Investigation of Graphene/Ag Nanocomposites Synthesis Parameters for Two Different Synthesis Methods

Çıplak, Zafer; Yıldız, Nuray; Çalımlı, Ayla

doi:10.1080/1536383x.2014.894025

Cited by 263 publications

(124 citation statements)

References 38 publications

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“…As compared with GO, most of those functional groups of the GO peaks significantly decreased in GO-Ag NPs. This result occurs because the interaction between Ag NPs and GO decrease the intensity signal [46]. Obviously, the disappearance of the groups C=O and C-O at 1733 cm −1 and 1220 cm −1 suggests that Ag NPs were bonded to GO via those groups [47].…”

Section: Synthesis Of Go Ag Nps and Go-ag Npsmentioning

confidence: 97%

Synergistic Antibacterial Activity of Silver-Loaded Graphene Oxide towards Staphylococcus Aureus and Escherichia Coli

et al. 2020

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In this study, the physicochemical and surface properties of the GO–Ag composite promote a synergistic antibacterial effect towards both Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. Aureus) bacteria. GO–Ag NPs have a better bactericidal effect on E. coli (73%) and S. Aureus (98.5%) than pristine samples (pure Ag or GO). Transmission electron microscopy (TEM) confirms that the GO layers folded entire bacteria by attaching to the membrane through functional groups, while the Ag NPs penetrated the inner cell, thus damaging the cell membrane and leading to cell death. Cyclic voltammetry (CV) tests showed significant redox activity in GO–Ag NPs, enabling good catalytic performance towards H2O2 reduction. Strong reactive oxygen species (ROS) in GO–Ag NPs suggests that ROS might be associated with bactericidal activity. Therefore, the synergy between the physicochemical effect and ROS production of this material is proposed as the mechanism of its antibacterial activity.

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Section: Synthesis Of Go Ag Nps and Go-ag Npsmentioning

confidence: 97%

Synergistic Antibacterial Activity of Silver-Loaded Graphene Oxide towards Staphylococcus Aureus and Escherichia Coli

et al. 2020

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“…Figure 5 shows the comparison between the pure molecules absorption spectra, while figures 6 and 7 represent the absorption spectra for coronene and ovalene in the visible/near-UV region up to 5.5 eV, as given by * -G B3LYP 6 31 TDDFT calculations, for each substituted configuration with the corresponding original counterpart. Table 5 reports the wavelengths of the main peaks appaering in the cross-section of coronene and ovalene here calculated with the dominant peak in the experimental absorbance of graphene after [32]. While coronene and ovalene, considered as nanometric portions of infinite graphene sheets, show spectra characterized by a rich structure with different peaks, the experimental absorbance of graphene is distinguished by the presence of a single dominant structure, quite broaden, which covers roughly the same wavelength range.…”

Section: Optical Propertiesmentioning

confidence: 99%

Si-atoms substitutions effects on the electronic and optical properties of coronene and ovalene

2018

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We report a computational comparative study of the ground and excited states properties of graphene nanoribbons, analyzing the case of coronene (C 24 H 12 ) and ovalene (C 32 H 14 ) and their silicon-atoms substituted counterparts with single, double and triple atomic insertions. We used density functional theory (DFT) and time-dependent DFT to quantify the effects on the electronic and optical properties as a result of the chemical modifications. In particular, we compared ground-state total energies, electron affinities, ionization energies, fundamental gaps and optical absorption spectra, between the original systems and each substituted one. For both the molecules, we observed a general reduction of the fundamental gap after chemical modification. Concerning the optical properties, therefore, we observed a redshift of the optical onset in all the cases; in particular, we have found that, in one ovalene and coronene trimer-substituted configuration, the absorption edge takes place in the IR.

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“…The most pronounced, in the region of ∼ 3,300–3,600 cm −1 , is characteristic of vibrations of the O–H bonds, it shows a significant amount of adsorbed water in the material structure. The peak in the region of ∼ 2,130 cm −1 is characteristic of vibrations of the cumulated double C=C or the C=O bonds . It should be noted that in the spectra of the starting components used for the nanocomposite synthesis (GO and p‐benzoquinone) is absent.…”

Section: Resultsmentioning

confidence: 70%

“…A schematic representation of polyhydroquinone/graphene nanocomposite material synthesis in the region of ∼ 2,130 cm À 1 is characteristic of vibrations of the cumulated double C=C or the C=O bonds. [42][43][44][45][46] It should be noted that in the spectra of the starting components used for the nanocomposite synthesis (GO and p-benzoquinone) is absent. Presumably, it appears as a result of the formation of carbon bonds during the modification of the graphene surface with the hydroquinone polymer structures.…”

Section: Characteristics Of Phq/graphene Nanocompositementioning

confidence: 99%

Removal of Copper(II) and Zinc(II) Ions in Water on a Newly Synthesized Polyhydroquinone/Graphene Nanocomposite Material: Kinetics, Thermodynamics and Mechanism

et al. 2019

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An effective polyhydroquinone/graphene nanocomposite was developed to remove Cu(II) and Zn(II) metal ions in water. The composite nanomaterial was characterized by FT‐IR, SEM, TEM, XRD, Raman spectroscopy, and thermo‐gravimetry. The surface of the material was heterogeneous with 10–20 nm particle size. The adsorption capacity of Cu(II) and Zn(II) metal ions were 40.9 and 24.8 μgg−1, respectively. The sorption followed Langmuir, Freundlich, Tempkin and D−Rs models. The process of adsorption was successfully described by pseudo‐second‐order model, thereby indicating the chemical nature of the main adsorption mechanism. Thus, it can be argued that the adsorption proceeded in a mixed‐diffusion mode, with a significant contribution of a large number of high affinity active sites located on the adsorbent surface. The uptake time was 60 and 15 minutes for Cu(II) and Zn(II) at pH 6.0; indicating fast hydro‐friendly nature and making the method applicable to solve water pollution in real life problems. Therefore, the reported method may be used to remove Cu(II) and Zn(II) metal ions in any water resource.

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Investigation of Graphene/Ag Nanocomposites Synthesis Parameters for Two Different Synthesis Methods

Cited by 263 publications

References 38 publications

Synergistic Antibacterial Activity of Silver-Loaded Graphene Oxide towards Staphylococcus Aureus and Escherichia Coli

Synergistic Antibacterial Activity of Silver-Loaded Graphene Oxide towards Staphylococcus Aureus and Escherichia Coli

Si-atoms substitutions effects on the electronic and optical properties of coronene and ovalene

Removal of Copper(II) and Zinc(II) Ions in Water on a Newly Synthesized Polyhydroquinone/Graphene Nanocomposite Material: Kinetics, Thermodynamics and Mechanism

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