Well-Aligned Graphene Oxide Nanosheets Decorated with Zinc Oxide Nanocrystals for High Performance Photocatalytic Application

2015 ◽  
Vol 14 (03) ◽  
pp. 1550007 ◽  
Author(s):  
K. Kaviyarasu ◽  
C. Maria Magdalane ◽  
E. Manikandan ◽  
M. Jayachandran ◽  
R. Ladchumananandasivam ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Graphene Oxide ◽  
High Performance ◽  
Chemical Reduction ◽  
Visible Region ◽  
Single Layer ◽  
Single Layer Graphene ◽  
Graphene Oxides ◽  
X Ray ◽  
Nanoscale Structures

Graphene oxide (GO) nanosheets modified with zinc oxide nanocrystals were achieved by a green wet-chemical approach. As-obtained products were characterized by XRD, Raman spectra, XPS, HR-TEM, EDS, PL and Photocatalytic studies. XRD studies indicate that the GO nanosheet have the same crystal structure found in hexagonal form of ZnO . The enhanced Raman spectrum of 2D bands confirmed formation of single layer graphene oxides. The gradual photocatalytic reduction of the GO nanosheet in the GO : ZnO suspension of ethanol was studied by using X-ray photoelectron (XPS) spectroscopy. The nanoscale structures were observed and confirmed using high resolution transmission electron microscopy (HR-TEM). The evolution of the elemental composition, especially the various numbers of layers were determined from energy dispersive X-ray spectra (EDS). PL properties of GO : ZnO nanosheet were found to be dependent on the growth condition and the resultant morphology revealed that GO nanosheet were highly transparent in the visible region. The photocatalytic performance of GO : ZnO nanocomposites was performed under UV irradiation. Therefore, the ZnO nanocrystals in the GO : ZnO composite could be applied in gradual chemical reduction and consequently tuning the electrical conductivity of the graphene oxide nanosheet.

scholarly journals A new method to exfoliate Graphite oxide and application for synthesis Graphene by chemical method

2014 ◽  
Vol 17 (2) ◽  
pp. 27-34
Author(s):  
Tam Thanh Mai ◽  
Nhan Thuc Chi Ha ◽  
Huy Thuc Ha
Keyword(s):  
Graphene Oxide ◽  
Polyethylene Oxide ◽  
Graphite Oxide ◽  
Single Layer ◽  
New Method ◽  
Single Layer Graphene ◽  
X Ray ◽  
Exfoliated Graphene ◽  
Graphene Paper ◽  
Crystalline Peak

A new method to separate graphite oxide (GO) modified by polyethylene oxide (PEO) by the aid of ultrasonic radiation was developed. Modified GO (graphene oxide or single layer of graphite oxide) did not show not appear crystalline peak (d002) on the X-Ray and took the form of a single layer graphene oxide on the image AFM and TEM. The exfoliated graphene oxide was reduced (RGO) to graphene by the reducing agent system HI – Acetic acid (HI-AcOH). The sheet resistance of RGOHI-AcOH is about 120 Ω/sq in the form graphene paper. In addition, FTIR, UV-Vis and Raman spectra showed more clearly about characteristics of graphite oxide, graphene oxide and RGOHI-AcOH.

X-Ray Photoelectron Spectroscopy Study on Reduction of Graphene Oxide with Hydrazine Hydrate

2011 ◽  
Vol 287-290 ◽  
pp. 539-543 ◽  
Author(s):  
Wen Shi Ma ◽  
Jun Wen Zhou ◽  
Xiao Dan Lin
Keyword(s):  
Graphene Oxide ◽  
Hydrazine Hydrate ◽  
Photoelectron Spectroscopy ◽  
Reduction Rate ◽  
Reduction Reaction ◽  
Chemical Compositions ◽  
Total Oxygen ◽  
Graphene Oxides ◽  
X Ray ◽  
Oxygen Groups

Graphene oxide was prepared through Hummers' method，then different reduced graphenes were prepared via reduction of graphene oxide with hydrazine hydrate for 1h、12h and 24h. X-ray photoelectron spectroscopy (XPS) was used for the characterization of graphene oxide and the reduced graphenes. The variation of the contents of carbon in carbon and oxygen functional groups and chemical compositions of graphene oxides were investigated through analysis the content of different carbon atoms in different reduced graphenes. The results showed that the reduction reaction was very fast in the first 1 h, the content of total oxygen bonded carbon atoms decreased from 83.6% to 22.1%, and then after the reduction rate became very slow. After 12h, the content of total oxygen bonded carbon atom is 19.56%, only 2.54% lower than that of 1h’s. At the same time, C-N was introduced in the graphene oxides; this increased the stereo-hindrance for hydrazine hydrate attacking the C-Oxygen groups, thus reduced the reduction rate. After reduction for 24h, there still exists 16.4% oxygen bonded carbon atoms and the total conversion ratio of graphene approaches 70%.

Inking Elastomeric Stamps with Micro-Patterned, Single Layer Graphene to Create High-Performance OFETs

2011 ◽  
Vol 23 (31) ◽  
pp. 3531-3535 ◽  
Author(s):  
Seok Ju Kang ◽  
Bumjung Kim ◽  
Keun Soo Kim ◽  
Yue Zhao ◽  
Zheyuan Chen ◽  
...  
Keyword(s):  
High Performance ◽  
Single Layer ◽  
Single Layer Graphene ◽  
Layer Graphene

Effects of single layer graphene and graphene oxide modification on the properties of phthalocyanine blue pigments

2020 ◽  
Vol 180 ◽  
pp. 108449 ◽  
Author(s):  
Dongjun Lv ◽  
Hsiu-Sun Sung ◽  
Xiujing Li ◽  
Xia Zhang ◽  
Zheng Li ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Single Layer ◽  
Single Layer Graphene ◽  
Layer Graphene

scholarly journals Magnetic-Dispersive Solid Phase Extraction Based on Graphene Oxide–Fe3O4 Nanocomposites Followed by High Performance Liquid Chromatography-Fluorescence for the Preconcentration and Determination of Terazosin Hydrochloride in Human Plasma

2019 ◽  
Vol 58 (2) ◽  
pp. 178-186 ◽  
Author(s):  
Yaser Pashaei ◽  
Bahram Daraei ◽  
Maryam Shekarchi
Keyword(s):  
High Performance Liquid Chromatography ◽  
Graphene Oxide ◽  
Human Plasma ◽  
High Performance ◽  
Solid Phase ◽  
Phase Extraction ◽  
Plasma Samples ◽  
Dispersive Solid Phase Extraction ◽  
X Ray

Abstract In the present study, a facile modified impregnation method was employed to synthesize superparamagnetic graphene oxide–Fe3O4 (GO–Fe3O4) nanocomposites. Based on the GO–Fe3O4 as adsorbent, a simple and fast magnetic-dispersive solid phase extraction followed by high performance liquid chromatography with fluorescence detection (M-dSPE–HPLC–FL) method was established and validated for the preconcentration and determination of terazosin hydrochloride (TRZ) in human plasma samples. The obtained nanomaterials were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy and vibrating sample magnetometry. Different parameters affecting the extraction efficiency, such as sample pH, amount of sorbent, extraction time, elution solvent and its volume and desorption time, were evaluated and optimized. The linearity of the proposed method was excellent over the range 0.3–50.0 ng mL−1 with an acceptable coefficient of determination (R2 = 0.9989). The limit of quantification and limit of detection were found to be 0.3 and 0.09 ng mL−1, respectively, and the preconcentration factor of 10 was achieved. Intra- and inter-day precision expressed as relative standard deviation (RSD %, n = 6) were between 2.2–3.8% and 4.7–6.4%, respectively. Accuracy, estimated by recovery assays, was 97.7–106.6% with RSD ≤ 5.2%. Ultimately, the applicability of the method was successfully confirmed by the extraction and determination of TRZ in human plasma samples.

scholarly journals Antibacterial Property of Composites of Reduced Graphene Oxide with Nano-Silver and Zinc Oxide Nanoparticles Synthesized Using a Microwave-Assisted Approach

2019 ◽  
Vol 20 (21) ◽  
pp. 5394 ◽  
Author(s):  
Yi-Huang Hsueh ◽  
Chien-Te Hsieh ◽  
Shu-Ting Chiu ◽  
Ping-Han Tsai ◽  
Chia-Ying Liu ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Antibacterial Activity ◽  
Graphene Oxide ◽  
Reductase Activity ◽  
Chemical Reduction ◽  
Membrane Integrity ◽  
Zno Nps ◽  
Nano Silver ◽  
E Coli ◽  
Microwave Assisted

Graphene oxide (GO) composites with various metal nanoparticles (NPs) are attracting increasing interest owing to their broad scope in biomedical applications. Here, microwave-assisted chemical reduction was used to deposit nano-silver and zinc oxide NPs (Ag and ZnO NPs) on the surface of reduced GO (rGO) at the following weight percentages: 5.34% Ag/rGO, 7.49% Ag/rGO, 6.85% ZnO/rGO, 16.45% ZnO/rGO, 3.47/34.91% Ag/ZnO/rGO, and 7.08/15.28% Ag/ZnO/rGO. These materials were tested for antibacterial activity, and 3.47/34.91% Ag/ZnO/rGO and 7.08/15.28% Ag/ZnO/rGO exhibited better antibacterial activity than the other tested materials against the gram-negative bacterium Escherichia coli K12. At 1000 ppm, both these Ag/ZnO/rGO composites had better killing properties against both E. coli K12 and the gram-positive bacterium Staphylococcus aureus SA113 than Ag/rGO and ZnO/rGO did. RedoxSensor flow cytometry showed that 3.47/34.91% Ag/ZnO/rGO and 7.08/15.28% Ag/ZnO/rGO decreased reductase activity and affected membrane integrity in the bacteria. At 100 ppm, these two composites affected membrane integrity more in E. coli, while 7.08/15.28% Ag/ZnO/rGO considerably decreased reductase activity in S. aureus. Thus, the 3.47/34.91% and 7.08%/15.28% Ag/ZnO/rGO nanocomposites can be applied not only as antibacterial agents but also in a variety of biomedical materials such as sensors, photothermal therapy, drug delivery, and catalysis, in the future.

Preparation of Nested g-C3N4 Fiber Surrounding Graphene Oxide and Its Photocatalytic Degradation of Rhodamine B

2020 ◽  
Vol 20 (9) ◽  
pp. 5445-5451
Author(s):  
Yi-Xin Wang ◽  
Min-Nan Chen ◽  
Hong Tao
Keyword(s):  
Graphene Oxide ◽  
Rhodamine B ◽  
Photoelectron Spectroscopy ◽  
Visible Region ◽  
High Photocatalytic Activity ◽  
Dyeing Wastewater ◽  
Nanofiber Membrane ◽  
X Ray ◽  
Printing And Dyeing Wastewater ◽  
Nested Structure

g-C3N4 and graphene oxide (GO) are simultaneously introduced into electrospun polyacrylonitrile (PAN) nanofibers to form a nested structure. By Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS), g-C3N4 has been perfectly introduced into the PAN@GO nanofiber membrane and affects the porosity of the fiber itself. Comparison of nested electrospinning PAN/PAN@GO and different proportions of PAN@g-C3N4/PAN@GO nanofibers has a different effect on reducing the concentration and absorption of rhodamine B (RhB) dye in the visible region. Combined with the advantages of g-C3N4 and GO and the performance of fibers in the photocatalytic process, the optimal nested PAN@g-C3N4/PAN@GO nanofibers were selected. These results indicate that the nested PAN@g-C3N4/PAN@GO nanofibers with high photocatalytic activity have great potential in the treatment of printing and dyeing wastewater.

Simplified Synthesis of 3D Flexible Reduced Graphene Oxide-Wrapped NiCo2O4 Nanowires for High-Performance Supercapacitor

2018 ◽  
Vol 10 (3) ◽  
pp. 358-364 ◽  
Author(s):  
Chao Pan ◽  
Hongyu Sun ◽  
Jingyi Gao ◽  
Yucai Hu ◽  
Jing Wang
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Current Density ◽  
Photoelectron Spectroscopy ◽  
High Performance ◽  
High Current Density ◽  
Three Dimensional ◽  
Simple Method ◽  
X Ray ◽  
Reduced Graphene

We introduced a simple method to construct novel three-dimensional (3D) flexible hierarchical nanocomposites by combining (1D) NiCo2O4 nanowires with 2D reduced graphene oxide (rGO) sheets. The hierarchical nanocomposite structure of rGO-wrapped NiCo2O4 (rGO-NiCo2O4) was confirmed by X-ray diffraction (XRD), Raman spectra, scanning electron microscopy (SEM), transmission electron microscope (TEM), and X-ray photoelectron spectroscopy (XPS). The results indicated that NiCo2O4 nanowires were successfully wrapped in rGO and the morphology of the rGO-NiCo2O4 showed a three-dimensional porous structure with NiCo2O4 being homogeneously distributed in the rGO. Given their apparent advantages, these two different nanostructures were evaluated as electrodes for high-performance supercapacitors. These electrodes exhibited a high capacitance of 1824.8 F·g–1 at a current density of 0.5 A·g–1, and an excellent cycling performance extending to 5000 cycles at a high current density of 4 A·g–1. Our results clearly demonstrate that rGO sheets on NiCo2O4 nanowires can substantially improve the capacitive performance of materials and ultimately increase the cycling stability of supercapacitors. The hierarchical binary nanocomposites show excellent electrochemical properties for energy storage applications, evidencing their potential application as supercapacitors.

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