scholarly journals Supercapacitive Performance of N-Doped Graphene/Mn3O4/Fe3O4 as an Electrode Material

2019 ◽  
Vol 9 (6) ◽  
pp. 1040 ◽  
Author(s):  
Beng Chong ◽  
Nur Azman ◽  
Muhammad Mohd Abdah ◽  
Yusran Sulaiman
Keyword(s):  
Charge Transfer ◽  
X Ray Diffraction ◽  
Capacity Retention ◽  
Supercapacitive Performance ◽  
X Ray ◽  
Nitrogen Doped ◽  
Nitrogen Doped Graphene ◽  
Doped Graphene ◽  
Transfer Behavior ◽  
A Current

Nitrogen-doped graphene (NDG) and mixed metal oxides have been attracting much attention as the combination of these materials resulted in enhanced electrochemical properties. In this study, a composite of nitrogen-doped graphene/manganese oxide/iron oxide (NDG/Mn3O4/Fe3O4) for a supercapacitor was prepared through the hydrothermal method, followed by freeze-drying. Field emission scanning electron microscopy (FESEM) images revealed that the NDG/Mn3O4/Fe3O4 composite displayed wrinkled-like sheets morphology with Mn3O4 and Fe3O4 particles attached on the surface of NDG. The presence of NDG, Mn3O4, and Fe3O4 was characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The electrochemical studies revealed that the NDG/Mn3O4/Fe3O4 composite exhibited the highest specific capacitance (158.46 F/g) compared to NDG/Fe3O4 (130.41 F/g), NDG/Mn3O4 (147.55 F/g), and NDG (74.35 F/g) in 1 M Na2SO4 at a scan rate of 50 mV/s due to the synergistic effect between bimetallic oxides, which provide richer redox reaction and high conductivity. The galvanostatic charge discharge (GCD) result demonstrated that, at a current density of 0.5 A/g, the discharging time of NDG/Mn3O4/Fe3O4 is the longest compared to NDG/Mn3O4 and NDG/Fe3O4, indicating that it had the largest charge storage capacity. NDG/Mn3O4/Fe3O4 also exhibited the smallest resistance of charge transfer (Rct) value (1.35 Ω), showing its excellent charge transfer behavior at the interface region and good cyclic stability by manifesting a capacity retention of 100.4%, even after 5000 cycles.

High Reversible Capacity of Nitrogen-Doped Graphene as an Anode Material for Lithium-Ion Batteries

2014 ◽  
Vol 1070-1072 ◽  
pp. 459-464
Author(s):  
Chang Jing Fu ◽  
Shuang Li ◽  
Qian Wang
Keyword(s):  
Graphene Oxide ◽  
Electron Microscope ◽  
Lithium Ion Batteries ◽  
Current Density ◽  
Lithium Ion ◽  
X Ray ◽  
Nitrogen Doped ◽  
Nitrogen Doped Graphene ◽  
Doped Graphene ◽  
A Current

Nitrogen-doped graphene (N-rGO) was synthesized in the process of preparation of reduced graphene oxide from the expanded graphite through the improved Hummers’ method. The morphology, structure and composition of nitrogen-doped graphene oxide (GO) and N-rGO were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The nitrogen content of N-rGO was approximately 5 at.%. The electrochemical performances of N-rGO as anode materials for lithium-ion batteries were evaluated in coin-type cells versus metallic lithium. Results showed that the obtained N-rGO exhibited a higher reversible specific capacity of 519 mAh g-1 at a current density of 100 mA⋅g-1 and 207.5 mAh⋅g-1 at a current density of 2000 mA⋅g-1. The excellent cycling stability and high-rate capability of N-rGO as anodes of lithium-ion battery were attributed to the large number of surface defects caused by the nitrogen doping, which facilitates the fast transport of Li-ion and electron on the interface of electrolyte/electrode.

Hydrogenation and dehydrogenation of nitrogen-doped graphene investigated by X-ray photoelectron spectroscopy

2015 ◽  
Vol 634 ◽  
pp. 89-94 ◽  
Author(s):  
F. Späth ◽  
W. Zhao ◽  
C. Gleichweit ◽  
K. Gotterbarm ◽  
U. Bauer ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
X Ray ◽  
Nitrogen Doped ◽  
Nitrogen Doped Graphene ◽  
Doped Graphene

Femtomolar sensitivity of bisphenol A photoelectrochemical aptasensor induced by visible light-driven TiO2 nanoparticle-decorated nitrogen-doped graphene

2016 ◽  
Vol 4 (37) ◽  
pp. 6249-6257 ◽  
Author(s):  
Lei Zhou ◽  
Ding Jiang ◽  
Xiaojiao Du ◽  
Danyang Chen ◽  
Jing Qian ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Bisphenol A ◽  
Visible Light ◽  
Charge Recombination ◽  
Tio2 Nanoparticle ◽  
Nitrogen Doped ◽  
Efficient Charge ◽  
Visible Light Driven ◽  
Nitrogen Doped Graphene ◽  
Doped Graphene

Efficient charge transfer takes place by coupling nitrogen doped graphene with TiO2 and the charge recombination of the composites is significantly suppressed, resulting enhanced photocurrent responses than pristine TiO2.

scholarly journals Nitrogen-Doped Graphene: The Influence of Doping Level on the Charge-Transfer Resistance and Apparent Heterogeneous Electron Transfer Rate

Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 1815 ◽  
Author(s):  
Maria Coros ◽  
Codruta Varodi ◽  
Florina Pogacean ◽  
Emese Gal ◽  
Stela M. Pruneanu
Keyword(s):  
Doping Level ◽  
Transfer Rate ◽  
Charge Transfer Resistance ◽  
Electron Transfer Rate ◽  
Transfer Resistance ◽  
X Ray ◽  
Nitrogen Doped ◽  
Heterogeneous Electron Transfer ◽  
Nitrogen Doped Graphene ◽  
Doped Graphene

Three nitrogen-doped graphene samples were synthesized by the hydrothermal method using urea as doping/reducing agent for graphene oxide (GO), previously dispersed in water. The mixture was poured into an autoclave and placed in the oven at 160 °C for 3, 8 and 12 h. The samples were correspondingly denoted NGr-1, NGr-2 and NGr-3. The effect of the reaction time on the morphology, structure and electrochemical properties of the resulting materials was thoroughly investigated using scanning electron microscopy (SEM) Raman spectroscopy, X-ray powder diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), elemental analysis, Cyclic Voltammetry (CV) and electrochemical impedance spectroscopy (EIS). For NGr-1 and NGr-2, the nitrogen concentration obtained from elemental analysis was around 6.36 wt%. In the case of NGr-3, a slightly higher concentration of 6.85 wt% was obtained. The electrochemical studies performed with NGr modified electrodes proved that the charge-transfer resistance (Rct) and the apparent heterogeneous electron transfer rate constant (Kapp) depend not only on the nitrogen doping level but also on the type of nitrogen atoms found at the surface (pyrrolic-N, pyridinic-N or graphitic-N). In our case, the NGr-1 sample which has the lowest doping level and the highest concentration of pyrrolic-N among all nitrogen-doped samples exhibits the best electrochemical parameters: a very small Rct (38.3 Ω), a large Kapp (13.9 × 10−2 cm/s) and the best electrochemical response towards 8-hydroxy-2′-deoxyguanosine detection (8-OHdG).

Octahedral high voltage LiNi0.5Mn1.5O4 spinel cathode: enhanced capacity retention of hybrid aqueous capacitors with nitrogen doped graphene

2015 ◽  
Vol 3 (23) ◽  
pp. 12386-12395 ◽  
Author(s):  
R. Aswathy ◽  
T. Kesavan ◽  
K. T. Kumaran ◽  
P. Ragupathy
Keyword(s):  
High Voltage ◽  
Capacity Retention ◽  
Nitrogen Doped ◽  
Nitrogen Doped Graphene ◽  
Doped Graphene ◽  
Good Contact ◽  
Spinel Cathode

A new hybrid aqueous supercapacitor (HSC) has been constructed using electrospun octahedral LiNi0.5Mn1.5O4 as the cathode and nitrogen doped graphene as the anode. HSC exhibits remarkable capacity retention upon cycling due to the presence of (111) planes on the surface of facets offering good contact between the electrodes and electrolyte.

A nanocrystalline structured NiO/MnO2@nitrogen-doped graphene oxide hybrid nanocomposite for high performance supercapacitors

2017 ◽  
Vol 41 (24) ◽  
pp. 15517-15527 ◽  
Author(s):  
Sivalingam Ramesh ◽  
K. Karuppasamy ◽  
Sabeur Msolli ◽  
Hyun-Seok Kim ◽  
Heung Soo Kim ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Current Density ◽  
High Performance ◽  
Composite Electrode ◽  
Cyclic Stability ◽  
Hybrid Nanocomposite ◽  
Nitrogen Doped ◽  
Nitrogen Doped Graphene ◽  
Doped Graphene ◽  
A Current

A nanocrystalline NiO@MnO2/NGO hybrid composite electrode showed specific capacitance of 1490 Fg−1 at a current density of 0.5 Ag−1 and retains 98% up to 2000 cycles indicating its good cyclic stability.

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