Pristine Graphite Oxide

Dimiev, Ayrat M.; Kosynkin, Dmitry V.; Alemany, Lawrence B.; Chaguine, Pavel; Tour, James M.

doi:10.1021/ja211531y

Cited by 404 publications

(403 citation statements)

References 30 publications

Supporting

Mentioning

367

Contrasting

Unclassified

Order By: Relevance

“…Table 1 Elemental analysis of GO dried at ambient conditions (S=O asymmetric stretching), which complies with literature data [9]. In the region 2250-1920 cm -1 a noise was recorded stemming from the spectrometer diamond attenuated total reflectance sampling accessory.…”

Section: Go Synthesis and Characterizationsupporting

confidence: 77%

Optimized Deposition of Graphene Oxide Langmuir-Blodgett Thin Films

Gerca

Kundziņš

Teivena

et al. 2014

Latvian Journal of Physics and Technical Sciences

View full text Add to dashboard Cite

Single sheet graphene (SG) is an innovative transparent material with high electrical and thermal conduction the use of which in transparent electrodes instead of traditional materials improves the performance of optoelectronic devices. In this study, graphene oxide (GO) has been obtained by a modified Hummer`s method followed by an advanced technique of water removal (lyophilisation). The Langmuir-Blodgett (LB) method was applied to transfer GO from suspension to substrate. To optimize the deposition process, as suspending and spreading solvents the benzene and benzene/methanol mixtures were chosen instead of previously studied water suspensions. The number of GO layers in suspension is reduced by exfoliation in order to obtain a single GO monolayer. For this purpose, sonication and centrifugation of GO sheets are carried out. Finally, the effect of variously treated glass substrate surfaces on the deposition efficiency has been studied. In the work, it is shown that ozonization of glass substrate improves the deposition outcome, while ozonization of indium tin oxide (ITO) glass substrate is necessary to perform such deposition. The obtained GO suspensions and LB thin films have been studied using a scanning electron microscope (SEM).

show abstract

Section: Go Synthesis and Characterizationsupporting

confidence: 77%

Optimized Deposition of Graphene Oxide Langmuir-Blodgett Thin Films

Gerca

Kundziņš

Teivena

et al. 2014

Latvian Journal of Physics and Technical Sciences

View full text Add to dashboard Cite

show abstract

“…21 Briefly, graphite powder (3.0 g) and 98% H 2 SO 4 (400 mL) were mixed at room temperature using a mechanical stirrer. After 10 min, KMnO 4 (3.0 g) was added, and the mixture turned green.…”

Section: Methodsmentioning

confidence: 99%

Graphene Oxide Fuel Cell

Tateishi

Hatakeyama

Ogata

et al. 2013

J. Electrochem. Soc.

View full text Add to dashboard Cite

Graphene oxide (GO) exhibits relatively high proton conduction even at low relative humidity (RH) and temperatures. Thus, multilayered GO film (GO paper) is a promising electrolyte in various cells and batteries. We report the in-plane and through-plane proton conductivities of GO paper at low RH and room temperature. The conductivities were 10 −5 -10 −4 S/cm at RH of 10-20%. We examined the performance of a graphene oxide fuel cell (GOFC) with GO paper as the electrolyte at low RH (<20%) and room temperature. We demonstrated that a simple membrane electrode assembly (MEA) based on Pt/GO/Pt system functioned as a H 2 /O 2 fuel cell. The GOFC with Pt/C electrodes afforded better fuel cell performance than a MEA composed of Pt/C electrodes and Nafion electrolyte. GO paper composed of nano-sized GO (nanoGO) flakes enhanced the performance of the GOFC, particularly the current density. Furthermore, a composite of Fe phthalocyanine (PcFe) /reduced GO (rGO)/TiO 2 could act as the Pt-free oxygen electrode in GOFC, although the fuel cell performance should be improved for practical applications. Our study suggests that a low cost GOFC without a Nafion electrolyte and noble metal electrodes could be fabricated in the near future. GO is a promising material because of its many excellent chemical and physical properties, which arise from various oxygenated functional groups.1-6 Multi-layered GO nanosheets (GO paper) exhibit high proton conduction. [7][8][9] The main oxygenated functional group in GO is epoxide. It acts as the site for proton transfer after water molecules bind to it, even at low RH and room temperature. 10 The relatively high proton conductivity under these conditions suggests that GO paper could act as a proton electrolyte in various cells and batteries. [11][12][13][14][15][16] The proton conductivity of the GO paper is lower than that of the conventional Nafion electrolyte, which is usually used at high RH (∼100%), 17,18 while the overall conduction of the GO paper will be similar to that of Nafion if the GO paper is less than a tenth of the thickness of the Nafion.It has been reported that various gases do not pass through the GO paper, even when the GO is very thin (0.1 μm).19 This means thin GO paper is well suited as an electrolyte for the H 2 /O 2 fuel cell, because of the high proton conduction and the H 2 and O 2 gas shielding. Nafion electrolytes must be thick in order to achieve gas shielding (>10 2 μm). Moreover, GO paper is much cheaper than Nafion. A mixture of GO paper and Nafion has been used as the electrolyte for a fuel cell, and it acted as an electrolyte even at relatively low RH (25%).8 Sulfonic acid functionalized GO (SGO) has been used as an electrolyte without Nafion, and tested in a H 2 /O 2 fuel cell at 25% RH and 40• C, with Pt/C electrodes. 12Here we report the performance of a simple H 2 /O 2 fuel cells with a 100% GO paper (< 1 atom% S) electrolyte (GOFC) as well as the proton conductivities at low RH and 23-25• C. ExperimentalSynthesis of GO and nanoGO.-The GO was prepared f...

show abstract

“…Graphene oxide (GO) [1][2][3] holds great promise for a variety of applications, including supercapacitors, [ 4,5 ] optical devices, [ 6 ] and mechanical actuators. [7][8][9] GO is a complex nonstoichiometric and hygroscopic material, and understanding and controlling its structural and physical chemical properties are matter of intense research.…”

Section: Introductionmentioning

confidence: 99%

“…[ 2,7,[9][10][11][12][13][14][15][16][17] Synthesized for the fi rst time in 1859, [ 18 ] today GO is generally obtained via the so-called modifi ed Hummers' methods. [ 3,13,19 ] These methods involve chemical oxidation of graphite and several solution processing steps in order to exfoliate, fi ltrate, and deposit graphene oxide fl akes on a substrate. The resulting paper-like material consists of a disorganized stacking of oxidized carbon platelets [ 3,13,19 ] which, due to their hydrophilic nature, are prone to adsorb and incorporate water molecules into the galleries of the fi lm.…”

Section: Introductionmentioning

confidence: 99%

Film Structure of Epitaxial Graphene Oxide on SiC: Insight on the Relationship Between Interlayer Spacing, Water Content, and Intralayer Structure

Zhao

Kim

Gennaro³

et al. 2014

Adv Materials Inter

View full text Add to dashboard Cite

International audienceChemical oxidation of multilayer graphene grown on silicon carbide yields films exhibiting reproducible characteristics, lateral uniformity, smoothness over large areas, and manageable chemical complexity, thereby opening opportunities to accelerate both fundamental understanding and technological applications of this form of graphene oxide films. Here, we investigate the vertical inter-layer structure of these ultra-thin oxide films. X-ray diffraction, atomic force microscopy, and IR experiments show that the multilayer films exhibit excellent inter-layer registry, little amount (<10%) of intercalated water, and unexpectedly large interlayer separations of about 9.35 Å. Density functional theory calculations show that the apparent contradiction of "little water but large interlayer spacing in the graphene oxide films" can be explained by considering a multilayer fi lm formed by carbon layers presenting, at the nanoscale, a non-homogenous oxidation, where non-oxidized and highly oxidized nano-domains coexist and where a few water molecules trapped between oxidized regions of the stacked layers are sufficient to account for the observed large inter-layer separations. This work sheds light on both the vertical and intra-layer structure of graphene oxide films grown on silicon carbide, and more in general, it provides novel insight on the relationship between inter-layer spacing, water content, and structure of graphene/graphite oxide materials

show abstract

Pristine Graphite Oxide

Cited by 404 publications

References 30 publications

Optimized Deposition of Graphene Oxide Langmuir-Blodgett Thin Films

Optimized Deposition of Graphene Oxide Langmuir-Blodgett Thin Films

Graphene Oxide Fuel Cell

Film Structure of Epitaxial Graphene Oxide on SiC: Insight on the Relationship Between Interlayer Spacing, Water Content, and Intralayer Structure

Contact Info

Product

Resources

About