scholarly journals Design of ZIF-67 MOF-derived Co3O4/NiCo2O4 nanosheets for supercapacitor electrode materials

2021 ◽  
pp. 174751982110412
Author(s):  
Jianning Li ◽  
Chunyong Zhang ◽  
Yingpin Wen ◽  
Yuyue Zhao ◽  
Yiwen Zhang ◽  
...  
Keyword(s):  
Metal Oxides ◽  
Metal Ion ◽  
Electrode Materials ◽  
Organic Ligand ◽  
Active Surface Area ◽  
Nickel Salt ◽  
Central Metal ◽  
Redox Potentials ◽  
Step Method ◽  
Supercapacitor Electrode

Binary transition metal oxides exhibit improved properties including good redox potentials and electrical conductivities compared with single metal oxides as electrode materials in energy storage. Herein, ZIF-67 is prepared by a one-step method using Co2+ as the central metal ion, 2-methylimidazole as the organic ligand, and methanol as an organic solvent at room temperature. Hollow NiCo2O4 and sheet-like Co3O4/NiCo2O4 derived from bimetallic imidazolate framework precursors were synthesized by adding cobalt and nickel ions in appropriate proportions. A hollow and porous structure is achieved for the reaction between a nickel salt and ZIF-67, and this unique nanostructure provides a high active surface area, which is beneficial to the electrochemical properties. Several samples are prepared and used as electrode materials for electrochemical tests in 6 M KOH. As a result, the Co3O4/NiCo2O4 electrode with a sheet nanostructure showed a high specific capacitance of 846 F g−1 at a current density of 0.5 A g−1. This Co3O4/NiCo2O4 electrode material is promising for future studies on high-performance supercapacitors to solve emerging energy-related problems. [Formula: see text]

Effect of Plating Solutions on Supercapacitor Characteristics of MnO2 Films

2010 ◽  
Vol 113-116 ◽  
pp. 1810-1813
Author(s):  
Fang Xiao ◽  
You Long Xu
Keyword(s):  
Electrode Materials ◽  
Electrochemical Impedance ◽  
Equivalent Circuit Model ◽  
Active Surface ◽  
Charge Transfer Resistance ◽  
Electrochemical Impedance Spectrum ◽  
Active Surface Area ◽  
Cyclic Voltammograms ◽  
Supercapacitor Electrode ◽  
Transfer Resistance

MnO2 films were electrodeposited on the Ti substrates by galvanostatic method in various plating solutions, which was MnCl2, Mn(NO3)2, MnSO4 and Mn(CH3COO)2 solutions, respectively. On X-ray diffraction test, Crystal structures of all MnO2 films were associated to α-MnO2 of tetragonal crystal system. Scanning electron microscopy results show that morphologies of MnO2 films were clearly different. Among them, MnO2 film prepared in Mn(CH3COO)2 solution presented a lot of cracks and holes. According to electrochemical impedance spectrum analysis, this MnO2 film presents the lowest charge-transfer resistance. Additionally, electrochemical active surface areas of MnO2 films were calculated on the basis of equivalent circuit model for impedance data. The result was found that MnO2 film prepared in Mn(CH3COO)2 solution showed the biggest electrochemical active surface area, which was about 382 cm2. Cyclic voltammograms were carried out for all the samples. MnO2 film formed in Mn(CH3COO)2 solution showed the highest special capacitance of 230 F g-1. The results suggest that Mn(CH3COO)2 solution is suitable for electrodepositing MnO2 film using supercapacitor electrode materials.

Recent advances in electrospun nanofibers for supercapacitors

2020 ◽  
Vol 8 (33) ◽  
pp. 16747-16789 ◽  
Author(s):  
Jie Liang ◽  
Haitao Zhao ◽  
Luchao Yue ◽  
Guangyin Fan ◽  
Tingshuai Li ◽  
...  
Keyword(s):  
Metal Oxides ◽  
Electrode Materials ◽  
Electrospun Nanofibers ◽  
Supercapacitor Electrode ◽  
Heteroatom Doping ◽  
Recent Advances ◽  
Supercapacitor Electrode Materials ◽  
Carbon Based

We summarize latest advances of electrospun nanofibers as supercapacitor electrode materials, providing an in-depth understanding of pore engineering, heteroatom doping, construction of carbon-based composites and metal oxides.

Highly porous graphitic biomass carbon as advanced electrode materials for supercapacitors

2017 ◽  
Vol 19 (17) ◽  
pp. 4132-4140 ◽  
Author(s):  
Youning Gong ◽  
Delong Li ◽  
Chengzhi Luo ◽  
Qiang Fu ◽  
Chunxu Pan
Keyword(s):  
Electrode Materials ◽  
Low Cost ◽  
Biomass Carbon ◽  
Step Method ◽  
Supercapacitor Electrode ◽  
One Step ◽  
Supercapacitor Electrode Materials ◽  
Highly Porous

3D porous graphitic biomass carbon as advanced supercapacitor electrode materials synthesized by a low-cost and effective one-step method.

Supercapacitor Electrode Materials Based on Activated Carbon /Polyaniline Doped with Nickel Salt

2011 ◽  
Vol 197-198 ◽  
pp. 1053-1056
Author(s):  
Yan Hong Tian ◽  
Xue Jun Zhang ◽  
Yu Zhao
Keyword(s):  
Activated Carbon ◽  
Electrode Materials ◽  
In Situ Polymerization ◽  
Nickel Content ◽  
Reference Electrode ◽  
Nickel Salt ◽  
Supercapacitor Electrode ◽  
Discharge Performance ◽  
Supercapacitor Electrode Materials ◽  
Charge Discharge

Two types of supercapacitor electrode materials have been synthesized: AC/PANI, activated carbon composites polyaniline by in-situ polymerization of aniline on the surface of activated carbon, and Ni-AC/PANI, the AC/PANI composite dopes with nickel. The microstructure of composites has been examined by scanning electron microscope (SEM). Fourier transform infrared spectroscopy (FI-IR) has been used to determine the molecular structure and chemical bond of the composites. The nickel content has been measured by atomic absorption spectrometry (AAS). The electrochemical performance of the composite has been characterized by cyclic voltammery and galvanostatic charge-discharge in 6mol•L-1 KOH solution using Hg/HgO as reference electrode. Due to the doping of nickel salt, Ni-AC/PANI shows desired microstructure, good high-current charge-discharge performance and good electrochemical behavior with an capacitance of 535F•g-1, 38.2% higher than that of AC/PANI.

Composites of metal oxides and intrinsically conducting polymers as supercapacitor electrode materials: the best of both worlds?

2019 ◽  
Vol 7 (25) ◽  
pp. 14937-14970 ◽  
Author(s):  
Lijun Fu ◽  
Qunting Qu ◽  
Rudolf Holze ◽  
Veniamin V. Kondratiev ◽  
Yuping Wu
Keyword(s):  
Composite Materials ◽  
Conducting Polymers ◽  
Metal Oxides ◽  
Electrode Materials ◽  
Supercapacitor Electrode ◽  
Intrinsically Conducting Polymers ◽  
Supercapacitor Electrode Materials

Composite materials combining intrinsically conducting polymers and metal oxides suggested as electrode materials in supercapacitors are reviewed with attention to achieved stability and specific functions and effects both components contribute to the performance of the materials.

Effect of solvent binding on UV-vis spectra and redox potentials of octaethylporphyrins containing first-row transition metal ions

2009 ◽  
Vol 13 (12) ◽  
pp. 1233-1242 ◽  
Author(s):  
Weihua Zhu ◽  
Xiaofeng Zhao ◽  
Zhongping Ou ◽  
Fan Zhou ◽  
Xiaohong Wang ◽  
...  
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Metal Ion ◽  
Binding Constants ◽  
Transition Metal Ions ◽  
Donor Number ◽  
Central Metal ◽  
Redox Potentials ◽  
Visible Spectra ◽  
Uv Visible

The UV-visible spectra and oxidation/reduction potentials for six octaethylporphyrins with first-row transition metal ions were measured in four non-aqueous solvents and then analyzed as a function of the Gutmann solvent parameters, donor number (DN) or acceptor number (AN). The utilized solvents were dichloromethane ( CH2Cl2 ), N, N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO) and pyridine (py). The investigated porphyrins were (OEP)M, where OEP = the dianion of octaethylporphyrin and M = CoII, NiII, CuII, ZnII, FeIIICl or MnIIICl . UV-visible spectra upon solvent (S) binding to give (OEP)M(S) or [ (OEP)M(S)2]+Cl- were monitored during a titration of the porphyrin in CH2Cl2 and formation constants ( logβ n, n = 1 or 2) for the ligand addition reactions were determined using standard equations. Five-coordinate (OEP)CoII(S) and (OEP)ZnII(S) are generated in CH2Cl2 solutions containing DMF, DMSO or py while six-coordinate [ (OEP)Mn(S)2]+Cl and [ (OEP)Fe(S)2]+Cl- are formed under the same solution conditions. The magnitudes of the solvent binding constants are discussed in terms of both the solvent donor/acceptor properties and the electronegativity (EN) or stability index (SI) of the porphyrin central metal ion. A comparison between solvent binding constants measured in this study for (OEP)M and literature data for (TPP)M with the same central metal ions is presented.

Protonation effects on dynamic flux properties of aqueous metal complexes

2009 ◽  
Vol 74 (10) ◽  
pp. 1543-1557 ◽  
Author(s):  
Herman P. Van Leeuwen ◽  
Raewyn M. Town
Keyword(s):  
Complex Formation ◽  
Metal Ion ◽  
Good Description ◽  
Minor Component ◽  
Outer Sphere ◽  
Metal Species ◽  
Central Metal ◽  
Inner Sphere ◽  
A Minor ◽  
Protonated Ligand

The degree of (de)protonation of aqueous metal species has significant consequences for the kinetics of complex formation/dissociation. All protonated forms of both the ligand and the hydrated central metal ion contribute to the rate of complex formation to an extent weighted by the pertaining outer-sphere stabilities. Likewise, the lifetime of the uncomplexed metal is determined by all the various protonated ligand species. Therefore, the interfacial reaction layer thickness, μ, and the ensuing kinetic flux, Jkin, are more involved than in the conventional case. All inner-sphere complexes contribute to the overall rate of dissociation, as weighted by their respective rate constants for dissociation, kd. The presence of inner-sphere deprotonated H2O, or of outer-sphere protonated ligand, generally has a great impact on kd of the inner-sphere complex. Consequently, the overall flux can be dominated by a species that is a minor component of the bulk speciation. The concepts are shown to provide a good description of experimental stripping chronopotentiometric data for several protonated metal–ligand systems.

Ti3C2Tx MXene for electrode materials of supercapacitors

2021 ◽  
Author(s):  
Rui Ma ◽  
Zetong Chen ◽  
Danna Zhao ◽  
Xujing Zhang ◽  
Jingting Zhuo ◽  
...  
Keyword(s):  
Electrode Materials ◽  
Supercapacitor Electrode ◽  
Supercapacitor Electrode Materials ◽  
Representative Member

To promote the development of supercapacitors and their applications in modern electronics, it is crucial to explore novel supercapacitor electrode materials. As a representative member of the rising 2D MXenes,...

Sign in / Sign up

Export Citation Format

Share Document