scholarly journals Alternate Layers of Cobalt Doped Tungsten Oxide and Reduced Graphene Oxide Composite as Electrode Material for Supercapacitor

2020 ◽  
Vol 32 (4) ◽  
pp. 822-826
Author(s):  
P. Dhilip ◽  
M. Niththiyanandam ◽  
N. Sethupathi ◽  
P. Mahalingam
Keyword(s):  
Graphene Oxide ◽  
Tungsten Oxide ◽  
Spray Pyrolysis ◽  
Specific Capacitance ◽  
Layered Structure ◽  
Spray Pyrolysis Technique ◽  
Cobalt Acetate ◽  
Acetate Solution ◽  
Reduced Graphene ◽  
Nebulized Spray Pyrolysis

Composites consist of layers of cobalt doped tungsten oxide and reduced graphitic oxide was prepared using jet nebulized spray pyrolysis technique. A mixture of ammonium tungstate and cobalt acetate solution was coated on glass substrate at 380 °C using jet nebulized spray pyrolysis technique. Spray technique is used to form the reduced graphene oxide (rGO) layer over the first layer and again ammonium tungstate and cobalt acetate solution coated over the surface of rGO and then calcined in nitrogen atmosphere at 450 °C for 2 h. The composite were characterized using XRD, SEM, PL, CV and EIS studies. The SEM and XRD reveal the layered structure. Cyclic voltammetry reveals the high specific capacitance 500 Fg-1 at 5 mV s-1 scan rate for 2 M Na2SO4 as electrolyte. Layered structure of CoWO4/rGO/CoWO4 composite enhances the specific capacitance. EIS gives the electrical series resistance of 7.9 Ω. The layered CoWO4/rGO/CoWO4 composite can be suitable electrode materials for supercapacitor.

Hybrid Supercapacitors Based on Self-Assembled Electrochemical Deposition of Reduced Graphene Oxide/Polypyrrole Composite Electrodes

2021 ◽  
Vol 16 (6) ◽  
pp. 949-956
Author(s):  
Jun Ma ◽  
Junaid Ali Syed ◽  
Dongyun Su
Keyword(s):  
Graphene Oxide ◽  
Specific Capacitance ◽  
Reduced Graphene Oxide ◽  
Electrochemical Deposition ◽  
High Energy ◽  
Carbon Cloth ◽  
Discharge Process ◽  
Rate Performance ◽  
Reduced Graphene ◽  
Self Assembled

Conductive polymers (CPs) have potential application to commercial energy storage because of their high electrochemical activity and low cost. However, an obstacle in developing CP-based supercapacitors is the degradation in their capacitance during the charge-discharge process that leads to poor rate performance. This study fabricates layers of a high-performance self-assembled polypyrrole/reduced graphene oxide (PPY/RGO) composite material on a carbon cloth through electrochemical deposition. The layered graphene improved the electrochemical properties of PPY. Carbon fiber rods were coated with the PPY/RGO composite layer, the thickness of which depends on the deposition time. Adequate capacitive behaviors were achieved by using 16 layers of polypyrrole/reduced graphene oxide, with a specific capacitance of 490 F g−1 (0.6 A g−1) and good rate performance. The results here provide a novel means of preparing graphene-based nanocomposites films for a variety of functions. A symmetric device was subsequently assembled by using electrodes featuring 16 layers of the polypyrrole/reduced graphene oxide composite. It yielded a specific capacitance of 205 F g−1 and a high energy density of 16.4 Wh kg−1. It also exhibited good cycle stability, with a capacitance retention rate of 85% for 5,000 cycles.

Modulation of oxygen functional groups and their influence on the supercapacitor performance of reduced graphene oxide

2020 ◽  
Vol 44 (44) ◽  
pp. 19022-19027
Author(s):  
Zegao Wang ◽  
Yuqing Wang ◽  
Xin Hao ◽  
Jingbo Liu ◽  
Yuanfu Chen ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Specific Capacitance ◽  
Reduced Graphene Oxide ◽  
Functional Groups ◽  
Oxygen Functional Groups ◽  
Reduced Graphene ◽  
Supercapacitor Performance

Through tuning the oxygen function groups, it was demonstrated that the specific capacitance of reduced graphene oxide can increase from 136 F g−1 to 182 F g−1.

scholarly journals Dissected carbon nanotubes functionalized by 1-hydroxyanthraquinone for high-performance asymmetric supercapacitors

RSC Advances ◽  
2017 ◽  
Vol 7 (76) ◽  
pp. 48341-48353 ◽  
Author(s):  
Xia Yang ◽  
Yuying Yang ◽  
Quancai Zhang ◽  
Xiaotong Wang ◽  
Yufeng An ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Graphene Oxide ◽  
Specific Capacitance ◽  
Reduced Graphene Oxide ◽  
High Performance ◽  
Rate Capability ◽  
High Specific Capacitance ◽  
Covalent Modification ◽  
Asymmetric Supercapacitors ◽  
Reduced Graphene

1-Hydroxyanthraquinone (HAQ) is selected to functionalize the dissected carbon nanotubes (rDCNTs) with reduced graphene oxide layers through non-covalent modification. The composite achieves high specific capacitance and ultrahigh rate capability.

Facile Synthesis of Modified MnO2/Reduced Graphene Oxide Nanocomposites and their Application in Supercapacitors

NANO ◽  
2020 ◽  
Vol 15 (08) ◽  
pp. 2050099
Author(s):  
Lijun Chen ◽  
Hongfeng Yin ◽  
Yuchao Zhang ◽  
Huidong Xie
Keyword(s):  
Electron Microscopy ◽  
Graphene Oxide ◽  
Specific Capacitance ◽  
Reduced Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
Electrode Materials ◽  
Normal Pressure ◽  
X Ray ◽  
Assembly Method ◽  
Reduced Graphene

Herein, KH-550 was used as surface modifier to prepare modified MnO2/reduced graphene oxide (M-MnO2/rGO) composite electrode materials by utilizing electrostatic interaction at low temperature and normal pressure. X-ray diffraction, scanning electron microscopy, transmission electron microscopy and X-ray photoelectron spectroscopy were adopted to characterize the material’s phase, morphology, and valence state of elements. The electrochemical properties of the material were measured using a three-electrode system. The results indicate a decrease in the size of the modified MnO2 particles, and that they were uniformly distributed on the rGO sheets. The M-MnO2/rGO composite attained a specific capacitance of 326[Formula: see text]F[Formula: see text]g[Formula: see text] in a solution of 1[Formula: see text]mol[Formula: see text]L[Formula: see text] Na2SO4 at a current density of 0.5[Formula: see text]A[Formula: see text]g[Formula: see text]. The specific capacitance of the material was 92.4% after 1000 cycles. The electrostatic self-assembly method effectively solved the problem of reducing the cycling stability while improving the specific capacitance of the composite materials, and further improved the possibility of applying MnO2/rGO in the field of supercapacitors.

Hydrogen storage in a chemical bond stabilized Co9S8–graphene layered structure

Nanoscale ◽  
2015 ◽  
Vol 7 (47) ◽  
pp. 20180-20187 ◽  
Author(s):  
Wei Qin ◽  
Lu Han ◽  
Hai Bi ◽  
Jiahuang Jian ◽  
Xiaohong Wu ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Hydrogen Storage ◽  
Reduced Graphene Oxide ◽  
Layered Structure ◽  
Storage Capacity ◽  
High Energy ◽  
Hydrogen Storage Capacity ◽  
Reduced Graphene ◽  
Milling Method ◽  
Energy Ball

With the high energy ball milling method, a Co9S8-decorated reduced graphene oxide (RGO) composite, which shows excellent hydrogen storage capacity, has been successfully fabricated with a well-organized layered structure.

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