Wednesday, July 23, 2014

Ni 3 C-assisted growth of carbon nanofibres 300 °C by thermal CVD

Ni-assisted thermal chemical vapor deposition (TCVD) is one of the most common techniques for the growth of carbon nanofibres/nanotubes (CNFs/CNTs). However, some fundamental issues related to the catalytic growth of CNFs/CNTs, such as the low-limit growth temperature, the limiting steps and the state of Ni, are still controversial. Here, we report the growth of CNFs at 300 °C; that is the lowest temperature for the growth of CNFs by TCVD using Ni as the catalyst so far. The results showed that the Ni existed in rhombohedral Ni 3 C, not in the normal form of face-centered cubic Ni, and the C atoms for building the CNFs were precipitated from the (001) planes of the faceted Ni 3 C nanoparticles. The CNFs are believed to be formed by the decomposition-formation cycle of metastable Ni 3 C that has a low-limit decomposition temperature of about 300 °C. Our results strongly suggest that TCVD is a valuable tool for the synthesis of CNFs/CNTs at temperatures b...

Bowen Yu, Shiliang Wang, Qiankun Zhang, Yuehui He, Han Huang and Jin Zou

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Graphitized silicon carbide microbeams: wafer-level, self-aligned graphene on silicon wafers

Currently proven methods that are used to obtain devices with high-quality graphene on silicon wafers involve the transfer of graphene flakes from a growth substrate, resulting in fundamental limitations for large-scale device fabrication. Moreover, the complex three-dimensional structures of interest for microelectromechanical and nanoelectromechanical systems are hardly compatible with such transfer processes. Here, we introduce a methodology for obtaining thousands of microbeams, made of graphitized silicon carbide on silicon, through a site-selective and wafer-scale approach. A Ni-Cu alloy catalyst mediates a self-aligned graphitization on prepatterned SiC microstructures at a temperature that is compatible with silicon technologies. The graphene nanocoating leads to a dramatically enhanced electrical conductivity, which elevates this approach to an ideal method for the replacement of conductive metal films in silicon carbide-based MEMS and NEMS devices.

Benjamin V Cunning, Mohsin Ahmed, Neeraj Mishra, Atieh Ranjbar Kermany, Barry Wood and Francesca Iacopi

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Ultra-toughened nylon 12 nanocomposites reinforced with IF-WS 2

Inorganic fullerene-like WS 2 nanoparticle- (IF-WS 2 ) reinforced nylon 12 nanocomposites have been prepared through effective ultrasonic mixing without using any surfactant, followed by molding at 220 °C. Morphological characterizations using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and microcomputed tomography (micro-CT) have revealed the excellent dispersion of IF-WS 2 nanoparticles in the nylon 12 matrix. X-ray diffraction (XRD) analyses have confirmed that a phase transition from α ′-phase to a more stable γ -phase took place during the sintering of nylon 12, regardless of the amount of IF-WS 2 added to the matrix. At a very low IF-WS 2 content of 2 wt%, the tensile strength and bending strength of the composites increased slightly by 27% and 28%, respectively. However, the toughness dramatically improved by 185% and 148% at IF-WS 2 additions of 0.25 and 0.5 wt%, respecti...

Fang Xu, Chunze Yan, Yat-Tarng Shyng, Hong Chang, Yongde Xia and Yanqiu Zhu

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Yellow-light generation and engineering in zinc-doped cadmium sulfide nanobelts with low-threshold two-photon excitation

Through a simple doping route with zinc ion as a dopant in cadmium sulfide nanobelts, a bright yellow-colored light was obtained. The detailed chromaticity and brightness of the light can be engineered by the dopant concentration and the pumping power, which are used to control the dominant wavelength to any fine yellow color, and even cover the sodium-yellow-line of 589 nm. The nanobelts were synthesized through a chemical vapor deposition method. The peak shift of the XRD result proves that the zinc ions as a dopant exist in the nanobelts rather than in the ZnCdS alloy formation. Time-resolved photoluminescence of the nanobelt reveals the existence of the defect-related state, which induces a red band to further mix with green band-edge emission to form the yellow light. Moreover, low-threshold two-photon excitation was observed in the proper Zn-doped cadmium sulfide nanobelts. The dopant and pumping power-tuned generation and engineering of the yellow light makes it possible t...

Xiaoxu Wang, Jing Li, Qisong Li, Bingkun Chen, Guangli Song, Wensheng Zhang, Lijie Shi, Bingsuo Zou and Ruibin Liu

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Uniform dispersion of graphene oxide in aluminum powder by direct electrostatic adsorption for fabrication of graphene/aluminum composites

The excellent properties of graphene promote it as an ideal reinforcement in composites. However, dispersing graphene homogenously into metals is a key challenge that limits the development of high-performance graphene-reinforced metal matrix composites. Here, via simple electrostatic interaction between graphene oxide (GO) and Al flakes, uniform distribution of reduced graphene oxide (RGO) in an Al matrix is achieved. The adsorption process of GO on Al flakes is efficient, as it can be completed in minutes and proceeds spontaneously without any chemical agents. GO can be partially reduced by the electron interchange during the adsorption process and could be thoroughly reduced after subsequent thermal annealing. A densified RGO/Al composite can be obtained by hot pressing the RGO/Al composite powders. By employing the preceding fabrication process, a composite reinforced with only 0.3 wt.% of RGO shows an 18 and 17% increase in elastic modulus and hardness, respectively, over un...

Zan Li, Genlian Fan, Zhanqiu Tan, Qiang Guo, Dingbang Xiong, Yishi Su, Zhiqiang Li and Di Zhang

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Tuesday, July 22, 2014

Ferromagnetic Exchange Coupling between Fe Phthalocyanine and Ni(111) Surface Mediated by the Extended States of Graphene

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The Journal of Physical Chemistry C

DOI: 10.1021/jp5041663




Andrea Candini, Valerio Bellini, David Klar, Valdis Corradini, Roberto Biagi, Valentina De Renzi, Kurt Kummer, Nicholas B. Brookes, Umberto del Pennino, Heiko Wende and Marco Affronte

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Reactivity of Pyrimidine on Clean Ru(0001): Experimental and Calculated Infrared Spectra

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The Journal of Physical Chemistry C

DOI: 10.1021/jp5021752




Ana R. Garcia, Adelino M. Galvão and Laura M. Ilharco

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Influence of the Temperature on the Proton Transport in Poly(styrene-co-divinylbenzene) Membranes from Molecular Dynamics Simulations

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The Journal of Physical Chemistry C

DOI: 10.1021/jp503908u




Esther Córdova-Mateo, Oscar Bertran and Carlos Alemán

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Dynamic Depolarized Light Scattering of Small Round Plasmonic Nanoparticles: When Imperfection is Only Perfect

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The Journal of Physical Chemistry C

DOI: 10.1021/jp504264f




Sandor Balog, Laura Rodriguez-Lorenzo, Christophe A. Monnier, Benjamin Michen, Marc Obiols-Rabasa, Lucia Casal-Dujat, Barbara Rothen-Rutishauser, Alke Petri-Fink and Peter Schurtenberger

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Chemical Basis of the Tribological Properties of AgTaO3 Crystal Surfaces

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The Journal of Physical Chemistry C

DOI: 10.1021/jp503673k




Hongyu Gao, Alberto Otero-de-la-Roza, Samir M. Aouadi, Ashlie Martini and Erin R. Johnson

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First-Principles Study of Chemical Stability of the Lithium Oxide Garnets Li7La3M2O12 (M = Zr, Sn, or Hf)

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The Journal of Physical Chemistry C

DOI: 10.1021/jp504314w




Sung Gu Kang and David S. Sholl

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Singlet–Singlet Exciton Annihilation in an Exciton-Coupled Squaraine-Squaraine Copolymer: A Model toward Hetero-J-Aggregates

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The Journal of Physical Chemistry C

DOI: 10.1021/jp5055809




Sebastian F. Völker, Alexander Schmiedel, Marco Holzapfel, Klaus Renziehausen, Volker Engel and Christoph Lambert

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DNA-Based Platinum Nanozymes for Peroxidase Mimetics

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The Journal of Physical Chemistry C

DOI: 10.1021/jp503242e




Yan Fu, Xuyin Zhao, Jinli Zhang and Wei Li

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All-Color Plasmonic Nanolasers with Ultralow Thresholds: Autotuning Mechanism for Single-Mode Lasing

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Nano Letters

DOI: 10.1021/nl501273u




Yu-Jung Lu, Chun-Yuan Wang, Jisun Kim, Hung-Ying Chen, Ming-Yen Lu, Yen-Chun Chen, Wen-Hao Chang, Lih-Juann Chen, Mark I. Stockman, Chih-Kang Shih and Shangjr Gwo

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Dye Aggregation Effect on Interfacial Electron-Transfer Dynamics in Zinc Phthalocyanine-Sensitized Solar Cells

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The Journal of Physical Chemistry C

DOI: 10.1021/jp500798c




Hiroyuki Matsuzaki, Takurou N. Murakami, Naruhiko Masaki, Akihiro Furube, Mutsumi Kimura and Shogo Mori

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Energy Transfer between Quantum Dots and Conjugated Dye Molecules

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The Journal of Physical Chemistry C

DOI: 10.1021/jp502033d




Gary Beane, Klaus Boldt, Nicholas Kirkwood and Paul Mulvaney

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Electrochemical Delithiation/Relithiation of LiCoPO4: A Two-Step Reaction Mechanism Investigated by in Situ X-ray Diffraction, in Situ X-ray Absorption Spectroscopy, and ex Situ 7Li/31P NMR Spectroscopy

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The Journal of Physical Chemistry C

DOI: 10.1021/jp503306v




Maximilian Kaus, Ibrahim Issac, Ralf Heinzmann, Stephen Doyle, Stefan Mangold, Horst Hahn, Venkata Sai Kiran Chakravadhanula, Christian Kübel, Helmut Ehrenberg and Sylvio Indris

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An Advanced Lithium-Ion Battery Based on a Graphene Anode and a Lithium Iron Phosphate Cathode

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Nano Letters

DOI: 10.1021/nl502429m




Jusef Hassoun, Francesco Bonaccorso, Marco Agostini, Marco Angelucci, Maria Grazia Betti, Roberto Cingolani, Mauro Gemmi, Carlo Mariani, Stefania Panero, Vittorio Pellegrini and Bruno Scrosati

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Correction to Surface Reconstruction-Induced Coincidence Lattice Formation Between Two-Dimensionally Bonded Materials and a Three-Dimensionally Bonded Substrate

Nano Letters

DOI: 10.1021/nl502672q




Jos E. Boschker, Jamo Momand, Valeria Bragaglia, Ruining Wang, Karthick Perumal, Alessandro Giussani, Bart J. Kooi, Henning Riechert and Raffaella Calarco

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Engineering the Band Structure of Nanoparticles by an Incommensurate Cover Layer

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The Journal of Physical Chemistry C

DOI: 10.1021/jp5060759




K. Schouteden, Z. Li, V. Iancu, D. A. Muzychenko, E. Janssens, P. Lievens and C. Van Haesendonck

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X-ray Spectroscopic Study of the Electronic Structure of Monazite- and Xenotime-Type Rare-Earth Phosphates

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The Journal of Physical Chemistry C

DOI: 10.1021/jp5051996




Mohamed Ruwaid Rafiuddin, Eric Mueller and Andrew P. Grosvenor

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Investigation of Drug–Model Cell Membrane Interactions Using Sum Frequency Generation Vibrational Spectroscopy: A Case Study of Chlorpromazine

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The Journal of Physical Chemistry C

DOI: 10.1021/jp503038m




Fu-Gen Wu, Pei Yang, Chi Zhang, Xiaofeng Han, Minghu Song and Zhan Chen

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