Toward ultralight high strength structural materials via collapsed carbon nanotube bonding
Publication date: January 2020Source: Carbon, Volume 156Author(s): Benjamin D. Jensen, Jae-Woo Kim, Godfrey Sauti, Kristopher E. Wise, Liang Dong, Haydn N.G. Wadley, Jin Gyu Park, Richard Liang, Emilie J. SiochiAbstractThe growing commercial availability of carbon nanotube (CNT) macro-assemblages such as sheet and yarn is making their use in structural composite components increasingly feasible. However, the mechanical properties of these materials continue to trail those of state-of-the-art carbon fiber composites due to relatively weak inter-tube load transfer. Forming covalent links between adjacent CNTs promises to mit...
Source: Carbon - October 12, 2019 Category: Materials Science Source Type: research

A flexible non-enzymatic glucose sensor based on copper nanoparticles anchored on laser-induced graphene
Publication date: January 2020Source: Carbon, Volume 156Author(s): Yue Zhang, Na Li, Yangjun Xiang, Debo Wang, Peng Zhang, Yanyan Wang, Shan Lu, Rongqing Xu, Jiang ZhaoAbstractAn original flexible enzyme-free glucose amperometric biosensor based on Cu nanoparticles anchored on laser-induced graphene (Cu NPs-LIG) composite is successfully developed by a simple substrate-assisted electroless deposition (SAED) technique. The as-prepared Cu NPs-LIG sensor demonstrates an excellent glucose sensitivity of 495 μA mM−1 cm−2, ultrafast response time less than 0.5 s and the prominently low detection limit of 0...
Source: Carbon - October 12, 2019 Category: Materials Science Source Type: research

Efficient electrocatalytic proton reduction on CoP nanocrystals embedded in microporous P, N Co-doped carbon spheres with dual active sites
Publication date: January 2020Source: Carbon, Volume 156Author(s): Ramireddy Boppella, Jaemin Park, Wooseok Yang, Jeiwan Tan, Jooho MoonAbstractA facile and scalable method is reported to develop CoP nanocrystals encapsulated in a P, N co-doped C matrix (PNC) as a highly efficient electrocatalyst for hydrogen evolution reaction (HER) in acidic and basic media. The synthesized CoP-PNC electrocatalysts exhibit large specific surface area of 1543 m2 g−1, hierarchical microporous structure, and high density of surface -active sites. The porous CoP-PNC electrocatalysts exhibit excellent HER electroactivity, delivering...
Source: Carbon - October 10, 2019 Category: Materials Science Source Type: research

Honeycomb-like porous carbon with N and S dual-doping as metal-free catalyst for oxygen reduction reaction
Publication date: January 2020Source: Carbon, Volume 156Author(s): Jian Yang, Fei Xiang, Heng Guo, Liping Wang, Xiaobin NiuAbstractIt has been a major challenge to dispose the unrenewable high-performance polymers (HPPs) after their large-scale application in our society. Here we report an approach to reuse one kind of HPP as carbon and sulfur sources in synthesizing nitrogen and sulfur dual-doped honeycomb-like porous carbon catalysts for oxygen reduction reaction. Briefly, poly(phenylene sulfide sulfone) with S atoms in polymer chain as sulfur source, dicyandiamide as nitrogen source and SiO2 nanoparticles as hard-templa...
Source: Carbon - October 9, 2019 Category: Materials Science Source Type: research

The structural properties of chemically derived graphene nanosheets/mesophase pitch-based composite carbon fibers with high conductivities
Publication date: January 2020Source: Carbon, Volume 156Author(s): Xingwei Zhang, Shuli Ning, Zhaokun Ma, Huaihe Song, Dingling Wang, Man Zhang, Baolin Fan, Su Zhang, Xi YanAbstractA series of mesophase pitch-based composite carbon fibers with various contents of chemically derived graphene nanosheets (CGNSs) were prepared through melt-spinning, stabilization, carbonization, and graphitization. By means of scanning electron microscopy, X-ray diffraction, single-filament testing, and resistivity testing, the effect of CGNSs content on the structures and properties of the composite carbon fibers were investigated. And the th...
Source: Carbon - October 9, 2019 Category: Materials Science Source Type: research

WOx/g-C3N4 layered heterostructures with controlled crystallinity towards superior photocatalytic degradation and H2 generation
Publication date: January 2020Source: Carbon, Volume 156Author(s): Xiao Zhang, Shuai He, San Ping JiangAbstractThe construction of g-C3N4 layered heterostructure is crucial to enhance charge carrier separation and expand the photo-adsorption in visible light region. Herein, amorphous and crystalline g-C3N4 nanosheets are produced by adjusting the thermal polycondensation process of precursors. WOx nanobelts are horizontally grown on ultrathin g-C3N4 nanosheets, resulting in the formation of WOx/g-C3N4 layered heterostructures rather than composites. The composition of WOx (WO3, WO2, W18O49) depends strongly on the preparat...
Source: Carbon - October 9, 2019 Category: Materials Science Source Type: research

N-doped hollow mesoporous carbon spheres by improved dissolution-capture for supercapacitor
Publication date: Available online 2 October 2019Source: CarbonAuthor(s): Juan Du, Yue Zhang, Haixia Wu, Senlin Hou, Aibing ChenAbstractN-doped hollow mesoporous carbon sphere (N-HMCS) has attracted increasing attention as supercapacitor materials due to its rich mesoporous structure, large cavity, high surface area and suitable N-doping, etc. Herein, an improved dissolution-capture method is applied for preparation of N-HMCS using 3-aminophenol-formaldehyde (AF) resin spheres as carbon precursor. In this process, AF resin spheres preparation, mesoporous silica coating, dissolution-capture are implemented by one-pot proces...
Source: Carbon - October 9, 2019 Category: Materials Science Source Type: research

Current density effect on current-carrying friction of amorphous carbon film
We report the current density effect in controlling current-carrying friction of amorphous carbon (a-C) film sliding against steel ball. The current density at the sliding interface was set to a constant value or cyclic variation value by adjusting the current intensity and the contact area for exploring the current-carrying friction behavior. The results showed that when the current density enhanced from 0 to 0.196 mA/μm2, the friction coefficient decreased from 0.20 to 0.03 and the run-in cycle shortened from about 100 to few cycles. When the current density cyclically varied during the sliding, the friction coefficie...
Source: Carbon - October 9, 2019 Category: Materials Science Source Type: research

Corrigendum to “Historical experiment to measure irradiation-induced creep of graphite” [Carbon 139 (2018) 279–288]
Publication date: Available online 3 October 2019Source: CarbonAuthor(s): Anne A. Campbell (Source: Carbon)
Source: Carbon - October 9, 2019 Category: Materials Science Source Type: research

Controllable synthesis of intercalated γ-Bi2MoO6/graphene nanosheet composites for high performance NO2 gas sensor at room temperature
Publication date: Available online 5 October 2019Source: CarbonAuthor(s): Lang He, He Lv, Laifeng Ma, Wenna Li, Jiaqi Si, Muhammad Ikram, Mohib Ullah, Hongyuan Wu, Ruihong Wang, Keying ShiAbstractIntercalated γ-Bi2MoO6/graphene nanosheet composites (BMO/GNCs) were prepared by vacuum-assistant and solvothermal technique. In BMO/GNCs, BMO nanoparticles (NPs) were uniformly distributed on the surface and interlayer of graphene nanosheets (GNs), simultaneously along with a large number of defects and interface on GNs and BMO NPs. As synthesized with solvothermal temperature at 160 °C and graphite content of 80 mg...
Source: Carbon - October 9, 2019 Category: Materials Science Source Type: research

Understanding cooperative loading in carbon nanotube fibres through in-situ structural studies during stretching
Publication date: January 2020Source: Carbon, Volume 156Author(s): Juan C. Fernández-Toribio, Anastasiia Mikhalchan, Cleis Santos, Álvaro Ridruejo, Juan J. VilatelaAbstractCarbon nanotube (CNT) fibres are firmly established as a new high-performance fibre, but their tensile mechanical properties remain a relatively small fraction of those of the constituent CNTs. Clear structure-property relations and accurate mechanical models are pressing requirements to bridge this gap. In this work we analyse the structural evolution and molecular stress transfer in CNT fibres by performing in-situ synchrotron wide- and s...
Source: Carbon - October 5, 2019 Category: Materials Science Source Type: research

Carbon fiber-promoted activation of catalyst for efficient growth of single-walled carbon nanotubes
Publication date: January 2020Source: Carbon, Volume 156Author(s): Benwu Xin, Wenke Gao, Zhonghai Ji, Shuchen Zhang, Liantao Xin, Lifen Zhao, Han Xue, Qianru Wu, Lili Zhang, Chang Liu, Jin Zhang, Maoshuai HeAbstractCarbon fibers are placed onto substrate surface with dispersed Co particles to promote the growth efficiency of single-walled carbon nanotubes (SWNTs). During chemical vapor deposition (CVD) process, micro-spaces are fabricated between the carbon fibers and the substrate surface, which modify the Knudsen number of CO and increase its efficient contact with cobalt oxide nanoparticles, enhancing the reduction of c...
Source: Carbon - October 5, 2019 Category: Materials Science Source Type: research

Structures formed by passage of current through graphite: flat or three-dimensional?
Publication date: January 2020Source: Carbon, Volume 156Author(s): Peter J.F. HarrisAbstractThe passage of an electric current, or the application of an electrostatic charge through graphite at high temperatures can produce dramatic structural transformations. These involve the formation of carbon structures made up of few-layer graphene with highly irregular morphologies, displaying many unusual features, including nanotube–graphene junctions. A number of studies of the transformed carbon have been carried out, but many aspects of its structure are still not understood. Here, transmission electron microscopy is used...
Source: Carbon - October 5, 2019 Category: Materials Science Source Type: research

Directly crosslinked dextran gels for SWCNT separation
In this study, five gels with different dextran concentrations were synthesized by directly crosslinking dextran with epichlorohydrin. The low dextran concentration gels work for metal/semiconductor separation and diameter sorting of semiconducting SWCNTs. This is evidence that the chemical structure in the gel that is responsible for the selective adsorption of semiconducting SWCNTs is dextran. However, high dextran concentration gels did not adsorb SWCNTs, although the adsorption site was dextran. Micro-Raman measurements on gel slices revealed that the high dextran concentration gel has a pore size too small to allow de...
Source: Carbon - October 5, 2019 Category: Materials Science Source Type: research

On the active sites for the oxygen reduction reaction catalyzed by graphene-based materials
Publication date: January 2020Source: Carbon, Volume 156Author(s): Ljubisa R. Radovic, Adolfo J.A. Salgado-Casanova, Camila V. Mora-VilchesAbstractAt the heart of the mechanism and efficiency of oxygen reduction is the identification of active sites in graphene-based electrocatalysts ranging from carbon blacks to heat-treated phthalocyanines. Distinction between the transfer of two or four electrons points to O2 dissociation as the essential mechanistic clue; here we examine this issue by exploiting the analogy with carbon oxidation, where production of CO vs. CO2 has long been a crucial point. We compare our computational...
Source: Carbon - October 2, 2019 Category: Materials Science Source Type: research

Self-limiting interactions in 2D–0D system: A case study of graphene oxide and 12-tungstophosphoric acid nanocomposite
Publication date: January 2020Source: Carbon, Volume 156Author(s): Z. Jovanović, Ž. Mravik, D. Bajuk-Bogdanović, S. Jovanović, S. Marković, M. Vujković, J. Kovač, D. Vengust, S. Uskoković-Marković, I. Holclajtner-AntunovićAbstractIn the present study we investigated the interaction between 12-tungstophosphoric acid (WPA) and graphene oxide (GO) in their nanocomposite by utilizing the loading of WPA as an intrinsic parameter for interaction tuning. The Fourier-transform infrared spectroscopy, temperature-programmed desorption, X-ray photoelectron spectroscopy, zeta-potential measurements, thermogravimetric analysi...
Source: Carbon - September 28, 2019 Category: Materials Science Source Type: research

Controlled joule-heating of suspended glassy carbon wires for localized chemical vapor deposition
Publication date: January 2020Source: Carbon, Volume 156Author(s): Albert Cisquella-Serra, Manuel Gamero-Castaño, Laia Ferrer-Argemi, Jenna Wardini, Marc MadouAbstractThis paper demonstrates for the first time localized chemical vapor deposition of WO3-x on a suspended glassy carbon wire. A process based on the photopatterning of an SU-8 scaffold, the near-field electrospinning of an SU-8 fiber, and their pyrolysis yields a monolithic carbon structure featuring a glassy carbon wire of known diameter and length, suspended on a glassy carbon scaffold. The temperature required for the deposition of WO3-x is generated b...
Source: Carbon - September 28, 2019 Category: Materials Science Source Type: research

Ultrathin Co3O4 nanosheets anchored on multi-heteroatom doped porous carbon derived from biowaste for high performance solid-state supercapacitor
Publication date: January 2020Source: Carbon, Volume 156Author(s): Yajun Ji, Yalei Deng, Fei Chen, Zhaoqi Wang, Yezhan Lin, Zhenhao GuanAbstractLow-cost multi-heteroatom doped porous carbons derived from agricultural waste were prepared as the base material. Then, the cobalt oxides nanosheets were anchored to the surface of the carbon material to obtain the composites. It was found that the adoption of porous carbon is of great significance for the improvement of materials properties. The presence of porous structure derived from carbon materials not only increases the stability of the material, but also facilitates the di...
Source: Carbon - September 28, 2019 Category: Materials Science Source Type: research

Charge-neutral epitaxial graphene on 6H–SiC(0001) via FeSi intercalation
Publication date: January 2020Source: Carbon, Volume 156Author(s): Xingyun Luo, Guojun Liang, Xiucai Sun, Yanlu Li, Fapeng Yu, Lei Wei, Xiufeng Cheng, Li Sun, Xian ZhaoAbstractGraphene grown epitaxially on SiC(0001) substrates always exhibits n-type doping due to the coupling interaction between the substrate and graphene. The electronic properties of epitaxial graphene are thus impaired relative to those of free-standing graphene, limiting its potential in device applications. In this work, by using first-principles calculations, we show that charge neutrality can be achieved by growing an FeSi intercalation layer between...
Source: Carbon - September 28, 2019 Category: Materials Science Source Type: research

Mitochondria-targeting supra-carbon dots: Enhanced photothermal therapy selective to cancer cells and their hyperthermia molecular actions
Publication date: Available online 27 September 2019Source: CarbonAuthor(s): Yanting Shen, Xue Zhang, Lijia Liang, Jing Yue, Dianshuai Huang, Weiqing Xu, Wei Shi, Chongyang Liang, Shuping XuAbstractCarbon dots (CDs) have been widely used in biological research including bioimaging, biosensing, and biomedicine because of their excellent biocompatibility. However, inefficient absorption of these CDs in the visible-to-near-infrared window limits their applications for many photo-sensitive cancer therapeutic strategies and in vivo imaging. Herein, novel supra-carbon dots (SCDs, approximately 20 nm) with high visible-NIR abso...
Source: Carbon - September 28, 2019 Category: Materials Science Source Type: research

Raman spectroscopy on hydrogenated graphene under high pressure
Publication date: Available online 27 September 2019Source: CarbonAuthor(s): Teerachote Pakornchote, Zachary M. Geballe, Udomsilp Pinsook, Thiti Taychatanapat, Wutthikrai Busayaporn, Thiti Bovornratanaraks, Alexander F. GoncharovAbstractWe applied laser-heating in diamond anvil cells (LHDAC) to synthesize a hydrogenated single-layer graphene (SLG) and to explore the pathway toward graphane (fully hydrogenated SLG). We employed Raman spectroscopy to investigate SLG on a Cu substrate that was compressed up to 8 GPa and 20 GPa with 2.2% and 4.6% compressive strain, respectively, followed by laser-heating. After laser-heat...
Source: Carbon - September 28, 2019 Category: Materials Science Source Type: research

Ultrafine MoO3 anchored in coal-based carbon nanofiber as anode for advanced lithium-ion batteries
Publication date: Available online 27 September 2019Source: CarbonAuthor(s): Xiaojuan Zhao, Wei Jia, Xueyan Wu, Yan Lv, Jieshan Qiu, Jixi Guo, Xingchao Wang, Dianzeng Jia, Junfeng Yan, Dongling WuAbstractMolybdenum trioxide (MoO3), which possesses unique layered nanostructure and high theoretical capacity, is currently under comprehensive research as one of the most promising lithium-ion anode materials. However, MoO3 suffers from sluggish electrode reaction kinetics and huge volume expansion, causing severe capacity fading during cycling processes. Herein, ultrafine MoO3 anchored in coal-based carbon fiber to form nanocom...
Source: Carbon - September 28, 2019 Category: Materials Science Source Type: research

Understanding the processing-structure-performance relationship of graphene and its variants as anode material for Li-ion batteries: A critical review
Publication date: January 2020Source: Carbon, Volume 156Author(s): Farjana J. Sonia, M. Aslam, Amartya MukhopadhyayAbstractGraphenic carbon, as the lower (or nano-) dimensional form of graphitic carbon, is expected to allow lithiation/delithiation of an electrode constituted by the same in lesser time and possess greater specific gravimetric Li-storage capacity, as compared to graphitic carbon. The aforementioned positive aspects of graphenic carbon are expected/predicted/observed primarily due to the lower dimensional scale, greater specific surface area (SSA) and presence of ‘defect’ sites. Nevertheless, the ...
Source: Carbon - September 28, 2019 Category: Materials Science Source Type: research

Probing the origin of the enhanced catalytic performance of sp3@sp2 nanocarbon supported Pd catalyst for CO oxidation
Publication date: Available online 26 September 2019Source: CarbonAuthor(s): Liyun Zhang, Yuxiao Ding, Yoobin Esther Koh, Bongjin Simon Mun, Kuang-Hsu Wu, Yiming Niu, Wen Shi, Bingsen ZhangAbstractTuning the fine structure of carbon support is crucial for modifying the metal-support interface (MSI) in order to harvest a high-performance catalysis. Herein, a core–shell sp3@sp2 nanocarbon (nanodiamond@graphene, ND@G) and a pure sp2 carbon derivative (onion-like carbon, OLC) were applied to support Pd nanoparticles. We found that Pd/ND@G displayed a superior catalytic activity for CO oxidation reaction with a TOF of 2.9...
Source: Carbon - September 26, 2019 Category: Materials Science Source Type: research

Boosting capacitive charge storage of 3D-printed micro-pseudocapacitors via rational holey graphene engineering
Publication date: December 2019Source: Carbon, Volume 155Author(s): Xiaocong Tian, Kang Tang, Hongyun Jin, Teng Wang, Xiaowei Liu, Wei Yang, Zhicheng Zou, Shuen Hou, Kun ZhouAbstractMicro-pseudocapacitors (MPCs) are prospective power source candidates with compatible sizes as well as superior power densities for miniaturized electronic devices; however, their limited capacitive charge storage characteristics are still hindering their further development. Herein, an optimized 3D printing technique is employed to build remarkable reduced holey graphene oxide (rHGO) supported MPC microelectrodes. In such microelectrodes, the ...
Source: Carbon - September 26, 2019 Category: Materials Science Source Type: research

Surface functionalization of epitaxial graphene using ion implantation for sensing and optical applications
Publication date: Available online 24 September 2019Source: CarbonAuthor(s): Priya Darshni Kaushik, Marius Rodner, G.B.V.S. Lakshmi, Ivan G. Ivanov, G. Greczynski, Justinas Palisaitis, Jens Eriksson, Pratima Solanki, Anver Aziz, Azher M. Siddiqui, Rositsa Yakimova, Mikael Syväjärvi, G. Reza YazdiAbstractSurface functionalization has been shown to allow tailoring of graphene lattice thus making it suitable for different applications like sensing, supercapacitance devices, drug delivery system and memory devices. In this work, surface functionalization of epitaxial graphene on SiC (EG/SiC) was done by ion beam tech...
Source: Carbon - September 26, 2019 Category: Materials Science Source Type: research

Laser-driven direct synthesis of carbon nanodots and application as sensitizers for visible-light photocatalysis
We present the first successful synthesis of monodisperse carbon nanodots (CNDs) with tunable photoluminescence (PL) carried out by laser pyrolysis of two common volatile organic precursors such as toluene and pyridine. Remarkably, the initial chemical composition of the precursor determines the formation of undoped or N-doped CNDs and their corresponding absorption response in the visible range (expanded for the latter). We demonstrate the control and versatility of this synthesis method to tune the final outcome and its potential to explore a great number of potential solvent candidates. Furthermore, we have successfully...
Source: Carbon - September 26, 2019 Category: Materials Science Source Type: research

Vertically aligned Juncus effusus fibril composites for omnidirectional solar evaporation
Publication date: Available online 23 September 2019Source: CarbonAuthor(s): Qian Zhang, Lipei Ren, Xingfang Xiao, Yali Chen, Liangjun Xia, Guomeng Zhao, Hongjun Yang, Xianbao Wang, Weilin XuAbstractDespite tremendous efforts to improve solar-driven steam generation, most solar evaporators are limited to unidirectional evaporation due to changes in the direction of solar irradiation under real-world conditions. Hence, the development of non-unidirectional evaporators, ideally allowing omnidirectional evaporation, remains a significant challenge. In this work, the first-ever vertically aligned activated carbon–juncus ...
Source: Carbon - September 25, 2019 Category: Materials Science Source Type: research

A flexible, scalable, and self-powered mid-infrared detector based on transparent PEDOT: PSS/graphene composite
Publication date: Available online 23 September 2019Source: CarbonAuthor(s): Mingyu Zhang, John T.W. YeowAbstractA flexible, self-powered and semi-transparent mid-infrared photodetector is demonstrated with graphene and poly(3,4-ethylenedioxythiophene): poly(4-styrenesulfonate) (PEDOT: PSS) composite on poly vinyl alcohol (PVA) substrate. The effective dispersion of graphene nanoplatelets within polymer chains has yielded a low requisite loading of graphene – only 3 wt% for the implement of a detector with optimized photo-thermoelectric effect, high flexibility and high transparency. Under a broadband infrared radi...
Source: Carbon - September 25, 2019 Category: Materials Science Source Type: research

Metal−organic frameworks self-templated cubic hollow Co/N/C@MnO2 composites for electromagnetic wave absorption
Publication date: Available online 23 September 2019Source: CarbonAuthor(s): Ruili Wang, Man He, Yuming Zhou, Shuangxi Nie, Yongjuan Wang, Wenqi Liu, Qiang He, Wenting Wu, Xiaohai Bu, Xiaoming YangAbstractGreen and facile strategies for fabricating hollow microwave absorption materials without harmful solvent etching have attracted extensive attention but still remain a challenge. Herein, the cubic hollow Co/N/C@MnO2 composites were prepared through metal–organic frameworks (MOFs) self-templated eco-friendly method with polydopamine (PDA) as carbon source and hierarchical MnO2 nanosheets were incorporated for improvi...
Source: Carbon - September 25, 2019 Category: Materials Science Source Type: research

Environmentally stable macroscopic graphene film with specific electrical conductivity exceeding metals
Publication date: Available online 24 September 2019Source: CarbonAuthor(s): Yingjun Liu, Mincheng Yang, Kai Pang, Fang Wang, Zhen Xu, Weiwei Gao, Chao GaoAbstractAir stable, lightweight, and electrically conductive carbon-based films are highly desired for flexible electronic devices and products. Graphene film, a macroscopic assembly of individual graphene sheets, holds great potential to replace conventional brittle pyrolytic carbon film due to the excellent electrical transport property and flexibility. However, the electrical conductivity of graphene film is still inferior to metallic conductors, usually unstable in a...
Source: Carbon - September 25, 2019 Category: Materials Science Source Type: research

Immobilization of fullerene C60 at cathodically polarized glassy carbon for generation of thin nucleophilic layers and their carboxylation and alkylation.
Publication date: Available online 24 September 2019Source: CarbonAuthor(s): Jacques Simonet, Viatcheslav JouikovAbstractFullerene-C60 deposited onto solid substrates (glassy carbon, gold) was polarized between 0 V and -2 V vs. Ag/AgCl/KClsat (aq) in polar aprotic solvents (dimethylformamide or acetonitrile) containing tetramethylammonium salts in the presence of electrophilic reagents, namely primary haloalkanes (Hal = Br, I) and carbon dioxide. The electrogenerated reduced forms of C60 (C60- to C604-, fullerene polyanions), show high reactivity towards various electrophiles which permits preparing C60 dicarboxylates whos...
Source: Carbon - September 25, 2019 Category: Materials Science Source Type: research

Tunable charge/size selective ion sieving with ultrahigh water permeance through laminar graphene membranes
Publication date: January 2020Source: Carbon, Volume 156Author(s): Wisit Hirunpinyopas, Pawin Iamprasertkun, Mark A. Bissett, Robert A.W. DryfeAbstractGraphene oxide (GO) and reduced graphene oxide (rGO) membranes have attracted significant attention as a potential technology for energy storage, gas separation, and water purification applications. However, these membranes have a significant drawback as they became swollen, hence unstable, after exposure to aqueous solutions. Here, we describe membranes produced from graphene prepared by liquid phase exfoliation, possessing a low oxygen content, unlike the GO/rGO systems ty...
Source: Carbon - September 25, 2019 Category: Materials Science Source Type: research

Enhanced and switchable silicon-vacancy photoluminescence in air-annealed nanocrystalline diamond films
Publication date: Available online 22 September 2019Source: CarbonAuthor(s): Bing Yang, Biao Yu, Haining Li, Nan Huang, Lusheng Liu, Xin JiangAbstractSilicon vacancy (SiV) centers in CVD-deposited nanodiamond particles or films always exhibit a photoluminescent (PL)-quenching behavior. Herein, in order to overcome this issue, air annealing of nanocrystalline diamond (NCD) films with uniform doping of Si atoms is employed to improve the PL emission efficiency of SiV centers. Without severe mass loss in diamond, SiV centers exhibit an increased PL emission intensity at 738 nm with an increased annealing temperature and tim...
Source: Carbon - September 23, 2019 Category: Materials Science Source Type: research

Understanding the mechanism of carbonization and Koh activation of polyaniline leading to enhanced electrosorption performance
Publication date: Available online 22 September 2019Source: CarbonAuthor(s): Rafael L. Zornitta, Kamilla M. Barcelos, Francisco G.E. Nogueira, Luís A.M. RuotoloAbstractCapacitive deionization (CDI) emerged as new a water desalination technology in which ions are removed from brackish water by being attracted and stored in two polarized electrodes. The electrode material plays a very important role affecting other fundamental parameters such as the salt adsorption capacity (SAC), conductivity, desalination kinetics, and energy consumption. Typically, the CDI electrodes are carbon-based materials, fulfilling requireme...
Source: Carbon - September 23, 2019 Category: Materials Science Source Type: research

One-step synthesis of carbon nanoparticles and yellow to blue fluorescent nanocarbons in flame reactors
Publication date: Available online 23 September 2019Source: CarbonAuthor(s): Mariano Sirignano, Carmela Russo, Anna CiajoloAbstractWe propose a one-step synthesis for the large production of carbon nanoparticles (CNP) based on a flame reactor synthesis approach in which the key tunable parameter is the fuel composition. Specifically, the properties of CNP including fluorescent nanocarbons could be varied by fueling a premixed flame with mixtures ranging from ethylene to benzene. CNP characterization was carried out through Raman and UV–Visible spectroscopy defining their in-plane crystallite size and optical band gap...
Source: Carbon - September 23, 2019 Category: Materials Science Source Type: research

A new twist in graphene research: Twisted graphene
This article overviews the recent developments in twisted graphene covering aspects related to its synthesis, the twist dependent properties and potential applications.Graphical abstract (Source: Carbon)
Source: Carbon - September 23, 2019 Category: Materials Science Source Type: research

Porous carbon nanosheets from biological nucleobase precursor as efficient pH-independent oxygen reduction electrocatalyst
Publication date: Available online 21 September 2019Source: CarbonAuthor(s): Baobing Huang, Yuchuan Liu, Qian Guo, Yuanxing Fang, Magdalena Titirici, Xinchen Wang, Zailai XieAbstractPyridinic-N configurations and intrinsic defects on nanocarbons have been regarded as potentially active-sites for the oxygen reduction reaction (ORR). In this work, a facile strategy is demonstrated to achieve pyridinic-N dominated porous carbon nanosheets with edge-enriched defective nature through the selection of the bio-precursor guanine as C/N sources. It is able to achieve high contents of pyridinic-N dominated (48.1% from gross N) speci...
Source: Carbon - September 22, 2019 Category: Materials Science Source Type: research

Assessment of graphene oxide ecotoxicity at several trophic levels using aquatic microcosms
This study highlights the importance of using such experimental systems to better encompass the ecotoxic potential of GO through the determination of toxicological routes and consequences on ecosystem's functioning.Graphical abstract (Source: Carbon)
Source: Carbon - September 22, 2019 Category: Materials Science Source Type: research

Towards a better understanding of the structure of diamanoïds and diamanoïd/graphene hybrids
We report new evidences confirming the sp2–C to sp3–C conversion from electron diffraction at low energy, Raman spectroscopy and Density Functional Theory (DFT) calculations. Partial sp2–C to sp3–C conversion generates couples of twisted, superimposed coherent domains (TCD), supposedly because of stress relaxation, which are evidenced by electron diffraction and Raman spectroscopy. TCDs come with the occurrence of a twisted bilayer graphene feature located at the interface between the upper diamanoïd domain and the non-converted graphenic domain underneath, as evidenced by a specific Raman sign...
Source: Carbon - September 22, 2019 Category: Materials Science Source Type: research

Solar light-driven photocatalytic degradation of phenol on S-doped nanoporous carbons: The role of functional groups in governing activity and selectivity
Publication date: January 2020Source: Carbon, Volume 156Author(s): Teresa J. Bandosz, Alfonso Policicchio, Marc Florent, Wanlu Li, Po S. Poon, Juan MatosAbstractMetal-free nanoporous carbons, either as received or sulfur doped, have been studied as photocatalysts for the degradation of phenol under solar light irradiation. The introduction of sulfur significantly enhanced both phenol adsorption and photodegradation. The texture and surface chemistry of the catalysts tested were evaluated using adsorption of nitrogen, thermal analysis, potentiometric titration and XPS. Various parameters related to the kinetics of phenol ad...
Source: Carbon - September 22, 2019 Category: Materials Science Source Type: research

Large improvement of CNT yarn electrical conductivity by varying chemical doping and annealing treatment
We present a new efficient CNT p-type dopant based on platinum chloride IV. It decreases the resistivity by a factor of 3 and is stable over half a year. The annealing treatments above 2000 °C dramatically improve the CNT structural quality by a decade. In addition, we show that the CNT yarn electrical resistivity decreases linearly with the CNT structural quality increase and we report the world record resistivity for an undoped CNT yarn spun from CNT array (0.76 mΩ cm). We reveal that the CNT structural quality is not the only factor needed to reach high electrical conductivities. The increase in CNT stru...
Source: Carbon - September 22, 2019 Category: Materials Science Source Type: research

Encapsulation of Co-based nanoparticle in N-doped graphitic carbon for efficient oxygen reduction reaction
Publication date: Available online 12 September 2019Source: CarbonAuthor(s): Chao Zhang, Jun Liu, Yixing Ye, Qi Chen, Changhao LiangAbstractDeveloping non-precious metal catalysts with high performance is highly desirable for oxygen reduction reaction (ORR). Here, we present the formation of graphene-supported Co-based nanoparticles (NPs) encapsulated in nitrogen-doped graphitic layers (Co@NC/rGO) for ORR application. Such composite electrocatalyst display activity with an onset potential of 0.98 V and a half-wave potential of 0.86 V in alkaline media, which is close to commercially used Pt/C electrocatalyst. Besides, ...
Source: Carbon - September 22, 2019 Category: Materials Science Source Type: research

Metal-organic framework derived carbon materials for electrocatalytic oxygen reactions: recent progress and future perspectives
Publication date: Available online 12 September 2019Source: CarbonAuthor(s): Lei Du, Lixin Xing, Gaixia Zhang, Shuhui SunAbstractThe electrocatalytic oxygen reactions, i.e. oxygen reduction/evolution reactions (ORR/OER), play a key role in electrochemical energy conversion and storage devices, including fuel cells, electrolyzers, and metal-air batteries, and have attracted significant attention in the past decades. Platinum-group metal (PGM)-free materials have been intensively investigated as alternatives to replace the well-accepted but costly PGM-based catalysts such as Pt for ORR and Ir/Ru (oxides) for OER. Particularl...
Source: Carbon - September 22, 2019 Category: Materials Science Source Type: research

Monitoring water and oxygen splitting at graphene edges and folds: Insights into the lubricity of graphitic materials
Publication date: Available online 16 September 2019Source: CarbonAuthor(s): Paolo Restuccia, Mauro Ferrario, M.C. RighiAbstractThe functionality of graphene as lubricant material is affected by extrinsic factors, such as the film thickness and the environmental conditions. Graphite lubricating capability depends as well on air humidity. To accurately describe the tribochemistry mechanisms underlying these behaviours we adopt a Quantum Mechanics/Molecular Mechanics approach. We show that reactive edges are able to cause a huge friction increase, which is quantified for graphene flakes between sliding diamond surfaces. More...
Source: Carbon - September 22, 2019 Category: Materials Science Source Type: research

Residue metals and intrinsic moisture in excess sludge influenced pore formation in the excess sludge derived activated carbon
In this study, the carbonization process was optimized as following: carbonization temperature of 900 °C, heating rate of 10 °C/min, and dwell time of 30 min. Moreover, the residue heavy metals and bound water remaining in the sludge were demonstrated to be important in the pore formation of the SAC. The metals acted as hard template to form the pores in the SAC after the metals were removed by acid wash. The bound water was found to be soft templates for forming pores due to its evaporation during carbonization. A maximum SBET of 1018.8 m2/g was achieved for the SAC when the bound moisture content was cont...
Source: Carbon - September 22, 2019 Category: Materials Science Source Type: research

Direct growth of mm-size twisted bilayer graphene by plasma-enhanced chemical vapor deposition
Publication date: Available online 21 September 2019Source: CarbonAuthor(s): Yen-Chun Chen, Wei-Hsiang Lin, Wei-Shiuan Tseng, Chien-Chang Chen, George.R. Rossman, Chii-Dong Chen, Yu-Shu Wu, Nai-Chang YehAbstractPlasma enhanced chemical vapor deposition (PECVD) techniques have been shown to be an efficient method to achieve single-step synthesis of high-quality monolayer graphene (MLG) without the need of active heating. Here we report PECVD-growth of single-crystalline hexagonal bilayer graphene (BLG) flakes and mm-size BLG films with the interlayer twist angle controlled by the growth parameters. The twist angle has been ...
Source: Carbon - September 22, 2019 Category: Materials Science Source Type: research

Carbon dots as an additive for improving performance in water-based lubricants for amorphous carbon (a-C) coatings
In this study, it is first demonstrated that CDs perform excellently when used as lubricant additives for water-lubricated amorphous carbon (a-C) contacts. The results show that the introduction of CDs into water at a concentration of 0.1 wt% could reduce friction and wear in a-C contacts by 33% and 80%, respectively. Additionally, the lubricating performance of CDs is highly sensitive to its adding concentration. The excellent tribological performance of CDs results from the minimized CDs sediment particles (deposited in situ on worn a-C surfaces) and the reduced friction and wear via nano-bearing and nano-filling mecha...
Source: Carbon - September 22, 2019 Category: Materials Science Source Type: research

The magic sized carbon clusters on the transition metal surfaces with a four-fold symmetry
Publication date: Available online 21 September 2019Source: CarbonAuthor(s): Xiuyun Zhang, Feng DingAbstractIn order to understand the metal surface type dependent graphene chemical vapor deposition (CVD) growth, we have systematically explored the structural evolution of carbon clusters on Cu(100) substrate by using density functional theory (DFT) calculation. It is revealed that the most stable carbon clusters, Cn (n = 1–32), experience a structural transition from linear sp1 atom chain to sp2 2D network at a critical cluster size of n = 13. The highly stable sp2 network structures on a Cu(100) facet are mo...
Source: Carbon - September 22, 2019 Category: Materials Science Source Type: research

The hetero-assembly of reduced graphene oxide and hydroxide nanosheets as superlattice materials in PMS activation
In this study, we addressed this problem after incorporating the nanosheets of reduced graphene oxide (rGO) in the layers of hydroxides (LDHs) as Fe-rGO LDH hetero-composite. Based on the first order kinetic model, the fabricated composite showed excellent phenol removal with degradation rate constant of 0.16 min−1, 5–100 times higher than Fe-LDH/rGO or other control catalysts. This enhanced catalytic activity was resulted from the systematic assembly of both monolayered rGO and LDHs as superlattice materials, avoiding the aggregation of rGO during the reaction and thus promote the interfacial electron transf...
Source: Carbon - September 22, 2019 Category: Materials Science Source Type: research