scholarly journals Preparation and Application of CQDs/Ni(OH)20.75H2O as Electrodes in Supercapacitors

2021 ◽  
Vol 2097 (1) ◽  
pp. 012023
Author(s):  
Yunlong Zhou ◽  
Hanxiu Fu ◽  
Junwen Peng ◽  
Weize Chen ◽  
Kunfeng Cen ◽  
...  

Abstract In this paper, a hydrothermal synthesis method for preparation Carbon Quantum Dots (CQDs)/Ni(OH)20.75H2O composite electrode material, and loaded on Nickel Foam(NF) by rolling method. The crystal phase, structure, morphology and the reaction process were characterized by X-ray diffractometer (XRD) and scanning electron microscopy (SEM). The electrochemical properties of the composite were measured by cyclic voltammetry impedance spectroscopy and couple method charge-discharge techniques. The results showed that the composites material was evenly adhered to nickel foam. When the current density is 1 A g−1, the specific capacity of CQDs/Ni (OH) 20.75H2O composite can reach 2115.4 Fg−1, which is close to 5 times of Ni (OH) 20.75 H2O electrode material.

Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2195
Author(s):  
Kannadasan Thiagarajan ◽  
Dhandapani Balaji ◽  
Jagannathan Madhavan ◽  
Jayaraman Theerthagiri ◽  
Seung Jun Lee ◽  
...  

In the present study, the synthesis of CoWO4 (CWO)–Ni nanocomposites was conducted using a wet chemical method. The crystalline phases and morphologies of the Ni nanoparticles, CWO, and CWO–Ni composites were analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDAX). The electrochemical properties of CWO and CWO–Ni composite electrode materials were assessed by cyclic voltammetry (CV), and galvanostatic charge–discharge (GCD) tests using KOH as a supporting electrolyte. Among the CWO–Ni composites containing different amounts of Ni1, Ni2, and Ni3, CWO–Ni3 exhibited the highest specific capacitance of 271 F g−1 at 1 A g−1, which was greater than that of bare CWO (128 F g−1). Moreover, the CWO–Ni3 composite electrode material displayed excellent reversible cyclic stability and maintained 86.4% of its initial capacitance after 1500 discharge cycles. The results obtained herein demonstrate that the prepared CWO–Ni3 nanocomposite is a promising electrode candidate for supercapacitor applications.


2015 ◽  
Vol 73 (3) ◽  
pp. 486-492 ◽  
Author(s):  
Zhi-Lin Cheng ◽  
Shuai Han

A novel composite electrode material based on a N-doped TiO2-loaded NaY zeolite membrane (N-doped TiO2/NaY zeolite membrane) for photoelectrocatalysis was presented. X-ray diffraction (XRD), scanning electron microscopy (SEM), UV–visible (UV-vis) and X-ray photoelectron spectroscopy (XPS) characterization techniques were used to analyze the structure of the N-doped TiO2/NaY zeolite membrane. The XRD and SEM results verified that the N-doped TiO2 nanoparticles with the size of ca. 20 nm have been successfully loaded on the porous stainless steel-supported NaY zeolite membrane. The UV-vis result showed that the N-doped TiO2/NaY zeolite membrane exhibited a more obvious red-shift than that of N-TiO2 nanoparticles. The XPS characterization revealed that the doping of N element into TiO2 was successfully achieved. The photoelectrocatalysis performance of the N-doped TiO2/NaY zeolite membrane composite electrode material was evaluated by phenol removal and also the effects of reaction conditions on the catalytic performance were investigated. Owing to exhibiting an excellent catalytic activity and good recycling stability, the N-doped TiO2/NaY zeolite membrane composite electrode material was of promising application for photoelectrocatalysis in wastewater treatment.


RSC Advances ◽  
2016 ◽  
Vol 6 (50) ◽  
pp. 43959-43963 ◽  
Author(s):  
Bangning Sun ◽  
Xinping He ◽  
Xijin Leng ◽  
Yang Jiang ◽  
Yudong Zhao ◽  
...  

In this study, we report a binder-free in situ approach to synthesize a polyaniline–NiO composite on a nickel foam as a supercapacitor electrode.


Crystals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 76
Author(s):  
Ruiyu Wang ◽  
Mengfan Zhang ◽  
Hao Xu ◽  
Shuo Guo ◽  
Mengqi Chi ◽  
...  

In this study, a novel assisted liquid−phase plasma electrolysis was developed to realize one−step synthesis of popcorn biomass−derived porous carbon/cobalt tetroxide (popcorn−carbon/Co3O4) composites, effectively improving the structural stability and conductivity of Co3O4. The phase structure, morphologies, chemical composition, and weight ratio of the as−prepared popcorn−carbon/Co3O4 composites were systematically analyzed. The results of X−ray diffraction (XRD), Raman spectrometer, Fourier infrared spectrometer (FTIR), X−ray photoelectron spectrometer (XPS), and thermogravimetry analyzer (TG) proved the synthesis of the popcorn−carbon/Co3O4 composites. Co3O4 nanoparticles were distributed relatively uniformly on the popcorn−carbon surface. The electrochemical properties of the popcorn−carbon/Co3O4 composite electrode materials were analyzed for exploring the influence of different Co/C ratios on the electrochemical properties of composites. The results showed that the popcorn−carbon/Co3O4 composite electrode materials prepared under 200:1 mass ratio of Co(NO3)2·6H2O and popcorn−carbon possessed a specific capacitance and specific capacity of almost 1264 F/g (594 C/g) at a current density of 1 A/g, exhibiting a better electrochemical property. The efficient, fast, and novel assisted liquid−phase plasma electrolysis provides a new method for the preparation of composite electrode materials on the supercapacitors.


2015 ◽  
Vol 16 (2) ◽  
pp. 355-359
Author(s):  
О.M. Khemiy ◽  
І.М. Budzulyak ◽  
O.V. Morushko ◽  
Yu.Yu. Stubrov ◽  
I.P. Yaremiy ◽  
...  

The paper presents the results of studies of the structure and electrochemical properties of composite β-Ni(OH)2/C. It is shown that the diffractograms composite sintered β-Ni(OH)2/C in addition to peaks characteristic NiO, there is a broad diffraction peak at 23 °, which can be attributed to the activated carbon. Found that the composite electrode based on β-Ni(OH)2/C has a specific capacity, which is almost 25 times higher than the capacity for the output of nickel hydroxide at a current of 1 mA.


2020 ◽  
Vol 20 (8) ◽  
pp. 4815-4823
Author(s):  
Yingying Huang ◽  
Duo Weng ◽  
Shumei Kang ◽  
Jinlin Lu

In this study, MnO2 with different nanostructures (nanorods, nanospheres, nanoflowers, nanolychee) were obtained using a facile chemical method by adding different amounts of sulfuric acid for application in supercapacitors. Structure, morphology and composition were examined by X-ray diffractometer, Brunauer-Emmett-Teller, Fourier transform infrared, etc. Electrochemistry performances were tested by Autolab and LANHE CT2001A test system. Results indicated that the nanoflower MnO2 (F-MnO2) exhibited largest specific surface area, which was 83.17 m2 g−1. Electrode materials were tested in different electrolytes, including 6.0 M KOH, 1.0 M LiNO3 and 1.0 M LiOH. The F-MnO2 electrode material displayed the best electrochemical properties, and its specific capacitance was 171 F g−1 at 1 A g−1. Moreover, F-MnO2 electrode material showed splendid cycling durability was 130.9% of original value after 1000 cycles. These results demonstrated that the F-MnO2 electrode material should be a promising candidate for application in supercapacitors.


2017 ◽  
Vol 1 (3) ◽  
pp. 529-539 ◽  
Author(s):  
Qi Xun Xia ◽  
Je Moon Yun ◽  
Rajaram S. Mane ◽  
Lei Li ◽  
Jianjian Fu ◽  
...  

We synthesize a hierarchically porous electrode material with a high specific capacity composed of nickel oxide (NiO) nanosheets and perforated graphene (PG) sheets grown on a three-dimensional (3D) macroporous nickel foam via a facile hydrothermal method.


Author(s):  
Jingxuan Zhao ◽  
Zhibo Zhao ◽  
Yang Sun ◽  
Xiangdong Ma ◽  
Meidan Ye ◽  
...  

Taking into account of time-confusing preparation processing and unsatisfied desalination capacity of carbon nanomaterials, exploring efficient electrode materials remains a great challenge for practical capacitive deionization (CDI) application. In this...


Author(s):  
Xinyue Li ◽  
Marco Fortunato ◽  
Anna Maria Cardinale ◽  
Angelina Sarapulova ◽  
Christian Njel ◽  
...  

AbstractNickel aluminum layered double hydroxide (NiAl LDH) with nitrate in its interlayer is investigated as a negative electrode material for lithium-ion batteries (LIBs). The effect of the potential range (i.e., 0.01–3.0 V and 0.4–3.0 V vs. Li+/Li) and of the binder on the performance of the material is investigated in 1 M LiPF6 in EC/DMC vs. Li. The NiAl LDH electrode based on sodium alginate (SA) binder shows a high initial discharge specific capacity of 2586 mAh g−1 at 0.05 A g−1 and good stability in the potential range of 0.01–3.0 V vs. Li+/Li, which is better than what obtained with a polyvinylidene difluoride (PVDF)-based electrode. The NiAl LDH electrode with SA binder shows, after 400 cycles at 0.5 A g−1, a cycling retention of 42.2% with a capacity of 697 mAh g−1 and at a high current density of 1.0 A g−1 shows a retention of 27.6% with a capacity of 388 mAh g−1 over 1400 cycles. In the same conditions, the PVDF-based electrode retains only 15.6% with a capacity of 182 mAh g−1 and 8.5% with a capacity of 121 mAh g−1, respectively. Ex situ X-ray photoelectron spectroscopy (XPS) and ex situ X-ray absorption spectroscopy (XAS) reveal a conversion reaction mechanism during Li+ insertion into the NiAl LDH material. X-ray diffraction (XRD) and XPS have been combined with the electrochemical study to understand the effect of different cutoff potentials on the Li-ion storage mechanism. Graphical abstract The as-prepared NiAl-NO3−-LDH with the rhombohedral R-3 m space group is investigated as a negative electrode material for lithium-ion batteries (LIBs). The effect of the potential range (i.e., 0.01–3.0 V and 0.4–3.0 V vs. Li+/Li) and of the binder on the material’s performance is investigated in 1 M LiPF6 in EC/DMC vs. Li. Ex situ X-ray photoelectron spectroscopy (XPS) and ex situ X-ray absorption spectroscopy (XAS) reveal a conversion reaction mechanism during Li+ insertion into the NiAl LDH material. X-ray diffraction (XRD) and XPS have been combined with the electrochemical study to understand the effect of different cutoff potentials on the Li-ion storage mechanism. This work highlights the possibility of the direct application of NiAl LDH materials as negative electrodes for LIBs.


Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 661
Author(s):  
Zhiwei Ying ◽  
Xinwei Chen ◽  
He Li ◽  
Xinqi Liu ◽  
Chi Zhang ◽  
...  

Soybean dreg is a by-product of soybean products production, with a large consumption in China. Low utilization value leads to random discarding, which is one of the important sources of urban pollution. In this work, porous biochar was synthesized using a one-pot method and potassium bicarbonate (KHCO3) with low-cost soybean dreg (SD) powder as the carbon precursor to investigating the adsorption of methylene blue (MB). The prepared samples were characterized with scanning electron microscopy (SEM), transmission electron microscopy (TEM), elemental analyzer (EA), Brunauer-Emmett-Teller (BET), X-ray diffractometer (XRD), Raman spectroscopy (Raman), Fourier transform infrared spectrometer (FTIR), and X-ray photoelectron spectroscopy (XPS). The obtained SDB-K-3 showed a high specific surface area of 1620 m2 g−1, a large pore volume of 0.7509 cm3 g−1, and an average pore diameter of 1.859 nm. The results indicated that the maximum adsorption capacity of SDB-K-3 to MB could reach 1273.51 mg g−1 at 318 K. The kinetic data were most consistent with the pseudo-second-order model and the adsorption behavior was more suitable for the Langmuir isotherm equation. This study demonstrated that the porous biochar adsorbent can be prepared from soybean dreg by high value utilization, and it could hold significant potential for dye wastewater treatment in the future.


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