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1.
The Carbon sphere@Nickel sulfide core-shell nanocomposites for different mole ratios of Carbon sphere (0:1; 0.5:1 and 1:1) have been synthesized by a facile low temperature water-bath method without any further calcination. XRD studies on the core-shell nanocomposites show that characteristic peaks associated with rhombohedral phase structure of nickel sulfide have been retained. TEM morphology presents the interlinked core-shell of Carbon sphere@Nickel sulfide composite with grass-leaf dexterity for better ionic diffusion. BET study confirms the formation of mesoporous structure with high surface area. The existence of elements and its electronic configuration is noted through XPS. The electrochemical studies on pristine nickel sulfide and its Carbon sphere@Nickel sulfide core-shell composites reveal that Carbon sphere@Nickel sulfide (0.5:1) exhibits high specific capacitance of 1022?F?g?1 at a current density of 1?A?g?1. It shows good cyclic performance even beyond 4000 consecutive charge/discharge cycles at a relatively high current density of 20?A?g?1 with the ~83% of retention. 相似文献
2.
K. A. Sree Raj Afsal S. Shajahan Dr. Brahmananda Chakraborty Dr. Chandra Sekhar Rout 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(29):6662-6669
In this work, the ternary hybrid structure VSe2/SWCNTs/rGO is reported for supercapacitor applications. The ternary composite exhibits a high specific capacitance of 450 F g−1 in a symmetric cell configuration, with maximum energy density of 131.4 Wh kg−1 and power density of 27.49 kW kg−1. The ternary hybrid also shows a cyclic stability of 91 % after 5000 cycles. Extensive density functional theory (DFT) simulations on the structure as well as on the electronic properties of the binary hybrid structure VSe2/SWCNTs and the ternary hybrid structure VSe2/SWCNTs/rGO have been carried out. Due to a synergic effect, there are enhanced density of states near the Fermi level and higher quantum capacitance for the hybrid ternary structure compared to VSe2/SWCNTs, leading to higher energy and power density for VSe2/SWCNTs/rGO, supporting our experimental observation. Computed diffusion energy barrier of electrolyte ions (K+) predicts that ions move faster in the ternary structure, providing higher charge storage performance. 相似文献
3.
The surface charge is a key concept in electrochemistry. Mathematically, the surface charge is obtained from a spatial integration of the volume charge along a particular direction. Ambiguities thus arise in choosing the starting and ending points of the integration. As for electrocatalytic interfaces, the presence of chemisorbates further complicates the situation. In this minireview, I adopt a definition of the surface charge within a continuum picture of the electric double layer. I will introduce surface charging behaviors of firstly ordinary electrochemical interfaces and then electrocatalytic interfaces featuring partially charged chemisorbates. Particularly, the origin of nonmonotonic surface charging behaviors of electrocatalytic interfaces is explained using a primitive model. Finally, a brief account of previous studies on the nonmonotonic surface charging behavior is presented, as a subline of the spectacular history of electric double layer. 相似文献
4.
Dr. Oumaïma Gharbi Dr. Mai T. T. Tran Prof. Mark E. Orazem Dr. Bernard Tribollet Dr. Mireille Turmine Dr. Vincent Vivier 《Chemphyschem》2021,22(13):1371-1378
The different contributions of the interfacial capacitance are identified in the case of passive materials or thin protective coatings deposited on the electrode surface. The method is based on a graphical analysis of the EIS results to determine both the passive-film capacitance in the high-frequency domain and the double-layer capacitance in the low-frequency domain. The proposed analysis is shown to be independent of the physicochemical origins of the frequency dispersion of the interfacial capacitances which results, from an analysis point of view of the experimental results, in the use of a constant-phase element However, for a correct evaluation of the thin-film properties such as its thickness, the high-frequency data must be corrected for the double-layer contribution. In particular, it is shown that if the double-layer capacitance gives a frequency-dispersed response, it is necessary to correct the high-frequency part for the double-layer constant-phase elements. This is first demonstrated on synthetic data and then used for the determination of the thickness of thin oxide film formed on Al in neutral pH solution. 相似文献
5.
Dr. Eva Alvarez de Eulate Dr. Debbie S. Silvester Prof. Dr. Damien W. M. Arrigan 《Angewandte Chemie (International ed. in English)》2015,54(49):14903-14906
At the water–trihexyl(tetradecyl)phosphonium tris(pentafluoroethyl)trifluorophosphate ([P14,6,6,6][FAP]) ionic liquid interface, the unusual electrochemical transfer behavior of protons (H+) and deuterium ions (D+) was identified. Alkali metal cations (such as Li+, Na+, K+) did not undergo this transfer. H+/D+ transfers were assisted by the hydrophobic counter anion of the ionic liquid, [FAP]?, resulting in the formation of a mixed capacitive layer from the filling of the latent voids within the anisotropic ionic liquid structure. This phenomenon could impact areas such as proton‐coupled electron transfers, fuel cells, and hydrogen storage where ionic liquids are used as aprotic solvents. 相似文献
6.
《印度化学会志》2023,100(3):100896
Synthesis, characterization, surface morphology and electrochemical properties of non-stochiometric Nickel–Manganese oxide nanoparticles were carried out by urea assisted sol gel method. The Ni1-xMnxO (0.15≤ X ≤ 0.50) nanoparticle synthesized was found to be cubic and the existence of Mn3O4 and MnO2 phases were established and confirmed by X-ray Diffraction (XRD) studies. Thermo Gravimetric-Differential Thermal Analysis (TG-DTA) studies provided the calcination temperature of the xerogel at 600 °C, wherein the lattice strain and the size of the nanoparticles were determined through Williamson Hall (WH) Plot. The surface morphology characteristics of these nanoclusters were authenticated by Scanning Electron Microscope (SEM) techniques. Further, electroanalytical techniques were employed as a tool in establishing the nanocomposite as an intriguing material to act as a capacitor at enhanced efficiency compared to that of conventional capacitors. The electrochemical competence of the electrode was established through cyclic voltammogram, (CV) and Electrochemical Impedance Spectral (EIS) studies. The values of capacitance for Ni1-xMnxO, (0.15≤ X ≤ 0.5) nanoparticles varied from 7000 to 8000 mFg?1, measured at 20 mVs?1scan rate in 1.0 M Na2SO4and the temperature dependent conductance property for Ni0.85Mn0.15O electrode verified the Arrhenius Equation. The synthesis of a biodegradable polymer, Poly Butylene Sebacate (PBS) employed as conducting polymer for ultra capacitor applications is comparatively superior and definitely provides an edge over other capacitors in existence which is predominanantly attributed to its biodegradability nature. Further, the specific capacitance of PBS- Ni0.85Mn0.15O composite electrode was found to be 5180 mFg?1 which clearly illustrates that these composites are potential candidates of the type biodegradable supercapacitors that are evolving transient sources of power in the future and the biodegradability of the polymer-metal oxide composite electrode fetches more significance in terms of disposal of electronic and electrical wares. 相似文献
7.
《印度化学会志》2023,100(1):100830
Different metals (Zn, Cu, Pb) were electrodeposited on indium tin oxide (ITO/metal). ITO/metal was used as a substrate for ZnO and PbS deposition, and finally the PbS surface was encapsulated with ZnS. The electrochemical capacitance, CEC, of each thin layer was calculated from the cyclic voltammetry data and plotted against the applied potential. The plots showed different electrochemical capacity pattern (ECP) for PbS with different metal substrates. It seems that these patterns are effectively controlled by the ECP of the metal substrates. Also, the PbS CEC values were calculated from electrochemical impedance spectroscopy, EIS, to be compared with PbS CEC values obtained from cyclic voltammetry. The results of this comparison were completely consistent with each other and confirm different metal as a substrate effects on the PbS and may lead to a structure with different ECP. In the X-ray diffraction pattern, the presence of different preferential orientation of metal crystals was confirmed, which have been leaded to the formation of PbS deposits with different ECP. 相似文献
8.
通过化学镀和电化学镀的方法制备了一种Ni(OH)2电化学活性材料修饰三聚氰胺泡沫(MF)可压缩骨架的超级电容器电极材料MF/Ni(OH)2。MF/Ni(OH)2可压缩电极材料表现出最佳的电容性能,例如循环稳定性(即使在40 mA/cm-3的电流密度下经过2000次充放电循环后,可压缩电极仍能保持90.63%的初始电容)和可压缩稳定性(即使在压缩率为50%时,仍具有97.88%的电容保持率)。层状可压缩超级电容器由MF/Ni(OH)2弹性材料作为阳极,镍/碳(Ni/C)为阴极以及实验室中常用的滤纸作隔膜材料组成。这种超级电容器装置在不同的压缩下表现出良好的电化学性能和优异的压缩稳定性。最后,使用可压缩的超级电容器来点亮LED灯,以展示其在柔性电子设备中的应用。这些优化的电化学和机械性能表明MF/Ni(OH)2可作为可压缩超级电容器的应用中的候选电极。 相似文献
9.
The ability to achieve high areal capacitance for oxide-based supercapacitor electrodes with high active mass loadings is critical for practical applications. This paper reports the feasibility of the fabrication of Mn3O4-multiwalled carbon nanotube (MWCNT) composites by the new salting-out method, which allows direct particle transfer from an aqueous synthesis medium to a 2-propanol suspension for the fabrication of advanced Mn3O4-MWCNT electrodes for supercapacitors. The electrodes show enhanced capacitive performance at high active mass loading due to reduced particle agglomeration and enhanced mixing of the Mn3O4 particles and conductive MWCNT additives. The strategy is based on the multifunctional properties of octanohydroxamic acid, which is used as a capping and dispersing agent for Mn3O4 synthesis and an extractor for particle transfer to the electrode processing medium. Electrochemical studies show that high areal capacitance is achieved at low electrode resistance. The electrodes with an active mass of 40.1 mg cm−2 show a capacitance of 4.3 F cm−2 at a scan rate of 2 mV s−1. Electron microscopy studies reveal changes in electrode microstructure during charge-discharge cycling, which can explain the increase in capacitance. The salting-out method is promising for the development of advanced nanocomposites for energy storage in supercapacitors. 相似文献
10.
Dr. Kyriaki Manoli Dr. Maria Magliulo Dr. Mohammad Yusuf Mulla M. Sc. Mandeep Singh Prof. Luigia Sabbatini Prof. Gerardo Palazzo Prof. Luisa Torsi 《Angewandte Chemie (International ed. in English)》2015,54(43):12562-12576
Thin‐film transistors can be used as high‐performance bioelectronic devices to accomplish tasks such as sensing or controlling the release of biological species as well as transducing the electrical activity of cells or even organs, such as the brain. Organic, graphene, or zinc oxide are used as convenient printable semiconducting layers and can lead to high‐performance low‐cost bioelectronic sensing devices that are potentially very useful for point‐of‐care applications. Among others, electrolyte‐gated transistors are of interest as they can be operated as capacitance‐modulated devices, because of the high capacitance of their charge double layers. Specifically, it is the capacitance of the biolayer, being lowest in a series of capacitors, which controls the output current of the device. Such an occurrence allows for extremely high sensitivity towards very weak interactions. All the aspects governing these processes are reviewed here. 相似文献