Search

Your search keyword '"C nanotubes"' showing total 5 results
Start Over Descriptor "C nanotubes"
5 results on '"C nanotubes"'

1. Review of nanostructured current collectors in lithium-sulfur batteries.

Author

Kong, Long, Peng, Hong-Jie, Huang, Jia-Qi, and Zhang, Qiang

Abstract

Lithium-sulfur (Li-S) batteries are receiving increasing attention because of their high theoretical energy density and the natural abundance of S. However, their practical applications are impeded by the low areal S loading in the cathode and the fatal Li dendrites in the anode of the Li−S cells, which yield an inferior practical energy density and introduce safety concerns, respectively. In this review, we focus on an emerging approach-the nanostructured current collector-to overcome these two critical challenges for Li−S batteries. We describe the general attributes of nanostructured current collectors and examine how these attributes enhance the S utilization with a high S loading and suppress the Li dendrites by regulating the Li-deposition behavior. We present various assembly blocks that have been used for the construction of advanced nanostructured current collectors to build better S cathodes and Li anodes. Finally, we investigate the current challenges and possible solutions regarding the practical applications of nanostructured current collectors in Li−S batteries. [ABSTRACT FROM AUTHOR]

Published
2017
Full Text
View/download PDF

2. Preservation of C hexagons in the transformation of C allotropes.

Author

Bucknum, Michael and Castro, Eduardo

Subjects
*CARBON, *HEXAGONS, *TRANSFORMATION groups, *PARTICLE swarm optimization, *NANOTUBES, *ACENES
Abstract

Theoretical work by Zhao et al. in (ACS Nano Lett 266(5):7226-7234, ) employing a novel 'particle swarm methodology' has predicted the pressure-induced collapse of various, respective 1-dimensional members of the (n, 0) C nanotube family, into their corresponding 3-dimensional network C patterns realized as the various C-based hexagonites. In particular, the so-called (6, 0) nanotubes, in which the circumference of this nanotube type is comprised of a polyacene-like belt of six benzene-like tiles, is predicted by Zhao et al. to spontaneously collapse with extreme pressure in to the parent member of the C-based hexagonite family of lattices. This prediction is supported by an independent theoretical analysis of crystallographic data obtained in a synchrotron-nanotube experiment conducted in a diamond anvil cell in 2005 by Wang et al. Such nanotube-hexagonite phase transformations of C, are termed here as 'hexagon-preserving-carbon-allotrope-transformations', as the hexagonal C rings are preserved in the C phase transformations. By analogy, the classical phase transformation of C-based graphene to C-based diamond is described as a 'hexagon-preserving-carbon-allotrope-transformation'. The details of these descriptive labels are discussed in this communication. [ABSTRACT FROM AUTHOR]

Published
2014
Full Text
View/download PDF

3. Single-walled carbon nanotube electronics.

Author

McEuen, P.L., Fuhrer, M.S., and Hongkun Park

Abstract

Single-walled carbon nanotubes (SWNTs) have emerged as a very promising new class of electronic materials. The fabrication and electronic properties of devices based on individual SWNTs are reviewed. Both metallic and semiconducting SWNTs are found to possess electrical characteristics that compare favorably to the best electronic materials available. Manufacturability issues, however, remain a major challenge [ABSTRACT FROM PUBLISHER]

Published
2002
Full Text
View/download PDF

4. Remarkable electrochemical stability of one-step synthesized Pd nanoparticles supported on graphene and multi-walled carbon nanotubes

Author

Horacio Esteban Troiani, Gilberto Maia, María Elisa Martins, Ana Arenillas, Pablo S. Fernández, Cauê A. Martins, Giuseppe A. Camara, and Fábio de Lima

Subjects
Nanotecnología, Materials science, Renewable Energy, Sustainability and the Environment, Graphene, graphene, chemistry.chemical_element, Nanotechnology, Context (language use), INGENIERÍAS Y TECNOLOGÍAS, Carbon black, Carbon nanotube, Nano-materiales, Electrochemistry, Catalysis, law.invention, chemistry.chemical_compound, Pd nanoparticles, chemistry, law, General Materials Science, Electrical and Electronic Engineering, C nanotubes, Carbon, Ethylene glycol, potential cycling
Abstract

Anodes and cathodes of fuel cells are usually composed of metallic nanoparticles (NPs) dispersed on carbon, in order to increase their active area. Since the degradation of the catalyst affects the performance of the fuel cells, understanding the stability of its components is pivotal to make these systems more reliable. As such, graphene sheets and carbon nanotubes have been employed as alternative supports to improve the stability of anodes in fuel cells. In this context, we have used polyvinylpyrrolidone (PVP) combined with a one-step chemical reduction induced by ethylene glycol to synthesize Pd NPs dispersed on chemically converted graphene (CCG). We compared the electrochemical stability of Pd NPs supported on carbon black (C), multi-walled carbon nanotubes (MWCNTs) and CCG. MWCNTs and CCG make Pd NPs electrochemically more stable than carbon black. Pd/CCG catalysts are more stable than Pd/MWCNTs during the first potential cycles, while Pd/MWCNTs showed a higher long-term stability. These results allow us to consider a competition between agglomeration of NPs and degradation of the support, where the agglomeration seems to be limited by the available surface area of the support. Fil: Martins, Cauê A.. Universidade Federal do Mato Grosso do Sul; Brasil. Universidade Federal da Grande Dourados; Brasil Fil: Fernández, Pablo Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentina Fil: De Lima, Fabio. Universidade Federal do Mato Grosso do Sul; Brasil Fil: Troiani, Horacio Esteban. Comisión Nacional de Energía Atómica. Gerencia del Area de Investigación y Aplicaciones No Nucleares. Gerencia de Física (Centro Atómico Bariloche); Argentina Fil: Martins, María Elisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentina Fil: Arenillas de la Puente, Ana. Instituto Nacional del Carbón; España. Consejo Superior de Investigaciones Científicas; España Fil: Gilberto, Maia. Universidade Federal do Mato Grosso do Sul; Brasil Fil: Camara, Giuseppe A.. Universidade Federal do Mato Grosso do Sul; Brasil

Published
2014
Full Text
View/download PDF

5. High dielectric nanocrystalline materials on carbon nanotubes for vacuum electronics

Author

Marco Rossi, Francesco Toschi, Vito Sessa, Silvia Orlanducci, V. Guglielmotti, Emanuela Tamburri, and Maria Letizia Terranova

Subjects
Settore CHIM/03 - Chimica Generale e Inorganica, Materials science, Fabrication, Carbon nanotube actuators, field emission, C nanotubes, coating, Physics::Optics, Nanotechnology, Heterojunction, Dielectric, Carbon nanotube, Electron, Condensed Matter::Mesoscopic Systems and Quantum Hall Effect, Nanocrystalline material, law.invention, Optical properties of carbon nanotubes, Condensed Matter::Materials Science, law, carbon nanotubes, high dielectric materials, vacuum electronics
Abstract

Carbon nanotubes coated with dielectric layers are excellent candidates as starting blocks for vacuum electronic systems. The heterojunctions formed where carbon nanotubes and dielectrics combine may find wide applications for the fabrication of electron emission microdevices and for the assembling of sensors and detectors.

Published
2009

Catalog

Books, media, physical & digital resources
See catalog results