Selective liquid sorption properties of hydrophobized graphite oxide nanostructures

Dékány, Imre; Krüger-Grasser, R.; Weiß, André

doi:10.1007/s003960050283

Cited by 141 publications

(15 citation statements)

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“…The average thickness of the flakes was 1.5-2 nm as derived from the topographical height profile ( Figure 5B) which corresponds to the black line in the higher magnification image (Figure 5A right). This value is larger than the value of 0.61 nm predicted for a single graphene oxide layer (Dékány et al, 1998) and is attributed to the ODA layer positioned underneath the GO sheet. Even without the presence of ODA molecules, the height of single GO layers was reported to be in the range of 1.1 ± 0.2 nm due to the existence of absorbed water molecules (Schniepp et al, 2006;Gómez-Navarro et al, 2007).…”

Section: Resultscontrasting

confidence: 64%

Mapping of Graphene Oxide and Single Layer Graphene Flakes—Defects Annealing and Healing

et al. 2018

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Graphene has outstanding properties that make it an auspicious material for many applications. This work presents the production of graphene oxide (GO) via the Langmuir-Blodgett process and the subsequent restoration of single layer graphene flakes (SLGF) via the chemical reduction, and thermal annealing of the GO. Scanning electron microscopy (SEM) and optical images were used to evaluate the morphology and surface coverage of the substrate with GO flakes. Through this technique, smooth dispersion, controllable development, and population of the GO single flakes on the Si substrate without size limitation have been achieved. The height distribution of the GO was monitored after each processing step by AFM measurements. Additionally, the effects of each process on the structure of the samples was systematically studied via 2D Laser Raman spectroscopy (LRS) mapping. The determination of the layer number on each graphene flake was accomplished by monitoring the observed Raman shifts as a function of the position and confirmed via AFM measurements. The spectroscopic analysis of the single flakes was performed in order to study their topography and identify their quality as a function of the processing steps. Via the topographic 2D analysis of both the first-and second-order vibrational modes as a function of the position on the crystal, the degree of graphitization and/or the presence of defects, as well as the presence of internal stresses were mapped. Such a systematic determination of the effects of reduction and annealing on the structure of single layer graphene from reduced GO produced via the Langmuir-Blodgett process is reported for the first time in literature.

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Section: Resultscontrasting

confidence: 64%

Mapping of Graphene Oxide and Single Layer Graphene Flakes—Defects Annealing and Healing

et al. 2018

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“…The surface coverage is quite high; the GO platelets in the transferred layer are contacting each other, with hardly any overlap but only small voids between them, forming a nearly continuous, close-packed array. Because of the ODA layer below the GO sheet, the average height of the flakes of 0.9-1.5 nm, as derived from topographical height profile, is larger than the value of 0.61 nm predicted for a single GO layer (Dekany et al, 1998). However, it is difficult to conclude anything on the orientation of the ODA molecules (straight or inclined) from these images because the height of single GO layers without ODA has also been reported in the literature to be larger than 0.61 nm, namely of the order of 1.1 ± 0.2 nm [see, for example, Schniepp et al (2006) and Gomez-Navarro et al (2007)] probably due to the presence of adsorbed water molecules.…”

Section: Structure Control Of Hybrid Oda-go Layermentioning

confidence: 60%

“…The peak at 289.3 eV in the ODA-GO-ODA spectrum (at 289.1 eV for ODA-GO-ODA-C 60 ) is attributed to carboxyl groups created during the oxidation of GO. The additional peak at 290.5 eV in the ODA-GO-ODA-C 60 spectrum is due to the C1s shake up features of C 60 (Maxwell et al, 1994), resulting from π-π* transitions excited in the photoemission process, and therefore gives additional support to the presence of fullerenes in the hybrid multilayer (Felicissimo et al, 2009;Gengler et al, 2012a). Finally, upon reduction and subsequent annealing at 700°C the C1s spectral intensity due to oxygen-containing functional groups of graphite oxide (Figure 5) is significantly lower as compared to before the treatment, indicating a partial reconstruction of the graphene network expected to result in a better electrical conductivity (see below).…”

Section: Characterization Of Hybrid Graphene/fullerene Multilayersmentioning

confidence: 93%

A Bottom-Up Approach for the Synthesis of Highly Ordered Fullerene-Intercalated Graphene Hybrids

et al. 2015

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Much of the research effort on graphene focuses on its use as a building block for the development of new hybrid nanostructures with well-defined dimensions and properties suitable for applications such as gas storage, heterogeneous catalysis, gas/liquid separations, nanosensing, and biomedicine. Toward this aim, here we describe a new bottom-up approach, which combines self-assembly with the Langmuir-Schaefer deposition technique to synthesize graphene-based layered hybrid materials hosting fullerene molecules within the interlayer space. Our film preparation consists in a bottom-up layer-by-layer process that proceeds via the formation of a hybrid organo-graphene oxide Langmuir film. The structure and composition of these hybrid fullerene-containing thin multilayers deposited on hydrophobic substrates were characterized by a combination of X-ray diffraction, Raman and X-ray photoelectron spectroscopies, atomic force and scanning electron microscopies, and conductivity measurements. The latter revealed that the presence of C 60 within the interlayer spacing leads to an increase in electrical conductivity of the hybrid material as compared to the organo-graphene matrix alone.

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“…This closely packed homogeneous array demonstrates the highly controllable formation of ODA-GO/C-dot hybrid layers. 32 The average thickness of the flakes is 1.0–1.5 nm, as derived from the topographical height profile (section analysis), corresponding to the size of single GO layers, 45 which is 6.1 Å. Moreover, uniform particles can be observed on top of the GO layers.…”

Section: Resultsmentioning

confidence: 98%

Graphene/Carbon Dot Hybrid Thin Films Prepared by a Modified Langmuir–Schaefer Method

Kouloumpis

Thomou²,

Chalmpes³

et al. 2017

ACS Omega

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The special electronic, optical, thermal, and mechanical properties of graphene resulting from its 2D nature, as well as the ease of functionalizing it through a simple acid treatment, make graphene an ideal building block for the development of new hybrid nanostructures with well-defined dimensions and behavior. Such hybrids have great potential as active materials in applications such as gas storage, gas/liquid separation, photocatalysis, bioimaging, optoelectronics, and nanosensing. In this study, luminescent carbon dots (C-dots) were sandwiched between oxidized graphene sheets to form novel hybrid multilayer films. Our thin-film preparation approach combines self-assembly with the Langmuir–Schaefer deposition and uses graphene oxide nanosheets as template for grafting C-dots in a bidimensional array. Repeating the cycle results in a facile and low-cost layer-by-layer procedure for the formation of highly ordered hybrid multilayers, which were characterized by photoluminescence, UV–visible, X-ray photoelectron, and Raman spectroscopies, as well as X-ray diffraction and atomic force microscopy.

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Selective liquid sorption properties of hydrophobized graphite oxide nanostructures

Cited by 141 publications

References 1 publication

Mapping of Graphene Oxide and Single Layer Graphene Flakes—Defects Annealing and Healing

Mapping of Graphene Oxide and Single Layer Graphene Flakes—Defects Annealing and Healing

A Bottom-Up Approach for the Synthesis of Highly Ordered Fullerene-Intercalated Graphene Hybrids

Graphene/Carbon Dot Hybrid Thin Films Prepared by a Modified Langmuir–Schaefer Method

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