low temperature synthesis of one dimensional graphitic fibers with hollow structured morphology (VO-CF) by modified chemical vapor deposition using vegetable oil as a carbon source. Graphitization of the prepared phase is validated with various analytical tools. Prior to the fabrication of charge storage devices like Li-ion battery (LIB) and Li-ion capacitor (LIC), Li-insertion properties of VO-CF is studied in half-cell assembly. Mass adjustment between the electrodes are very crucial and adjusted for aforesaid energy storage devices. Pre-treatment or pre-lithiation is carried out using an electrochemical approach in Swagelok fittings with Li. LIB assembly with LiFePO4 delivered a maximum energy density of ∼233 Wh kg−1 whereas the LIC displayed the energy density of ∼112 Wh kg−1 when paired with activated carbon electrode. Both LIB and LIC assemblies rendered very decent cycling profiles for extended 500 and 10000 cycles, respectively.
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      PubDate: 2018-04-15T08:44:17Z
      DOI: 10.1016/j.carbon.2018.03.065
      Issue No: Vol. 134 (2018)
       
  • ZnFe2O4 nanoparticles-cotton derived hierarchical porous active carbon
           fibers for high rate-capability supercapacitor electrodes
    • Authors: Shuhua Yang; Zhenzhen Han; Fangyuan Zheng; Jing Sun; Zhensong Qiao; Xiaopeng Yang; Li Li; Cuncheng Li; Xuefeng Song; Bingqiang Cao
      Pages: 15 - 21
      Abstract: Publication date: August 2018
      Source:Carbon, Volume 134
      Author(s): Shuhua Yang, Zhenzhen Han, Fangyuan Zheng, Jing Sun, Zhensong Qiao, Xiaopeng Yang, Li Li, Cuncheng Li, Xuefeng Song, Bingqiang Cao
      ZnFe2O4 (ZFO) has attracted considerable attention for supercapacitors (SCs), but its performances are severely hindered by intrinsically low electronic conductivity, relatively low mechanical stability, and severe agglomeration during the charge-discharge process. Here, a novel cotton derived active carbon fiber (ACF) with hierarchical porous architecture is used as template/scaffold, ZnFe2O4 nanoparticles/active carbon fiber composites (ZFO-ACFs) are prepared, in which ZFO nanoparticles (∼20 nm) are confined into the larger nanopores (∼20 nm) of the cotton derived active carbon fiber (ACF) while the smaller nanopores (∼2.5 nm) still are preserved. The cotton derived ACF matrix not only controls the size of ZFO particles and avoids self-aggregation but also offers continuous electron pathway and rapid ion transport channel, and prevents the loss of active material (ZFO) during the electrochemical reaction. The ZFO-ACFs electrode exhibits high specific capacitance of 192 F g−1 (58.7 mAh g−1). Moreover, enhanced rate capability are also obtained.
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      PubDate: 2018-04-15T08:44:17Z
      DOI: 10.1016/j.carbon.2018.03.071
      Issue No: Vol. 134 (2018)
       
  • First-principles study of the role of strain and hydrogenation on C3N
    • Authors: Dandan Wang; Yu Bao; Tongshun Wu; Shiyu Gan; Dongxue Han; Li Niu
      Pages: 22 - 28
      Abstract: Publication date: August 2018
      Source:Carbon, Volume 134
      Author(s): Dandan Wang, Yu Bao, Tongshun Wu, Shiyu Gan, Dongxue Han, Li Niu
      C3N has been synthesized recently and demonstrated to possess specific physical and chemical properties. In this work, we investigated the strain effect on it's electronic and phonon properties and on the adsorption property of Li atom through first-principles calculations. Phonon dispersions demonstrate that the crystal structure of C3N is dynamical stable under tensile strain up to 14%. Calculation results show that C3N is always an indirect gap semiconductor as the applied tensile strain is 0%–12% and the band gap reaches its maximum at strain = 9%. While when strain is 13% and 14%, C3N become metallic. Li atom prefers to occupy the C-C hexagonal sites on C3N surface with a diffusion barrier of 0.43eV and the adsorption energies of different adsorption configurations increase with strain. What's more, phonon dispersion calculations and ab initio molecular dynamics simulations reveal that the fully hydrogenated extension of C3N, C3NH3 has two stable conformations, in which one is an indirect semiconductor with band gap of 4.09eV while the other possesses a direct band gap of 2.88eV suitable for photocatalytic application. The strained and hydrogenated C3N with diverse structures and electronic properties provide new prospects in the applications of lithium ion batteries and photoelectrochemistry.
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      PubDate: 2018-04-15T08:44:17Z
      DOI: 10.1016/j.carbon.2018.03.068
      Issue No: Vol. 134 (2018)
       
  • Argon atoms insertion in diamond: New insights in identification of carbon
           C 1s peak in X-ray photoelectron spectroscopy analysis
    • Authors: Jean-François Veyan; Elida de Obaldia; Jesús J. Alcantar-Peña; Jorge Montes-Gutierrez; María J. Arellano-Jimenez; Miguel José Yacaman; Orlando Auciello
      Pages: 29 - 36
      Abstract: Publication date: August 2018
      Source:Carbon, Volume 134
      Author(s): Jean-François Veyan, Elida de Obaldia, Jesús J. Alcantar-Peña, Jorge Montes-Gutierrez, María J. Arellano-Jimenez, Miguel José Yacaman, Orlando Auciello
      The C 1s peak's electron binding energy position in X-ray photoelectron spectroscopy (XPS) analysis of single crystal diamond (SCD) and crystalline and polycrystalline diamond and graphite films has been extensively investigated. A key issue is the experimental identification of C 1s peaks position from graphite sp2 and diamond sp3 C-atoms bonding in the diamond lattice, based on expected energy shifts of C 1s peaks from theory. Because of material charging upon electron photoemission, the absolute binding energy of the C 1s/sp3 related peak cannot be determined. The systematic study of C 1s peaks from XPS analysis of crystalline diamond, polycrystalline diamond films and graphite show key findings: 1) Ar+ ion bombardment is a reliable technique to characterize Diamond vs graphite materials during XPS analysis; 2) A low energy peak reported as C 1s/sp2 bonding, is attributed to the C 1s/sp3 in the presence of Ar atoms inserted in the lattice. 3) The data show direct correlation between the energy of the Ar+ ion beam used for surface sputter-cleaning and binding energy shifts of XPS C 1s peaks.
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      PubDate: 2018-04-15T08:44:17Z
      DOI: 10.1016/j.carbon.2018.03.053
      Issue No: Vol. 134 (2018)
       
  • Domain-boundary independency of Raman spectra for strained graphene at
           strong interfaces
    • Authors: Yunlu Wang; Yang Wang; Chen Xu; Xuewei Zhang; Le Mei; Miao Wang; Yang Xia; Pei Zhao; Hongtao Wang
      Pages: 37 - 42
      Abstract: Publication date: August 2018
      Source:Carbon, Volume 134
      Author(s): Yunlu Wang, Yang Wang, Chen Xu, Xuewei Zhang, Le Mei, Miao Wang, Yang Xia, Pei Zhao, Hongtao Wang
      Strains in graphene play a significant role in graphene-based flexible devices, but many aspects of the domain boundary effects in strained graphene remain unclear, such as the evolution of Raman spectra. Here we present a systematic investigation on the domain boundary effects on the Raman spectra of strained graphene, using a designed strong interface formed by formvar resins. We achieve in single-crystal graphene by far the largest strain up to 2%, significantly improved from the previous highest value of 1.3%, as well as the redshift and splitting for its G and 2D peaks. More importantly, the Raman spectra of strained bi-crystal graphene with a domain boundary show that the spectral evolution follows the same trend as the single crystal, and this trend was also confirmed by the result in polycrystalline graphene, demonstrating that the straining effect on the G and 2D peaks of graphene at strong interfaces is actually independent of its domain boundaries, different from the previous report of graphene deposited on weak interfaces. We attribute it to the efficient interfacial stress transfer at the formvar interfaces, and believe they can provide new insights into the understanding of graphene mechanical behaviors and valuable guidance for graphene-based flexible electronics.
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      PubDate: 2018-04-15T08:44:17Z
      DOI: 10.1016/j.carbon.2018.03.069
      Issue No: Vol. 134 (2018)
       
  • Nanoparticle activated and directed assembly of graphene into a nanoscroll
    • Authors: Karteek K. Bejagam; Samrendra Singh; Sanket A. Deshmukh
      Pages: 43 - 52
      Abstract: Publication date: August 2018
      Source:Carbon, Volume 134
      Author(s): Karteek K. Bejagam, Samrendra Singh, Sanket A. Deshmukh
      Graphene nanoscrolls (GNS) have emerged as an important class of materials with applications in the field of lubrication, energy storage devices, and catalysis. However, the formation of GNS even with existing advanced experimental techniques could be very challenging. Here, we investigate the ability of diamond, nickel (Ni), platinum (Pt), and gold (Au) nanoparticles (NPs) in activating, guiding, and stabilizing the GNS by performing reactive molecular dynamics (RMD) simulations. NPs of certain diameters, when placed on a free-standing graphene sheet, can activate either wrapping or scrolling of the graphene. This activation is due to non-bonded interactions between graphene and NPs. However, for a complete wrap and scroll formation and its stabilization both graphene-graphene and NPNP interactions were also critical. Surface atoms of Ni and Pt NPs undergo reconstruction during the wrapping or scrolling of graphene, suggesting that the NP-graphene interactions are more favorable as compared to NPNP and graphene-graphene interactions. We have identified new energy criteria which must be satisfied to facilitate a complete GNS formation for the graphene-NP systems investigated in the present study. Overall, our study can provide a new method to design metal-graphene hybrid materials that can be used for a variety of applications.
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      PubDate: 2018-04-15T08:44:17Z
      DOI: 10.1016/j.carbon.2018.03.077
      Issue No: Vol. 134 (2018)
       
  • Phenol-degrading sludge as a promising precursor for capacitive carbon
           material: Disclosing key factors for the nanostructure and high
           capacitance
    • Authors: Weiming Feng; Yali Ye; Zhenchao Lei; Chunhua Feng; Chaohai Wei; Shaowei Chen
      Pages: 53 - 61
      Abstract: Publication date: August 2018
      Source:Carbon, Volume 134
      Author(s): Weiming Feng, Yali Ye, Zhenchao Lei, Chunhua Feng, Chaohai Wei, Shaowei Chen
      The use of sludge, a side product of wastewater treatment, as a precursor for the synthesis of high-capacitance carbon is environmentally benign; however, the key factors influencing the structure of the carbon, and accordingly, its capacitive performance, remain unknown. We demonstrate that the physicochemical and electrochemical properties are remarkably different among four different sludge-derived carbons: those obtained from municipal wastewater sludge, coking wastewater sludge, phenol-acclimated municipal wastewater sludge, and phenol-acclimated coking wastewater sludge (denoted as MSC, CSC, P-MSC, and P-CSC, respectively). Hierarchical mesoporous graphene-like carbon was obtained from the acclimated sludge (particularly for P-CSC) with a high surface area, sufficient degree of graphitization, good electrical conductivity, and rich N and P doping. Accordingly, the P-CSC electrode delivered a large specific capacitance (416.1 F g−1 at 1 A g−1), good rate capability (retention ratio of 80.7% from 1 to 15 A g−1), and long-term cycling stability (retention ratio of 96.9% after 10,000 cycles), outperforming the MSC, CSC, and P-MSC electrodes. After conducting a series of control experiments, we determined that the contents of Fe, N, and P in the sludge, and the affinity of the microorganisms and particles/flocs in the sludge are crucial to the final characteristics of the sludge-derived carbon.
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      PubDate: 2018-04-15T08:44:17Z
      DOI: 10.1016/j.carbon.2018.03.057
      Issue No: Vol. 134 (2018)
       
  • A facile approach to fabricating ultrathin layers of reduced graphene
           oxide on planar solids
    • Authors: Alexandra I. Zvyagina; Elizaveta K. Melnikova; Alexei A. Averin; Alexander E. Baranchikov; Alexey R. Tameev; Vladimir V. Malov; Alexander A. Ezhov; Dmitry A. Grishanov; Jenny Gun; Elizaveta V. Ermakova; Vladimir V. Arslanov; Maria A. Kalinina
      Pages: 62 - 70
      Abstract: Publication date: August 2018
      Source:Carbon, Volume 134
      Author(s): Alexandra I. Zvyagina, Elizaveta K. Melnikova, Alexei A. Averin, Alexander E. Baranchikov, Alexey R. Tameev, Vladimir V. Malov, Alexander A. Ezhov, Dmitry A. Grishanov, Jenny Gun, Elizaveta V. Ermakova, Vladimir V. Arslanov, Maria A. Kalinina
      Fabrication of graphene-based surface coatings through self-assembly may provide an affordable alternative to chemical vacuum deposition. Herein, we exploited the self-assembly of graphene oxide at the oil/water interfaces to form monolayers of 2D carbons on solid surfaces with different surface energy. We showed that interfacial monolayers with controlled packing density of graphene oxide can be deposited on the hydrophilic surfaces such as silicon wafers and quartz glass as well as on the hydrophobic surface of Teflon. Graphene oxide attained flat arrangements in the monolayers on hydrophilic surfaces and yielded the films of partially scrolled particles on the surface of Teflon. The as-formed graphene oxide surface coatings underwent rapid reduction under microwave irradiation at 1000 W. The efficiency of reduction was dependent on the ability of the supporting material to absorb microwaves: silicon wafer > quartz glass > Teflon. The single layers of graphene oxide reduced on the surface of silicon wafers showed extraordinary low sheet resistance 1.2 kΩ·sq−1, whereas those on Teflon exhibited low electrical properties (3.0 × 105 kΩ·sq−1). The results suggest that this facile and scalable soft-matter method for producing surface films of graphene oxide can be extended to other practically relevant combinations of graphene-based colloids and supporting materials.
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      PubDate: 2018-04-15T08:44:17Z
      DOI: 10.1016/j.carbon.2018.03.075
      Issue No: Vol. 134 (2018)
       
  • Surface and in-depth distribution of sp2 and sp3 coordinated carbon atoms
           in diamond-like carbon films modified by argon ion beam bombardment during
           growth
    • Authors: J. Zemek; J. Houdkova; P. Jiricek; M. Jelinek
      Pages: 71 - 79
      Abstract: Publication date: August 2018
      Source:Carbon, Volume 134
      Author(s): J. Zemek, J. Houdkova, P. Jiricek, M. Jelinek
      Carbon atom coordination at diamond-like carbon (DLC) film surfaces and in sub-surface regions has been determined nondestructively from high-energy resolved C 1s photoelectron spectra, X-ray induced C KVV Auger electron spectra, and angular-resolved C 1s spectra (ARXPS) aided by maximum entropy method (MEM). The spectra were recorded from hydrogen-free DLC films prepared by a pulsed laser deposition under medium energy Ar ion beam assisted growth. The sp3 and sp2 fractions determined from C 1s and C KVV spectra recorded at the normal emission angle differ substantially. This indicates an inhomogeneous depth-resolved distribution of the fractions. The result is validated by the analysis of angular-resolved C 1s spectra using the MEM approach. In-depth reconstructions of the carbon bonding states show that sp2 coordination is dominant at the surfaces. We found that Ar ion beam assisted growth induces a C sp2 peak beneath the surface. The peak shifts towards the surface and is growing with Ar ion energy. C sp3 hybridization is dominant in deeper layers. The in-depth reconstruction is further supported by the depth-dependent mass density determined from the low-loss electron spectra excited at various primary electron energy. The results are discussed within the subplantation model.
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      PubDate: 2018-04-15T08:44:17Z
      DOI: 10.1016/j.carbon.2018.03.072
      Issue No: Vol. 134 (2018)
       
  • A comprehensive dual beam approach for broadband control of ultrafast
           optical nonlinearity in reduced graphene oxide
    • Authors: Sayantan Bhattacharya; Arup Ghorai; Shivam Raval; Manobina Karmakar; Anupam Midya; Samit Kumar Ray; Prasanta Kumar Datta
      Pages: 80 - 91
      Abstract: Publication date: August 2018
      Source:Carbon, Volume 134
      Author(s): Sayantan Bhattacharya, Arup Ghorai, Shivam Raval, Manobina Karmakar, Anupam Midya, Samit Kumar Ray, Prasanta Kumar Datta
      A unique delay-dependent dynamic switching of optical nonlinearity in terms of saturation absorption (SA) and excited state absorption (ESA) in graphene oxide (GO) and reduced graphene oxide (RGO2 and RGO100) is achieved with an optical pump and white light super-continuum probe only above a threshold pump intensity. Infrared and chemical reduction are used to obtain RGO2 and RGO100 respectively. The switching regime of probe wavelength can be modulated by varying either pump wavelength or degree of reduction. When pumped at 415 nm, the threshold pump intensity to obtain switching property decreases to 9 GW/cm2 for RGO2 from 18 GW/cm2 in GO and the tunability range shifts from 471 to 526 nm for as grown GO to 519–623 nm in maximally reduced RGO2. Though the saturation intensity of intrinsic non-degenerate two photon absorption (nd-TPA) is found to be lower in GO (4.3 GW/cm2) than RGO2 (18.2 GW/cm2), nd-TPA coefficient increases from 0.0015 cm/GW (GO) to 0.0026 cm/GW (RGO2) with increasing reduction. The detailed kinetics of the scattering processes show variation as a function of pump power, probe wavelength and degree of reduction. A model band diagram based on amorphous-carbon model and a Tauc analysis are used to explain the unusual nonlinear optical properties.
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      PubDate: 2018-04-15T08:44:17Z
      DOI: 10.1016/j.carbon.2018.03.082
      Issue No: Vol. 134 (2018)
       
  • Cellulose nanocrystals effect on the stabilization of polyacrylonitrile
           composite films
    • Authors: Jeffrey Luo; Huibin Chang; Po-Hsiang Wang; Robert J. Moon; Satish Kumar
      Pages: 92 - 102
      Abstract: Publication date: August 2018
      Source:Carbon, Volume 134
      Author(s): Jeffrey Luo, Huibin Chang, Po-Hsiang Wang, Robert J. Moon, Satish Kumar
      The stabilization kinetics of polyacrylonitrile-co-methacrylic acid (PAN-co-MAA) and cellulose nanocrystal (CNC) composite films were studied with up to 40 wt% CNC loading using differential scanning calorimetry (DSC). It was determined that the addition of CNC reduced the activation energy of the polyacrylonitrile cyclization reaction by 16% irrespective of the CNC loading in the range of 5–40 wt%. There was also a development of a new exothermic peak in the PAN-co-MAA/CNC composite films after cyclization not seen in the neat PAN-co-MAA and neat CNC samples, indicating a different set of reactions occurring. Fourier transform infrared spectroscopy (FTIR) and wide-angle X-ray diffraction (WAXD) demonstrated that CNC within the PAN-co-MAA/CNC composite films were more thermally stable than the neat CNC film. Additionally, for the composite films, their reaction rate constants for cyclization and oxidations were found to be higher than neat PAN-co-MAA at certain temperatures, indicating that the addition of CNC into PAN-co-MAA can reduce the energy needed for stabilization.
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      PubDate: 2018-04-15T08:44:17Z
      DOI: 10.1016/j.carbon.2018.03.078
      Issue No: Vol. 134 (2018)
       
  • Structural characteristics and strain behaviors of two-dimensional C3N :
           First principles calculations
    • Authors: Li-Bin Shi; Yan-Yan Zhang; Xiao-Ming Xiu; Hai-Kuan Dong
      Pages: 103 - 111
      Abstract: Publication date: August 2018
      Source:Carbon, Volume 134
      Author(s): Li-Bin Shi, Yan-Yan Zhang, Xiao-Ming Xiu, Hai-Kuan Dong
      In this study, structural characteristics and strain behaviors of C 3 N are investigated by first principles calculations. First, we investigate the stacking behaviors of C 3 N , and find the most stable order. Then, the band structure of C 3 N is investigated. We attempt to explain the disagreements between theoretical and experimental band gaps by impurity phase and biaxial strain. The band alignment at α − Al 2 O 3 / C 3 N interface is presented. The valence band offset (VBO) and conduction band offset (CBO) are larger than 1.49 eV, which suggest that the interface is a promising candidate used on short channel transistors. Finally, the strain behavior of C 3 N is studied. It is found that the monolayer C 3 N at 273 K can withstand up to a strain level of ε = 12% for zigzag and armchair uniaxial strain, and ε = 10% for ab biaxial strain. The band edge position, effective mass and band gap under the strain are presented. The CBO increases with the strain, which suggests that appropriate tensile strain can effectively prevent the leakage current of the device. Our investigation can provide valuable information for insight into the novel C 3 N materials.
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      PubDate: 2018-04-15T08:44:17Z
      DOI: 10.1016/j.carbon.2018.03.076
      Issue No: Vol. 134 (2018)
       
  • Size-controlled synthesis of urchin-like reduced graphene oxide
           microspheres with high pack density by emulsion-assisted in-situ assembly
           and their supercapacitor performance
    • Authors: Fang Yue; Guanqing Gao; Fengting Li; Yiqun Zheng; Shifeng Hou
      Pages: 112 - 122
      Abstract: Publication date: August 2018
      Source:Carbon, Volume 134
      Author(s): Fang Yue, Guanqing Gao, Fengting Li, Yiqun Zheng, Shifeng Hou
      We report a facile water-in-oil (W/O) emulsion method to fabricate urchin-like reduced graphene oxide microspheres (UrGOMSs) with tunable sizes and structures. The success of this synthesis relies on the use of polyethyleneimine and ethylenediamine, acted as an emulsifier and weak crosslinker, respectively, to assist the formation of graphene hydrogel in emulsion droplets, followed by thermal treatment to remove the water. The diameter of the UrGOMSs could be controlled in the range of 2.30–4.58 μm by varying the water-oil ratio and thus the size of emulsion droplets. The UrGOMSs show crumpled surface and urchin-like structure with assembly of graphene nanosheets, which can supply large amount of accessible surface area and efficient ion diffusion pathways. The specific surface area of the structures is up to 356.33 m2 g−1 with high pack density of 1.37 g cm−3. When used as electrode materials in supercapacitors, the UrGOMSs exhibit high volumetric capacitance of 527.6 F cm−3 at 10 mV s−1 and 452.1 F cm−3 at 0.2 A g−1. Furthermore, they also exhibit excellent long-term cycling stability. After 5000 cycles, the capacity retention is around 99.43%. These results indicate the feasibility of the novel strategy for designing densely assembled graphene microspheres for supercapacitors.
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      PubDate: 2018-04-15T08:44:17Z
      DOI: 10.1016/j.carbon.2018.03.074
      Issue No: Vol. 134 (2018)
       
  • Computational analysis for the interface mechanics of carbon fibers with
           radially-grown carbon nanotubes
    • Authors: Nithya Subramanian; Bonsung Koo; Karthik Rajan Venkatesan; Aditi Chattopadhyay
      Pages: 123 - 133
      Abstract: Publication date: August 2018
      Source:Carbon, Volume 134
      Author(s): Nithya Subramanian, Bonsung Koo, Karthik Rajan Venkatesan, Aditi Chattopadhyay
      An atomistic modeling framework to investigate the interface/interphase of composite architecture with carbon fibers containing radially-grown carbon nanotubes (often called fuzzy fibers) is detailed in this paper. A polymeric functional coating for the carbon fiber surface, which also serves as a substrate for the CNT growth, is explicitly modeled. The tensile and transverse moduli of the fuzzy fiber/epoxy interphase is computed from virtual deformation simulations and compared to experimental values reported in literature, in order to validate the nanoscale model. Furthermore, the effect of the polymer substrate is studied by modeling the local interphase mechanics. Various modes of virtual loading provide the cohesive behavior of the local substrate/epoxy interphase. Conclusions are presented by comparing the material response of the interphase with and without the polymeric substrate. The integration of results from the nanoscale to an atomistically-informed subcell-based continuum level model is also demonstrated in the paper.
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      PubDate: 2018-04-15T08:44:17Z
      DOI: 10.1016/j.carbon.2018.03.090
      Issue No: Vol. 134 (2018)
       
  • Polycyclic aromatic compounds-modified graphitic carbon nitride for
           efficient visible-light-driven hydrogen evolution
    • Authors: Kui Li; Miao Sun; Wei-De Zhang
      Pages: 134 - 144
      Abstract: Publication date: August 2018
      Source:Carbon, Volume 134
      Author(s): Kui Li, Miao Sun, Wei-De Zhang
      Polycyclic aromatic compounds with strong conjugated effect, possess the advantage of improving electronic polarizability, thus accelerating the electron transportation. Here, a facile copolymerization between urea and polycyclic aromatic compounds (benzoic acid, naphthoic acid and anthroic acid) has been applied to constructing aromatic rings-grafted graphitic carbon nitride (GCN) photocatalysts. Incorporation of aromatic rings in the GCN network is an effective protocol to extend its π-conjugated system for visible light harvesting and improves the charge transfer efficiency for prolonging lifetime of photogenerated charge carriers in photocatalytic reactions. The corresponding characterization methods demonstrate that the aromatic rings-modified GCN can effectively narrow the bandgap to favor broad band visible light absorption and suppress recombination of electrons and holes. Remarkably, the moderate conjugated effect of aromatic rings (naphthalene) is crucial to promote charge separation. The developed naphthalene-grafted GCN achieves the highest water splitting performance with hydrogen evolution rate up to 102.1 μmol h−1, nearly 3.5 times of that of the GCN, and apparent quantum efficiency reaches 5.6% at 450 nm. This finding reveals that the conjugated effect of aromatic rings is significant to control photocatalytic property and brings new ideas for designing aromatic system-modified GCN as highly active photocatalysts towards solar-to-chemical energy conversion.
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      PubDate: 2018-04-15T08:44:17Z
      DOI: 10.1016/j.carbon.2018.03.089
      Issue No: Vol. 134 (2018)
       
  • Utilizing SO2 as self-installing gate to regulate the separation
           properties of porous graphenes
    • Authors: Yuanzhen Li; Chao Wu
      Pages: 145 - 152
      Abstract: Publication date: August 2018
      Source:Carbon, Volume 134
      Author(s): Yuanzhen Li, Chao Wu
      We theoretically verify the reversible decoration of the pores of two-dimensional membranes to achieve tailorable separation. We show that SO2 molecules can be used as “self-installing”doors to dynamically adjust the pore size of porous graphene sheets. For H atom-passivated porous graphene sheets (e.g. the pore16 model with pore size of 7.9 × 5.9 Å, small molecules such as H2, CO2, CH4 can pass through freely), it can efficiently separate linear alkane molecules from their monobranched isomers (e.g. selectivity of 47500:1 for butane over isobutane). While after a SO2 molecule is strongly adsorbed over pore16 as a partially closed gate, a mixture of smaller molecules like H2/CH4 can be separated successfully, with a selectivity of about 8100:1. The installed molecular gate can be uninstalled by heating, thus the porous membranes can be redecorated to meet the needs of other separation targets. This design principle can be extended to other porous membranes.
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      PubDate: 2018-04-15T08:44:17Z
      DOI: 10.1016/j.carbon.2018.04.004
      Issue No: Vol. 134 (2018)
       
  • NIR-responsive carbon dots for efficient photothermal cancer therapy at
           low power densities
    • Authors: Bijiang Geng; Dewen Yang; Dengyu Pan; Liang Wang; Fengfeng Zheng; Wenwen Shen; Chen Zhang; Xiaokai Li
      Pages: 153 - 162
      Abstract: Publication date: August 2018
      Source:Carbon, Volume 134
      Author(s): Bijiang Geng, Dewen Yang, Dengyu Pan, Liang Wang, Fengfeng Zheng, Wenwen Shen, Chen Zhang, Xiaokai Li
      Carbon dots (CDs) with unique optical properties are a stable and highly biocompatible fluorescent material offering enormous application potential in optical imaging and photothermal cancer therapy (PTT). However, the low photothermal conversion efficiency and the high power density still impede the development of CDs in PTT. Herein, the nitrogen and oxygen co-doped CDs (N-O-CDs) with strong absorbance in the near infrared (NIR) region were prepared from 1,3,6-trinitropyrene (TNP) and N-containing polymer of branched polyethylenimine (BPEI) via a one-step molecular fusion route. The as-prepared black N-O-CDs with high photostability and superb biocompatibility can be utilized not only as a new fluorescence imaging agent but also as an excellent PTT agent in vivo. The structure, optical properties, bioimaging, photothermal effect in vitro, and therapeutic efficiency in vivo of the N-O-CDs are investigated. The low power density (0.8 W cm−2) and high photothermal conversion efficiency (η = 38.3%) facilitate N-O-CDs to act as an ideal theranostic agent for fluorescence imaging and photothermal therapy in vitro and in vivo. This work highlights CDs as an excellent candidate for efficient cancer therapy.
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      PubDate: 2018-04-15T08:44:17Z
      DOI: 10.1016/j.carbon.2018.03.084
      Issue No: Vol. 134 (2018)
       
  • Comparing space adaptability of diamond-like carbon and molybdenum
           disulfide films toward synergistic lubrication
    • Authors: Wenhua Zhuang; Xiaoqiang Fan; Wen Li; Hao Li; Lin Zhang; Jinfang Peng; Zhenbing Cai; Jiliang Mo; Guangan Zhang; Minhao Zhu
      Pages: 163 - 173
      Abstract: Publication date: August 2018
      Source:Carbon, Volume 134
      Author(s): Wenhua Zhuang, Xiaoqiang Fan, Wen Li, Hao Li, Lin Zhang, Jinfang Peng, Zhenbing Cai, Jiliang Mo, Guangan Zhang, Minhao Zhu
      Space irradiation-induced damage to onefold lubricants including four multialkylated cyclopentanes (MACs) space greases, Chromium doped diamond-like carbon (Cr-DLC) and molybdenum disulfide (MoS2) films was first investigated under simulated space environment (atomic oxygen (AO) and proton (PR)). Then solid-grease synergistic lubrication systems were prepared via spinning four space greases on Cr-DLC and MoS2 film, and their tribological behaviors were evaluated under simulated space environment including ultra-vacuum, AO and PR irradiation, low temperature (−100 °C). The irradiated damage mechanism and friction mechanism were explored by surface/interface analysis techniques. The results demonstrates that Cr-DLC film have better space adaptability than MoS2 film because irradiation induced partial transition of Cr-DLC’s micro-structure with the decrease in I D /I G ratio from 1.50 to 1.26 and the increase of sp3 content from 0.24 to 0.59, while the surface morphology and micro-structure of MoS2 film have dramatically changed. Solid-grease synergistic lubrication systems provide excellent friction-reducing and anti-wear behaviors (friction coefficient can be reduced up to below 0.05 under the special working conditions). Such excellent tribological performance of Cr-DLC-grease lubrication coatings is attributed to the friction-induced graphitization at the sliding interface, while that of MoS2 film mainly depends on its original structure/merits under greases lubrication.
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      PubDate: 2018-04-15T08:44:17Z
      DOI: 10.1016/j.carbon.2018.03.059
      Issue No: Vol. 134 (2018)
       
  • Three-dimensional electrical conductive scaffold from biomaterial-based
           carbon microfiber sponge with bioinspired coating for cell proliferation
           and differentiation
    • Authors: Xuelong Chen; Yingjie Wu; Vivek Damodar Ranjan; Yilei Zhang
      Pages: 174 - 182
      Abstract: Publication date: August 2018
      Source:Carbon, Volume 134
      Author(s): Xuelong Chen, Yingjie Wu, Vivek Damodar Ranjan, Yilei Zhang
      Electrical responsive scaffolds are important for regulating adhesion, mitigation, and proliferation of electroactive cells in tissue engineering. Conventional approaches to fabricate suitable scaffolds with enhanced electrical conductivity require multiple steps including the surface coating of conductive polymers or the encapsulation of conductive fillers. In this work, a new type of three-dimensional porous carbon fiber sponge-based electrical conductive scaffold with a fiber diameter of 8.1 (±2.1) μm was fabricated by one-step high-temperature carbonization at 800 °C from an abundantly available biomaterial - cotton. The as-carbonized cotton has a suitable pore size from several dozens to hundreds of micrometers, low toxicity, and good biocompatibility. Its hydrophilicity and biocompatibility were further modified by surface oxidation and polydopamine coating. The topological feature, surface functional groups, hydrophilicity, and electrical conductivity of the carbonized cotton were studied. The as-carbonized, oxidized, and polydopamine-coated scaffolds have electrical conductivities of 32.6, 44.9 and 128.2 S/m, respectively. The cytocompatibility and the effect of electrical stimulation on cell behavior were evaluated by cell culture with and without electrical stimulation. It was observed that the polydopamine coating significantly improved the hydrophilicity and cytocompatibility. The electrical stimulation accelerated cell proliferation and differentiation of nerve cells. This work demonstrated that carbonized biomaterial represents a promising material category that can be used for tissue engineering especially in electroactive tissues.
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      PubDate: 2018-04-15T08:44:17Z
      DOI: 10.1016/j.carbon.2018.03.064
      Issue No: Vol. 134 (2018)
       
  • Early stage of CVD graphene synthesis on Ge(001) substrate
    • Authors: L. Di Gaspare; A.M. Scaparro; M. Fanfoni; L. Fazi; A. Sgarlata; A. Notargiacomo; V. Miseikis; C. Coletti; M. De Seta
      Pages: 183 - 188
      Abstract: Publication date: August 2018
      Source:Carbon, Volume 134
      Author(s): L. Di Gaspare, A.M. Scaparro, M. Fanfoni, L. Fazi, A. Sgarlata, A. Notargiacomo, V. Miseikis, C. Coletti, M. De Seta
      In this work we shed light on the early stage of the chemical vapor deposition of graphene on Ge(001) surfaces. By a combined use of μ-Raman and x-ray photoelectron spectroscopies, and scanning tunneling microscopy and spectroscopy, we were able to individuate a carbon precursor phase to graphene nucleation which coexists with small graphene domains. This precursor phase is made of C aggregates with different size, shape and local ordering which are not fully sp2 hybridized. In some atomic size regions these aggregates show a linear arrangement of atoms as well as the first signature of the hexagonal structure of graphene. The carbon precursor phase evolves in graphene domains through an ordering process, associated to a re-arrangement of the Ge surface morphology. This surface structuring represents the embryo stage of the hills-and-valleys faceting featured by the Ge(001) surface for longer deposition times, when the graphene domains coalesce to form a single layer graphene film.
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      PubDate: 2018-04-23T08:22:29Z
      DOI: 10.1016/j.carbon.2018.03.092
      Issue No: Vol. 134 (2018)
       
  • Low-energy hydrogen uptake by small-cage Cn and Cn-1B fullerenes
    • Authors: F. Javier Dominguez-Gutierrez; Predrag S. Krstic; Stephan Irle; Remigio Cabrera-Trujillo
      Pages: 189 - 198
      Abstract: Publication date: August 2018
      Source:Carbon, Volume 134
      Author(s): F. Javier Dominguez-Gutierrez, Predrag S. Krstic, Stephan Irle, Remigio Cabrera-Trujillo
      We present a theoretical study of the hydrogen uptake capability of carbon fullerene cages Cn and their boron-doped heterofullerene equivalents Cn-1B, with n = 20, 40, and 60, irradiated by hydrogen atoms in an impact energy range of 0.1–100 eV. In order to predict exohedral and endohedral hydrogen captures as well as the scattering probability of hydrogen for various cage types and sizes, we perform quantum-classical molecular dynamics (QCMD) calculations using the self-consistent-charge density-functional tight-binding (SCC-DFTB) method. Maximum endohedral hydrogen capture probabilities of 20% for n = 60 and 14% for n = 40 are found at impact energies close to 15 eV for both Cn and Cn-1B systems. For n = 20, however, endohedral capture is observed at a maximum of 2%, while the exohedral capture reaches a maximum of 5% both at 15 eV. Similar results for the hydrogen capture are obtained by classical molecular dynamics based on the ReaxFF potential. Finally, the stopping cross section per carbon atom from the QCMD simulations for all cage sizes displays a linear dependence on the projectile velocity with a threshold at 0.8 eV, and extrapolates well to the available theoretical data.
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      PubDate: 2018-04-15T08:44:17Z
      DOI: 10.1016/j.carbon.2018.03.085
      Issue No: Vol. 134 (2018)
       
  • Regeneration of PFOS loaded activated carbon by hot water and subsequent
           aeration enrichment of PFOS from eluent
    • Authors: Wei Wang; Ziwen Du; Shubo Deng; Mohammadtaghi Vakili; Lu Ren; Pingping Meng; Ayiguli Maimaiti; Bin Wang; Jun Huang; Yujue Wang; Gang Yu
      Pages: 199 - 206
      Abstract: Publication date: August 2018
      Source:Carbon, Volume 134
      Author(s): Wei Wang, Ziwen Du, Shubo Deng, Mohammadtaghi Vakili, Lu Ren, Pingping Meng, Ayiguli Maimaiti, Bin Wang, Jun Huang, Yujue Wang, Gang Yu
      Regeneration and reuse of spent activated carbon (AC) as well as recovery of the desorbed pollutants are challenging in the application of adsorption technology. In this study, the regeneration of perfluorooctanesulfonate (PFOS)-saturated coal-based granular AC by hot water and subsequent aeration method to enrich PFOS from eluent were investigated. The regeneration time, water temperature and solid-liquid ratio affected the regeneration efficiency of PFOS treated AC. PFOS was desorbed quickly from the AC within 30 min by hot water. High water temperature (92 °C) and low solid-liquid ratio (0.5) led to the highest desorption of 36.7% in one cycle (6 h). Over 90% PFOS on the spent AC was desorbed by 92 °C hot water with the solid-liquid ratio of 0.5 after six cycles. Subsequent experiments were conducted to enrich PFOS, and aeration of the regeneration eluent achieved the enrichment factors of 50.6–62.0 for PFOS at initial PFOS concentrations of 10–100 μg/L. The concentration of PFOS in the concentrated solution was 2.2 g/L following sequential sorption, regeneration and aeration treatments when the influent PFOS concentration was 2.7 μg/L.
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      PubDate: 2018-04-15T08:44:17Z
      DOI: 10.1016/j.carbon.2018.04.005
      Issue No: Vol. 134 (2018)
       
  • Preparation of magnetic hierarchical porous carbon spheres with graphitic
           features for high methyl orange adsorption capacity
    • Authors: Adisak Siyasukh; Yothin Chimupala; Nattaporn Tonanon
      Pages: 207 - 221
      Abstract: Publication date: August 2018
      Source:Carbon, Volume 134
      Author(s): Adisak Siyasukh, Yothin Chimupala, Nattaporn Tonanon
      This report describes the successful use of a template-free method in a microemulsion system for the preparation of magnetic hierarchical porous carbon (MHPC) spheres, which possess high adsorption capability for methyl orange (MO) in aqueous solution, easy separability from water by magnetic force after the MO removal, and reusability that allowed MO to be adsorbed several times. MHPC spheres are produced by water-in-oil emulsification coupled with sol-gel polymerization of resorcinol containing Fe(NO3)3 and formaldehyde to make spherical carbon precursors with a macroporous framework inside, followed by carbonization with N2 or CO2 activation to transform them into MHPC spheres. Carbonization at temperatures higher than 800 °C resulted in not only graphitic feature formation, but also both micro- and mesopores in the macroporous framework. Moreover, CO2 activation at 900 °C both remarkably enhanced the graphitic features and increased the mesopore volume to 2.16 cm3/g. The magnetic property could be developed by both carbonization and CO2 activation at 900 °C. MHPC spheres obtained from CO2 activation developed tremendous adsorption capacities, as high as 1522.6 mg/g under neutral conditions, which were suitable to be reused for MO removal for at least four consecutive cycles without efficiency loss.
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      PubDate: 2018-04-15T08:44:17Z
      DOI: 10.1016/j.carbon.2018.03.093
      Issue No: Vol. 134 (2018)
       
  • Nanoconfined SnS in 3D interconnected macroporous carbon as durable anodes
           for lithium/sodium ion batteries
    • Authors: Pan Xue; Nana Wang; Yunxiao Wang; Yaohui Zhang; Yuanlin Liu; Bin Tang; Zhongchao Bai; Shixue Dou
      Pages: 222 - 231
      Abstract: Publication date: August 2018
      Source:Carbon, Volume 134
      Author(s): Pan Xue, Nana Wang, Yunxiao Wang, Yaohui Zhang, Yuanlin Liu, Bin Tang, Zhongchao Bai, Shixue Dou
      Nanoconfined SnS in 3D interconnected macroporous carbon (3D SnS/C) has been produced using silica opals as template following a carbonization and sulfuration route. The electrochemical properties of the 3D SnS/C were examined comprehensively as anode materials for lithium/sodium ion batteries (LIBs/SIBs). It delivers a high specific capacity of 869 mA h g−1 at 1 A g−1 after 1000 cycles in LIBs and 400 mA h g−1 at 100 mA g−1 after 100 cycles in SIBs. The rate performance is also excellent (550 mA h g−1 at 3 A g−1 in LIBs and 220.9 mA h g−1 at 5 A g−1 in SIBs). The outstanding electrochemical performance of the 3D SnS/C is ascribed to its 3D porous carbon interconnected structure and nanoconfined SnS nanoparticles distributing broadly in carbon matrix, which not only improve the conductivity, but also keep the structure integrity, and as a result of enhancing the cycling stability of the material. In addition, this facile and novelty strategy can be potentially utilized for preparing other 3D metal sulfides interconnected macroporous carbon composite for energy storage.
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      PubDate: 2018-04-15T08:44:17Z
      DOI: 10.1016/j.carbon.2018.04.003
      Issue No: Vol. 134 (2018)
       
  • On-off-on fluorescent nanosensor for Fe3+ detection and cancer/normal cell
           differentiation via silicon-doped carbon quantum dots
    • Authors: Ge Gao; Yao-Wen Jiang; Hao-Ran Jia; Jingjing Yang; Fu-Gen Wu
      Pages: 232 - 243
      Abstract: Publication date: August 2018
      Source:Carbon, Volume 134
      Author(s): Ge Gao, Yao-Wen Jiang, Hao-Ran Jia, Jingjing Yang, Fu-Gen Wu
      In this study, an on-off-on fluorescent nanosensor based on carbon quantum dots (or carbon dots, CDs) was successfully fabricated for Fe3+ detection and selective imaging of cancerous cells in vitro and in vivo. The multifunctional CDs were prepared by a one-pot solvothermal treatment of glycerol and a silane molecule (N-[3-(trimethoxysilyl)propyl]ethylenediamine, DAMO). The as-prepared CDs exhibited excellent fluorescence (FL) properties and favorable biocompatibility, and could realize wash-free cell imaging both in vitro (e.g., for bacterial and fungal cells) and in vivo (e.g., for zebrafish embryos). On the other hand, the fluorescence of CDs can respond to Fe3+ selectively and sensitively, with a very low detection limit of 16 nM. Besides, detection of Fe3+ in living cells and zebrafish was also successfully realized by the CDs. Moreover, it was found that glutathione (GSH) could enhance the fluorescence of the mixed solution of CDs and Fe3+ (CDs/Fe3+), and such a property could be utilized to efficiently distinguish cancerous cells from normal ones based on the difference in the content of GSH of the two types of cells. More importantly, GSH also realized the enhanced fluorescence signals of CDs/Fe3+ in tumor site in vivo after intravenous injection, indicating the potential of CDs/Fe3+ for imaging-guided precision cancer diagnosis.
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      PubDate: 2018-04-15T08:44:17Z
      DOI: 10.1016/j.carbon.2018.02.063
      Issue No: Vol. 134 (2018)
       
  • Effect of surface termination on the reactivity of nano-sized diamond
           particle surfaces for bio applications
    • Authors: K. Larsson; Y. Tian
      Pages: 244 - 254
      Abstract: Publication date: August 2018
      Source:Carbon, Volume 134
      Author(s): K. Larsson, Y. Tian
      Nanodiamond has displayed some unique physical and chemical properties compared to bulk diamond, which broadens its applications invarious areas. The here presented investigations have focused on the combined effect of diamond surface planes and termination on surface reactivity. Then especially towards adhered important biomolecules for bone regeneration and vascularization. Moreover, a more detailed picture of nanodiamond quantum confinements is still missing from a theoretical point of view. An evaluation of realistic models for nano-diamond (ND) particles of various sizes will here be presented. In addition, the adhesions of various biomolecules, both in vacuum and in a liquid environment, as a function of surface plane and termination, will also be presented. It was shown possible to model nanodiamond particles of size larger than 2 nm with (100) and (111) surface planes. For the situation with biomolecule adhesion to the nanodiamond surfaces, there is a large similarity between the results for the diamond (111) and (100)- 2x1surfaces. For both of these surfaces, even though the water solvation will create much stronger biomolecular adhesion energies, there is a resemblance in order of adhesion energy for the various systems (i.e., solvated vs. non-solvated).
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      PubDate: 2018-04-15T08:44:17Z
      DOI: 10.1016/j.carbon.2018.03.031
      Issue No: Vol. 134 (2018)
       
  • Oxygen surface groups analysis of carbonaceous samples pyrolysed at low
           temperature
    • Authors: Gabriela Hotová; Václav Slovák; Olívia S.G.P. Soares; José L. Figueiredo; Manuel F.R. Pereira
      Pages: 255 - 263
      Abstract: Publication date: August 2018
      Source:Carbon, Volume 134
      Author(s): Gabriela Hotová, Václav Slovák, Olívia S.G.P. Soares, José L. Figueiredo, Manuel F.R. Pereira
      The basis of recently developed quantitative TG-MS analysis was used for the evaluation of TPD-MS measurements in order to characterize the changes in the surface chemistry of carbon cryogels after the oxidation/activation treatment. This methodology was applied to the analysis of partially pyrolysed carbon cryogels (400 °C), which were oxidized/activated in four different ways (phosphoric acid, Fenton like reaction, ammonium persulfate with sulfuric acid and nitric acid with hydrogen peroxide). The quantitative TPD-MS evaluation enables analysis of all the evolved gases during the sample heating (without the calibration of all gases) and distinguishes the carbonization process from the decomposition of the more thermally stable oxygen surface groups (analysis of the effect of oxidation/activation reagents). The activation by H3PO4 results in the hydrolysis and esterification of anhydrides, lactones and phenols and creation of phosphoric acid esters (C-O-P), which decompose into C3-P=O linkages with the CO evolution. All the oxidation treatments had a similar effect on the surface chemistry. The amounts of carboxylic acids and anhydrides increased significantly, while the amount of lactones and phenol groups decreased (oxidized into carbonyls). Application of TG-MS fundamentals to the evaluation of TPD-MS profiles from a wide range of samples allows determining all the gaseous products.
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      PubDate: 2018-04-15T08:44:17Z
      DOI: 10.1016/j.carbon.2018.03.067
      Issue No: Vol. 134 (2018)
       
  • Microwave absorption properties of 3D cross-linked Fe/C porous nanofibers
           prepared by electrospinning
    • Authors: Fengyi Wang; Yunqiang Sun; Deren Li; Bo Zhong; Zhiguo Wu; Shiyong Zuo; De Yan; Renfu Zhuo; Juanjuan Feng; Pengxun Yan
      Pages: 264 - 273
      Abstract: Publication date: August 2018
      Source:Carbon, Volume 134
      Author(s): Fengyi Wang, Yunqiang Sun, Deren Li, Bo Zhong, Zhiguo Wu, Shiyong Zuo, De Yan, Renfu Zhuo, Juanjuan Feng, Pengxun Yan
      Well dispersed core/shell structure Fe nanopowders (FeNPs) produced by high energy ion beam evaporation (HEIBE) are added to polyacrylonitrile/N, N-Dimethylformamide (PAN/DMF) solution containing vegetable oil to prepare Fe/C porous nanofibers (FeCPNFs) by electrospinning as electromagnetic microwave absorption material. The FeCPNFs have 3D cross-linked network structure with low graphitization degree. The permittivity and permeability behaviors of the composites made from FeCPNFs and wax are studied in the frequency range of 2.00–18.00 GHz. Mainly due to impedance matching, electric loss, magnetic loss, attenuation constant and “geometrical effect” the FeCPNFs have good microwave absorption properties. The reflection loss (RL) of FeCPNFs can reach − 56.6 dB at matching frequency (4.96 GHz) and matching thickness (4.29 mm). The RL value can also reach −26.1 dB at 11.68 GHz, and effective absorption bandwidth (RL ≤ − 10.0 dB) is 3.00 GHz with a thickness of 2.00 mm. Moreover, under the matching frequency and matching thickness a good absorption performance (RL ≤ − 15.0 dB) from 2.00 GHz to 18.00 GHz is obtained.
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      PubDate: 2018-04-15T08:44:17Z
      DOI: 10.1016/j.carbon.2018.03.081
      Issue No: Vol. 134 (2018)
       
  • Fe intercalation under graphene and hexagonal boron nitride in-plane
           heterostructure on Pt(111)
    • Authors: Igor Píš; Silvia Nappini; Federica Bondino; Tevfik Onur Menteş; Alessandro Sala; Andrea Locatelli; Elena Magnano
      Pages: 274 - 282
      Abstract: Publication date: August 2018
      Source:Carbon, Volume 134
      Author(s): Igor Píš, Silvia Nappini, Federica Bondino, Tevfik Onur Menteş, Alessandro Sala, Andrea Locatelli, Elena Magnano
      Metal nanostructures confined between sp2 hybridized 2D materials and solid supports are attracting attention for their potential application in new nanotechnologies. Model studies under well-defined conditions are valuable for understanding the fundamental aspects of the phenomena under 2D covers. In this work we investigate the intercalation of iron atoms through a single layer of mixed graphene and hexagonal boron nitride on Pt(111) using a combination of spectroscopic and microscopic techniques. Thermally activated diffusion of iron proceeds preferentially under graphene and only partially under hexagonal boron nitride areas. When oxygen is coadsorbed with iron, the intercalation rate is higher, and formation of B2O3 and oxygenated B–C species is observed. Our results suggest the possibility of confining ferromagnetic layers under heterostructures of graphene and hexagonal boron nitride with potential technological implications in the fields of spintronics, magnetic data storage or chemistry under 2D covers.
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      PubDate: 2018-04-15T08:44:17Z
      DOI: 10.1016/j.carbon.2018.03.086
      Issue No: Vol. 134 (2018)
       
  • Synergistic effects of carbon nanotube and carbon fiber on heat generation
           and electrical characteristics of cementitious composites
    • Authors: G.M. Kim; B.J. Yang; H.N. Yoon; H.K. Lee
      Pages: 283 - 292
      Abstract: Publication date: August 2018
      Source:Carbon, Volume 134
      Author(s): G.M. Kim, B.J. Yang, H.N. Yoon, H.K. Lee
      The heat generation and electrical characteristics of cementitious composites incorporating carbon nanotube (CNT) and carbon fiber under various heating conditions were investigated in this study. Specifically, the synergistic effects of carbon nanotube and carbon fiber on the heat generation and electrical characteristics of cementitious composites were experimentally investigated. The test results show that the addition of carbon fiber improved the heat generation capability and the electrical stability of the cementitious composites incorporating CNT during heating. The long-term durability of construction materials is an important issue, however, there is a practical limit to measuring a property of specimen for a very long time in a laboratory level experiment. In addition, a modified micromechanical model was proposed here to estimate the long-term effect of heating on the electrical characteristics of cementitious composites. The model parameters were derived from the experimental results, and a series of numerical simulations was conducted to explore the influence of model parameters on the resistance of the composites. Comparisons between experimental data and the present predictions were made to assess the potential of the proposed model.
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      PubDate: 2018-04-15T08:44:17Z
      DOI: 10.1016/j.carbon.2018.03.070
      Issue No: Vol. 134 (2018)
       
  • Enhancement and modulation of photonic spin Hall effect by defect modes in
           photonic crystal with graphene
    • Authors: Jie Li; Tingting Tang; Li Luo; Jianquan Yao
      Pages: 293 - 300
      Abstract: Publication date: August 2018
      Source:Carbon, Volume 134
      Author(s): Jie Li, Tingting Tang, Li Luo, Jianquan Yao
      Photonic spin Hall effect (PSHE) holds great potential applications for manipulating photon spins. However, the efficient control of PSHE in a particular optical structure is still difficult to realize. In this paper, we report enhanced and magnetically tunable PSHE of reflected light in one-dimensional photonic crystals (1D-PC) with a defect layer. By inserting monolayer graphene into the defect layer of 1D-PC, large polarization rotation and strong photon spin-orbit interaction of reflected light are obtained. Due to the optical field confinement by defect mode, the Kerr rotation angle of reflected light is near 90° and the spin-dependent splitting is about 15 times the wavelength at a specific incident wavelength. In addition, a static perpendicular magnetic field increasing from 1T to 11T shows greatly modulation effect on Kerr rotation angle and spin-dependent splitting. These results pave the way toward the design of spin-based photonic devices in the future.
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      PubDate: 2018-04-15T08:44:17Z
      DOI: 10.1016/j.carbon.2018.03.094
      Issue No: Vol. 134 (2018)
       
  • Organic solar cells based on graphene derivatives and eutectic alloys
           vacuum-free deposited as top electrodes
    • Authors: Daniel Romero-Borja; José-Luis Maldonado; Oracio Barbosa-García; Mario Rodríguez; Arxel de León; Salvador Fernández; Enrique Pérez-Gutiérrez
      Pages: 301 - 309
      Abstract: Publication date: August 2018
      Source:Carbon, Volume 134
      Author(s): Daniel Romero-Borja, José-Luis Maldonado, Oracio Barbosa-García, Mario Rodríguez, Arxel de León, Salvador Fernández, Enrique Pérez-Gutiérrez
      Here is presented the use of two graphene derivatives in organic solar cells (OSCs) based on PTB7:[70]PCBM active layer. Reduced graphene oxide (rGO) was used as hole transport layer (HTL). Also, solution-processable functionalized graphene (SPFG) was incorporated as a third component in the active layer. Furthermore, the top electrode was either Field’s metal (FM): Bi/In/Sn or BS: Bi/Sn, eutectic alloys that melt at 62 and 138 °C, respectively; they are vacuum-free deposited by drop coating under normal atmosphere conditions. For OSCs with rGO as HTL, thin films were prepared by reiterative spin-deposition and thermal reduction of GO after each deposition. The best results were achieved for 6-rGO with a PCE = 5.50%, similar to that reached in control devices, i.e., PEDOT:PSS as HTL. On the other hand, ternary active layers were prepared by blending SPFG, at different weight ratios: 0, 2, 4, and 6 wt. %, with PTB7:[70]PCBM. An increment in PCE (6.73%) for OSCs with 4 wt. % of SPFG was found, which is 22% larger than that of the reference devices. Finally, PCEs of 5.52% and 5.31% were reached in OSCs fabricated and tested under normal room conditions with FM and BS, respectively.
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      PubDate: 2018-04-15T08:44:17Z
      DOI: 10.1016/j.carbon.2018.03.083
      Issue No: Vol. 134 (2018)
       
  • Chevron-based graphene nanoribbon heterojunctions: Localized effects of
           lateral extension and structural defects on electronic properties
    • Authors: Paulo S. Costa; Jacob D. Teeter; Axel Enders; Alexander Sinitskii
      Pages: 310 - 315
      Abstract: Publication date: August 2018
      Source:Carbon, Volume 134
      Author(s): Paulo S. Costa, Jacob D. Teeter, Axel Enders, Alexander Sinitskii
      Graphene nanoribbon (GNR) heterojunctions have been synthesized by a bottom-up approach on an Au (111) substrate from a mixture of two structurally similar but visually distinct chevron-type molecular precursors. The resulting heterojunctions were composed of the units of chevron GNRs (cGNRs) and new laterally extended chevron GNRs (eGNRs), which contained an additional benzene ring. Because of their intentional visual difference, cGNR and eGNR units could be conveniently distinguished in scanning tunneling microscopy images. Differential conductance (dI/dV) mapping of GNR heterojunctions revealed differences in electronic structures of cGNRs and eGNRs. Interestingly, the characteristic conduction band states of cGNRs in the dI/dV maps were shown to be sensitive to the effects of both lateral extension of ribbons and the edge defects, emphasizing the importance of synthesizing GNRs and GNR heterojunctions with atomic precision. The dI/dV maps further showed that both effects could be localized within the corresponding GNR units even if they are bonded to structurally and electronically different neighbors, which suggests a possibility of engineering complex GNR-based electronic nanostructures with nanoscale modulation of properties. The new eGNR units could be potentially combined with other chevron-type GNRs, such as nitrogen-doped cGNRs, into a variety of new GNR heterojunctions.
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      PubDate: 2018-04-15T08:44:17Z
      DOI: 10.1016/j.carbon.2018.03.054
      Issue No: Vol. 134 (2018)
       
  • One-step electrochemical strategy for in-situ synthesis of S,N-codoped
           graphene as metal-free catalyst for oxygen reduction reaction
    • Authors: Fang Liu; Fushuang Niu; Tao Chen; Jingrui Han; Zhen Liu; Wenrong Yang; Yuanhong Xu; Jingquan Liu
      Pages: 316 - 325
      Abstract: Publication date: August 2018
      Source:Carbon, Volume 134
      Author(s): Fang Liu, Fushuang Niu, Tao Chen, Jingrui Han, Zhen Liu, Wenrong Yang, Yuanhong Xu, Jingquan Liu
      A simple and economic method was developed for synthesizing efficient S,N-codoped graphene based catalyst for oxygen reduction reaction via a one-step electrochemical exfoliation of graphite rod in melamine and (NH4)2SO4 mixture solution. On one hand, melamine and (NH4)2SO4 co-worked as electrolyte to enhance the exfoliation efficiency of graphite into graphene nanosheets. On the other hand, they also provided nitrogen and sulphur sources for in-situ codoping of the as-prepared graphene. As evidenced, the N and S elements are distributed uniformly throughout the graphene nanosheets which possessed larger interlayer spacing, more lattice disorder and higher defect density. Accordingly, the obtained SNG shows efficient ORR catalytic activity with an onset potential of 0.88 V and a dominant four-electron transfer mechanism (n = 3.98 at 0.5 V), long-time durability and excellent methanol tolerance, which are comparable or superior to those of commercial Pt/C catalysts.
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      PubDate: 2018-04-15T08:44:17Z
      DOI: 10.1016/j.carbon.2018.04.007
      Issue No: Vol. 134 (2018)
       
  • Thiolated-graphene-based supercapacitors with high energy density and
           stable cycling performance
    • Authors: Santhakumar Kannappan; Hao Yang; Karthikeyan Kaliyappan; Rajesh Kumar Manian; Amaresh Samuthira Pandian; Yun Sung Lee; Jae-Hyung Jang; Wu Lu
      Pages: 326 - 333
      Abstract: Publication date: August 2018
      Source:Carbon, Volume 134
      Author(s): Santhakumar Kannappan, Hao Yang, Karthikeyan Kaliyappan, Rajesh Kumar Manian, Amaresh Samuthira Pandian, Yun Sung Lee, Jae-Hyung Jang, Wu Lu
      We report supercapacitors based on thiolated-graphene (T-graphene) with stable charging and discharging performance at high current density. The T-graphene was synthesized using low cost NaSH as a reducing agent to reduce graphene oxide. X-ray diffraction (XRD) and x-ray photoelectron spectroscopy (XPS) studies reveal that NaSH is an effective reducing agent in removing oxygen containing groups from graphene oxide. The highly reduced T-graphene with a C/O ratio of 28 was used as the supercapacitor electrode material. At a current density of 2.5 Ag-1, the T-graphene supercapacitor exhibited an electrochemical capacitance of 195 Fg-1, a power density of 4.3 kWkg−1and an energy density of 83.4 Whkg−1. The time required to discharge 83.4Whkg−1 at 2.5 Ag-1 is around 69 s. At a current density of 7.5 Ag-1, the cell exhibited a specific capacitance of about 137 Fg-1 and retained 98% of its initial capacitance value after 10,000 cycles. This superior performance of supercapacitor can be ascribed to highly reduced and porous T-graphene with minimum restacking due to its crumpled nature. The resulting supercapacitors having stable performance at high current density are suitable for fast charging-discharging applications.
      Graphical abstract image

      PubDate: 2018-04-15T08:44:17Z
      DOI: 10.1016/j.carbon.2018.02.036
      Issue No: Vol. 134 (2018)
       
  • Room and elevated temperature lithium-ion storage in structurally Tailored
           submicron carbon spheres with mechanistic Elucidation
    • Authors: Arthur D. Dysart; Xin Li Phuah; Lok Kumar Shrestha; Katsuhiko Ariga; Vilas G. Pol
      Pages: 334 - 344
      Abstract: Publication date: August 2018
      Source:Carbon, Volume 134
      Author(s): Arthur D. Dysart, Xin Li Phuah, Lok Kumar Shrestha, Katsuhiko Ariga, Vilas G. Pol
      Lithium-ion storage in monodisperse submicron carbon spheres (SCS) depends on the inert atmosphere thermal treatment of sonochemically formed polymeric precursors. Battery electrodes of SCS present great initial capacity up to 861 and 1111 A h kg−1 at ambient temperatures 27 and 50 °C, respectively, when cycled at specific current 25 A h kg−1. Beyond initial formation cycles, interestingly, the gravimetric capacity of SCS increases by up to 58% after cycle 50 if cycled up to 3.0 V. Furthermore, capacity change becomes more intense until failure when cycled at 50 °C due to enhanced lithium kinetics. During the first 30 cycles, in situ electrochemical impedance spectroscopy illustrates capacity evolution is coincident with changing capacitive behavior. Subsequently, a model is proposed to relate evolving specific capacity to morphological changes before and during galvanostatic cycling. Further mechanistic support is provided by quantitative characterization of nano-crystallites and phase disorder by X-ray powder diffraction (Scherrer equation) and Raman spectroscopy (peak fitting), elemental composition by organic elemental analysis, and textural properties by isothermal nitrogen sorption. This work provides valuable insight on pertinent ex situ and in situ factors influencing extended voltage applications of synthetic carbons in rechargeable lithium-ion batteries.
      Graphical abstract image

      PubDate: 2018-04-15T08:44:17Z
      DOI: 10.1016/j.carbon.2018.01.024
      Issue No: Vol. 134 (2018)
       
  • 3D self-assembly synthesis of hierarchical porous carbon from petroleum
           asphalt for supercapacitors
    • Authors: Lei Pan; Yixian Wang; Han Hu; Xinxin Li; Jialiang Liu; Lu Guan; Wei Tian; Xiaobo Wang; Yanpeng Li; Mingbo Wu
      Pages: 345 - 353
      Abstract: Publication date: August 2018
      Source:Carbon, Volume 134
      Author(s): Lei Pan, Yixian Wang, Han Hu, Xinxin Li, Jialiang Liu, Lu Guan, Wei Tian, Xiaobo Wang, Yanpeng Li, Mingbo Wu
      A facile and scalable three-dimensional self-assembly template synthesis of hierarchical porous carbon method is developed. During the synthesis, KCl with face-centered cubic crystal is adopted to guide the growth of 3D porous carbon networks. Remarkably, the intimate interconnect porous feature not only significantly speeds up the electron transfer via shortened ion diffusion distance, but also exposes the electrochemically accessible active sites through ultrahigh surface area up to 3581 m2 g−1. As electrodes for button type supercapacitors, the HPC electrode shows a high capacitance of 277 F g−1 at 0.05 A g−1, superior rate performance of 194 F g−1 at 20 A g−1 and excellent cyclic stability of 95.1% after 10000 charge and discharge cycles at 2 A g−1 in 6 M KOH electrolyte. Furthermore, the HPC based symmetric supercapacitors possess high specific energy density of 14.2 Wh kg−1 at a power density of 445 W kg−1 operated in the wide voltage range of 1.8 V in the Na2SO4 electrolyte. This work opens up a facile way for efficient and scaled-up production of low-cost electrode materials with high performance for other energy storage devices.
      Graphical abstract image

      PubDate: 2018-04-15T08:44:17Z
      DOI: 10.1016/j.carbon.2018.04.008
      Issue No: Vol. 134 (2018)
       
  • Substitutional nitrogen atom in diamond. A quantum mechanical
           investigation of the electronic and spectroscopic properties
    • Authors: Anna Maria Ferrari; Simone Salustro; Francesco Silvio Gentile; William C. Mackrodt; Roberto Dovesi
      Pages: 354 - 365
      Abstract: Publication date: August 2018
      Source:Carbon, Volume 134
      Author(s): Anna Maria Ferrari, Simone Salustro, Francesco Silvio Gentile, William C. Mackrodt, Roberto Dovesi
      This paper reports the fully-relaxed lattice and electronic structures, vibrational spectra, and hyperfine coupling constants of the substitutional N s defect in diamond, derived from B3LYP calculations constructed from all-electron Gaussian basis sets and based on periodic supercells. Mulliken analyses of the charge and spin distributions indicate that the defect comprises a single unpaired electron distributed very largely over both the negatively-charged substituted site and one of the four nearest-neighbour carbon sites, which relaxes away from the impurity. This leads to a local C 3v symmetry, with the nitrogen ‘lone pair’ lying along the C 3 axis and pointed towards the ‘dangling’ bond of the shifted carbon neighbour. The calculated band gap is 5.85 eV, within which a singly-occupied, majority spin donor band is found ∼2.9 eV above the valence band, and an unoccupied, minority spin acceptor band ∼0.9 eV below the conduction band. Atom-projected densities of states of the donor and acceptor levels show that, contrary to a widespread description, ∼30% only of the donor band derives from nitrogen states per se, with the majority weight corresponding to states associated with the shifted carbon atom. The defect formation energy is estimated to be ∼3.6 eV. The calculated IR spectrum of the impurity centre shows several features between 800 and 1400 cm−1, all of which are absent in the perfect crystal, for symmetry reasons. These show substantial agreement with recent experimental observations. The calculated hyperfine constants related to the coupling of the unpaired electron spin to the N and C nuclei, for which the Fermi contact terms vary from over 200 MHz to less than 3 MHz, are generally in good agreement with the largest experimental values, both in terms of absolute magnitudes and site assignments. The agreement is less good for the smallest two values, for which the experimental assignments are less certain. The results lend support to previous suggestions that some of the weaker lines in the observed spectra, notably those below ∼7 MHz, which are difficult to assign unambiguously, might result from the overlap of lines from different sites.
      Graphical abstract image

      PubDate: 2018-04-15T08:44:17Z
      DOI: 10.1016/j.carbon.2018.03.091
      Issue No: Vol. 134 (2018)
       
  • Electrochemical performance of a coaxial fiber-shaped asymmetric
           supercapacitor based on nanostructured MnO2/CNT-web paper and Fe2O3/carbon
           fiber electrodes
    • Authors: Bebi Patil; Suhyun Ahn; Seongil Yu; Hyeonjun Song; Youngjin Jeong; Ju Hwan Kim; Heejoon Ahn
      Pages: 366 - 375
      Abstract: Publication date: August 2018
      Source:Carbon, Volume 134
      Author(s): Bebi Patil, Suhyun Ahn, Seongil Yu, Hyeonjun Song, Youngjin Jeong, Ju Hwan Kim, Heejoon Ahn
      The fiber-shaped supercapacitor is a promising energy storage device in wearable and portable electronics because of its high flexibility, small size, and light weight. However, most of the reported fiber-shaped supercapacitors have exhibited low capacitance and energy density due to the limited surface area between the two fiber electrodes and operating voltage range. Herein, we successfully developed a coaxial fiber-shaped asymmetric supercapacitor (CFASC) made from MnO2/CNT-web paper as a cathode coupled with Fe2O3/carbon fiber as an anode with a high operating voltage of 2.2 V. The prepared CFASC device showed a high volumetric energy density of 0.43 mWh cm−3 at a power density of 0.02 W cm−3, which is comparable to those of previously reported fiber-shaped supercapacitors. Additionally, CFASC exhibited good rate capability, long cycle life, and high volumetric capacitance (0.67 F cm−3) with excellent flexibility. The promising performance of CFASC illustrated its potential for portable and wearable energy storage devices.
      Graphical abstract image

      PubDate: 2018-04-15T08:44:17Z
      DOI: 10.1016/j.carbon.2018.03.080
      Issue No: Vol. 134 (2018)
       
  • Ablative and catalytic behavior of carbon-based porous thermal protection
           materials in nitrogen plasmas
    • Authors: Gerard L. Vignoles; Alessandro Turchi; Daniele Bianchi; Pierre Blaineau; Xavier Lamboley; Damien Le Quang Huy; Cyril Levet; Olivier Caty; Olivier Chazot
      Pages: 376 - 390
      Abstract: Publication date: August 2018
      Source:Carbon, Volume 134
      Author(s): Gerard L. Vignoles, Alessandro Turchi, Daniele Bianchi, Pierre Blaineau, Xavier Lamboley, Damien Le Quang Huy, Cyril Levet, Olivier Caty, Olivier Chazot
      Heat shields used to protect space capsules during very high-speed atmospheric entry incorporate lightweight insulating refractories based on carbon-fiber preforms. These ablators, with up to 80% porosity, present exceptional thermal and chemical properties. A joint experimental and modeling approach to study such materials is presented, which contributes to improving their design in relevant operating conditions. Samples were tested in an inductively coupled plasma at 1.5 kPa and 25 kPa pressures, with surface temperatures ranging from 1500 to 2800 K. The recession rate was measured in-situ and the local flow conditions were reconstructed numerically from experimental data. The porous medium was imaged by X-ray Computerized Micro-Tomography (CMT), and the depth affected by the gas-solid interaction phenomena due to the plasma exposure was extracted from these data. A simple analytical model has been derived to relate observable and reconstructed quantities and the fiber-scale reaction constants. Image-based numerical simulations of ablation by nitridation, with simultaneous catalytic recombination of atomic nitrogen, were compared to the analytical model and used to extract the intrinsic, fiber-scale reaction rate constants from test data. Results show, among others, that the fiber-scale nitridation rate constant is close to the rate of graphite nitridation, and that it decreases strongly with pressure.
      Graphical abstract image

      PubDate: 2018-04-15T08:44:17Z
      DOI: 10.1016/j.carbon.2018.03.087
      Issue No: Vol. 134 (2018)
       
  • Constructing hierarchical porous carbon via tin punching for efficient
           electrochemical energy storage
    • Authors: Peng Wang; Jijian Xu; Feng Xu; Wei Zhao; Peng Sun; Zhichao Zhang; Meng Qian; Fuqiang Huang
      Pages: 391 - 397
      Abstract: Publication date: August 2018
      Source:Carbon, Volume 134
      Author(s): Peng Wang, Jijian Xu, Feng Xu, Wei Zhao, Peng Sun, Zhichao Zhang, Meng Qian, Fuqiang Huang
      To achieve large-scale preparation of high-performance carbon materials for electrochemical energy storage with a simple and cost-effective method remains a challenge. Here, we report a novel approach to synthesize hierarchical porous carbon with a low melting point metal tin (Sn) as pore forming agent. An aqueous processed tin chloride-polyethylene glycol (SnCl2-PEG) gel is used as precursor to form Sn/Carbon (Sn/C) composites with homogeneously distributed ultrafine Sn particles (<2 nm) by pyrolysis. After etching Sn nanoparticles, hierarchical porous carbon with high specific surface area (SSA: 846 m2 g−1) and abundant pore structure (coexistence of mesopore and micropore) was obtained. The SSA, pore size distribution and pore volume were successfully tuned by controlling the size of the Sn nanoparticle. The capacitive performance of the as-prepared hierarchical porous carbon was evaluated in 1 M H2SO4, which exhibits excellent specific capacitance of 240 F g−1. In order to further increase the electrochemical performance, N-doped porous carbon was fabricated by thermal nitridation in ammonia, which shows favorable features for electrochemical energy storage such as high specific surface area (1175 m2 g−1), uniform micropore volume (0.46 cm3 g−1) and rich nitrogen-doping (4.45 wt%). This N-doped sample exhibits outstanding specific capacitances of 360 F g−1 and excellent cycling stability in aqueous electrolytes. The above achievements indicate that combining low melting point metal as pore forming agent with a sol-gel protocol can be a unique and reliable method for preparation of high performance supercapacitor electrode materials.
      Graphical abstract image

      PubDate: 2018-04-15T08:44:17Z
      DOI: 10.1016/j.carbon.2018.04.012
      Issue No: Vol. 134 (2018)
       
 
 
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