Synthesis of C60 intercalated graphite

Gupta, Vinay; Scharff, P.; Risch, K.; Romanus, Henri; Müller, R.

doi:10.1016/j.ssc.2004.05.018

Cited by 55 publications

(45 citation statements)

References 11 publications

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“…Gupta and coworkers recently reported such a material (see Figure 2). 12 Our calculations confirm the experimentally observed structure and atomization energy of this new car- bon phase. The fullerene intercalants simultaneously spread the graphene layers and enhance the H 2 -host interaction, leading to a reasonable potential hydrogen storage medium.…”

Section: H 2 Storage In Carbon Nanostructuressupporting

confidence: 81%

Novel carbon materials can store and sieve hydrogen

Heine¹

2007

SPIE Newsroom

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Carbon-based nanostructures are potential H 2 storage devices for automotive applications due to their light weight and useful mechanical and chemical properties.Global warming and the shortage of fossil fuels provide motivation for the replacement of traditional combustion engines. The electrochemical oxidation of molecular hydrogen is an efficient, sustainable, and environmentally friendly alternative for automotive applications. When implemented with modern fuel cells, this technology offers high energy efficiency in an effectively pollution-free process. Given a hydrogen economy, the biggest challenge for this technology is H 2 gas storage. At ambient conditions, a liter of hydrogen gas contains less than 0.1% of the energy in the same volume of n-octane or gasoline.The current prototype H 2 tanks are high-pressure (700bar) bottles and liquid hydrogen cryodevices. Both solutions are awkward for routine mobile applications, prompting an ongoing search for alternative storage materials. 1, 2 The most likely possibilities are materials in which the H 2 is either chemisorbed or physisorbed. In chemisorption, H 2 is chemically bound in a host material, such as a metal hydride. In physisorption the gas is bound to the host through weak van der Waals forces. Chemisorption is often hampered by slow loading and/or unloading due to activation barriers for the chemical reactions involved. Devices based on H 2 physisorption have thus far demonstrated insufficient mechanical stability and persistence as well low volumetric storage capacities, although the latter is debated. 2,3 We aim to better understand the guest-host interaction of carbon nanostructures with H 2 and other gases, as such nanostructures are among the most promising physisorption-based, lightweight H 2 storage materials. Our work predicts maximum theoretically possible storage capacities as well as suggests new materials that may be useful as H 2 storage media. MethodologyWe employ multi-scale simulation techniques to investigate the H 2 -host system and its properties. Using an approximate density-functional scheme with van-der-Waals corrections, 4, 5 we determine the mechanical and structural properties of carbon nanostructures. Then, we model H 2 interactions with the host using an additive Rutherford potential, with parameters fitted to high-level ab initio calculations (second order Möller-Plesset perturbation theory, coupled-cluster with single and double perturbative triple excitations) on model systems. We solve the stationary Schrödinger equations for the motion of the H 2 center of mass inside the nanostructure on a numerical grid, with periodic boundary conditions applied. We neglect the internal degrees of freedom of the hydrogen molecule and interactions between the molecules. The result is the the energy spectrum ε i of bound H 2 , together with corresponding eigenstates Ψ i , determined in the ideal gas approximation. The equilibrium constant K eq for hydrogen adsorption is then calculated as a function of temperature T using standard the...

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Section: H 2 Storage In Carbon Nanostructuressupporting

confidence: 81%

Novel carbon materials can store and sieve hydrogen

Heine¹

2007

SPIE Newsroom

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“…The diminution of the interlayer spacing distance reduced the van der Waals interaction between planes so that it can be envisaged as a route to form graphene and nano-ribbons [269]. The list of metals and small molecules that can be embedded in between graphene planes is huge and not exhaustive here: Alkali-metals (K, Li, Cs, Rb); alkali-earth-metals (Be, Ca, Ba); halogens; C 60 [270] [266,273]. Superconductivity has been observed in many GICs (with the highest critical temperature found at a relatively high temperature, 11.5 K, for CaC 6 , see references [266]) and multiwavelength Raman spectroscopy is a central characterization tool because superconductivity may be due to electron-phonon interaction and mediated by phonons [276].…”

Section: Graphite Intercalated Compoundsmentioning

confidence: 99%

A Guide to and Review of the Use of Multiwavelength Raman Spectroscopy for Characterizing Defective Aromatic Carbon Solids: from Graphene to Amorphous Carbons

2017

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sp 2 hybridized carbons constitute a broad class of solid phases composed primarily of elemental carbon and can be either synthetic or naturally occurring. Some examples are graphite, chars, soot, graphene, carbon nanotubes, pyrolytic carbon, and diamond-like carbon. They vary from highly ordered to completely disordered solids and detailed knowledge of their internal structure and composition is of utmost importance for the scientific and engineering communities working with these materials. Multiwavelength Raman spectroscopy has proven to be a very powerful and non-destructive tool for the characterization of carbons containing both aromatic domains and defects and has been widely used since the 1980s. Depending on the material studied, some specific spectroscopic parameters (e.g., band position, full width at half maximum, relative intensity ratio between two bands) are used to characterize defects. This paper is addressed first to (but not limited to) the newcomer in the field, who needs to be guided due to the vast literature on the subject, in order to understand the physics at play when dealing with Raman spectroscopy of graphene-based solids. We also give historical aspects on the development of the Raman spectroscopy technique and on its application to sp 2 hybridized carbons, which are generally not presented in the literature. We review the way Raman spectroscopy is used for sp 2 based carbon samples containing defects. As graphene is the building block for all these materials, we try to bridge these two worlds by also reviewing the use of Raman spectroscopy in the characterization of graphene and nanographenes (e.g., nanotubes, nanoribbons, nanocones, bombarded graphene). Counterintuitively, because of the Dirac cones in the electronic structure of graphene, Raman spectra are driven by electronic properties: Phonons and electrons being coupled by the double resonance mechanism. This justifies the use of multiwavelength Raman spectroscopy to better characterize these materials. We conclude with the possible influence of both phonon confinement and curvature of aromatic planes on the shape of Raman spectra, and discuss samples to be studied in the future with some complementary technique (e.g., high resolution transmission electron microscopy) in order to disentangle the influence of structure and defects.

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“…A possible route to achieve this is by synthesizing novel carbon-based architectures of large surface area, suitable for storage pores, like carbon nanoscrolls (CNSs) 24 and fullerene intercalated graphite sheets. 25 Calculations performed on these materials by Mpourmpakis et al 26 and Kuc et al 27 revealed that they are very promising since an enhancement on the storage of hydrogen was observed. Nevertheless, despite the enhancement, the total amount of hydrogen stored in those structures remains far from the D.O.E.…”

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confidence: 99%

Pillared Graphene: A New 3-D Network Nanostructure for Enhanced Hydrogen Storage

2008

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A multiscale theoretical approach was used to investigate hydrogen storage in a novel three-dimensional carbon nanostructure. This novel nanoporous material has by design tunable pore sizes and surface areas. Its interaction with hydrogen was studied thoroughly via ab initio and grand canonical Monte Carlo calculations. Our results show that, if this material is doped with lithium cations, it can store up to 41 g H 2 /L under ambient conditions, almost reaching the DOE volumetric requirement for mobile applications.Hydrogen is considered to be one of the most promising energy fuels for automobiles, and its use can be further extended to smaller portable devices, like mobile phones and laptops. It can be stored in either liquid or gas phase, provided that an efficient storage device exists. United States' Department of Energy (D.O.E.) has established requirements that have to be met by 2010, regarding the reversible storage of hydrogen according to which the required gravimetric density should be 6 wt % and the volumetric capacity should be 45 g of H 2 /L.1 By moving in that direction, the appropriate material for hosting hydrogen has to be developed.Initially, metal alloys, such as LaNi 5 , TiFe, and MgNi, were proposed as storage tanks since by chemical hydrogenation they form metal hydrides. Hydrogen can then be released by dehydrogenation of the hydride. Regarding vehicle applications, metal hydrides can be distinguished into high or low temperature materials. This depends on the temperature at which hydrogen absorption or desorption is taking place and if this is above or below 150°C, respectively. La-based and Ti-based alloys are examples of some low temperature materials with their main drawback as the very low gravimetric capacity (<2 wt %) they provide. 2,3 Controversially, high temperature materials like Mg-based alloys can reach a theoretical maximum capacity of 7.6 wt %, suffering though from poor hydrogenation/ dehydrogenation kinetics and thermodynamics. [3][4][5] In every case, metal alloys, besides the cost, are heavy for commercial production focused on mobile applications.On the other hand, light nanoporous materials can store hydrogen by physisorption that allows fast loading and unloading. However, as the interaction between H 2 and host material is dominated by weak van der Waals forces, only a small amount of H 2 can be stored at room temperature. In this case, high surface area and appropriate pore size are key parameters for achieving high hydrogen storage. Nanoporous carbon structures fulfill this criterion, placing them since the beginning among of the best candidates for hydrogen storage media. [6][7][8][9] After the synthesis of carbon nanotubes (CNTs), 10 the scientific research focused on their storage capability. Initial studies showed indeed that CNTs can be considered as a good material for reversible hydrogen storage, 11-13 but it was revealed later that under ambient conditions, pristine CNTs are not that promising.14-16 Further studies showed that doping CNTs with lithi...

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Synthesis of C60 intercalated graphite

Cited by 55 publications

References 11 publications

Novel carbon materials can store and sieve hydrogen

Novel carbon materials can store and sieve hydrogen

A Guide to and Review of the Use of Multiwavelength Raman Spectroscopy for Characterizing Defective Aromatic Carbon Solids: from Graphene to Amorphous Carbons

Pillared Graphene: A New 3-D Network Nanostructure for Enhanced Hydrogen Storage

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