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  Subjects -> CHEMISTRY (Total: 908 journals)
    - ANALYTICAL CHEMISTRY (56 journals)
    - CHEMISTRY (642 journals)
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CHEMISTRY (642 journals)                  1 2 3 4 | Last

Showing 1 - 200 of 735 Journals sorted alphabetically
2D Materials     Hybrid Journal   (Followers: 14)
Accreditation and Quality Assurance: Journal for Quality, Comparability and Reliability in Chemical Measurement     Hybrid Journal   (Followers: 30)
ACS Catalysis     Hybrid Journal   (Followers: 53)
ACS Chemical Neuroscience     Hybrid Journal   (Followers: 23)
ACS Combinatorial Science     Hybrid Journal   (Followers: 23)
ACS Macro Letters     Hybrid Journal   (Followers: 27)
ACS Medicinal Chemistry Letters     Hybrid Journal   (Followers: 44)
ACS Nano     Hybrid Journal   (Followers: 328)
ACS Photonics     Hybrid Journal   (Followers: 15)
ACS Symposium Series     Full-text available via subscription  
ACS Synthetic Biology     Hybrid Journal   (Followers: 25)
Acta Chemica Iasi     Open Access   (Followers: 6)
Acta Chimica Slovaca     Open Access   (Followers: 2)
Acta Chimica Slovenica     Open Access   (Followers: 1)
Acta Chromatographica     Full-text available via subscription   (Followers: 8)
Acta Facultatis Medicae Naissensis     Open Access  
Acta Metallurgica Sinica (English Letters)     Hybrid Journal   (Followers: 7)
Acta Scientifica Naturalis     Open Access   (Followers: 2)
adhäsion KLEBEN & DICHTEN     Hybrid Journal   (Followers: 8)
Adhesion Adhesives & Sealants     Hybrid Journal   (Followers: 9)
Adsorption Science & Technology     Open Access   (Followers: 7)
Advanced Functional Materials     Hybrid Journal   (Followers: 62)
Advanced Science Focus     Free   (Followers: 5)
Advances in Chemical Engineering and Science     Open Access   (Followers: 77)
Advances in Chemical Science     Open Access   (Followers: 21)
Advances in Chemistry     Open Access   (Followers: 27)
Advances in Colloid and Interface Science     Full-text available via subscription   (Followers: 20)
Advances in Drug Research     Full-text available via subscription   (Followers: 26)
Advances in Environmental Chemistry     Open Access   (Followers: 7)
Advances in Enzyme Research     Open Access   (Followers: 11)
Advances in Fluorine Science     Full-text available via subscription   (Followers: 9)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 17)
Advances in Heterocyclic Chemistry     Full-text available via subscription   (Followers: 12)
Advances in Materials Physics and Chemistry     Open Access   (Followers: 27)
Advances in Nanoparticles     Open Access   (Followers: 17)
Advances in Organometallic Chemistry     Full-text available via subscription   (Followers: 17)
Advances in Polymer Science     Hybrid Journal   (Followers: 45)
Advances in Protein Chemistry     Full-text available via subscription   (Followers: 19)
Advances in Protein Chemistry and Structural Biology     Full-text available via subscription   (Followers: 20)
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: 4)
African Journal of Pure and Applied Chemistry     Open Access   (Followers: 8)
Agrokémia és Talajtan     Full-text available via subscription   (Followers: 2)
Al-Kimia : Jurnal Penelitian Sains Kimia     Open Access  
Alchemy : Journal of Chemistry     Open Access   (Followers: 3)
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: 68)
American Journal of Biochemistry and Molecular Biology     Open Access   (Followers: 22)
American Journal of Chemistry     Open Access   (Followers: 34)
American Journal of Plant Physiology     Open Access   (Followers: 13)
American Mineralogist     Hybrid Journal   (Followers: 15)
Anadolu University Journal of Science and Technology A : Applied Sciences and Engineering     Open Access  
Analyst     Full-text available via subscription   (Followers: 37)
Angewandte Chemie     Hybrid Journal   (Followers: 187)
Angewandte Chemie International Edition     Hybrid Journal   (Followers: 273)
Annales Universitatis Mariae Curie-Sklodowska, sectio AA – Chemia     Open Access   (Followers: 1)
Annals of Clinical Chemistry and Laboratory Medicine     Open Access   (Followers: 4)
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: 15)
Antiviral Chemistry and Chemotherapy     Open Access   (Followers: 2)
Applied Organometallic Chemistry     Hybrid Journal   (Followers: 9)
Applied Spectroscopy     Full-text available via subscription   (Followers: 26)
Applied Surface Science     Hybrid Journal   (Followers: 34)
Arabian Journal of Chemistry     Open Access   (Followers: 6)
ARKIVOC     Open Access   (Followers: 1)
Asian Journal of Biochemistry     Open Access   (Followers: 3)
Asian Journal of Chemistry and Pharmaceutical Sciences     Open Access  
Atomization and Sprays     Full-text available via subscription   (Followers: 4)
Australian Journal of Chemistry     Hybrid Journal   (Followers: 7)
Autophagy     Hybrid Journal   (Followers: 4)
Avances en Quimica     Open Access  
Biochemical Pharmacology     Hybrid Journal   (Followers: 11)
Biochemistry     Hybrid Journal   (Followers: 382)
Biochemistry Insights     Open Access   (Followers: 7)
Biochemistry Research International     Open Access   (Followers: 7)
BioChip Journal     Hybrid Journal  
Bioinorganic Chemistry and Applications     Open Access   (Followers: 11)
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: 2)
Biomacromolecules     Hybrid Journal   (Followers: 24)
Biomass Conversion and Biorefinery     Partially Free   (Followers: 10)
Biomedical Chromatography     Hybrid Journal   (Followers: 6)
Biomolecular NMR Assignments     Hybrid Journal   (Followers: 3)
BioNanoScience     Partially Free   (Followers: 5)
Bioorganic & Medicinal Chemistry     Hybrid Journal   (Followers: 143)
Bioorganic & Medicinal Chemistry Letters     Hybrid Journal   (Followers: 93)
Bioorganic Chemistry     Hybrid Journal   (Followers: 10)
Biopolymers     Hybrid Journal   (Followers: 20)
Biosensors     Open Access   (Followers: 2)
Biotechnic and Histochemistry     Hybrid Journal   (Followers: 1)
Bitácora Digital     Open Access  
Boletin de la Sociedad Chilena de Quimica     Open Access  
Bulletin of the Chemical Society of Ethiopia     Open Access   (Followers: 1)
Bulletin of the Chemical Society of Japan     Full-text available via subscription   (Followers: 25)
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: 12)
Canadian Mineralogist     Full-text available via subscription   (Followers: 7)
Carbohydrate Research     Hybrid Journal   (Followers: 25)
Carbon     Hybrid Journal   (Followers: 70)
Catalysis for Sustainable Energy     Open Access   (Followers: 10)
Catalysis Reviews: Science and Engineering     Hybrid Journal   (Followers: 10)
Catalysis Science and Technology     Hybrid Journal   (Followers: 10)
Catalysis Surveys from Asia     Hybrid Journal   (Followers: 3)
Catalysts     Open Access   (Followers: 14)
Cellulose     Hybrid Journal   (Followers: 13)
Cereal Chemistry     Full-text available via subscription   (Followers: 5)
ChemBioEng Reviews     Full-text available via subscription   (Followers: 2)
ChemCatChem     Hybrid Journal   (Followers: 8)
Chemical and Engineering News     Free   (Followers: 23)
Chemical Bulletin of Kazakh National University     Open Access  
Chemical Communications     Full-text available via subscription   (Followers: 75)
Chemical Engineering Research and Design     Hybrid Journal   (Followers: 28)
Chemical Physics Letters : X     Open Access  
Chemical Research in Chinese Universities     Hybrid Journal   (Followers: 3)
Chemical Research in Toxicology     Hybrid Journal   (Followers: 22)
Chemical Reviews     Hybrid Journal   (Followers: 218)
Chemical Science     Open Access   (Followers: 29)
Chemical Technology     Open Access   (Followers: 36)
Chemical Vapor Deposition     Hybrid Journal   (Followers: 5)
Chemie in Unserer Zeit     Hybrid Journal   (Followers: 57)
Chemie-Ingenieur-Technik (Cit)     Hybrid Journal   (Followers: 21)
ChemInform     Hybrid Journal   (Followers: 8)
Chemistry     Open Access  
Chemistry & Biodiversity     Hybrid Journal   (Followers: 7)
Chemistry & Biology     Full-text available via subscription   (Followers: 33)
Chemistry & Industry     Full-text available via subscription   (Followers: 9)
Chemistry - A European Journal     Hybrid Journal   (Followers: 183)
Chemistry - An Asian Journal     Hybrid Journal   (Followers: 16)
Chemistry and Materials Research     Open Access   (Followers: 21)
Chemistry Central Journal     Open Access   (Followers: 4)
Chemistry Education Research and Practice     Free   (Followers: 5)
Chemistry in Education     Open Access   (Followers: 9)
Chemistry International     Open Access   (Followers: 3)
Chemistry Letters     Full-text available via subscription   (Followers: 46)
Chemistry of Materials     Hybrid Journal   (Followers: 281)
Chemistry of Natural Compounds     Hybrid Journal   (Followers: 10)
Chemistry World     Full-text available via subscription   (Followers: 21)
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: 3)
Chemometrics and Intelligent Laboratory Systems     Hybrid Journal   (Followers: 15)
Chemosensors     Open Access  
ChemPhysChem     Hybrid Journal   (Followers: 12)
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: 22)
Chromatography     Open Access   (Followers: 3)
Chromatography Research International     Open Access   (Followers: 5)
Cogent Chemistry     Open Access   (Followers: 2)
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: 7)
Combinatorial Chemistry & High Throughput Screening     Hybrid Journal   (Followers: 4)
Combustion Science and Technology     Hybrid Journal   (Followers: 23)
Comments on Inorganic Chemistry: A Journal of Critical Discussion of the Current Literature     Hybrid Journal   (Followers: 2)
Communications Chemistry     Open Access   (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: 13)
Computational Chemistry     Open Access   (Followers: 2)
Computers & Chemical Engineering     Hybrid Journal   (Followers: 10)
Coordination Chemistry Reviews     Full-text available via subscription   (Followers: 4)
Copernican Letters     Open Access   (Followers: 1)
Corrosion Series     Full-text available via subscription   (Followers: 7)
Critical Reviews in Biochemistry and Molecular Biology     Hybrid Journal   (Followers: 8)
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   (Followers: 2)
Current Metabolomics     Hybrid Journal   (Followers: 6)
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: 9)
Current Science     Open Access   (Followers: 77)
Current Topics in Medicinal Chemistry     Hybrid Journal   (Followers: 9)
Current Trends in Biotechnology and Chemical Research     Open Access   (Followers: 2)
Dalton Transactions     Full-text available via subscription   (Followers: 26)

        1 2 3 4 | Last

Similar Journals
Journal Cover
C - Journal of Carbon Research
Number of Followers: 3  

  This is an Open Access Journal Open Access journal
ISSN (Online) 2311-5629
Published by MDPI Homepage  [215 journals]
  • C, Vol. 5, Pages 14: RKKY Interaction in Graphene at Finite Temperature

    • Authors: Eugene Kogan
      First page: 14
      Abstract: In our publication from eight years ago (Kogan, E. 2011, vol. 84, p. 115119), we calculated Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction between two magnetic impurities adsorbed on graphene at zero temperature. We show in this short paper that the approach based on Matsubara formalism and perturbation theory for the thermodynamic potential in the imaginary time and coordinate representation which was used then, can be easily generalized, and calculate RKKY interaction between the magnetic impurities at finite temperature.
      Citation: C
      PubDate: 2019-03-31
      DOI: 10.3390/c5020014
      Issue No: Vol. 5, No. 2 (2019)
  • C, Vol. 5, Pages 15: Preparation of MgO-Templated N-Doped Mesoporous
           Carbons from Polyvinylpyrrolidone: Effect of Heating Temperature on Pore
           Size Distribution

    • Authors: Takada, Kurihara
      First page: 15
      Abstract: Magnesium oxide (MgO)-templated nitrogen (N)-doped mesoporous carbons were prepared by using polyvinylpyrrolidone (PVP) as a raw material and magnesium lactate (Mglac) as a precursor for the MgO template to examine the influence of heating temperature and MgO precursor (magnesium acetate was used in similar previous studies) on the pore size and nitrogen content. The MgO-templated carbon was obtained by heating the PVP/Mglac mixture in an inert atmosphere followed by an acid treatment for MgO removal. The mesopore size of the carbons was approximately 4 nm regardless of heating temperature, corresponding to the crystallite size of the MgO template estimated via X-ray diffraction. This indicates that the mesopore of approximately 4 nm was generated using the MgO template. However, larger pores were also found to exist. This result indicates that the larger pores generated through processes other than the MgO templating, likely the thermal decomposition of PVP, are contained in the templated carbon. The volume of the larger pores and the specific surface area increased with increasing heating temperature. The nitrogen content of the carbon decreased as the heating temperature was increased, but it was found to be irrelevant to the MgO precursor.
      Citation: C
      PubDate: 2019-04-02
      DOI: 10.3390/c5020015
      Issue No: Vol. 5, No. 2 (2019)
  • C, Vol. 5, Pages 16: Plasma-Derived Graphene-Based Materials for Water
           Purification and Energy Storage

    • Authors: Nikolas Natter, Nikolaos Kostoglou, Christian Koczwara, Christos Tampaxis, Theodore Steriotis, Ram Gupta, Oskar Paris, Claus Rebholz, Christian Mitterer
      First page: 16
      Abstract: Several crucial problems, such as rapid population growth and extended demands for food, water and fuels, could lead to a severe lack of clean water and an energy crisis in the coming decade. Therefore, low-cost and highly-efficient technologies related to filtration of alternative water supplies (e.g., purification of wastewater and water-rich liquids) and advanced energy storage (e.g., supercapacitors) could play a crucial role to overcome such challenges. A promising class of solid materials for these purposes is exfoliated graphene, and more specifically, its nanoporous forms that exhibit large specific surface areas and pore volumes. In the current work, two plasma-exfoliated graphene-based materials with distinctive morphological and porosity features, including non-porous and low-specific surface area platelets versus nanoporous and high-specific surface area flakes, were tested as filters for water purification purposes (i.e., decolourization and deacidification) and as electrodes for supercapacitors (i.e., ion electrosorption). The findings of this study suggest that a nanoporous and large specific surface area graphene-based material promotes the water purification behaviour by removing contaminants from water-based solutions as well as the energy storage performance by confining ions of aqueous electrolytes.
      Citation: C
      PubDate: 2019-04-03
      DOI: 10.3390/c5020016
      Issue No: Vol. 5, No. 2 (2019)
  • C, Vol. 5, Pages 17: A Multifunctional Wearable Device with a
           Graphene/Silver Nanowire Nanocomposite for Highly Sensitive Strain Sensing
           and Drug Delivery

    • Authors: Shi, Liu, Kopecki, Cowin, Lee, Pai, Lowe, Zhong
      First page: 17
      Abstract: Advances in wearable, highly sensitive and multifunctional strain sensors open up new opportunities for the development of wearable human interface devices for various applications such as health monitoring, smart robotics and wearable therapy. Herein, we present a simple and cost-effective method to fabricate a multifunctional strain sensor consisting of a skin-mountable dry adhesive substrate, a robust sensing component and a transdermal drug delivery system. The sensor has high piezoresisitivity to monitor real-time signals from finger bending to ulnar pulse. A transdermal drug delivery system consisting of polylactic-co-glycolic acid nanoparticles and a chitosan matrix is integrated into the sensor and is able to release the nanoparticles into the stratum corneum at a depth of ~60 µm. Our approach to the design of multifunctional strain sensors will lead to the development of cost-effective and well-integrated multifunctional wearable devices.
      Citation: C
      PubDate: 2019-04-04
      DOI: 10.3390/c5020017
      Issue No: Vol. 5, No. 2 (2019)
  • C, Vol. 5, Pages 18: Electrochemical Properties of Graphene Oxide
           Nanoribbons/Polypyrrole Nanocomposites

    • Authors: Johara Al Dream, Camila Zequine, K. Siam, Pawan K. Kahol, S. R. Mishra, Ram K. Gupta
      First page: 18
      Abstract: Graphene is a highly studied material due to its unique electrical, optical, and mechanical properties. Graphene is widely applied in the field of energy such as in batteries, supercapacitors, and solar cells. The properties of graphene can be further improved by making nanocomposites with conducting polymers. In this work, graphene oxide nanoribbons (GONRs) were synthesized by unzipping multiwall carbon nanotubes. Graphene nanoribbons were used to make nanocomposites with polypyrrole for energy storage applications. The synthesized nanocomposites were structurally and electrochemically characterized to understand their structure and electrochemical properties. The electrochemical characterizations of these nanocomposites were carried out using cyclic voltammetry. The specific capacitance of the nanocomposites was observed to decrease with increasing scan rates. The highest specific capacitance of 2066 F/g was observed using cyclic voltammetry for the optimized nanocomposite of GONR and polypyrrole. Our study suggests that the electrochemical properties of graphene or polypyrrole can be improved by making their composites and that they could be successfully used as electrode materials for energy storage applications. This study can also be extended to the self-assembly of other conducting polymers and graphene nanoribbons through a simple route for various other applications.
      Citation: C
      PubDate: 2019-04-12
      DOI: 10.3390/c5020018
      Issue No: Vol. 5, No. 2 (2019)
  • C, Vol. 5, Pages 19: Bioimaging Applications of Carbon Nanodots: A Review

    • Authors: Kasouni, Chatzimitakos, Stalikas
      First page: 19
      Abstract: Carbon nanodots (CNDs) is the newest member of carbon-based nanomaterials and one of the most promising for the development of new, advanced applications. Owing to their unique and unparalleled physicochemical and photoluminescent properties, they are considered to be a rising star among nanomaterials. During the last decade, many applications have been developed based on CNDs. Among others, they have been used as bioimaging agents to label cells and tissues. In this review, we will discuss the advancements in the applications of CNDs in in the field of imaging, in all types of organisms (i.e., prokaryotes, eukaryotes, and animals). Selective imaging of one type of cells over another, imaging of (bio)molecules inside cells and tumor-targeting imaging are some of the studies that will be discussed hereafter. We hope that this review will assist researchers with obtaining a holistic view of the developed applications and hit on new ideas so that more advanced applications can be developed in the near future.
      Citation: C
      PubDate: 2019-04-22
      DOI: 10.3390/c5020019
      Issue No: Vol. 5, No. 2 (2019)
  • C, Vol. 5, Pages 20: Temperature-Dependence of Solvent-Induced Stokes
           Shift and Fluorescence Tunability in Carbon Nanodots

    • Authors: Sciortino, Cannas, Messina
      First page: 20
      Abstract: We carried out a cryogenic investigation on the optical properties of carbon dots, aiming to better understand their emission mechanism and the role of the solvent. The solvatochromic Stokes shift is quantified by a low temperature approach which allows freezing of the photo-excited state of carbon dots, preventing any solvation relaxation. Moreover, the reduction in temperature helps to identify the dynamical inhomogeneous contribution to the broadening of the emission band; therefore, disentangling the role of solvent from other types of broadening, such as the homogeneous and the static inhomogeneous contributions.
      Citation: C
      PubDate: 2019-04-24
      DOI: 10.3390/c5020020
      Issue No: Vol. 5, No. 2 (2019)
  • C, Vol. 5, Pages 21: Finger-Like Carbon-Based Nanostructures Produced by
           Combustion of Flour-Based Sticks (Spaghetti)

    • Authors: Frederik Ossler, Crispin J. D. Hetherington
      First page: 21
      Abstract: Biomass is becoming particularly important as a starting material for advanced carbon structures. In this study, we found interesting nanostructures on the surface of burnt spaghetti using scanning electron microscopy, transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy (EDX) for analysis. The structures were elongated and finger-like, with evidence that the tubes have shell and core components. The shell was carbon that included amorphous and layered graphene structures. EDX showed enriched potassium and phosphorous in the core and at the tip of the tubes. The results indicate that tube formation depends on phase separation of polar/ionic and nonpolar moieties when water is produced in the biomass from the pyrolysis/combustion. The tube growth is most probably due to the raising pressure of vapor that cannot escape through the carbon film that is formed at the surface of the stick from flame heat. This process resembles glass blowing or volcanic activity, where the carbon acts as the glass or earth’s crust, respectively. These observations suggest that new interesting tubular nanostructures with different properties on the inside and outside can be produced in a relatively simple way, utilizing processes of combustion of starch-rich biomass materials.
      Citation: C
      PubDate: 2019-04-29
      DOI: 10.3390/c5020021
      Issue No: Vol. 5, No. 2 (2019)
  • C, Vol. 5, Pages 22: Sustainable Recycling of Formic Acid by Bio-Catalytic
           CO2 Capture and Re-Hydrogenation

    • Authors: Zhao, Yu, Shanbhag, Holt, Zhong, He
      First page: 22
      Abstract: Formic acid (FA) is a promising reservoir for hydrogen storage and distribution. Its dehydrogenation releases CO2 as a by-product, which limits its practical application. A proof of concept for a bio-catalytic system that simultaneously combines the dehydrogenation of formic acid for H2, in-situ capture of CO2 and its re-hydrogenation to reform formic acid is demonstrated. Enzymatic reactions catalyzed by carbonic anhydrase (CA) and formate dehydrogenase (FDH) under ambient condition are applied for in-situ CO2 capture and re-hydrogenation, respectively, to develop a sustainable system. Continuous production of FA from stripped CO2 was achieved at a rate of 40% using FDH combined with sustainable co-factor regeneration achieved by electrochemistry. In this study, the complete cycle of FA dehydrogenation, CO2 capture, and re-hydrogenation of CO2 to FA has been demonstrated in a single system. The proposed bio-catalytic system has the potential to reduce emissions of CO2 during H2 production from FA by effectively using it to recycle FA for continuous energy supply.
      Citation: C
      PubDate: 2019-05-01
      DOI: 10.3390/c5020022
      Issue No: Vol. 5, No. 2 (2019)
  • C, Vol. 5, Pages 23: Vertically Aligned Few-Layered Graphene-Based
           Non-Cryogenic Bolometer

    • Authors: Yadav, Khan, Kundu, Rani, Soin, McLaughlin, Misra, Hazra
      First page: 23
      Abstract: In this study, we report the photoresponse of vertically aligned few-layered graphene (VAG) upon infra-red (IR) irradiation at room temperature. Four probe measurements showed the current–voltage (I–V) characteristic of electrical switching during pulsed IR irradiation. The photoresponse reported here for VAG was significantly higher than that reported for carbon nanotube (CNT) samples. Our investigation shows that such a photoresponse arose solely from the bolometric effect, where the conductivity changed with temperature. The resistance magnitude of the VAGs increased ~two fold for each 6 °C increase in temperature. Also, the Thermal Coefficient of Resistance (TCR) in this region was ~11%/K, which is the highest TCR value reported for any carbon nanomaterial.
      Citation: C
      PubDate: 2019-05-02
      DOI: 10.3390/c5020023
      Issue No: Vol. 5, No. 2 (2019)
  • C, Vol. 5, Pages 24: Recent Advancements in Doped/Co-Doped Carbon Quantum
           Dots for Multi-Potential Applications

    • Authors: Kandasamy
      First page: 24
      Abstract: Carbon quantum dots (CQDs)/carbon nanodots are a new class of fluorescent carbon nanomaterials having an approximate size in the range of 2–10 nm. The majority of the reported review articles have discussed about the development of the CQDs (via simple and cost-effective synthesis methods) for use in bio-imaging and chemical-/biological-sensing applications. However, there is a severe lack of consolidated studies on the recently developed CQDs (especially doped/co-doped) that are utilized in different areas of application. Hence, in this review, we have extensively discussed about the recent development in doped and co-doped CQDs (using elements/heteroatoms—e.g., boron (B), fluorine (F), nitrogen (N), sulphur (S), and phosphorous (P)), along with their synthesis method, reaction conditions, and/or quantum yield (QY), and their emerging multi-potential applications including electrical/electronics (such as light emitting diode (LED) and solar cells), fluorescent ink for anti-counterfeiting, optical sensors (for detection of metal ions, drugs, and pesticides/fungicides), gene delivery, and temperature probing.
      Citation: C
      PubDate: 2019-05-06
      DOI: 10.3390/c5020024
      Issue No: Vol. 5, No. 2 (2019)
  • C, Vol. 5, Pages 25: Fabrication of Graphene-Reinforced Nanocomposites
           with Improved Fracture Toughness in Net Shape for Complex 3D Structures
           via Digital Light Processing

    • Authors: Zuying Feng, Yan Li, Chenxing Xin, Danna Tang, Wei Xiong, Han Zhang
      First page: 25
      Abstract: A solvent-free method to fabricate graphene-reinforced nanocomposites in net shape via digital light processing (DLP) 3D printing has been developed in this work. The effect of graphene nanofillers on resin viscosity and wettability for various printing parameters has been examined, with a systematic characterization of the mechanical and thermomechanical properties. With the addition of 0.5 wt.% graphene nanoplatelets in the resin, the flexural modulus and fracture toughness have been improved by 14% and 28% from neat resin, respectively. Thermomechanical properties of graphene-reinforced nanocomposites were also enhanced compared with the neat resin, without scarification in their printability. The feasibility of utilizing the DLP method to fabricate a fracture toughness specimen (KIC test) without complex skill-dependent notch preparation steps was explored, with different notch tip angles printed for net-shaped specimens. This provided a simple and versatile way to perform a quick examination of reinforcing efficiency from nanofillers at very low cost with high resolution and reproducibility. To demonstrate the suitability of current resins for complexly shaped structures, a gyroid scaffold for tissue engineering applications based on current graphene nanocomposite resins has been successfully fabricated via DLP, showing the great potential of current photocurable resins for applications in various fields such as tissue engineering or personalized medical devices without the cost barriers of traditional methods.
      Citation: C
      PubDate: 2019-05-09
      DOI: 10.3390/c5020025
      Issue No: Vol. 5, No. 2 (2019)
  • C, Vol. 5, Pages 26: Highly Active, High Specific Surface Area Fe/C/N ORR
           Electrocatalyst from Liquid Precursors by Combination of CO2 Laser
           Pyrolysis and Single NH3 Thermal Post-Treatment

    • Authors: Henri Perez, Virginie Jorda, Jackie Vigneron, Mathieu Frégnaux, Arnaud Etcheberry, Axelle Quinsac, Yann Leconte, Olivier Sublemontier
      First page: 26
      Abstract: This paper reports original results on the synthesis and characterization of Fe/C/N ORR electrocatalysts obtained by a combination of CO2 laser pyrolysis and thermal post-treatment. The precursor liquid media, consisting in a 14 g·L−1 iron III acetylacetonate solution in toluene, was aerosolized and then exposed to a CO2 laser beam for pyrolysis in continuous flow. Ammonia was used in the pyrolysis process, both as the laser wavelength absorbing gas (i.e., energy transfer agent) and as the sole source of nitrogen. After the laser pyrolysis step, the material was submitted to thermal post-treatment under argon on the one hand, and ammonia on another hand. The three materials—one as-prepared, one thermally treated under argon, and one thermally treated under ammonia—were characterized, in particular, through specific surface area determination, XPS analysis, and ORR measurement. It was found that both kinds of thermal treatment significantly improved the ORR performances, which were evaluated on porous electrodes. Indeed, while the as-prepared material showed an ORR onset potential at ≈790 mV vs. the standard hydrogen electrode (SHE) in HClO4 1M, the argon treatment increased the latter to ≈820 mV, and the ammonia treatment led to a very high value of ≈910 mV. Selectivities of 3.65 and 3.93 were measured for the argon and ammonia treated materials, respectively. The outstanding ORR performance resulting from the ammonia treatment is probably related to the very high BET specific surface area measured at 1130 m2·g−1, which was notably obtained without using any templating or sacrificial component in the precursor media.
      Citation: C
      PubDate: 2019-05-14
      DOI: 10.3390/c5020026
      Issue No: Vol. 5, No. 2 (2019)
  • C, Vol. 5, Pages 27: Methods for the Treatment of Cattle Manure—A

    • Authors: Carolina Font-Palma
      First page: 27
      Abstract: Environmental concerns, caused by greenhouse gases released to the atmosphere and overrunning of nutrients and pathogens to water bodies, have led to reducing direct spread onto the land of cattle manure. In addition, this practice can be a source of water and air pollution and toxicity to life by the release of undesirable heavy metals. Looking at the current practices, it is evident that most farms separate solids for recycling purposes, store slurries in large lagoons or use anaerobic digestion to produce biogas. The review explores the potential for cattle manure as an energy source due to its relatively large calorific value (HHV of 8.7–18.7 MJ/kg dry basis). This property is beneficial for thermochemical conversion processes, such as gasification and pyrolysis. This study also reviews the potential for upgrading biogas for transportation and heating use. This review discusses current cattle manure management technologies—biological treatment and thermochemical conversion processes—and the diverse physical and chemical properties due to the differences in farm practices.
      Citation: C
      PubDate: 2019-05-15
      DOI: 10.3390/c5020027
      Issue No: Vol. 5, No. 2 (2019)
  • C, Vol. 5, Pages 3: An Overview of the Recent Progress in the Synthesis
           and Applications of Carbon Nanotubes

    • Authors: Gul Rahman, Zainab Najaf, Asad Mehmood, Salma Bilal, Anwar ul Haq Ali Shah, Shabeer Ahmad Mian, Gulam Ali
      First page: 3
      Abstract: Carbon nanotubes (CNTs) are known as nano-architectured allotropes of carbon, having graphene sheets that are wrapped forming a cylindrical shape. Rolling of graphene sheets in different ways makes CNTs either metals or narrow-band semiconductors. Over the years, researchers have devoted much attention to understanding the intriguing properties CNTs. They exhibit some unusual properties like a high degree of stiffness, a large length-to-diameter ratio, and exceptional resilience, and for this reason, they are used in a variety of applications. These properties can be manipulated by controlling the diameter, chirality, wall nature, and length of CNTs which are in turn, synthesis procedure-dependent. In this review article, various synthesis methods for the production of CNTs are thoroughly elaborated. Several characterization methods are also described in the paper. The applications of CNTs in various technologically important fields are discussed in detail. Finally, future prospects of CNTs are outlined in view of their commercial applications.
      Citation: C
      PubDate: 2019-01-03
      DOI: 10.3390/c5010003
      Issue No: Vol. 5, No. 1 (2019)
  • C, Vol. 5, Pages 4: Experimental Investigation of the Mechanisms of Salt
           Precipitation during CO2 Injection in Sandstone

    • Authors: Yen Adams Sokama-Neuyam, Jann Rune Ursin, Patrick Boakye
      First page: 4
      Abstract: Deep saline reservoirs have the highest volumetric CO2 storage potential, but drying and salt precipitation during CO2 injection could severely impair CO2 injectivity. The physical mechanisms and impact of salt precipitation, especially in the injection area, is still not fully understood. Core-flood experiments were conducted to investigate the mechanisms of external and internal salt precipitation in sandstone rocks. CO2 Low Salinity Alternating Gas (CO2-LSWAG) injection as a potential mitigation technique to reduce injectivity impairment induced by salt precipitation was also studied. We found that poor sweep and high brine salinity could increase salt deposition on the surface of the injection area. The results also indicate that the amount of salt precipitated in the dry-out zone does not change significantly during the drying process, as large portion of the precipitated salt accumulate in the injection vicinity. However, the distribution of salt in the dry-out zone was found to change markedly when more CO2 was injected after salt precipitation. This suggests that CO2 injectivity impairment induced by salt precipitation is probably dynamic rather than a static process. It was also found that CO2-LSWAG could improve CO2 injectivity after salt precipitation. However, below a critical diluent brine salinity, CO2-LSWAG did not improve injectivity. These findings provide vital understanding of core-scale physical mechanisms of the impact of salt precipitation on CO2 injectivity in saline reservoirs. The insight gained could be implemented in simulation models to improve the quantification of injectivity losses during CO2 injection into saline sandstone reservoirs.
      Citation: C
      PubDate: 2019-01-08
      DOI: 10.3390/c5010004
      Issue No: Vol. 5, No. 1 (2019)
  • C, Vol. 5, Pages 5: Acknowledgement to Reviewers of C in 2018

    • Authors: C Editorial Office
      First page: 5
      Abstract: Rigorous peer-review is the corner-stone of high-quality academic publishing [...]
      Citation: C
      PubDate: 2019-01-09
      DOI: 10.3390/c5010005
      Issue No: Vol. 5, No. 1 (2019)
  • C, Vol. 5, Pages 6: Convenient Preparation of Graphene Oxide from
           Expandable Graphite and Its Characterization by Positron Annihilation
           Lifetime Spectroscopy

    • Authors: Guido Panzarasa, Giovanni Consolati, Marco Scavini, Mariangela Longhi, Fiorenza Quasso
      First page: 6
      Abstract: Graphene oxide (GO) is conveniently prepared from expandable graphite using a simplified Hummers’ method. The product is thoroughly characterized by usual techniques (UV-vis, Fourier-transform infrared (FTIR) and Raman spectroscopies, zeta potential, electron microscopy, X-ray diffraction, nitrogen adsorption) to confirm the success of synthesis. Positron annihilation lifetime spectroscopy (PALS) is then used to extract information on the microenvironment in between the layers of graphene oxide.
      Citation: C
      PubDate: 2019-01-11
      DOI: 10.3390/c5010006
      Issue No: Vol. 5, No. 1 (2019)
  • C, Vol. 5, Pages 7: Electrochemical Reaction in Hydrogen Peroxide and
           Structural Change of Platinum Nanoparticle-Supported Carbon Nanowalls
           Grown Using Plasma-Enhanced Chemical Vapor Deposition

    • Authors: Masakazu Tomatsu, Mineo Hiramatsu, Hiroki Kondo, Kenji Ishikawa, Takayoshi Tsutsumi, Makoto Sekine, Masaru Hori
      First page: 7
      Abstract: Hydrogen peroxide (H2O2) reactions on platinum nanoparticle-decorated carbon nanowalls (Pt-CNWs) under potential applications were investigated on a platform of CNWs grown on carbon fiber paper (CFP) using plasma-enhanced chemical vapor deposition. Through repeated cyclic voltammetry (CV), measurements of 1000 cycles using the Pt-CNW electrodes in phosphate-buffered saline (PBS) solution with 240 μM of H2O2, the observed response peak currents of H2O2 reduction decreased with the number of cycles, which is attributed to decomposition of H2O2. After CV measurements for a total of 3000 cycles, the density and height of CNWs were reduced and their surface morphology changed. Energy-dispersive X-ray (EDX) compositional mapping revealed agglomeration of Pt nanoparticles around the top edges of CNWs. The degradation mechanism of Pt-CNWs under potential application with H2O2 is discussed by focusing on the behavior of OH radicals generated by the H2O2 reduction.
      Citation: C
      PubDate: 2019-01-24
      DOI: 10.3390/c5010007
      Issue No: Vol. 5, No. 1 (2019)
  • C, Vol. 5, Pages 8: Effects of Ion Bombardment Energy Flux on Chemical
           Compositions and Structures of Hydrogenated Amorphous Carbon Films Grown
           by a Radical-Injection Plasma-Enhanced Chemical Vapor Deposition

    • Authors: Hirotsugu Sugiura, Hiroki Kondo, Takayoshi Tsutsumi, Kenji Ishikawa, Masaru Hori
      First page: 8
      Abstract: Hydrogenated amorphous carbon (a-C:H) films have attracted much attention, because of their excellent physical and chemical properties, such as high mechanical hardness, chemical robustness, a wide variety of optical bandgaps, and so forth. Although an ion bombardment energy has been regarded as essential in the well-know subplantation model, it alone is inadequate especially in complicated reactions of a plasma-enhanced chemical vapor deposition process. In this study, an ion bombardment energy flux (ΓEi) was proposed as a crucial factor to determine chemical compositions and structures of a-C:H films. To obtain the amounts of ΓEi, electron densities, hydrogen (H) excitation temperatures, and negative direct current (DC) self-bias voltage (-VDC) were measured. The deposition rate increased, and sp2-C clusters incorporation was induced by the ΓEi. With increasing ΓEi, photoluminescence (PL) backgrounds in Raman spectra decreased, while spin densities in electron spin resonance (ESR) measurements increased. These results suggested the H content of a-C:H film decreased depending on the amount of ΓEi. The ΓEi is one of the crucial factors to determine the properties of the a-C:H films.
      Citation: C
      PubDate: 2019-01-24
      DOI: 10.3390/c5010008
      Issue No: Vol. 5, No. 1 (2019)
  • C, Vol. 5, Pages 9: Novel Tubular Carbon Membranes Prepared from Natural

    • Authors: Xuezhong He
      First page: 9
      Abstract: The novel tubular carbon membranes produced from natural materials are, for the first time, reported. The novelty of this idea is to use natural rattans as precursors for making carbon membranes to address the challenges of cellulose polymers. The rattan precursors were carbonized to present evenly distributed channels inside the tubular carbon membranes. Each channel has an inner diameter of 2 × 10−4 m with a dense-selective inner layer and a porous outer layer. Future work on selection of suitable rattans, proper pre-treatment, carbon structure tailoring can be conducted to open a new research field of carbon membranes/materials.
      Citation: C
      PubDate: 2019-02-01
      DOI: 10.3390/c5010009
      Issue No: Vol. 5, No. 1 (2019)
  • C, Vol. 5, Pages 10: Rice Husk-Derived High Surface Area Nanoporous Carbon
           Materials with Excellent Iodine and Methylene Blue Adsorption Properties

    • Authors: Lok Kumar Shrestha, Mamata Thapa, Rekha Goswami Shrestha, Subrata Maji, Raja Ram Pradhananga, Katsuhiko Ariga
      First page: 10
      Abstract: Iodine and methylene blue adsorption properties of the high surface area nanoporous carbon materials derived from agro-waste and rice husk is reported. Rice husk was pre-carbonized at 300 °C in air followed by leaching out the silica nanoparticles by extraction with sodium hydroxide solution. The silica-free rice husk char was mixed with chemical activating agents sodium hydroxide (NaOH), zinc chloride (ZnCl2), and potassium hydroxide (KOH) separately at a mixing ratio of 1:1 (wt%) and carbonized at 900 °C under a constant flow of nitrogen. The prepared carbon materials were characterized by scanning electron microscopy (SEM), Fourier transformed-infrared spectroscopy (FT-IR), powder X-ray diffraction (pXRD), and Raman scattering. Due to the presence of bimodal micro- and mesopore structures, KOH activated samples showed high specific surface area ca. 2342 m2/g and large pore volume ca. 2.94 cm3/g. Oxygenated surface functional groups (hydroxyl, carbonyl, and carboxyl) were commonly observed in all of the samples and were essentially non-crystalline porous particle size of different sizes (<200 μm). Adsorption study revealed that KOH activated samples could be excellent material for the iodine and methylene blue adsorption from aqueous phase. Iodine and methylene blue number were ca. 1726 mg/g and 608 mg/g, respectively. The observed excellent iodine and methylene blue adsorption properties can be attributed to the well-developed micro- and mesopore structure in the carbon material. This study demonstrates that the agricultural waste, rice husk, and derived nanoporous carbon materials would be excellent adsorbent materials in water purifications.
      Citation: C
      PubDate: 2019-02-22
      DOI: 10.3390/c5010010
      Issue No: Vol. 5, No. 1 (2019)
  • C, Vol. 5, Pages 11: Plasma Oxidation Printing into DLC and Graphite for
           Surface Functionalization

    • Authors: Tatsuhiko Aizawa, Kenji Wasa, Yoshiro Nogami
      First page: 11
      Abstract: A diamond-like carbon (DLC) film, coated on a AISI420-J2 stainless steel substrate and vertically aligned graphite (VAG), was structured by high-density plasma oxidation to work as a DLC-punch for micro-stamping and DLC-nozzle array for micro-dispensing, in addition to acting as a copper-plated thermal spreader, respectively. Thick DLC films were micro-patterned by maskless lithography and directly plasma-etched to remove the unmasked regions. Thick VAG (Ca plates were micro-patterned by screen-printing and selectively etched to activate the surface. Raman spectroscopy as well as electric resistivity measurement proved that there was no degradation of VAG by this surface activation. Wet plating was utilized to prove that copper wettability was improved by this surface treatment.
      Citation: C
      PubDate: 2019-03-11
      DOI: 10.3390/c5010011
      Issue No: Vol. 5, No. 1 (2019)
  • C, Vol. 5, Pages 12: Fluorescent Carbon Dots Ink for Gravure Printing

    • Authors: Apostolos Koutsioukis, Vassiliki Belessi, Vasilios Georgakilas
      First page: 12
      Abstract: In the present article, we describe the use of highly fluorescent carbon dots (CDs) for the preparation of an effective water-based carbon dot ink (CD-ink) for gravure printing. Carbon dots were prepared hydrothermally from citrate and triethylenetetramine, and mixed properly with certain resins that are used in gravure inks. The as-produced CD gravure ink was used successfully for printing high quality fluorescent images.
      Citation: C
      PubDate: 2019-03-14
      DOI: 10.3390/c5010012
      Issue No: Vol. 5, No. 1 (2019)
  • C, Vol. 5, Pages 13: Novel Biobased Polyol Using Corn Oil for Highly
           Flame-Retardant Polyurethane Foams

    • Authors: Sneha Ramanujam, Camila Zequine, Sanket Bhoyate, Brooks Neria, Pawan K. Kahol, Ram K. Gupta
      First page: 13
      Abstract: A novel bio-based polyol was synthesized using corn oil and 2-mercaptoethanol via thiol-ene reaction as an alternative to petroleum-based polyol for the synthesis of polyurethane foams. The polyol was analyzed using wet chemical techniques to obtain hydroxyl number and viscosity. Infrared spectroscopy and gel permeation chromatography were used to confirm the structural properties of the foams. Flame-retardant polyurethane foams were prepared by the addition of different concentrations of dimethyl methyl phosphonate (DMMP) in final foam composition. The effect of DMMP on the thermo-mechanical properties of the polyurethane foams was analyzed. The TGA analysis showed improved stability of the final char with addition of DMMP in the foams. All the foams maintained a well-defined cellular structure and over 95% of closed cell content. The horizontal burning test showed reduced burning time and weight loss from 115 s and 38 wt.% for the neat foams, to 3.5 s and 5.5 wt.% for DMMP-containing foams (1.94 wt.% P). The combustion test using cone calorimeter showed a considerable reduction in heat release rate and total heat release. Thus, our study shows that corn-oil based polyol can be used to produce renewable polyol for industrially producible rigid polyurethane foams. The addition of a small amount of DMMP could result in a significant reduction in the flame-retardant properties of the polyurethane foams.
      Citation: C
      PubDate: 2019-03-14
      DOI: 10.3390/c5010013
      Issue No: Vol. 5, No. 1 (2019)
  • C, Vol. 5, Pages 1: Carbon-Based Magnetic Nanocarrier for Controlled Drug
           Release: A Green Synthesis Approach

    • Authors: Jessica R. P. Oliveira, Raquel O. Rodrigues, Lillian Barros, Isabel C. F. R. Ferreira, Luís F. Marchesi, Martina Koneracka, Alena Jurikova, Vlasta Zavisova, Helder T. Gomes
      First page: 1
      Abstract: In this study, hydrophilic magnetic nanoparticles were synthesized by green routes using a methanolic extract of Rubus ulmifolius Schott flowers. The prepared magnetic nanoparticles were coated with carbon-based shell for drug delivery application. The nanocomposites were further chemically functionalized with nitric acid and, sequentially, with Pluronic® F68 (CMNPs-plur) to enhance their colloidal stability. The resulting material was dispersed in phosphate buffer solution at pH 7.4 to study the Doxorubicin loading. After shaking for 48 h, 99.13% of the drug was loaded by the nanocomposites. Subsequently, the drug release was studied in different working phosphate buffer solutions (i.e., PB pH 4.5, pH 6.0 and pH 7.4) to determine the efficiency of the synthesized material for drug delivery as pH-dependent drug nanocarrier. The results have shown a drug release quantity 18% higher in mimicking tumor environment than in the physiological one. Therefore, this study demonstrates the ability of CMNPs-plur to release a drug with pH dependence, which could be used in the future for the treatment of cancer "in situ" by means of controlled drug release.
      Citation: C
      PubDate: 2018-12-28
      DOI: 10.3390/c5010001
      Issue No: Vol. 5, No. 1 (2018)
  • C, Vol. 5, Pages 2: Nanostructure Quantification of Carbon Blacks

    • Authors: Madhu Singh, Randy L. Vander Wal
      First page: 2
      Abstract: Carbon blacks are an extensively used manufactured product. There exist different grades by which the carbon black is classified, based on its purpose and end use. Different properties inherent to the various carbon black types are a result of their production processes. Based on the combustion condition and fuel used, each process results in a carbon black separate from those obtained from other processes. These carbons differ in their aggregate morphology, particle size, and particle nanostructure. Nanostructure is key in determining the material’s behavior in bulk form. A variety of carbon blacks have been analyzed and quantified for their lattice parameters and structure at the nanometer scale, using transmission electron microscopy and custom-developed fringe analysis algorithms, to illustrate differences in nanostructure and their potential relation to observed material properties.
      Citation: C
      PubDate: 2018-12-31
      DOI: 10.3390/c5010002
      Issue No: Vol. 5, No. 1 (2018)
  • C, Vol. 4, Pages 52: Kinetic and Equilibrium Study of the Adsorption of
           CO2 in Ultramicropores of Resorcinol-Formaldehyde Aerogels Obtained in
           Acidic and Basic Medium

    • Authors: Jhonatan R. Guarín Romero, Juan Carlos Moreno-Piraján, Liliana Giraldo Gutierrez
      First page: 52
      Abstract: In this work, aerogels were prepared using resorcinol-formaldehyde as a precursor in two synthetic routes, one basic and one acidic, to perform the adsorption of CO2 at 0 °C and atmospheric pressure. Aerogels were Characterization by N2 and CO2 Physisorption, Raman Spectroscopy, Scanning Electron Microscopy, and Infrared Spectroscopy. In general, was found that aerogels have a polymeric, disordered, three-dimensional structure and have a microporous surface. Langmuir, Freundlich, Sips and Toth equilibrium models present a good data fit of CO2 adsorption at relative pressure ranging between 1 × 10−4 and 3 × 10−2. The diffusion intra-particle kinetic model explains the setps of this process; the Elovich model also showed a good fit, therefore, there are an energetic heterogeneity of the CO2 superficial adsorption sites. The aerogel carbonized in basic medium at 1050 °C (ACB 1050) material was the best adsorbent of this pollutant, reaching an adsorption capacity of 6.43 mmol g−1.
      Citation: C
      PubDate: 2018-09-20
      DOI: 10.3390/c4040052
      Issue No: Vol. 4, No. 4 (2018)
  • C, Vol. 4, Pages 53: Design and Preparation of Biomass-Derived Carbon
           Materials for Supercapacitors: A Review

    • Authors: Yang Liu, Jiareng Chen, Bin Cui, Pengfei Yin, Chao Zhang
      First page: 53
      Abstract: The synthesis and application of biomass-derived carbon in energy storage have drawn increasing research attention due to the ease of fabrication, cost-effectiveness, and sustainability of the meso/microporous carbon produced from various biological precursors, including plants, fruits, microorganisms, and animals. Compared to the artificial nanostructured carbons, such as fullerene, carbon nanotube and graphene, the biomass-derived carbons may obtain superior capacitance, rate performance and stability in supercapacitor applications ascribing to their intrinsic nanoporous and hierarchical structures. However, challenges remain in processing techniques to obtain biomass-derived carbons with high carbon yield, high energy density, and controllable graphitic microstructures, which may require a clear understanding over the chemical and elemental compositions, and the intrinsic microstructural characteristics of the biological precursors. Herein we present comprehensive analyses over the impacts of the chemical and elemental compositions of the precursors on the carbon yield of the biomass, as well as the mechanism of chemical activation on the nanoporous structure development of the biomass-derived carbons. The structure–property relationship and functional performance of various biomass-derived carbons for supercapacitor applications are also discussed in detail and compared. Finally, useful insights are also provided for the improvements of biomass-derived carbons in supercapacitor applications.
      Citation: C
      PubDate: 2018-09-25
      DOI: 10.3390/c4040053
      Issue No: Vol. 4, No. 4 (2018)
  • C, Vol. 4, Pages 54: A Metal-Free Carbon-Based Catalyst: An Overview and
           Directions for Future Research

    • Authors: Pitchaimani Veerakumar, Pounraj Thanasekaran, Thiruvengadam Subburaj, King-Chuen Lin
      First page: 54
      Abstract: Metal-free carbon porous materials (CPMs) have gained the intensive attention of scientists and technologists because of their potential applications, ranging from catalysis to energy storage. Various simple and facile strategies are proposed for the preparation of CPMs with well-controlled sizes, shapes, and modifications on the surface. The extraordinary tenability of the pore structure, the environmental acceptability, the unique surface and the corrosion resistance properties allow them to be suitable materials for a large panel of catalysis applications. This review briefly outlines the different signs of progresses made towards synthesizing CPMs, and their properties, including catalytic efficiency, stability, and recyclability. Finally, we make a comparison of their catalytic performances with other nanocomposites, and we provide an outlook on the expected developments in the relevant research works.
      Citation: C
      PubDate: 2018-09-27
      DOI: 10.3390/c4040054
      Issue No: Vol. 4, No. 4 (2018)
  • C, Vol. 4, Pages 55: A Tailor-Made Protocol to Synthesize Yolk-Shell
           Graphene-Based Magnetic Nanoparticles for Nanomedicine

    • Authors: Raquel O. Rodrigues, Giovanni Baldi, Saer Doumett, Juan Gallo, Manuel Bañobre-López, Goran Dražić, Ricardo C. Calhelha, Isabel C. F. R. Ferreira, Rui Lima, Adrián M. T. Silva, Helder T. Gomes
      First page: 55
      Abstract: A simple tailor-made protocol to synthesize graphene-based magnetic nanoparticles (GbMNPs) for nanomedicine is herein reported. Different GbMNPs with very distinctive physicochemical and toxicological properties were synthesized by adjusting the number of carbon precursors in the coating of superparamagnetic iron oxide nanoparticles. In vitro tests show the ability to use these GbMNPs as intelligent and on-demand drug nanocarrier systems for drug delivery, exhibiting the following features: good colloidal stability, good loading capacity of the chemotherapeutic drug doxorubicin, high pH-controlled release of the encapsulated drug (targeting tumour acidic pH conditions), superparamagnetic behaviour and biocompatibility. Due to their combined properties (i.e., physicochemical, magnetic, and biocompatibility), GbMNPs show high potentiality to be combined with other biomedical techniques, such as magnetic hyperthermia, which can represent an enhancement in the treatment of cancer.
      Citation: C
      PubDate: 2018-10-13
      DOI: 10.3390/c4040055
      Issue No: Vol. 4, No. 4 (2018)
  • C, Vol. 4, Pages 56: Crucial Factors for the Application of Functional
           Nanoporous Carbon-Based Materials in Energy and Environmental Applications

    • Authors: Martin Oschatz, Ralf Walczak
      First page: 56
      Abstract: This special issue of C—Journal of Carbon Research is dedicated to “Functional Nanoporous Carbon-Based Materials”. It contains contributions reporting on the synthesis of nanoporous carbons for the adsorption of proteins, their applications in electrochemical energy storage/conversion, and on the characterization/modification of their surface chemistry. Nanoporous carbon-based materials are widely researched, but at the same time, the field is still full of unutilized potential. The atomic construction of the carbon framework, pore sizes, pore geometries, presence of heteroatoms, particle size and shape, and many other “internal screws” are available; in the end, the high potential of carbon-based materials will only be fully explored if the interplay of these crucial factors is precisely controlled. This article is a summary of what we consider important for future targeted improvement of porous carbon nanomaterials for energy and environmental applications.
      Citation: C
      PubDate: 2018-10-17
      DOI: 10.3390/c4040056
      Issue No: Vol. 4, No. 4 (2018)
  • C, Vol. 4, Pages 57: Carbon Dioxide Emissions Research and Sustainable
           Transportation in the Sports Industry

    • Authors: Stavros Triantafyllidis
      First page: 57
      Abstract: The sports industry is an institution that has large responsibility toward global environmental pollution. Over the past decade sports organizations have initiated a variety of environmentally sustainable practices. In this paper, the role of research in CO2 emissions generated by the sports industry pursuits is highlighted. This report recommends that strategic management approaches and policy development are required to control this dangerous environmental pollutant. Specifically, proactive sustainable innovations and policies that mandate alternative transportation behaviors are suggested. In conclusion, after reviewing the current literature, it is proposed that sports associations should apply specific practices in sports events with focus on spectators’ mobility choices such as sustainable transportation.
      Citation: C
      PubDate: 2018-10-25
      DOI: 10.3390/c4040057
      Issue No: Vol. 4, No. 4 (2018)
  • C, Vol. 4, Pages 58: Fullerene-to-MWCNT Structural Evolution Synthesized
           by Arc Discharge Plasma

    • Authors: Muhammad Sufi Roslan, Misbahul Muneer Abd Rahman, Muhamad Hanif Jofri, Kashif Tufail Chaudary, Azam Mohamad, Jalil Ali
      First page: 58
      Abstract: The growth of multi-walled carbon nanotubes (MWCNTs) has been extensively studied using electron microscopy. The ex situ structural behavior was examined to investigate the growth of the MWCNTs under different environments and pressures using electron microscopy. The arc discharge plasma technique was applied to synthesize the MWCNTs by evaporating carbon through the arc plasma between two cylindrical graphite rods, with a background pressure of 10−2 to 102 mbar, inside a vacuum chamber under different ambient environments. The results showed that long MWCNT structures were successfully grown. We suggest that the mechanism involves: (i) fullerene formation; (ii) the elongation of fullerenes; and (iii) the growth of MWCNTs. Agglomeration with other structures then forms MWCNT bundles. We note that the pressure and environment in the vacuum chamber can affect the structure of the MWCNTs.
      Citation: C
      PubDate: 2018-10-25
      DOI: 10.3390/c4040058
      Issue No: Vol. 4, No. 4 (2018)
  • C, Vol. 4, Pages 59: Enhancing Anaerobic Digestion: The Effect of Carbon
           Conductive Materials

    • Authors: Judith González, Marta E. Sánchez, Xiomar Gómez
      First page: 59
      Abstract: Anaerobic digestion is a well-known technology which has been extensively studied to improve its performance and yield biogas from substrates. The application of different types of pre-treatments has led to an increase in biogas production but also in global energy demand. However, in recent years the use of carbon conductive materials as supplement for this process has been studied resulting in an interesting way for improving the performance of anaerobic digestion without greatly affecting its energy demand. This review offers an introduction to this interesting approach and covers the different experiences performed on the use of carbon conductive materials proposing it as a feasible alternative for the production of energy from biomass, considering also the integration of anaerobic digestion and thermal valorisation.
      Citation: C
      PubDate: 2018-11-01
      DOI: 10.3390/c4040059
      Issue No: Vol. 4, No. 4 (2018)
  • C, Vol. 4, Pages 60: Development of La Doped Ni/CeO2 for CH4/CO2 Reforming

    • Authors: Federica Menegazzo, Cristina Pizzolitto, Elena Ghedini, Alessandro Di Michele, Giuseppe Cruciani, Michela Signoretto
      First page: 60
      Abstract: Methane dry reforming (MDR) allows the transformation of carbon dioxide and methane, the two main greenhouse gases, into syngas. Given the high endothermicity of the process, it is necessary to produce a catalytic system that is very active, selective and resistant to coking deactivation; this work focuses on the development of a heterogeneous catalyst based on nickel supported on cerium oxide. Several strategies of synthesis of the catalysts were studied with particular attention to the lanthanum addition methodology. Both supports and catalysts, fresh and used, were deeply characterized by different techniques (N2 physisorption, TPR, XRD, SEM). The effect of temperature on activity and selectivity of the different catalysts was also studied. A positive effect of lanthanum addition is strongly related to the synthetic methodology. Incipient wetness impregnation of lanthanum precursor on an already calcined ceria has led to the best catalytic activity. This behaviour is due to a more effective interaction between nickel and the support, which results in a higher dispersion of the active phase. The structural modifications have led to an improvement of the redox pump of the ceria, reducing the formation of coke during the reaction and improving the stability on time on stream.
      Citation: C
      PubDate: 2018-11-07
      DOI: 10.3390/c4040060
      Issue No: Vol. 4, No. 4 (2018)
  • C, Vol. 4, Pages 61: Microwave-Driven Plasma-Mediated Methane Cracking:
           Product Carbon Characterization

    • Authors: Randy Vander Wal, Arupananda Sengupta, Evan Musselman, George Skoptsov
      First page: 61
      Abstract: Methane is the primary industrial H2 source, with the vast majority produced by steam reforming of methane—a highly CO2- and water-intensive process. Alternatives to steam reforming, such as microwave-driven plasma-mediated methane decomposition, offer benefits of no water consumption and zero CO2 process emissions while also producing solid carbon formed by pyrolytic reactions and aided by a plasma reactive environment. The economic viability of pyrolytic methane decomposition as a hydrogen source will depend upon the commercial applications of the solid carbon product—which, in turn, will depend upon its physical and chemical characteristics. This study focuses on material characterization of the solid carbon (secondary) product. Characterization by high-resolution transmission electron microscopy reveals forms ranging from graphitic to amorphous. Thermogravimetric analyses reveal three forms by their differing oxidative reactivity, while X-ray diffraction analyses support the different crystalline forms as suggested by Thermogravimetric analysis. Plasma perturbation of the radical pool, elevating radical temperatures and boosting concentrations, is proposed as altering the reaction paths towards solid carbon formation, resulting in the different sp2 forms.
      Citation: C
      PubDate: 2018-11-08
      DOI: 10.3390/c4040061
      Issue No: Vol. 4, No. 4 (2018)
  • C, Vol. 4, Pages 62: Physicochemical Properties of Activated Carbon: Their
           Effect on the Adsorption of Pharmaceutical Compounds and
           Adsorbate–Adsorbent Interactions

    • Authors: Valentina Bernal, Liliana Giraldo, Juan Carlos Moreno-Piraján
      First page: 62
      Abstract: The adsorption of salicylic acid, acetaminophen, and methylparaben (pharmaceutical products derived from phenol) on carbons activated with different surface chemistries was carried out. We evaluated the effect of the physicochemical properties of the adsorbent and adsorbates on the adsorption capacity. A study of the adsorbate–adsorbent interactions via immersion calorimetry in the analytes solutions at different concentrations was included, in addition to the equilibrium data analysis. The results show that the pharmaceutical compounds (2.28–0.71 mmol g−1) have lower adsorption capacities in the activated carbon with the highest content of oxygenated groups (acids), while the activated carbons with amphoteric characteristics increase the capacities of adsorption (2.60–1.38 mmol g−1). This behavior may be associated with the increased affinity between the adsorbent and solvent due to the presence of polar groups, which was corroborated by the high immersion enthalpy value in water (ΔHimmH2O = −66.6 J g−1). The equilibrium data, adjusted to the Freundlich adsorption model, indicated that the heterogeneous adsorption processes involve immersion enthalpy values between −9.42 and −24.3 J g−1.
      Citation: C
      PubDate: 2018-11-19
      DOI: 10.3390/c4040062
      Issue No: Vol. 4, No. 4 (2018)
  • C, Vol. 4, Pages 63: A Review on the Synthesis and Characterization of
           Biomass-Derived Carbons for Adsorption of Emerging Contaminants from Water

    • Authors: Jorge Bedia, Manuel Peñas-Garzón, Almudena Gómez-Avilés, Juan J. Rodriguez, Carolina Belver
      First page: 63
      Abstract: This review analyzes the preparation and characterization of biomass-derived carbons and their application as adsorbents of emerging contaminants from water. The study begins by identifying the different types of emerging contaminants more often found in water streams, including a brief reference to the available technologies for their removal. It also describes the biomass sources that could be used for the synthesis of biochars and activated carbons (AC). The characterization of the adsorbents and the different approaches that can be followed to learn about the adsorption processes are also detailed. Finally, the work reviews literature studies focused on the adsorption of emerging contaminants on biochars and activated carbons synthesized from biomass precursors.
      Citation: C
      PubDate: 2018-11-19
      DOI: 10.3390/c4040063
      Issue No: Vol. 4, No. 4 (2018)
  • C, Vol. 4, Pages 64: Pt Nanocluster Co-Catalysts for Photocatalytic Water

    • Authors: Cameron J. Shearer, Jason F. Alvino, Munkhbayar Batmunkh, Gregory F. Metha
      First page: 64
      Abstract: Degussa P25 is a benchmark form of TiO2 used worldwide in photocatalysis studies. Currently, no such benchmark exists for co-catalysts, which are essential for many photocatalytic reactions. Here, we present the preparation of Pt nanocluster co-catalysts on TiO2 using an unmodified commercial source and equipment that is commonly available. Transmission electron microscopy reveals that the procedure produces TiO2 decorated with Pt atoms and nanoclusters (1–5 atoms). Optical reflectance and X-ray diffraction measurements show that the procedure does not affect the TiO2 polymorph or ultraviolet-visible (UV-Vis) absorbance. Gas phase photocatalytic splitting of heavy water (D2O) shows that the Pt nanocluster-decorated TiO2 outperforms Pt nanoparticle (produced by photodeposition) decorated TiO2 in D2 production. Pt nanoclusters, produced directly from a commercial source, with high co-catalyst activity, are prime candidates to be used in benchmark photocatalytic reactions.
      Citation: C
      PubDate: 2018-11-22
      DOI: 10.3390/c4040064
      Issue No: Vol. 4, No. 4 (2018)
  • C, Vol. 4, Pages 65: Investigation of Nanographene Produced by In-Liquid
           Plasma for Development of Highly Durable Polymer Electrolyte Fuel Cells

    • Authors: Vladislav Gamaleev, Kengo Kajikawa, Keigo Takeda, Mineo Hiramatsu
      First page: 65
      Abstract: Recently, polymer electrolyte fuel cells (PEFCs) are attracting a lot of attention owing to their small size and relatively low working temperature (below 80 °C), which enables their usage in automobiles and household power generation. However, PEFCs have a problem with decreased output caused by corrosion of amorphous carbon, which is commonly used as a catalytic carrier. This problem could be solved by the usage of carbon nanostructures with a stronger crystal structure than amorphous carbon. In this work, nanographene supported by Pt nanoparticles was synthesized and examined for possible applications in the development of PEFCs with increased durability. Nanographene was synthesized by in-liquid plasma generated in ethanol using alternating current (AC) high voltage. A membrane electrode assembly (MEA) was constructed, where Pt nanoparticle-supported nanographene was used as the catalytic layer. Power generation characteristics of the MEA were evaluated and current density for the developed MEA was found to be approximately 240 mA/cm2. From the electrochemical evaluation, it was found that the durability of Pt nanoparticle-supported nanographene was about seven times higher than that of carbon black.
      Citation: C
      PubDate: 2018-11-23
      DOI: 10.3390/c4040065
      Issue No: Vol. 4, No. 4 (2018)
  • C, Vol. 4, Pages 66: Physical Activation of Wooden Chips and the Effect of
           Particle Size, Initial Humidity, and Acetic Acid Extraction on the
           Properties of Activated Carbons

    • Authors: Davide Bergna, Henrik Romar, Ulla Lassi
      First page: 66
      Abstract: In this research study, two different wooden biomasses (birch and pine) were thermally carbonized and steam-activated into activated carbons in a one-stage process. The effects of particle size and humidity (as received and oven-dried) on the properties, such as specific surface areas, pore volumes, and pore size distributions, of the final activated carbon characteristics were examined. Another set of biomasses (birch, spruce, and pine) was pre-treated before carbonization and the activation steps through an extractive process using a weak acetic acid in Soxhlet extractors. According to the results, the dried samples had a slightly lower surface area, while no difference was observed in the yields. For the extracted samples, there was a significant difference, especially in the pore size distributions, compared to the non-extracted samples. There appeared to be a shift from a meso-microporous distribution to a microporous distribution caused by the extractive pre-treatment.
      Citation: C
      PubDate: 2018-12-05
      DOI: 10.3390/c4040066
      Issue No: Vol. 4, No. 4 (2018)
  • C, Vol. 4, Pages 67: Carbon Nanodots: A Review—From the Current
           Understanding of the Fundamental Photophysics to the Full Control of the
           Optical Response

    • Authors: Alice Sciortino, Andrea Cannizzo, Fabrizio Messina
      First page: 67
      Abstract: Carbon dots (CDs) are an emerging family of nanosystems displaying a range of fascinating properties. Broadly speaking, they can be described as small, surface-functionalized carbonaceous nanoparticles characterized by an intense and tunable fluorescence, a marked sensitivity to the environment and a range of interesting photochemical properties. CDs are currently the subject of very intense research, motivated by their possible applications in many fields, including bioimaging, solar energy harvesting, nanosensing, light-emitting devices and photocatalyis. This review covers the latest advancements in the field of CDs, with a focus on the fundamental understanding of their key photophysical behaviour, which is still very debated. The photoluminescence mechanism, the origin of their peculiar fluorescence tunability, and their photo-chemical interactions with coupled systems are discussed in light of the latest developments in the field, such as the most recent results obtained by femtosecond time-resolved experiments, which have led to important steps forward in the fundamental understanding of CDs. The optical response of CDs appears to stem from a very complex interplay between the electronic states related to the core structure and those introduced by surface functionalization. In addition, the structure of CD energy levels and the electronic dynamics triggered by photo-excitation finely depend on the microscopic structure of any specific sub-type of CD. On the other hand, this remarkable variability makes CDs extremely versatile, a key benefit in view of their very wide range of applications.
      Citation: C
      PubDate: 2018-12-13
      DOI: 10.3390/c4040067
      Issue No: Vol. 4, No. 4 (2018)
  • C, Vol. 4, Pages 68: Structure of Carbon Materials Explored by Local
           Transmission Electron Microscopy and Global Powder Diffraction Probes

    • Authors: Karolina Jurkiewicz, Mirosława Pawlyta, Andrzej Burian
      First page: 68
      Abstract: Transmission electron microscopy and neutron or X-ray diffraction are powerful techniques available today for characterization of the structure of various carbon materials at nano and atomic levels. They provide complementary information but each one has advantages and limitations. Powder X-ray or neutron diffraction measurements provide structural information representative for the whole volume of a material under probe but features of singular nano-objects cannot be identified. Transmission electron microscopy, in turn, is able to probe single nanoscale objects. In this review, it is demonstrated how transmission electron microscopy and powder X-ray and neutron diffraction methods complement each other by providing consistent structural models for different types of carbons such as carbon blacks, glass-like carbons, graphene, nanotubes, nanodiamonds, and nanoonions.
      Citation: C
      PubDate: 2018-12-19
      DOI: 10.3390/c4040068
      Issue No: Vol. 4, No. 4 (2018)
  • C, Vol. 4, Pages 38: High-Surface-Area Mesoporous Activated Carbon from
           Hemp Bast Fiber Using Hydrothermal Processing

    • Authors: Md Zakir Hossain, Wei Wu, William Z. Xu, Muhammad B. I. Chowdhury, Anil Kumar Jhawar, Devin Machin, Paul A. Charpentier
      First page: 38
      Abstract: Synthesis of activated carbon from waste biomass is of current interest towards sustainability. The properties of biomass-derived activated carbon largely depend on the carbonization process. This study reports the preparation of mesoporous activated carbon with extremely high surface area from hemp bast fiber using hydrothermal processing. Hot water processing (390–500 °C) followed by activation using KOH and NaOH was investigated at different mass ratios. The described approach was found to enhance the mesoporosity (centered at 3.0 to 4.5 nm) of the hemp-derived activated carbon (HAC) from activation [confirmed by BJH (Barrett-Joyner-Halenda) pore size distribution and TEM (transmission electron microscopy) imaging]. BET (Brunauer-Emmett-Teller) results showed that the product has an extremely high surface area (2425 m2/g) while the surface functional groups (–OH, –COOH, C=C/C–C) were confirmed by FTIR (Fourier transform infrared spectroscopy) and further quantified by XPS (X-ray photoelectron spectroscopy). Increasing KOH concentration was found to enhance the surface area with a maximum biochar-to-KOH (g/g) ratio of 1:3. The crystallite domain size of HAC was determined using Raman spectroscopy of different wavelengths. The procedure described in this study is an environmentally friendly scalable route for the mass production of activated carbon using hemp fiber.
      Citation: C
      PubDate: 2018-06-25
      DOI: 10.3390/c4030038
      Issue No: Vol. 4, No. 3 (2018)
  • C, Vol. 4, Pages 39: CUBIT: Capacitive qUantum BIT

    • Authors: Sina Khorasani
      First page: 39
      Abstract: In this letter, it is proposed that cryogenic quantum bits can operate based on the nonlinearity due to the quantum capacitance of two-dimensional Dirac materials, and in particular graphene. The anharmonicity of a typical superconducting quantum bit is calculated, and the sensitivity of quantum bit frequency and anharmonicity with respect to temperature are found. Reasonable estimates reveal that a careful fabrication process can reveal expected properties, putting the context of quantum computing hardware into new perspectives.
      Citation: C
      PubDate: 2018-07-02
      DOI: 10.3390/c4030039
      Issue No: Vol. 4, No. 3 (2018)
  • C, Vol. 4, Pages 40: Controlling the Surface Oxygen Groups of
           Polyacrylonitrile-Based Carbon Nanofiber Membranes While Limiting Fiber

    • Authors: Yi Han, Ruoshi Li, Christian Brückner, Timothy M. Vadas
      First page: 40
      Abstract: Enhancing the performance of nanofibrous carbons requires the specific chemical functionalization of the surface, while limiting material degradation or causing other detrimental changes in the surface area and pore structures. We compare traditional oxidation protocols using HNO3, HNO3/H2SO4, and KMnO4 with the much less used oxidants RuO4 and OsO4, in tandem with secondary oxidants (such as KMnO4 or Oxone®), for their ability to form carboxylic acids on the surface of polyacrylonitrile-based activated carbon nanofiber membrane (ACNF) materials. While the traditional methods increased the carboxylic acid contents, they also destroyed the macrostructure of the ACNF, concomitant with the loss of up to 17 wt.% of the material. RuO4-mediated oxidations proved also to be too harsh. On the contrary, some of the OsO4-based protocols were characterized by very high mass yields; significant increase in carboxylic acid functionalization (6.3 µmol/mg) compared with the unmodified ACNF (1.7 µmol/mg), but with no concomitant loss of macrostructure, as measured by the retention of the Brunauer-Emmett-Teller (BET) surface area; and average pore width. While there was some reduction in micropore volume, the microporosity of the material remained high. The temperature-programmed desorption mass spectrometry (up to 1000 °C) indicated the presence of both single and adjacent carboxylic acid groups. We thus identified mild and highly effective reaction conditions for the functionalization of carbon nanomaterials without undue degradation of their physical properties.
      Citation: C
      PubDate: 2018-07-09
      DOI: 10.3390/c4030040
      Issue No: Vol. 4, No. 3 (2018)
  • C, Vol. 4, Pages 41: Comparison of the Properties of Activated Carbons
           Produced in One-Stage and Two-Stage Processes

    • Authors: Davide Bergna, Toni Varila, Henrik Romar, Ulla Lassi
      First page: 41
      Abstract: Activated carbons (ACs) can be produced from biomass in a thermal process either in a direct carbonization-activation process or by first carbonizing the biomass and later activating the bio-chars into activated carbons. The properties of the ACs are dependent on the type of process used for production. In this study, the properties of activated carbons produced in one-stage and two-stage processes are considered. Activated carbons were produced by physical activation of two types of starting materials: bio chars produced from spruce and birch chips in a commercial carbonization plant and from the corresponding raw chips. The activated carbons produced were characterized regarding specific surfaces, pore volumes, and pore size distributions. The un-activated bio chars had varying surface areas, 190 and 140 m2 g−1 for birch and spruce, respectively, and pore volumes of 0.092 and 0.067 cm3 g−1, respectively. On the other hand, 530–617 and 647–679 m2 g−1 for activated bio chars from birch and spruce, respectively, and pore volumes 0.366–0.509 and 0.545–0.555 cm3 g−1, respectively, were obtained. According to the results obtained, two slightly different types of activated carbons are produced depending on whether a one-stage or a two-stage carbonization and activation process is used. The ACs produced in the one-stage process had higher specific surface areas (SSA), according to the BET-model (Brunauer–Emmett–Teller), compared to the ones produced in a two-stage process (761–940 m2 g−1 vs. 540–650 m2 g−1, respectively). In addition, total pore volumes were higher in ACs from the one-stage process, but development of micro-pores was greater compared to those of the two-stage process. This indicates that the process can have an influence on the ACs’ porosity. There was no significant difference in total carbon content in general between the one-stage and two-stage processes for spruce and birch samples, but some differences were seen between the starting materials. Especially in the one-stage procedure with 2 and 4 h steam activation, there was nearly a 10% difference in carbon content between the spruce and birch samples.
      Citation: C
      PubDate: 2018-07-16
      DOI: 10.3390/c4030041
      Issue No: Vol. 4, No. 3 (2018)
  • C, Vol. 4, Pages 42: Synthesis of Graphene Nanosheets through Spontaneous
           Sodiation Process

    • Authors: Deepak-George Thomas, Emrah Kavak, Niloofar Hashemi, Reza Montazami, Nicole N. Hashemi
      First page: 42
      Abstract: Graphene is one of the emerging materials in the nanotechnology industry due to its potential applications in diverse areas. We report the fabrication of graphene nanosheets by spontaneous electrochemical reaction using solvated ion intercalation into graphite. The current literature focuses on the fabrication of graphene using lithium metal. Our procedure uses sodium metal, which results in a reduction of costs. Using various characterization techniques, we confirmed the fabrication of graphene nanosheets. We obtained an intensity ratio (ID/IG) of 0.32 using Raman spectroscopy, interlayer spacing of 0.39 nm and our XPS results indicate that our fabricated compound is relatively oxidation free.
      Citation: C
      PubDate: 2018-07-23
      DOI: 10.3390/c4030042
      Issue No: Vol. 4, No. 3 (2018)
  • C, Vol. 4, Pages 43: Synthesis and Characterization of
           Carbon/Nitrogen/Iron Based Nanoparticles by Laser Pyrolysis as Non-Noble
           Metal Electrocatalysts for Oxygen Reduction

    • Authors: Henri Perez, Virginie Jorda, Pierre Bonville, Jackie Vigneron, Mathieu Frégnaux, Arnaud Etcheberry, Axelle Quinsac, Aurélie Habert, Yann Leconte
      First page: 43
      Abstract: This paper reports original results on the synthesis of Carbon/Nitrogen/Iron-based Oxygen Reduction Reaction (ORR) electrocatalysts by CO2 laser pyrolysis. Precursors consisted of two different liquid mixtures containing FeOOH nanoparticles or iron III acetylacetonate as iron precursors, being fed to the reactor as an aerosol of liquid droplets. Carbon and nitrogen were brought by pyridine or a mixture of pyridine and ethanol depending on the iron precursor involved. The use of ammonia as laser energy transfer agent also provided a potential nitrogen source. For each liquid precursor mixture, several syntheses were conducted through the step-by-step modification of NH3 flow volume fraction, so-called R parameter. We found that various feature such as the synthesis production yield or the nanomaterial iron and carbon content, showed identical trends as a function of R for each liquid precursor mixture. The obtained nanomaterials consisted in composite nanostructures in which iron based nanoparticles are, to varying degrees, encapsulated by a presumably nitrogen doped carbon shell. Combining X-ray diffraction and Mossbauer spectroscopy with acid leaching treatment and extensive XPS surface analysis allowed the difficult question of the nature of the formed iron phases to be addressed. Besides metal and carbide iron phases, data suggest the formation of iron nitride phase at high R values. Interestingly, electrochemical measurements reveal that the higher R the higher the onset potential for the ORR, what suggests the need of iron-nitride phase existence for the formation of active sites towards the ORR.
      Citation: C
      PubDate: 2018-07-30
      DOI: 10.3390/c4030043
      Issue No: Vol. 4, No. 3 (2018)
  • C, Vol. 4, Pages 44: Individual Gas Molecules Detection Using Zinc
           Oxide–Graphene Hybrid Nanosensor: A DFT Study

    • Authors: Ingrid Torres, Sadegh Mehdi Aghaei, Amin Rabiei Baboukani, Chunlei Wang, Shekhar Bhansali
      First page: 44
      Abstract: Surface modification is a reliable method to enhance the sensing properties of pristine graphene by increasing active sites on its surface. Herein, we investigate the interactions of the gas molecules such as NH3, NO, NO2, H2O, and H2S with a zinc oxide (ZnO)–graphene hybrid nanostructure. Using first-principles density functional theory (DFT), the effects of gas adsorption on the electronic and transport properties of the sensor are examined. The computations show that the sensitivity of the pristine graphene to the above gas molecules is considerably improved after hybridization with zinc oxide. The sensor shows low sensitivity to the NH3 and H2O because of the hydrogen-bonding interactions between the gas molecules and the sensor. Owing to observable alterations in the conductance, large charge transfer, and high adsorption energy; the sensor possesses extraordinary potential for NO and NO2 detection. Interestingly, the H2S gas is totally dissociated through the adsorption process, and a large number of electrons are transferred from the molecule to the sensor, resulting in a substantial change in the conductance of the sensor. As a result, the ZnO–graphene nanosensor might be an auspicious catalyst for H2S dissociation. Our findings open new doors for environment and energy research applications at the nanoscale.
      Citation: C
      PubDate: 2018-08-09
      DOI: 10.3390/c4030044
      Issue No: Vol. 4, No. 3 (2018)
  • C, Vol. 4, Pages 45: Photoelectrochemical Response of WO3/Nanoporous
           Carbon Anodes for Photocatalytic Water Oxidation

    • Authors: Alicia Gomis-Berenguer, Jesús Iniesta, David J. Fermín, Conchi O. Ania
      First page: 45
      Abstract: This work demonstrates the ability of nanoporous carbons to boost the photoelectrochemical activity of hexagonal and monoclinic WO3 towards water oxidation under irradiation. The impact of the carbonaceous phase was strongly dependent on the crystalline structure and morphology of the semiconductor, substantially increasing the activity of WO3 rods with hexagonal phase. The incorporation of increasing amounts of a nanoporous carbon of low functionalization to the WO3 electrodes improved the quantum yield of the reaction and also affected the dynamics of the charge transport, creating a percolation path for the majority carriers. The nanoporous carbon promotes the delocalization of the charge carriers through the graphitic layers. We discuss the incorporation of nanoporous carbons as an interesting strategy for improving the photoelectrochemical performance of nanostructured semiconductor photoelectrodes featuring hindered carrier transport.
      Citation: C
      PubDate: 2018-08-10
      DOI: 10.3390/c4030045
      Issue No: Vol. 4, No. 3 (2018)
  • C, Vol. 4, Pages 46: Improving Spinnability of Hyper-Coal Derived
           Spinnable Pitch through the Hydrogenation with 1,2,3,4-Tetrahydroquinoline

    • Authors: Jianxiao Yang, Wei Wu, Xiaxiang Zhang, Kui Shi, Xuanke Li, Seong-Ho Yoon
      First page: 46
      Abstract: The proper hydrogenation of Hyper-coal (HPC) using 1,2,3,4-tetrahydroquinoline (THQ) was able to decrease the oxygen content and adjust the molecular structure of HPC for preparing the spinnable pitch with high softening point (SP). The spinnable pitch prepared from the THQ-soluble (QS) fraction of HPC as a precursor consisted of more naphthenic carbon groups than that prepared from the 1-methylnaphthalene (1-MN) soluble (MNS) fraction of HPC. The HPC-QS derived spinnable pitch showed excellent spinning performance even though the SP of 260 °C, and the tensile strength of the resultant carbon fiber was increased to 1350 MPa with a diameter around 8 µm under the only carbonization temperature of at 800 °C for 5 min.
      Citation: C
      PubDate: 2018-08-19
      DOI: 10.3390/c4030046
      Issue No: Vol. 4, No. 3 (2018)
  • C, Vol. 4, Pages 47: Operando DRIFTS-MS Study of WGS and rWGS Reaction on
           Biochar-Based Pt Catalysts: The Promotional Effect of Na

    • Authors: José L. Santos, Luis F. Bobadilla, Miguel A. Centeno, José A. Odriozola
      First page: 47
      Abstract: Biochar-based Pt catalysts, unpromoted and Na-promoted, were prepared by an incipient wetness impregnation method and characterised by Inductively coupled plasma mass spoectrometry (ICP-MS) analysis, X-ray diffraction, N2 adsorption and transmission, and scanning electron microscopy. It was demonstrated that a sodium promoter modifies the acid-base properties of the support, altering the Pt-support interaction. An operando Diffuse reflectance infrared fourier transform spectroscopy-mass spectrometry (DRIFTS-MS) study was performed to gain insights into the reaction pathways and the mechanism of the Water-Gass-Shift (WGS) and the Reverse Water-Gass-Shift (rWGS) reactions. It was demonstrated that the addition of Na enhances the catalytic performance due to the changes induced by the alkali in the electronic structure of the Pt active sites. This effect favours the activation of H2O molecules during the WGS reaction and the dissociation of CO2 during the rWGS reaction, although it may also favour the consecutive CO methanation pathway.
      Citation: C
      PubDate: 2018-08-21
      DOI: 10.3390/c4030047
      Issue No: Vol. 4, No. 3 (2018)
  • C, Vol. 4, Pages 48: Catalytic Performances of Au–Pt Nanoparticles on
           Phosphorous Functionalized Carbon Nanofibers towards HMF Oxidation

    • Authors: Sebastiano Campisi, Sofia Capelli, Davide Motta, Felipe Trujillo, Thomas Davies, Laura Prati, Nikolaos Dimitratos, Alberto Villa
      First page: 48
      Abstract: Herein, we reported the utilization of pre-formed Au–Pt nanoparticles deposited on phosphorus functionalized carbons as effective catalysts for the oxidation of 5-hydroxymethylfurfural (HMF) to furandicarboxylic acid (FDCA). Au–Pt nanoparticles have been prepared by a two-step methodology using polyvinyl alcohol (PVA) as protective agent and a combination of NaBH4 and H2 as reducing agents. Three carbon nanofibers (CNFs) with different graphitization degrees have been functionalized through treatment with an H3PO4–HNO3 mixture at 150 °C, in order to incorporate P groups on carbon surface. Surface and structural properties of the synthesized functionalized materials have been investigated by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. The structural and surface properties of carbon nanofibers determine the amount of P-functionalities, which is a key parameter affecting the catalytic performances of Au–Pt. Indeed, the highest activity and stability has been achieved for Au–Pt deposited on the sample, which showed the largest amount of P-groups on the surface.
      Citation: C
      PubDate: 2018-08-28
      DOI: 10.3390/c4030048
      Issue No: Vol. 4, No. 3 (2018)
  • C, Vol. 4, Pages 49: Graphene Nanoribbon as Potential On-Chip Interconnect
           Material—A Review

    • Authors: Arnab Hazra, Sukumar Basu
      First page: 49
      Abstract: In recent years, on-chip interconnects have been considered as one of the most challenging areas in ultra-large scale integration. In ultra-small feature size, the interconnect delay becomes more pronounced than the gate delay. The continuous scaling of interconnects introduces significant parasitic effects. The resistivity of interconnects increases because of the grain boundary scattering and side wall scattering of electrons. An increased Joule heating and the low current carrying capability of interconnects in a nano-scale dimension make it unreliable for future technology. The devices resistivity and reliability have become more and more serious problems for choosing the best interconnect materials, like Cu, W, and others. Because of its remarkable electrical and its other properties, graphene becomes a reliable candidate for next-generation interconnects. Graphene is the lowest resistivity material with a high current density, large mean free path, and high electron mobility. For practical implementation, narrow width graphene sheet or graphene nanoribbon (GNR) is the most suitable interconnect material. However, the geometric structure changes the electrical property of GNR to a small extent compared to the ideal behavior of graphene film. In the current article, the structural and electrical properties of single and multilayer GNRs are discussed in detail. Also, the fabrication techniques are discussed so as to pattern the graphene nanoribbons for interconnect application and measurement. A circuit modeling of the resistive-inductive-capacitive distributed network for multilayer GNR interconnects is incorporated in the article, and the corresponding simulated results are compared with the measured data. The performance of GNR interconnects is discussed from the view of the resistivity, resistive-capacitive delay, energy delay product, crosstalk effect, stability analysis, and so on. The performance of GNR interconnects is well compared with the conventional interconnects, like Cu, and other futuristic potential materials, like carbon nanotube and doped GNRs, for different technology nodes of the International Technology Roadmap for Semiconductors (ITRS).
      Citation: C
      PubDate: 2018-08-30
      DOI: 10.3390/c4030049
      Issue No: Vol. 4, No. 3 (2018)
  • C, Vol. 4, Pages 50: A New Approach of Fabricating Graphene
           Nanoplates@Natural Rubber Latex Composite and Its Characteristics and
           Mechanical Properties

    • Authors: Duong Duc La, Tuan Anh Nguyen, Viet Do Quoc, Tham Thi Nguyen, Duy Anh Nguyen, Linh Nguyen Pham Duy, Nghia Phan Trung, Sheshanath V. Bhosale
      First page: 50
      Abstract: Graphene has been demonstrated to be one of the most promising candidates to use as filler to improve the electrical, thermal, chemical and mechanical properties of natural rubber due to exceptional high surface area, superior electrical and thermal conductivity, and remarkable gas impermeability resistance. In this study, graphene nanoplates (GNPs) were mass-produced by a one-step chemical exfoliation of natural graphite and used as a filler for the fabrication of GNPs@natural rubber composite by a simple mixing method. The resultant GNPs/rubber composite was characterized by using scanning electron microscopy (SEM), and a rheometer. The prepared graphene nanoplates had a thickness of less than 10 nm and a lateral size of tens of microns. The GNPs@rubber composite revealed an exceptional improvement of abrasion loss up to seven to ten fold, along with an approximately 400%, 200% and 30% increment of elongation at break, tear strength and tensile strength, respectively. Other mechanical properties, such as hardness, compression set and rebound, as well as the effect of the GNPs loadings on the mechanical properties of the composite, were also investigated in detail.
      Citation: C
      PubDate: 2018-09-06
      DOI: 10.3390/c4030050
      Issue No: Vol. 4, No. 3 (2018)
  • C, Vol. 4, Pages 51: Activated Carbons Derived from High-Temperature
           Pyrolysis of Lignocellulosic Biomass

    • Authors: Cristian I. Contescu, Shiba P. Adhikari, Nidia C. Gallego, Neal D. Evans, Bryan E. Biss
      First page: 51
      Abstract: Biomass pyrolysis to produce biofuel and hydrogen yields large amounts of charred byproducts with low commercial value. A study was conducted to evaluate their potential for being converted into higher value activated carbons by a low-cost process. Six chars derived from various lignocellulosic precursors were activated in CO2 at 800 °C to 30–35% weight loss, and their surface area and porosity were characterized by nitrogen adsorption at 77 K. It was found that, in similar activation conditions, the surface area of the activated carbons correlates with the activation energy of the oxidation reaction by CO2, which in turn varies inversely with the carbon yield after thermolysis in nitrogen at 1000 °C. Since lignin is the most thermally-stable component of lignocellulosic biomass, these results demonstrate, indirectly, that robust, lignin-rich vegetal precursors are to be preferred to produce higher quality activated carbons. The chars derived from white pine (pinus strobus) and chestnut oak (quercus prinus) were converted to activated carbons with the highest surface area (900–1100 m2/g) and largest mesopores volume (0.85–1.06 cm3/g). These activated carbons have properties similar to those of commercially-available activated carbons used successfully for removal of pollutants from aqueous solutions.
      Citation: C
      PubDate: 2018-09-12
      DOI: 10.3390/c4030051
      Issue No: Vol. 4, No. 3 (2018)
  • C, Vol. 4, Pages 20: Eco-Friendly Synthesis of Nitrogen-Doped Mesoporous
           Carbon for Supercapacitor Application

    • Authors: Georges Moussa, Samar Hajjar-Garreau, Pierre-Louis Taberna, Patrice Simon, Camélia Matei Ghimbeu
      First page: 20
      Abstract: A sustainable and simple synthesis procedure involving the co-assembly of green phenolic resin and amphiphilic polymer template in water/ethanol mixture at room temperature to synthesize nitrogen doped mesoporous carbon is reported herein. Guanine is proposed as a novel nitrogen-based precursor which is able to create H-bondings both with the phenolic resin and the template allowing the formation of mesoporous carbons with nitrogen atoms uniformly distributed in their framework. The influence of the synthesis procedure, template amount and annealing temperature on the carbon textural properties, structure and surface chemistry were investigated. For several conditions, carbon materials with ordered pore size and high nitrogen content (up to 10.6 at %) could be achieved. The phase separation procedure combined with optimal amount of template favor the formation of ordered mesoporous carbons with higher specific surface area while the increase in the temperature induces a decrease in the surface area and amount of heteroatoms (N and O). The electrochemical performances as electrode in supercapacitors were evaluated in acidic medium and the capacitance was closely related to the material conductivity and surface chemistry.
      Citation: C
      PubDate: 2018-03-30
      DOI: 10.3390/c4020020
      Issue No: Vol. 4, No. 2 (2018)
  • C, Vol. 4, Pages 21: Boehm Titration Revisited (Part I): Practical Aspects
           for Achieving a High Precision in Quantifying Oxygen-Containing Surface
           Groups on Carbon Materials

    • Authors: Jan Schönherr, Johannes Buchheim, Peter Scholz, Philipp Adelhelm
      First page: 21
      Abstract: Practical aspects of the Boehm titration method are evaluated for obtaining reliable results in the quantification of oxygen-containing surface groups in a short time. Analytical criteria such as accuracy, repeatability, precision, and robustness are applied. Oxidized multi-walled carbon nanotubes (MWCNTs) are used as the model substance. Different reaction bases (NaHCO3(aq), Na2CO3(aq), NaOH(aq)) are applied and treatment times are studied. We also show that smaller amounts of carbon material can be reliably analyzed by using an autotitrator combined with a pH electrode. We find that indirect titration with Na2CO3 results in the highest titration precision and accuracy despite the lower base strength compared with NaOH. Therefore, CO2 impurities do not have to be removed and only 7 min is necessary for one titration. The titration error with respect to the proposed method is 0.15% of the aliquot volume. The mixing method during the carbon treatment with bases (stirring, shaking, ultrasound treatment) has no influence on the result as long as one allows a few hours for the reaction to complete. Finally, we provide a standard operating procedure for obtaining results with high precision during Boehm titration.
      Citation: C
      PubDate: 2018-04-06
      DOI: 10.3390/c4020021
      Issue No: Vol. 4, No. 2 (2018)
  • C, Vol. 4, Pages 22: Boehm Titration Revisited (Part II): A Comparison of
           Boehm Titration with Other Analytical Techniques on the Quantification of
           Oxygen-Containing Surface Groups for a Variety of Carbon Materials

    • Authors: Jan Schönherr, Johannes R. Buchheim, Peter Scholz, Philipp Adelhelm
      First page: 22
      Abstract: The use of the Boehm titration (BT) method as an analytical tool for the quantification of oxygen-containing surface groups is systematically investigated for oxidized carbon black, carbon nanotubes and two active carbons with specific surface areas between 60 and 1750 m2 g−1. The accuracy of the BT method is quantitatively compared with results from elemental analysis (EA), temperature programmed desorption (TPD), and X-ray photoelectron spectroscopy (XPS). Overall, the results from TPD are in line with the values obtained by BT. Both show the equal ratio of the oxygen groups to each other. Within the series of carbon samples, all methods provide similar trends for the total oxygen content yet the absolute numbers are deviating significantly. Reasons for these discrepancies are discussed and linked to the specific characteristics of the different methods. As the BT method is a solution based method, it only probes the surface fraction of the carbon that is accessible to the base solution. That means, it probes the relevant fraction for applications where carbon is in contact to aqueous solutions. Overall, the BT method can be conveniently applied to a broad range of carbon materials as long as the samples are sufficiently hydrophilic and of the enough sample amount is provided.
      Citation: C
      PubDate: 2018-04-11
      DOI: 10.3390/c4020022
      Issue No: Vol. 4, No. 2 (2018)
  • C, Vol. 4, Pages 23: Development of Electrode Materials of Lithium-Ion
           Battery Utilizing Nanospaces

    • Authors: Takunori Minamisawa, Kyoichi Oshida, Nozomi Kobayashi, Akinobu Ando, Daiki Misawa, Tomoyuki Itaya, Minoru Moriyama, Kozo Osawa, Toshimitsu Hata, Yuta Sugiyama, Hiroto Iguchi, Naoya Kobayashi
      First page: 23
      Abstract: To develop high capacity electrode materials for lithium-ion battery (LIB), dissimilar materials are mixed and, as a result, carbon nanofibers containing silicon (Si) nanoparticles and its components are successfully created by electrospinning method and some heat treatments. Tetraethoxysilane (TEOS) and Si nanoparticles are adopted as additives of carbon nanofibers because of their huge potential for obtaining high capacity. In this research, therefore, we develop TEOS/Si hybrid carbon nanofibers. Consequently, some samples obtain much higher charging/discharging capacity than the theoretical capacity for graphite (372 mAh/g, LiC6) even after second cycle.
      Citation: C
      PubDate: 2018-04-13
      DOI: 10.3390/c4020023
      Issue No: Vol. 4, No. 2 (2018)
  • C, Vol. 4, Pages 24: Supercapacitor Electrode Based on Activated Carbon
           Wool Felt

    • Authors: Ana Claudia Pina, Alejandro Amaya, Jossano Saldanha Marcuzzo, Aline C. Rodrigues, Mauricio R. Baldan, Nestor Tancredi, Andrés Cuña
      First page: 24
      Abstract: An electrical double-layer capacitor (EDLC) is based on the physical adsorption/desorption of electrolyte ions onto the surface of electrodes. Due to its high surface area and other properties, such as electrochemical stability and high electrical conductivity, carbon materials are the most widely used materials for EDLC electrodes. In this work, we study an activated carbon felt obtained from sheep wool felt (ACF’f) as a supercapacitor electrode. The ACF’f was characterized by elemental analysis, scanning electron microscopy (SEM), textural analysis, and X-ray photoelectron spectroscopy (XPS). The electrochemical behaviour of the ACF’f was tested in a two-electrode Swagelok®-type, using acidic and basic aqueous electrolytes. At low current densities, the maximum specific capacitance determined from the charge-discharge curves were 163 F·g−1 and 152 F·g−1, in acidic and basic electrolytes, respectively. The capacitance retention at higher current densities was better in acidic electrolyte while, for both electrolytes, the voltammogram of the sample presents a typical capacitive behaviour, being in accordance with the electrochemical results.
      Citation: C
      PubDate: 2018-04-16
      DOI: 10.3390/c4020024
      Issue No: Vol. 4, No. 2 (2018)
  • C, Vol. 4, Pages 25: Development and Characterization of Biomimetic
           Carbonated Calcium-Deficient Hydroxyapatite Deposited on Carbon Fiber

    • Authors: Quentin Picard, Florian Olivier, Sandrine Delpeux, Jérôme Chancolon, Fabienne Warmont, Sylvie Bonnamy
      First page: 25
      Abstract: Calcium phosphate and derivatives have been known for decades as bone compatible biomaterials. In this work, the chemical composition, microtexture, and structure of calcium phosphate deposits on carbon cloths were investigated. Three main types of deposits, obtained through variation of current density in using the sono-electrodeposition technique, were elaborated. At low current densities, the deposit consists in a biomimetic, plate-like, carbonated calcium-deficient hydroxyapatite (CDA), likely resulting from the in situ hydrolysis of plate-like octacalcium phosphate (OCP), while at higher current densities the synthesis leads to a needle-like carbonated CDA. At intermediate current densities, a mixture of plate-like and needle-like carbonated CDA is deposited. This established that sono-electrodeposition is a versatile process that allows the coating of the carbon scaffold with biomimetic calcium phosphate while tuning the morphology and chemical composition of the deposited particles, thereby bringing new insights in the development of new biomaterials for bone repair.
      Citation: C
      PubDate: 2018-04-23
      DOI: 10.3390/c4020025
      Issue No: Vol. 4, No. 2 (2018)
  • C, Vol. 4, Pages 26: Investigation of the Catalytic Performance of Pd/CNFs
           for Hydrogen Evolution from Additive-Free Formic Acid Decomposition

    • Authors: Felipe Sanchez, Davide Motta, Ludovica Bocelli, Stefania Albonetti, Alberto Roldan, Ceri Hammond, Alberto Villa, Nikolaos Dimitratos
      First page: 26
      Abstract: In recent years, research efforts have focused on the development of safe and efficient H2 generation/storage materials toward a fuel-cell-based H2 economy as a long-term solution in the near future. Herein, we report the development of Pd nanoparticles supported on carbon nanofibers (CNFs) via sol-immobilisation and impregnation techniques. Thorough characterisation has been carried out by means of XRD, XPS, SEM-EDX, TEM, and BET. The catalysts have been evaluated for the catalytic decomposition of formic acid (HCOOH), which has been identified as a safe and convenient H2 carrier under mild conditions. The influence of preparation method was investigated and catalysts prepared by the sol-immobilisation method showed higher catalytic performance (PdSI/CNF) than their analogues prepared by the impregnation method (PdIMP/CNF). A high turnover frequency (TOF) of 979 h−1 for PdSI/CNF and high selectivity (>99.99%) was obtained at 30 °C for the additive-free formic acid decomposition. Comparison with a Pd/AC (activated charcoal) catalyst synthesised with sol-immobilisation method using as a support activated charcoal (AC) showed an increase of catalytic activity by a factor of four, demonstrating the improved performance by choosing CNFs as the preferred choice of support for the deposition of preformed colloidal Pd nanoparticles.
      Citation: C
      PubDate: 2018-05-01
      DOI: 10.3390/c4020026
      Issue No: Vol. 4, No. 2 (2018)
  • C, Vol. 4, Pages 27: Porous (Swiss-Cheese) Graphite

    • Authors: Joseph P. Abrahamson, Ramakrishnan Rajagopalan, Randy L. Vander Wal
      First page: 27
      Abstract: Porous graphite was prepared without the use of template by rapidly heating the carbonization products from mixtures of anthracene, fluorene, and pyrene with a CO2 laser. Rapid CO2 laser heating at a rate of 1.8 × 106 °C/s vaporizes out the fluorene-pyrene derived pitch while annealing the anthracene coke. The resulting structure is that of graphite with 100 nm spherical pores. The graphitizablity of the porous material is the same as pure anthracene coke. Transmission electron microscopy revealed that the interfaces between graphitic layers and the pore walls are unimpeded. Traditional furnace annealing does not result in the porous structure as the heating rates are too slow to vaporize out the pitch, thereby illustrating the advantage of fast thermal processing. The resultant porous graphite was prelithiated and used as an anode in lithium ion capacitors. The porous graphite when lithiated had a specific capacity of 200 mAh/g at 100 mA/g. The assembled lithium ion capacitor demonstrated an energy density as high as 75 Wh/kg when cycled between 2.2 V and 4.2 V.
      Citation: C
      PubDate: 2018-05-02
      DOI: 10.3390/c4020027
      Issue No: Vol. 4, No. 2 (2018)
  • C, Vol. 4, Pages 28: Aligned Carbon Nanotube Arrays Bonded to Solid
           Graphite Substrates: Thermal Analysis for Future Device Cooling

    • Authors: Betty T. Quinton, Levi Elston, James D. Scofield, Sharmila M. Mukhopadhyay
      First page: 28
      Abstract: Carbon nanotubes (CNTs) are known for high thermal conductivity and have potential use as nano-radiators or heat exchangers. This paper focuses on the thermal performance of carpet-like arrays of vertically aligned CNTs on solid graphite substrates with the idea of investigating their behavior as a function of carpet dimensions and predicting their performance as thermal interface material (TIM) for electronic device cooling. Vertically aligned CNTs were grown on highly oriented pyrolytic graphite (HOPG) substrate, which creates a robust and durable all-carbon hierarchical structure. The multi-layer thermal analysis approach using Netzsch laser flash analysis system was used to evaluate their performance as a function of carpet height, from which their thermal properties can be determined. It was seen that the thermal resistance of the CNT array varies linearly with CNT carpet height, providing a unique way of decoupling the properties of the CNT carpet from its interface. This data was used to estimate the thermal conductivity of individual multi-walled nanotube strands in this carpet, which was about 35 W/m-K. The influence of CNT carpet parameters (aerial density, diameter, and length) on thermal resistance of the CNT carpet and its potential advantages and limitations as an integrated TIM are discussed.
      Citation: C
      PubDate: 2018-05-07
      DOI: 10.3390/c4020028
      Issue No: Vol. 4, No. 2 (2018)
  • C, Vol. 4, Pages 29: Pathogen-Imprinted Organosiloxane Polymers as
           Selective Biosensors for the Detection of Targeted E. coli

    • Authors: Maria T. Dulay, Naina Zaman, David Jaramillo, Alison C. Mody, Richard N. Zare
      First page: 29
      Abstract: Early detection of pathogens requires methods that are fast, selective, sensitive and affordable. We report the development of a biosensor with high sensitivity and selectivity based on the low-cost preparation of organosiloxane (OSX) polymers imprinted with E. coli-GFP (green fluorescent protein). OSX polymers with high optical transparency, no cracking, and no shrinkage were prepared by varying several parameters of the sol–gel reaction. The unique shape and chemical fingerprint of the targeted inactivated E. coli-GFP were imprinted into bulk polymers by replication imprinting where the polymer solution was dropcast onto a bacteria template that produced a replica of the bacterial shape and chemistry on the polymer surface upon removal of the template. Capture performances were studied under non-laminar flow conditions with samples containing inactivated E. coli-GFP and compared to inactivated S. typhimurium-GFP. Capture selectivity ratios are dependent on the type of alkoxysilanes used, the H2O:silane molar ratio, and the polymerization temperature. The bacteria concentration in suspension ranged from ~6 × 105 to 1.6 × 109 cells/mL. E. coli-imprinted OSX polymers with polyethylene glycol (PEG) differentiated between the targeted bacterium E. coli, and non-targeted bacteria S. typhimurium and native E. coli-GFP, achieving selectivity ratios up to 4.5 times higher than polydimethylsiloxane (PDMS) and OSX polymers without PEG.
      Citation: C
      PubDate: 2018-05-14
      DOI: 10.3390/c4020029
      Issue No: Vol. 4, No. 2 (2018)
  • C, Vol. 4, Pages 30: Nanocomposite-Based Aminated Polyethersulfone and
           Carboxylate Activated Carbon for Environmental Application. A Real Sample

    • Authors: Noof Alenazi, Mahmoud Hussein, Khalid Alamry, Abdullah Asiri
      First page: 30
      Abstract: Aminated polyethersulfone (PES–NH2) has been synthesized and used with carboxylated activated carbon (AC–COOH) as an adsorbent using two different methods: in situ and ex situ techniques. The chemical modification of polyethersulfone (PES) to introduce –NH2 functions was used to overcome the hydrophobicity of PES which maximizes its use in water treatment applications whereas applying AC–COOH to this polymer provides a promising effective method as an adsorbent-separation technique to remove dye pollutants from wastewater. The structure and characterization of aminated polyethersulfone with carboxylated activated carbon (PES–NH2–AC–COOH) were identified using proton nuclear magnetic resonance (1H-NMR), Fourier transform infrared (FT-IR spectroscopy), X-ray diffraction (XRD), thermal analysis (TA), and a scanning electron microscopy (SEM). The performance of PES–NH2 in situ and ex situ with AC–COOH was tested for the adsorption of cationic (methylene blue) and anionic (acid red 1) dyes from an aquatic environment. The results of the study showed a better thermal stability for the PES–NH2 with 20% AC–COOH with both in situ and ex situ techniques as well as an excellent adsorption performance in comparison with the bare PES–NH2. The resultant polymers displayed significantly high adsorption rates for the acid red dye (60% and 68%) and methylene blue dye (61% and 88%) by PES–NH2 with AC–COOH using in situ and ex situ techniques, respectively, in comparison with the control (PES–NH2) which showed lower adsorption rates for both dyes (21% for acid red and 33% for methylene blue). Lastly, the study experimental measurements found the most suitable model to describe the kinetic behavior of the acid red dye adsorption by our developed polymer (by PES–NH2 with AC–COOH) to be the pseudo-second-order kinetic model.
      Citation: C
      PubDate: 2018-05-15
      DOI: 10.3390/c4020030
      Issue No: Vol. 4, No. 2 (2018)
  • C, Vol. 4, Pages 31: Electrostatically Sprayed Reduced Graphene
           Oxide-Carbon Nanotubes Electrodes for Lithium-Ion Capacitors

    • Authors: Ebenezer Adelowo, Amin Baboukani, Chunhui Chen, Chunlei Wang
      First page: 31
      Abstract: Lithium-ion capacitors (LICs) comprising capacitor-type and battery-type electrodes are promising electrochemical energy storage systems to effectively combine the merits of lithium-ion batteries (LIBs) and electrochemical capacitors (ECs). It is expected that the energy density of LICs can be improved by utilizing electrodes that are capable of providing high specific capacity. Herein, we demonstrate a graphene-based LIC with reduced graphene oxide-carbon nanotube (rGO-CNT) film as capacitor-type electrode and pre-lithiated rGO-CNT film as battery-type electrode using 1 M LiPF6 in EC: EMC electrolyte. The rGO-CNT was prepared by electrostatic spray deposition (ESD), which offers advantages, such as simultaneous reduction and binder-free deposition of GO on a current collector and facile morphology control. The rGO-CNT shows high specific capacity and good cyclability as both capacitor-type and battery-type electrode materials. The rGO-CNT//lithiated rGO-CNT LIC delivered energy densities as high as 114.5 Wh Kg−1 and maximum power density of 2569 W kg−1. This indicates the promising potential of the ESD approach for the facile fabrication of graphene-based electrodes for high performance LICs.
      Citation: C
      PubDate: 2018-05-19
      DOI: 10.3390/c4020031
      Issue No: Vol. 4, No. 2 (2018)
  • C, Vol. 4, Pages 32: Morphological and Radio Frequency Characterization of
           Graphene Composite Films

    • Authors: Simone Quaranta, Mario Miscuglio, Ahmad Bayat, Patrizia Savi
      First page: 32
      Abstract: Graphene is a monolayer of carbon atoms which exhibits remarkable electronic and mechanical properties. Graphene based nano-materials have gained a lot of interest for many applications. In this paper, inks with three different graphene concentrations (12.5, 25, and 33 wt % in graphene) were prepared and deposited by screen printing. A detailed investigation of films’ surface morphology using Scanning Electron Microscope (SEM) and Atomic Force Microscopy (AFM) revealed that the graphene films present a homogeneous dispersion of the filler with a comparatively lower surface roughness at higher concentrations and negligible agglomerates. The films were then printed between copper electrodes on FR-4 substrate (trade name for glass-reinforced epoxy laminate material), commonly used in Radio Frequency (RF) circuits, and the measured scattering parameters analyzed. Finally, the reflection coefficient of a patch antenna, fabricated on FR-4 substrate with and without a stub loaded by a thin film were measured. The difference of the resonant frequency due to the different interaction between graphene flakes and polymer binders shows attractive features of functionalized graphene films for chemical and bio-sensing applications.
      Citation: C
      PubDate: 2018-05-20
      DOI: 10.3390/c4020032
      Issue No: Vol. 4, No. 2 (2018)
  • C, Vol. 4, Pages 33: Carbon Nanostructure Curvature Induced from the Rapid
           Release of Sulfur upon Laser Heating

    • Authors: Joseph P. Abrahamson, Randy L. Vander Wal
      First page: 33
      Abstract: Laboratory-generated synthetic soot from benzene and benzene–thiophene was neodymium-doped yttrium aluminum garnet (Nd:YAG) laser and furnace annealed. Furnace annealing of sulfur doped synthetic soot resulted in the formation of micro-cracks due to the high pressures caused by explosive sulfur evolution at elevated temperature. The heteroatom sulfur affected the carbon nanostructure in a different way than oxygen. Sulfur is thermally stable in carbon up to ~1000 °C and thus, played little role in the initial low temperature (500 °C) carbonization. As such, it imparted a relatively unobservable impact on the nanostructure, but rather, acted to cause micro-cracks upon rapid release in the form of H2S and CS2 during subsequent traditional furnace heat treatment. In contrast, Nd:YAG laser heating of the sulfur doped sample acted to induce curvature in the carbon nanostructure. The observed curvature was the result of carbon annealing occurring simultaneously with sulfur evolution due to the rapid heating rate.
      Citation: C
      PubDate: 2018-05-22
      DOI: 10.3390/c4020033
      Issue No: Vol. 4, No. 2 (2018)
  • C, Vol. 4, Pages 34: A Library of Doped-Graphene Images via Transmission
           Electron Microscopy

    • Authors: Phuong Viet Pham
      First page: 34
      Abstract: Much recent work has focused on improving the performance of graphene by various physical and chemical modification approaches. In particular, chemical doping of n-type and p-type dopants through substitutional and surface transfer strategies have been carried out with the aim of electronic and band-gap tuning. In this field, the visualization of (i) The intrinsic structure and morphology of graphene layers after doping by various chemical dopants, (ii) the formation of exotic and new chemical bonds at surface/interface between the graphene layers and the dopants is highly desirable. In this short review, recent advances in the study of doped-graphenes and of the n-type and p-type doping techniques through transmission electron microscopy (TEM) analysis and observation at the nanoscale will be addressed.
      Citation: C
      PubDate: 2018-05-28
      DOI: 10.3390/c4020034
      Issue No: Vol. 4, No. 2 (2018)
  • C, Vol. 4, Pages 35: A Wide Adsorption Range Hybrid Material Based on
           Chitosan, Activated Carbon and Montmorillonite for Water Treatment

    • Authors: Farida Bouyahmed, Min Cai, Laurence Reinert, Laurent Duclaux, Ratan Dey, Hicham Youcef, Mohammed Lahcini, Fabrice Muller, Sandrine Delpeux-Ouldriane
      First page: 35
      Abstract: Numerous adsorbent materials are developed and are able to face specific types of pollution, but none of them can manage the whole pollution. The purpose of this work is to develop a novel hybrid adsorbent, based on chitosan (CS) biopolymer, clay minerals and activated carbon (AC), having complementary adsorption properties and achieving a wide-spectrum water decontamination in a single treatment. Hybrid CS beads, containing dispersed clay and AC, were prepared from dispersions of solid adsorbents in a CS solution and its further coagulation in a basic medium. The porosity and the homogeneity of the hybrid beads were characterized by N2 adsorption at 77 K and Cryo-Scanning Electron Microscopy respectively. The interaction between CS and clay was characterized using X-ray diffraction. Water content and the amount of each adsorbent in the hydrogel beads were determined by thermogravimetric analysis. Such a composite material was still porous and presented a wide adsorption spectrum. As shown by their adsorption kinetics, hydrophobic anionic clofibric acid (CBA) and cationic metoprolol (MTP) were well adsorbed on AC containing beads (21 and 26 mg/g), respectively. Clays containing beads showed interesting adsorption properties towards cationic Zn2+ and MTP. The obtained composite beads were able to adsorb all the pollutant types: Zinc cations, and hydrophobic-charged organic molecules, such as pharmaceutical derivatives (clofibric acid and MTP).
      Citation: C
      PubDate: 2018-06-05
      DOI: 10.3390/c4020035
      Issue No: Vol. 4, No. 2 (2018)
  • C, Vol. 4, Pages 36: Trajectories of Graphitizable Anthracene Coke and
           Non-Graphitizable Sucrose Char during the Earliest Stages of Annealing by
           Rapid CO2 Laser Heating

    • Authors: Joseph Abrahamson, Abhishek Jain, Adri van Duin, Randy Vander Wal
      First page: 36
      Abstract: The earliest stages of annealing of graphitizable anthracene coke and non-graphitizable sucrose char were observed by rapid heating with a CO2 laser. Structural transformations were observed with transmission electron microscopy. Anthracene coke and sucrose char were laser heated to 1200 °C and 2600 °C for 0.25–300 s. The transformations are compared to traditional furnace heating at matching temperatures for a 1 h duration. Traditional furnace and CO2 laser annealing followed the same pathway, based upon equivalent end structures. Graphitizable anthracene coke annealed faster than non-graphitizable sucrose char. Sucrose char passed through a structural state of completely closed shell nanoparticles that opened upon additional heat treatment and gave rise to the irregular pore structure found in the end product. The observed curvature in sucrose char annealed at 2600 °C results from shell opening. The initial presence of curvature and loss by heat treatment argues that odd membered rings are present initially and not formed upon heat treatment. Thus, odd membered rings are not manufactured during the annealing process due to impinging growth of stacks, but are likely present in the starting structure. The observed unraveling of the closed shell structure was simulated with ReaxFF.
      Citation: C
      PubDate: 2018-06-11
      DOI: 10.3390/c4020036
      Issue No: Vol. 4, No. 2 (2018)
  • C, Vol. 4, Pages 37: Single Wall Carbon Nanotubes Synthesis through
           Methane Chemical Vapor Deposition over MCM-41–Co Catalysts: Variables

    • Authors: Frank Ramírez Rodríguez, Betty Lucy López, Luis Fernando Giraldo
      First page: 37
      Abstract: MCM-41–Co catalysts were tested in the synthesis of single wall carbon nanotubes (SWCNTs) through methane chemical vapor deposition (CVD), varying total cobalt content, synthesis temperature, methane flow rate, and deposition time. All variables showed a relationship with total carbon deposition, graphitic quality according to Raman results. Cobalt content showed a maximum activity at 4%, but the structural quality is best at 3%. Flow rate does not affect the quality up to 300 cm3 min−1, but deposition time leads to the formation of highly disordered carbon species passing methane for periods longer than 30 min, concluding that optimal variables are a methane deposition temperature of 800 °C, a 300 cm3 min−1 methane flow rate, and a 30 min of methane injection time, leading to a 5.4% carbon mass content and 5.1 G/D area ratios.
      Citation: C
      PubDate: 2018-06-19
      DOI: 10.3390/c4020037
      Issue No: Vol. 4, No. 2 (2018)
  • C, Vol. 4, Pages 3: Adsorption of Bovine Serum Albumin on Carbon-Based

    • Authors: Mykola Seredych, Lyuba Mikhalovska, Sergey Mikhalovsky, Yury Gogotsi
      First page: 3
      Abstract: The protein adsorption plays a very important role in biotechnology, biomolecular engineering and it is one of the main factors determining bio- and hemocompatibility of biomedical materials in medical applications, such as blood purification and wound healing. Here we report adsorption properties of two carbon-based materials, thermally expanded graphite (EGr) and graphene nanoplatelets (GnP), for bovine serum albumin (BSA), the most abundant blood plasma protein. The influence of the surface chemistry of expanded graphite on the mechanism of BSA adsorption was studied by using EGr modified with oxygen or nitrogen functionalities. Having low microporosity and the specific surface area in the range of 5 to 50 m2/g, the expanded graphite exhibits high protein adsorption capacity at high equilibrium concentrations, which makes this material a potential candidate for biomedical applications as a carrier for high molecular weight (HMW) drug delivery or adsorption of HMW metabolites. At low equilibrium concentrations, the effect of specific protein-surface functional groups interaction reveals the differences between the adsorption affinity of different surface modified EGr materials to BSA. The adsorption of BSA on GnP with a specific surface area of 286 m2/g and a developed micro-/mesoporous structure did not follow the same mechanism as seen with EGr materials. At low equilibrium concentration of BSA, GnP exhibits high adsorption efficiency. An important finding is that no release of nanoparticles from expanded graphite adsorbents was observed, which makes them potentially suitable for direct contact with blood and other tissues while very small nanoparticles were noticed in the case of graphene nanoplatelets.
      Citation: C
      PubDate: 2018-01-07
      DOI: 10.3390/c4010003
      Issue No: Vol. 4, No. 1 (2018)
  • C, Vol. 4, Pages 4: Transmission Electron Microscopy of Carbon: A Brief

    • Authors: Peter Harris
      First page: 4
      Abstract: Transmission electron microscopy (TEM) has been used in the study of solid carbon since the 1940s. A number of important forms of carbon have been discovered through the use of TEM, and our understanding of the microstructure of carbon has largely been gained through the application of TEM and associated techniques. This article is an attempt to present an historical review of the application of TEM to carbon, from the earliest work to the present day. The review encompasses both graphitic carbon and diamond, and spectroscopic techniques are covered, as well as imaging. In the final section of the review, the impact of aberration-corrected TEM on current carbon research is highlighted.
      Citation: C
      PubDate: 2018-01-12
      DOI: 10.3390/c4010004
      Issue No: Vol. 4, No. 1 (2018)
  • C, Vol. 4, Pages 5: Acknowledgement to Reviewers of C in 2017

    • Authors: C Editorial Office
      First page: 5
      Abstract: Peer review is an essential part in the publication process, ensuring that C (Journal of Carbon Research) maintains high quality standards for its published papers [...]
      Citation: C
      PubDate: 2018-01-12
      DOI: 10.3390/c4010005
      Issue No: Vol. 4, No. 1 (2018)
  • C, Vol. 4, Pages 6: Mechanical and Electrical Characterization of Carbon
           Fiber/Bucky Paper/Zinc Oxide Hybrid Composites

    • Authors: Suma Ayyagari, Marwan Al-Haik, Virginie Rollin
      First page: 6
      Abstract: The quest for multifunctional carbon fiber reinforced composites (CFRPs) expedited the use of several nano reinforcements such as zinc oxide nanorods (ZnO) and carbon nanotubes (CNTs). Zinc oxide is a semi-conductor with good piezoelectric and pyroelectric properties. These properties could be transmitted to CFRPs when a nanophase of ZnO is embedded within CFRPs. In lieu of ZnO nanorods, Bucky paper comprising mat of CNTs could be sandwiched in-between composite laminae to construct a functionally graded composite with enhanced electrical conductivities. In this study, different configurations of hybrid composites based on carbon fibers with different combinations of ZnO nanorods and Bucky paper were fabricated. The composites were tested mechanically via tensile and dynamic mechanical analysis (DMA) tests to examine the effect of the different nanoadditives on the stiffness, strength and the damping performance of the hybrid composites. Electrical resistivities of the hybrid composites were probed to examine the contributions of the different nanoadditives. The results suggest that there are certain hybrid composite combinations that could lead to the development of highly multifunctional composites with better strength, stiffness, damping and electrical conductivity.
      Citation: C
      PubDate: 2018-01-18
      DOI: 10.3390/c4010006
      Issue No: Vol. 4, No. 1 (2018)
  • C, Vol. 4, Pages 7: Hybrid Carbon-Based Clathrates for Energy Storage

    • Authors: Kwai Chan
      First page: 7
      Abstract: Hybrid carbon–silicon, carbon–nitrogen, and carbon–boron clathrates are new classes of Type I carbon-based clathrates that have been identified by first-principles computational methods by substituting atoms on the carbon clathrate framework with Si, N, and/or B atoms. The hybrid framework is further stabilized by embedding appropriate guest atoms within the cavities of the cage structure. Series of hybrid carbon–silicon, carbon–boron, carbon–nitrogen, and carbon-silicon-nitrogen clathrates have been shown to exhibit small positive values for the energy of formation, indicating that they may be metastable compounds and amenable to fabrication. In this overview article, the energy of formation, elastic properties, and electronic properties of selected hybrid carbon-based clathrates are summarized. Theoretical calculations that explore the potential applications of hybrid carbon-based clathrates as energy storage materials, electronic materials, or hard materials are presented. The computational results identify compositions of hybrid carbon–silicon and carbon–nitrogen clathrates that may be considered as candidate materials for use as either electrode materials for Li-ion batteries or as hydrogen storage materials. Prior processing routes for fabricating selected hybrid carbon-based clathrates are highlighted and the difficulties encountered are discussed.
      Citation: C
      PubDate: 2018-01-22
      DOI: 10.3390/c4010007
      Issue No: Vol. 4, No. 1 (2018)
  • C, Vol. 4, Pages 8: High-Performance Vanadium Redox Flow Batteries with
           Graphite Felt Electrodes

    • Authors: Trevor Davies, Joseph Tummino
      First page: 8
      Abstract: A key objective in the development of vanadium redox flow batteries (VRFBs) is the improvement of cell power density. At present, most commercially available VRFBs use graphite felt electrodes under relatively low compression. This results in a large cell ohmic resistance and limits the maximum power density. To date, the best performing VRFBs have used carbon paper electrodes, with high active area compression pressures, similar to that used in fuel cells. This article investigates the use of felt electrodes at similar compression pressures. Single cells are assembled using compression pressures of 0.2–7.5 bar and tested in a VRFB system. The highest cell compression pressure, combined with a thin Nafion membrane, achieved a peak power density of 669 mW cm−2 at a flow rate of 3.2 mL min−1 per cm2 of active area, more than double the previous best performance from a felt-VRFB. The results suggest that felt electrodes can compete with paper electrodes in terms of performance when under similar compression pressures, which should help guide electrode development and cell optimization in this important energy storage technology.
      Citation: C
      PubDate: 2018-01-25
      DOI: 10.3390/c4010008
      Issue No: Vol. 4, No. 1 (2018)
  • C, Vol. 4, Pages 9: Controlling the Incorporation of Phosphorus
           Functionalities on Carbon Nanofibers: Effects on the Catalytic Performance
           of Fructose Dehydration

    • Authors: Sebastiano Campisi, Felipe Sanchez Trujillo, Davide Motta, Thomas Davies, Nikolaos Dimitratos, Alberto Villa
      First page: 9
      Abstract: Phosphorylated carbons have been reported to be effective catalysts in dehydration reactions for biomass valorization. The amount and the nature of P groups are a key parameter affecting the catalytic performances of functionalized materials. Herein, we investigate the role of structural and surface properties of carbon-based materials, specifically carbon nanofibers, in determining the amount of P-functionalities. In order to incorporate P groups on carbon surfaces, various carbon nanofibers (CNFs) with different graphitization degrees have been functionalized through treatment with a H3PO4-HNO3 mixture at 150 °C. The pristine materials, as well as the functionalization protocol, were properly selected to achieve an effective functionalization without drastically altering the morphology of the samples. Surface and structural properties of the synthesized functionalized materials have been investigated by means of transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. The catalytic behavior of phosphorylated carbon nanofibers has been evaluated in the selective dehydration of fructose to hydroxymethylfurfural (HMF) to elucidate structure-activity relationships.
      Citation: C
      PubDate: 2018-01-27
      DOI: 10.3390/c4010009
      Issue No: Vol. 4, No. 1 (2018)
  • C, Vol. 4, Pages 10: Surface Observation and Magnetism of Oil-Extracted
           Botryococcus braunii Residues before and after Carbonization

    • Authors: Aohan Wang, Mikihide Demura, Makoto Watanabe, Kotaro Ohara, Takanari Kashiwagi, Kazuo Kadowaki, Eiji Kita, Jiuchao Dong, Hiromasa Goto
      First page: 10
      Abstract: Microalgae is a promising next-generational energy. In this research, we focus on oil-extracted Botryococcus braunii residues collected by adding polysilicato-iron (PSI) as a flocculant followed by carbonization under argon atmosphere. We conducted carbonization at various temperatures as a first attempt to reveal the fundamental properties of the carbonization process of the microbes. The carbons thus obtained by heat treatment at 900 °C present a unique magnetic behavior due to reduced magnetite (Fe3O4) inclusion, which is produced from polysilicato iron (Fe2O3) during the heating process. Experimental results suggest that this carbonic material can be applied as a heavy metal-capturing carbon and magnetic porous substrate catalyst. The effective use of the waste may open a new avenue for an energy-microbiology-materials system.
      Citation: C
      PubDate: 2018-02-02
      DOI: 10.3390/c4010010
      Issue No: Vol. 4, No. 1 (2018)
  • C, Vol. 4, Pages 11: Nitrogen-Doped Hollow Carbon Spheres with Embedded Co
           Nanoparticles as Active Non-Noble-Metal Electrocatalysts for the Oxygen
           Reduction Reaction

    • Authors: Ruohao Xing, Yao Zhou, Ruguang Ma, Qian Liu, Jun Luo, Minghui Yang, Jiacheng Wang
      First page: 11
      Abstract: Transition metal (Fe, Co, Ni) complexes on carbon nanomaterials are promising candidates as electrocatalysts towards the oxygen reduction reaction (ORR). In this paper, nitrogen-doped hollow carbon spheres with embedded Co nanoparticles were successfully prepared via a controllable synthesis strategy. The morphology characterization shows that the hollow carbon spheres possess an average diameter of ~150 nm with a narrow size distribution and a shell thickness of ~14.5 nm. The content of N doping ranges from 2.1 to 6.6 at.% depending on the calcination temperature from 900 to 1050 °C. Compared with commercial Pt/C, the Co-containing nitrogen-doped hollow carbon spheres prepared at 900 °C (CoNHCS-900) as an ORR electrocatalyst shows a half-wave potential shift of only ∆E1/2 = 55 mV, but a superior stability of about 90.2% maintenance after 20,000 s in the O2-saturated 0.1 M KOH at a rotating speed of 1600 rpm. This could be ascribed to the synergistic effects of N-containing moieties, Co-Nx species, and Co nanoparticles, which significantly increase the density of active sites and promote the charge transfer during the ORR process.
      Citation: C
      PubDate: 2018-02-09
      DOI: 10.3390/c4010011
      Issue No: Vol. 4, No. 1 (2018)
  • C, Vol. 4, Pages 12: Electrostatic Adsorption of Platinum onto Carbon
           Nanotubes and Nanofibers for Nanoparticle Synthesis

    • Authors: Ritubarna Banerjee, Jose Contreras-Mora, Susan McQuiston, Brandon Bolton, Bahareh Tavakoli Mehrabadi, John Regalbuto
      First page: 12
      Abstract: Strong Electrostatic Adsorption (SEA) has been demonstrated as a simple, scientific method to prepare well dispersed Pt nanoparticles over typical forms of carbon: activated, black, and graphitic carbons. Many varieties of specialty carbons have been invented in the last few decades including multi-walled nanotubes, nanofibers, graphene nanoplatelets, etc. In this work, we explore whether SEA can be applied to these specialty carbons for the synthesis of Pt nanoparticles. Over a number of oxidized and unoxidized multiwalled nanotubes and nanofibers, the point of zero charge (PZC) was measured and the uptake of anionic Pt complexes (Pt hexachloride, [PtCl6]2−, and cationic Pt complexes (platinum tetraammine, [Pt(NH3)4]2+) as functions of final pH were surveyed. Pt nanoparticles on the various supports were synthesized at the optimal pH and were characterized by x-ray diffraction (XRD) and scanning transmission electron microscopy (STEM). The specialty carbons displayed volcano-shaped uptake curves typical of electrostatic adsorption for both Pt anions at low pH and Pt cations at high pH. However, the regimes of uptake often did not correspond to the measured PZC, probably due to surface impurities from the carbon manufacturing process. This renders the measured PZC of these specialty carbons unreliable for predicting anion and cation uptake. On the other hand, the anion and cation uptake curves provide an “effective” PZC and do indicate the optimal pH for the synthesis of ultrasmall nanoparticle synthesis. High resolution STEM imaging also showed that with SEA it is possible to disperse nanoparticles on the surface as well as the inner walls of the specialty carbons.
      Citation: C
      PubDate: 2018-02-11
      DOI: 10.3390/c4010012
      Issue No: Vol. 4, No. 1 (2018)
  • C, Vol. 4, Pages 13: Phytosterol Recognition via Rationally Designed
           Molecularly Imprinted Polymers

    • Authors: Lachlan Schwarz, Brenda Leung, Basil Danylec, Simon Harris, Reinhard Boysen, Milton Hearn
      First page: 13
      Abstract: Molecularly imprinted polymers (MIPs) prepared via a semi-covalent imprinting strategy using stigmasteryl methacrylate as a polymerisable template have been evaluated by static binding methods for their ability to selectively capture other valuable phytosterol targets, including campesterol and brassicasterol. Design criteria based on molecular modelling procedures and interaction energy calculations were employed to aid the selection of the co-monomer type, as well as the choice of co-monomer:template ratios for the formation of the pre-polymerisation complex. These novel hybrid semi-covalently imprinted polymers employed N,N′-dimethylacryl-amide (N,N′-DMAAM) as the functional co-monomer and displayed specific binding capacities in the range 5.2–5.9 mg sterol/g MIP resin. Their binding attributes and selectivities towards phytosterol compounds were significantly different to the corresponding MIPs prepared via non-covalent procedures or when compared to non-imprinted polymers. Cross-reactivity studies using stigmasterol, ergosterol, cholesterol, campesterol, and brassicasterol as single analytes revealed the importance of the A-ring C-3-β-hydroxyl group and the orientational preferences of the D-ring alkyl chain structures in their interaction in the templated cavity with the N,N′-dimethylamide functional groups of the MIP. Finally, to obtain useful quantities of both campersterol and brassicasterol for these investigations, improved synthetic routes have been developed to permit the conversion of the more abundant, lower cost stigmasterol via a reactive aldehyde intermediate to these other sterols.
      Citation: C
      PubDate: 2018-02-12
      DOI: 10.3390/c4010013
      Issue No: Vol. 4, No. 1 (2018)
  • C, Vol. 4, Pages 14: Mechanochemical Functionalization of Carbon Black at
           Room Temperature

    • Authors: Desirée Leistenschneider, Katharina Zürbes, Christina Schneidermann, Sven Grätz, Steffen Oswald, Karl Wegner, Benjamin Klemmed, Lars Giebeler, Alexander Eychmüller, Lars Borchardt
      First page: 14
      Abstract: Carbon nanomaterials such as carbon blacks are intrinsically hydrophobic with limited wettability in aqueous media, thus restricting their potential applications. To improve their hydrophilicity, common methods tend to utilize harmful chemicals and conditions, such as a mixture of KMnO4 and H2SO4 or a complex and expensive synthesis setup. In our work, we report a simple method to improve the wettability of these materials by a mechanochemical treatment completed within 1 h at room-temperature utilizing a NH3 solution. Besides increasing the specific surface area of the carbon black from 67 m2·g−1 up to 307 m2·g−1, our process also incorporates nitrogen- and oxygen-containing functional groups into the carbon. This reduces the contact angle from 80° to 30°, confirming an enhanced wettability. Our work presents an easy, fast, and straightforward pathway towards the functionalization of carbon nanomaterials and can be of use in various applications where aqueous wettability is advantageous.
      Citation: C
      PubDate: 2018-02-13
      DOI: 10.3390/c4010014
      Issue No: Vol. 4, No. 1 (2018)
  • C, Vol. 4, Pages 15: Electrical and Tensile Properties of Carbon Black
           Reinforced Polyvinyl Chloride Conductive Composites

    • Authors: Iftekharul Islam, Shahin Sultana, Swapan Kumer Ray, Husna Parvin Nur, Md. Tofazzal Hossain, Walliullah Md. Ajmotgir
      First page: 15
      Abstract: Conductive polymer composites are becoming more important and useful in many electrical applications. This paper reports on the carbon black (CB) reinforced polyvinyl chloride (PVC) conductive composites. Conductive filler CB was reinforced with thermoplastic PVC by compression molding technique to make conductive composites. The particle size of CB was measured, as it affects the electrical conductivity of the composites. Different types of CB-PVC compression-molded composites were prepared, using CB contents from 5 to 30 wt %. The electrical and tensile properties of these composites were studied and compared. Improved electrical properties were obtained for all CB-PVC conductive polymer composites compared to virgin PVC composite. However, the tensile properties of the CB-PVC composites increased up to 15 wt % CB loading, and then decreased, and elongation at break decreased with increasing CB loading. The structure of the CB, PVC and CB-PVC composites were studied by attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopic analysis. ATR-FTIR spectra provide evidence of the formation of CB-PVC composites. The microstructural analyses showed a good dispersion of CB in PVC matrix.
      Citation: C
      PubDate: 2018-02-22
      DOI: 10.3390/c4010015
      Issue No: Vol. 4, No. 1 (2018)
  • C, Vol. 4, Pages 16: Silica Precursor Effect on the Physical and Chemical
           Properties of Cobalt Incorportated MCM-41 Catalysts and Their Performance
           towards Single Wall Carbon Nanotubes

    • Authors: Frank Ramírez Rodríguez, Luis Giraldo, Betty Lopez
      First page: 16
      Abstract: In this work, mesoporous silica (MCM-41) and a cobalt-incorporated catalyst (Co-MCM-41) were prepared using colloidal silica Cab-O-Sil, sodium silicate and tetraethylorthosilicate (TEOS) as the silica sources and cobalt nitrate as the cobalt source. Their physicochemical properties were analyzed, and their catalytic performance for the synthesis of single-wall carbon nanotubes (SWCNT) during chemical vapor deposition (CCVD) of methane was evaluated. When Cab-O-Sil was used, it was possible to incorporate 3% (nominal) cobalt with a good dispersion and without losing mesoporosity, resulting in minimal formation of superficial cobalt oxide. In contrast, the other catalysts product superficial cobalt oxide, according to the temperature programmed reduction (TPR) analysis. Co-MCM-41 prepared using Cab-O-Sil showed the best performance during the formation of SWCNT with a good regularity and selectivity without forming multi-wall carbon nanotubes or amorphous carbon structures.
      Citation: C
      PubDate: 2018-02-22
      DOI: 10.3390/c4010016
      Issue No: Vol. 4, No. 1 (2018)
  • C, Vol. 4, Pages 17: Catalytic Growth of Carbon Nanotubes by Direct Liquid
           Injection CVD Using the Nanocluster

    • Authors: Gibran L. Esquenazi, Bruce Brinson, Andrew R. Barron
      First page: 17
      Abstract: The growth of carbon nanotubes (CNTs) by direct liquid injection chemical vapor deposition (DLICVD) has been studied using the polyoxometalate cluster [HxPMo12O40⊂H4Mo72Fe30(O2CMe)15O254(H2O)98-y(EtOH)y] (FeMoC) as the catalyst with either ethanol or toluene as the carbon source. In order to screen different growth conditions a single large batch of FeMoC is required in order to eliminate variation in the catalyst precursor. The preparation of 6 g of FeMoC is possible by scaling (10×) literature reagent ratios. DLICVD studies of the FeMoC derived carbon product were evaluated by Raman spectroscopy and scanning electron microscopy (SEM) to determine the quality (G:D ratio) and purity of CNT content. With the use of ethanol as the carbon source, increasing the temperature in the injection zone (aspiration temperature) above 250 °C increases the yield, and results in a slight increase in the G:D ratio. The maximum yield is obtained with a growth temperature of 900 °C, while the G:D ratio is the highest at higher temperatures. Faster solution injection rates increase yield, but with a significant decrease in G:D, in fact no CNTs are observed in the product for the highest injection rate (10 mL/h). An optimum catalyst concentration of 1.25 wt.% is found, which influences both the catalyst:C and catalyst:H ratios within the system. Growth at 800 °C is far more efficient for toluene as a carbon source than ethanol. The resulting “process map” allows for large quantities of CNTs to be prepared by DLICVD.
      Citation: C
      PubDate: 2018-03-02
      DOI: 10.3390/c4010017
      Issue No: Vol. 4, No. 1 (2018)
  • C, Vol. 4, Pages 18: Current Progress of Si/Graphene Nanocomposites for
           Lithium-Ion Batteries

    • Authors: Yinjie Cen, Richard Sisson, Qingwei Qin, Jianyu Liang
      First page: 18
      Abstract: The demand for high performance lithium-ion batteries (LIBs) is increasing due to widespread use of portable devices and electric vehicles. Silicon (Si) is one of the most attractive candidate anode materials for next generation LIBs. However, the high-volume change (>300%) during lithium ion alloying/de-alloying leads to poor cycle life. When Si is used as the anode, conductive carbon is needed to provide the necessary conductivity. However, the traditional carbon coating method could not overcome the challenges of pulverization and unstable Solid Electrolyte Interphase (SEI) layer during long-term cycling. Since 2010, Si/Graphene composites have been vigorously studied in hopes of providing a material with better cycling performance. This paper reviews current progress of Si/Graphene nanocomposites in LIBs. Different fabrication methods have been studied to synthesize Si/Graphene nanocomposites with promising electrochemical performances. Graphene plays a key enabling role in Si/Graphene anodes. However, the desired properties of graphene for this application have not been systematically studied and understood. Further systematic investigation of the desired graphene properties is suggested to better control the Si/Graphene anode performance.
      Citation: C
      PubDate: 2018-03-19
      DOI: 10.3390/c4010018
      Issue No: Vol. 4, No. 1 (2018)
  • C, Vol. 4, Pages 19: TEM Nano-Moiré Pattern Analysis of a Copper/Single
           Walled Carbon Nanotube Nanocomposite Synthesized by Laser Surface

    • Authors: Jay Tu
      First page: 19
      Abstract: In our previous studies, we have developed a wet process to synthesize a copper-single walled carbon nanotube (Cu–SWCNT) metal nanocomposite with excellent mechanical properties. The nanostructure of this Cu–SWCNT composite was confirmed independently by energy-dispersive X-ray spectroscopy mapping, spectroscopy measurements, and Transmission Electron Microscope (TEM) images with discernable SWCNT clusters in nano sizes. However, TEM images with discernable nano-sized SWCNT clusters are rare. In this paper, we present analysis of indirect TEM image patterns, such as moiré fringes, to infer the existence of SWCNT clusters within the copper matrix. Moiré fringes or patterns in the TEM images of a Cu–SWCNT nanocomposite could be generated due to the overlapping of more than one thin crystals with similar periodic arrangements of atoms, promoted by SWCNT clusters. However, the presence of moiré patterns is not a sufficient or a necessary condition for the existence of SWCNT clusters. It was found that based on the overlapping angle of two periodic arrangements, it is feasible to distinguish the moiré fringes induced by SWCNT clusters from those by other factors, such as dislocations. The ability to identify SWCNTs within the copper matrix based on indirect TEM moiré patterns helps to widen the usability of TEM images.
      Citation: C
      PubDate: 2018-03-20
      DOI: 10.3390/c4010019
      Issue No: Vol. 4, No. 1 (2018)
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