A systematic investigation on the effect of Reducing Agents towards Specific Capacitance of NiMg@OH/ Reduced Graphene Oxide Nanocomposites

2021 ◽  
pp. 1-13
Author(s):  
Shireesha K ◽  
Divya V ◽  
Pranitha G ◽  
Ashok Ch ◽  
Shilpa Chakra Ch ◽  
...  
2021 ◽  
Vol 63 (12) ◽  
pp. 1184-1190
Author(s):  
Yifan Cui ◽  
Rong Li ◽  
Liuqin Lai ◽  
Huimin Dai ◽  
Siyu Su ◽  
...  

Abstract The chemical reduction of graphene oxide is an effective method for the synthesis of reduced graphene oxide, having the obvious advantages of low cost and large scale applicability. Our work produced reduced graphene oxide through a simple water bath reduction approach using various reducing agents of N2H4 × H2O, NaBH4, Na2S2O3, HI, and a reference sample without reducing agent at the same reduction temperature and duration time, by which reduced graphene oxides represented as N-RGO, B-RGO, S-RGO, I-RGO, and RGO0 were fabricated. Subsequently, unbonded flexible electrodes based on carbon cloth were fabricated with the reduced graphene oxides mentioned above, whereupon the structure, morphology and electrochemical performance were characterized. The electrochemical results indicate that the order of specific capacitances is N-RGO > B-RGO > S-RGO > RGO0 > I-RGO, while I-RGO’s potential window is wider than that of the others. As a result, N-RGO displays the best electrochemical performance among all reduced graphene oxides, with a specific capacitance as high as 176.0 F × g-1 and 77.8 % of the initial specific capacitance maintained at a high current density of 20 A × g-1.


2019 ◽  
Vol 55 (76) ◽  
pp. 11438-11441 ◽  
Author(s):  
Thaar M. D. Alharbi ◽  
Amira R. M. Alghamdi ◽  
Kasturi Vimalanathan ◽  
Colin L. Raston

Reduced graphene oxide (rGO) is generated from GO dispersed in water under continuous flow in the absence of harsh reducing agents, in a vortex fluidic device, such that the processing is scalable with uniformity of the product.


2021 ◽  
Vol 16 (6) ◽  
pp. 949-956
Author(s):  
Jun Ma ◽  
Junaid Ali Syed ◽  
Dongyun Su

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.


2020 ◽  
Vol 44 (44) ◽  
pp. 19022-19027
Author(s):  
Zegao Wang ◽  
Yuqing Wang ◽  
Xin Hao ◽  
Jingbo Liu ◽  
Yuanfu Chen ◽  
...  

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.


RSC Advances ◽  
2017 ◽  
Vol 7 (76) ◽  
pp. 48341-48353 ◽  
Author(s):  
Xia Yang ◽  
Yuying Yang ◽  
Quancai Zhang ◽  
Xiaotong Wang ◽  
Yufeng An ◽  
...  

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.


NANO ◽  
2020 ◽  
Vol 15 (08) ◽  
pp. 2050099
Author(s):  
Lijun Chen ◽  
Hongfeng Yin ◽  
Yuchao Zhang ◽  
Huidong Xie

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.


2019 ◽  
Vol 8 (9) ◽  
pp. M71-M74
Author(s):  
Lynliana Unjan ◽  
Fong Kwong Yam ◽  
Khi Poay Beh ◽  
Raed Abdalrheem ◽  
Joshua John Samuel ◽  
...  

2020 ◽  
Vol 20 (8) ◽  
pp. 4854-4859 ◽  
Author(s):  
Lei Chen ◽  
Xu Chen ◽  
Yaqiong Wen ◽  
Bixia Wang ◽  
Yangchen Wu ◽  
...  

Nitrogen-enriched reduced graphene oxide electrode material can be successfully prepared through a simple hydrothermal method. The morphology and microstructure of ready to use electrode material is measured by field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD). Physical characterizations revealed that nitrogen-enriched reduced graphene oxide electrode material possessed high specific surface area of 429.6 m2 · g−1, resulting in high utilization of electrode materials with electrolyte. Electrochemical performance of nitrogen-enriched reduced graphene oxide electrode was also investigated by cyclic voltammetry (CV), galvanostatic charge/discharge measurements and electrochemical impedance spectroscopy (EIS) in aqueous in 6 M KOH with a three-electrode system, which displayed a high specific capacitance about 223.5 F · g−1 at 1 mV · s−1. More importantly, nitrogenenriched reduced graphene oxide electrode exhibited outstanding stability with 100% coulombic efficiency and with no specific capacitance loss under 2 A · g−1 after 10000 cycles. The supercapacitive behaviors indicated that nitrogen-enriched reduced graphene oxide can be a used as a promising electrode for high-performance super-capacitors.


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