Divergent mechanisms for thermal reduction of graphene oxide and their highly different ion affinities

Le, Giang T.T.; Manyam, Jedsada; Opaprakasit, Pakorn; Chanlek, Narong; Grisdanurak, Nurak; Sreearunothai, Paiboon

doi:10.1016/j.diamond.2018.09.006

Cited by 62 publications

(19 citation statements)

References 78 publications

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“…The strong broad band in the range 2700-3700 cm −1 is due to O-H stretching in alcohols, carboxylic acids, and water [36]. The peak at 1725 cm −1 is associated with C=O stretching of both carbonyl and carboxylic groups, whereas the sharp peak at 1582 cm −1 is characteristic of C=C skeletal vibrations of non-oxidized domains and/or of asymmetrical stretching of C=O in carboxylate salts [37][38][39]. The peak at 1399 cm −1 may be attributed to the O-H bending of tertiary alcohols as well as symmetric stretching of C=O in carboxylates salts [36,40].…”

Section: Characterization Of Go: Chemical Composition Morphological and Structural Propertiesmentioning

confidence: 99%

Extra-Low Dosage Graphene Oxide Cementitious Nanocomposites: A Nano- to Macroscale Approach

et al. 2021

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The impact of extra-low dosage (0.01% by weight of cement) Graphene Oxide (GO) on the properties of fresh and hardened nanocomposites was assessed. The use of a minimum amount of 2-D nanofiller would minimize costs and sustainability issues, therefore encouraging the market uptake of nanoengineered cement-based materials. GO was characterized by X-ray Photoelectron Spectroscopy (XPS), Fourier-transform infrared spectroscopy (FTIR), Atomic Force Microscopy (AFM), X-ray Diffraction (XRD), and Raman spectroscopy. GO consisted of stacked sheets up to 600 nm × 800 nm wide and 2 nm thick, oxygen content 31 at%. The impact of GO on the fresh admixtures was evaluated by rheology, flowability, and workability measurements. GO-modified samples were characterized by density measurements, Scanning Electron Microscopy (SEM) analysis, and compression and bending tests. Permeability was investigated using the boiling-water saturation technique, salt ponding test, and Initial Surface Absorption Test (ISAT). At 28 days, GO-nanocomposite exhibited increased density (+14%), improved compressive and flexural strength (+29% and +13%, respectively), and decreased permeability compared to the control sample. The strengthening effect dominated over the adverse effects associated with the worsening of the fresh properties; reduced permeability was mainly attributed to the refining of the pore network induced by the presence of GO.

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Section: Characterization Of Go: Chemical Composition Morphological and Structural Propertiesmentioning

confidence: 99%

Extra-Low Dosage Graphene Oxide Cementitious Nanocomposites: A Nano- to Macroscale Approach

et al. 2021

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“…The rGO was extracted from GO by thermal reduction GO has been reduced by keeping it at reduction temperature (300°C) a sudden change in temperature causes elimination of functional groups and oxygen atoms from carbon planes and exfoliation of GO takes place to produce rGO [26]. The rGO can be considered as chemically-derived graphene, whose structure varied from one layer to multilayers [27]. Ag-doped rGO with various concentration ratios was synthesized hydrothermally, using 800 mg GO nanosheets incorporated with (25, 50, 75, and 100 mg) Ag in 80 ml deionized water under vigorously stirring for 20 min.…”

Section: Synthesis Of Ag/rgomentioning

confidence: 99%

Hydrothermal Synthesis of Silver Decorated Reduced Graphene Oxide (rGO) Nanoflakes with Effective Photocatalytic Activity for Wastewater Treatment

et al. 2020

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Graphene oxide (GO) was obtained through modified hummers method, and reduced graphene oxide (rGO) was acquired by employing heat treatment. Various concentrations (2.5, 5, 7.5, and 10 wt. %) of silver (Ag) were incorporated in GO nanosheets by adopting hydrothermal approach. Synthesized Ag decorated rGO photocatalyst Ag/rGO was characterized using X-ray diffraction (XRD) to determine phase purity and crystal structure. XRD patterns showed the formation of GO to Ag/rGO. Molecular vibration and functional groups were determined through Fourier Transform Infrared spectroscopy (FTIR). Optical properties and a decrease in bandgap with insertion of Ag were confirmed with UV-Visible (Uv-Vis) spectrophotometer and photoluminescence (PL). Electronic properties and disorders in carbon structures were investigated through Raman spectroscopy that revealed the existence of characteristic bands (D and G). Surface morphology of prepared samples was examined with field emission scanning electron microscope (FESEM). Homogeneous distribution, size, and spherical shape of Ag NPs over rGO sheets were further confirmed with the help of high-resolution transmission electron microscope (HR-TEM). Dye degradation of doped and undoped samples was examined through Uv-Vis spectra. Experimental results indicated that photocatalytic activity of Ag@rGO enhanced with increased doping ratio owing to diminished electron-hole pair recombination. Therefore, it is suggested that Ag@rGO can be used as a beneficial and superior photocatalyst to clean environment and wastewater.

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“…The rGO was extracted from GO by thermal reduction GO has been reduced by keeping it at reduction temperature (300˚C) a sudden change in temperature causes elimination of functional groups and oxygen atoms from carbon planes and exfoliation of GO takes place to produce rGO [26]. The rGO can be considered as chemically-derived graphene, whose structure varied from one layer to multilayers [27]. Ag-doped rGO with various concentration ratios was synthesized hydrothermally, using 800 mg…”

Section: Synthesis Of Ag/rgomentioning

confidence: 99%

Hydrothermal Synthesis of Silver Decorated Reduced Graphene Oxide (rGO) Nanoflakes with effective Photocatalytic Activity for Wastewater Treatment

Ikram

Raza

Imran

et al. 2020

Preprint

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Graphene oxide (GO) was obtained through modified hummers method and reduced graphene oxide (rGO) was acquired by employing heat treatment. Various concentrations (2.5, 5, 7.5 and 10 wt.%) of silver (Ag) were incorporated in GO nanosheets by adopting hydrothermal approach. Synthesized Ag decorated rGO photocatalyst Ag/rGO was characterized using X-ray diffraction (XRD) to determine phase purity and crystal structure. XRD patterns showed the formation of GO to Ag/rGO. Molecular vibration and functional groups were determined through Fourier Transform Infrared spectroscopy (FTIR). Optical properties and a decrease in bandgap with insertion of Ag were confirmed with UV-visible (Uv-vis.) spectrophotometer and Photoluminescence (PL). Electronic properties and disorders in carbon structures were investigated through Raman spectroscopy that revealed the existence of characteristic bands (D and G). Surface morphology of prepared samples was examined with Field Emission Scanning Electron Microscope (FESEM). Homogeneous distribution, size and spherical shape of Ag NPs over rGO sheets were further confirmed with the help of High-Resolution Transmission Electron Microscope (HR-TEM). Dye degradation of doped and undoped samples was examined through Uv-vis. spectra. Experimental results indicated that photocatalytic activity of Ag@rGO enhanced with increased doping ratio owing to diminished electron-hole pair recombination. Therefore, it is suggested that Ag@rGO can be used as a beneficial and superior photocatalyst to clean environment and wastewater.

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Divergent mechanisms for thermal reduction of graphene oxide and their highly different ion affinities

Cited by 62 publications

References 78 publications

Extra-Low Dosage Graphene Oxide Cementitious Nanocomposites: A Nano- to Macroscale Approach

Extra-Low Dosage Graphene Oxide Cementitious Nanocomposites: A Nano- to Macroscale Approach

Hydrothermal Synthesis of Silver Decorated Reduced Graphene Oxide (rGO) Nanoflakes with Effective Photocatalytic Activity for Wastewater Treatment

Hydrothermal Synthesis of Silver Decorated Reduced Graphene Oxide (rGO) Nanoflakes with effective Photocatalytic Activity for Wastewater Treatment

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