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Articles 481 - 510 of 1823

Full-Text Articles in Chemistry

Preparations And Electrochemical Performances Of Carbon Coated Silicon/Graphite Composites, Tian-Yi Gao, Zheng-Liang Gong Jun 2018

Preparations And Electrochemical Performances Of Carbon Coated Silicon/Graphite Composites, Tian-Yi Gao, Zheng-Liang Gong

Journal of Electrochemistry

In this work, the carbon coated silicon (Si@C) composite materials were synthesized based on the industrial silicon powder (600 meshes) via a high energy ball milling combing with in-situ carbon coating (carbonization) method. The Si@C/graphite (Si/C) composite anode materials were prepared by a simple mechanical ball-milling approach. The effects of carbon coating and the ratio of Si to graphite on electrochemical performances of Si/graphite composite materials were investigated systematically. Compared with the nano-Si/graphite composites, the Si/C composites showed higher reversible capacity, better rate capability and cycle performance. The Si@C materials composited of amorphous carbon and crystal silicon with the primary …

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Carbon Composite Fe3O4 Nanoparticles Based Electrochemical Sensor For Hydrogen Peroxide Detection, Si-Yu Zhang, Hui-Juan Wang, Shu-Fang Li, Jian-Ying Qu Jun 2018

Carbon Composite Fe3O4 Nanoparticles Based Electrochemical Sensor For Hydrogen Peroxide Detection, Si-Yu Zhang, Hui-Juan Wang, Shu-Fang Li, Jian-Ying Qu

Journal of Electrochemistry

In this work, a novel hydrogen peroxide electrochemical sensor was constructed with ferroferric oxide (Fe3O4) magnetic nanoparticles, which demonstrated good electrocatalytic activity for hydrogen peroxide. There existed a good linear relationship between the concentration of hydrogen peroxide and the oxidation peak current in the range of 1.00 × 10-6 ~ 1.00 × 10-3 mol·L-1 (R = 0.9980) with the detection limit of 6.60 × 10-7 mol·L-1. The sensor exhibited good anti-interference ability, high reproducibility and stability.

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Simulation Of Fractal Growth On Metal Wire Electrode, Li-Feng Ding, Pei-Yuan Mao, Jun Cheng, Yu-Lan Niu, Yu-Hao Wen, Wei Chen Jun 2018

Simulation Of Fractal Growth On Metal Wire Electrode, Li-Feng Ding, Pei-Yuan Mao, Jun Cheng, Yu-Lan Niu, Yu-Hao Wen, Wei Chen

Journal of Electrochemistry

During processes of metal electrodepostion, there exist many complex morphological forms such as dendritic growing in the cathode deposited metal edge, which will seriously affect the quality of the electrodeposited product and current efficiency during machining. Investigations on dendritic crystal growing process and morphology could help controlling growth of electrolysis precipitate. In this work, Python and Matlab softwares were used, and the model of parallel electrode electrodeposition was established based on the diffusion-limited aggregation (DLA) model. By analyzing the law of fractal growth at different conditions of the particles number, probability, electrode spacing, the movement step length and orientation drift, …

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Lead Modified Nanoporous Platinum Electro-Catalysts For Formic Acid Oxidation, Yuan-Yuan Zhang, Qing-Feng Yi, Ge-Kun-Kun Zuo, Tao Zou, Xiao-Ping Liu, Xiu-Lin Zhou Jun 2018

Lead Modified Nanoporous Platinum Electro-Catalysts For Formic Acid Oxidation, Yuan-Yuan Zhang, Qing-Feng Yi, Ge-Kun-Kun Zuo, Tao Zou, Xiao-Ping Liu, Xiu-Lin Zhou

Journal of Electrochemistry

Platinum (Pt) catalysts modified by other suitable metals significantly enhance their electrochemical activities for formic acid oxidation. In this work, a titanium-supported nanoporous network platinum (nanoPt/Ti) electrode was prepared using a hydrothermal method. The as-prepared nanoPt/Ti electrode was modified with a certain amount of lead by using cyclic voltammetry for different scan cycle numbers (n), namely, n = 10, 15, 20 and 30, to synthesize the novel lead-modified nanoporous Pt (nanoPb(n)-Pt/Ti) electrodes. Electro-oxidation of formic acid on these electrodes was studied with cyclic voltammetry (CV), chronoamperometry and chronopotentiometry in sulfuric acid solution. CV curves showed that both nanoPt/Ti …

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Chemical Stability Investigations Of Catalyst Layer In Pemfc, Yan-Yan Gao, Ming Hou, Yong-Yi Jiang, Dong Liang, Jun Ai, Li-Min Zheng Jun 2018

Chemical Stability Investigations Of Catalyst Layer In Pemfc, Yan-Yan Gao, Ming Hou, Yong-Yi Jiang, Dong Liang, Jun Ai, Li-Min Zheng

Journal of Electrochemistry

This work was intended to study the effect of free radicals on the chemical stability of catalyst layer via ex situ accelerated stress test (AST). Fenton reagent was used as the free radical provider in this research. Apart from the decomposition of Nafion in catalyst layer, the agglomerated Pt nanoparticles and the corroded carbon support were also observed after being treated in Fenton reagent for 100 h. Firstly, the existence of fluoride (F) ions evidenced the chemical decomposation of Nafion after being attacked by trace radical species, which was supported by the intensity decrease in the C-F stretching and vibration …

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Lithium And The Foreseeable Future, Paolo Vargas May 2018

Lithium And The Foreseeable Future, Paolo Vargas

Mechanical Engineering Undergraduate Honors Theses

This paper aims to clarify the uncertainties regarding worldwide lithium resource availability in the years to come. Previous studies made on the subject are presented with some ambiguity and this work intends to fill the gaps. The information and data presented throughout this script with respect to global lithium resources and reserves are mostly based on data released by the United States Geological Survey (USGS). Lithium resource availability in the future is a point of paramount significance primarily for the automotive, portable electronics, and the power generation industry. Since, a change of supply would ultimately affect the price of lithium, …

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Electrochemical Oxidation Of P-Chlorophenol On Porous Ti/Bdd Electrode Cooperated With Cathode Dechlorination, Rong-Ling Chen, Wei-Min Huang, Ya-Peng He, Jun Shi, Hai-Bo Lin Apr 2018

Electrochemical Oxidation Of P-Chlorophenol On Porous Ti/Bdd Electrode Cooperated With Cathode Dechlorination, Rong-Ling Chen, Wei-Min Huang, Ya-Peng He, Jun Shi, Hai-Bo Lin

Journal of Electrochemistry

The electrochemical oxidation of p-chlorophenol on porous Ti/BDD electrode cooperated with synergistic effect of cathode dechlorination was studied. Electrochemical degradation tests of p-chlorophenol were conducted in single and double compartment electrolytic cells separately, and the results showed that the mineralization happened mainly in the anode region. The product of chloride ions produced from the cathodic reduction of 4-chlorophenol in the single cell migrated to the anode region and further generated active chlorine toward electro-catalytic oxidation. At the same time, the chloride ion produced from the cathode of the double cell was difficult to be migrated to the anode region, which …

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Preparations And Corrosion Protection Investigations Of Diethylene Triamine Penta(Methylene Phosphonic Acid)-Zn2+ Conversion Coatings On Cold Rolled Steel Substrates, Wei He, Ru Yan, Ying-Qi Wang, Xiang Gao, Hou-Yi Ma Apr 2018

Preparations And Corrosion Protection Investigations Of Diethylene Triamine Penta(Methylene Phosphonic Acid)-Zn2+ Conversion Coatings On Cold Rolled Steel Substrates, Wei He, Ru Yan, Ying-Qi Wang, Xiang Gao, Hou-Yi Ma

Journal of Electrochemistry

Novel diethylene triamine penta(methylene phosphonic acid) (DTPMPA)-zinc ion (Zn2+) conversion coatings with uniform blue color and excellent corrosion protection were directly formed on the cold rolled steel (CRS) substrates by immersing a CRS plate into the film-forming solutions containing the appropriate concentrations of DTPMPA and Zn2+ ion at the proper pH. In this paper, surface morphologies and elemental compositions of DTPMPA-Zn2+ conversion coatings were characterized by SEM and EDS, respectivey. The surface functional groups, chemical constituents and binding modes to the substrates were investigated by means of FTIR and XPS methods. The influences of DTPMPA concentrations …

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Synthesis And Electrochemical Properties Of Li3V2(Bo3)3/C Anode Materials For Lithium-Ion Batteries, You Wang, Yi-Wen Zeng, Xing Zhong, Xing Liu, Quan Tang Apr 2018

Synthesis And Electrochemical Properties Of Li3V2(Bo3)3/C Anode Materials For Lithium-Ion Batteries, You Wang, Yi-Wen Zeng, Xing Zhong, Xing Liu, Quan Tang

Journal of Electrochemistry

The Li3V2(BO3)3/C (LVB/C) composite materials were successfully synthesized in two steps:Firstly, a stoichiomertric mixture of Li2C2O4, V2O5, H3BO3, H2C2O4•H2O and ethanol was thoroughly ball-milled to get the precursors. Secondly, the precursors were post-calcinated to get the ultimate products. The calcination temperatures of 750 ℃, 800 ℃ and 850 ℃ were selected based on TG-DTA analyses. The crystal structures, surface morphologies and carbon contents of the samples calcinated at five conditions, …

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Electrochemical Performance Of Moo2-C Composite Coatings, Quan-Yi Li, Qi Yang, Yan-Hong Zhao Apr 2018

Electrochemical Performance Of Moo2-C Composite Coatings, Quan-Yi Li, Qi Yang, Yan-Hong Zhao

Journal of Electrochemistry

The molybdenum dioxide-carbon(MoO2-C)composite coatings on the surface of Cu foils were prepared by simple knife coating route and followed by sintering in vacuum. The morphology, composition, structure and electrochemical performance of the MoO2-C composite coatings were investigated. The results demonstrated that the MoO2-C composite coatings consist of MoO2 nano-particles with monoclinic crystal structure and amorphous carbon. Some MoO2 nano-particles with a size range of 5-30nm were loaded on the surface of carbon matrices; while some MoO2 nano-particles with a size of ~5nm were encapsulated inside. The composite coatings showed porous structure …

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Preparation Of Ni(Dpim)2Cl2 Complex For The Electrocatalytic Reduction Of Co2, Li-Pu Zhang, Dong-Fang Niu, Xin-Sheng Zhang Apr 2018

Preparation Of Ni(Dpim)2Cl2 Complex For The Electrocatalytic Reduction Of Co2, Li-Pu Zhang, Dong-Fang Niu, Xin-Sheng Zhang

Journal of Electrochemistry

A new Ni(dpim)2Cl2complex using 2-(diphenylphosphino)-1-methylimidazole (dpim) as ligand was prepared and served as a catalyst for the electrochemical reduction of CO2. The electrochemical redox behavior of Ni(dpim)2Cl2 in CH3CN/TPABF4 solution under nitrogen atmosphere showed the two-electron irreversible reduction at -0.7 V and one-electron quasi-reversible reduction at -1.3 V. After bubbling CO2 into the electrolyte, the reduction peak appeared at -1.3 V became irreversible and the peak current increased from 0.48 mA·cm-2 to 0.55 mA·cm-2. Moreover, the peak current at -1.3 V could further increase …

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Preparation And Properties Of Manganese Oxide And Polyaniline-Carbon Composite Electrode, Tian-Tian Zhou, Bing Wu, Chao Deng, Ying Gao Apr 2018

Preparation And Properties Of Manganese Oxide And Polyaniline-Carbon Composite Electrode, Tian-Tian Zhou, Bing Wu, Chao Deng, Ying Gao

Journal of Electrochemistry

The polyaniline-carbon (PAnC) electrode was prepared by the polymerization of aniline monomer and activated carbon in ice water bath, and followed by chemical deposition of manganese dioxide MnO2-PAnC composite material. The specific capacitance of MnO2-PAnC reached 459 F•g-1. The cyclic voltammetric results showed a small deformation in the voltammogram curve obtained with the MnO2-PAnC electrode at high scan rate, indicating good reversibility and capacitive properties. The AC impedance results revealed that the MnO2-PAnC electrode displayed the smallest charge transfer resistance and the fastest diffusion
rate of surface ions than other …

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Preparation Of Co3O4/Ti Electrocatalytic Membrane Electrode For Catalytic Oxidation Of Benzyl Alcohol, Yu-Mei Zheng, Zhen Yin, Hong Wang, Jian-Xin Li Apr 2018

Preparation Of Co3O4/Ti Electrocatalytic Membrane Electrode For Catalytic Oxidation Of Benzyl Alcohol, Yu-Mei Zheng, Zhen Yin, Hong Wang, Jian-Xin Li

Journal of Electrochemistry

The cobalt oxide(Co3O4) nanoparticles were loaded on microporous Ti membrane to prepare Co3O4/Ti electrocatalytic membrane electrode by dip-coating method. The microstructures and electrochemical properties of Co3O4/Ti electrocatalytic membrane were investigated. The Co3O4/Ti electrocatalytic membrane reactor (ECMR) assembled by using the Co3O4/Ti electrocatalytic membrane as an anode was adopted for catalytic oxidation of benzyl alcohol to produce benzaldehyde and benzoic acid.The effects of different operation parameters on benzyl alcohol conversion, and selectivity to benzaldehyde and benzoic acid of ECMR were studied. …

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Simulation Analysis In Dynamic Performance Of Proton Exchange Membrane Fuel Cell Under Starting Condition, Yan Xiao, Ying-Jie Chang, Wei Zhang, Qiu-Hong Jia Apr 2018

Simulation Analysis In Dynamic Performance Of Proton Exchange Membrane Fuel Cell Under Starting Condition, Yan Xiao, Ying-Jie Chang, Wei Zhang, Qiu-Hong Jia

Journal of Electrochemistry

Based on the equivalent circuit model, by considering both the dynamic gas pressure model and the dynamic heat transfer model, a lumped parameter model is developed. The start process of the fuel cell is simulated by using SIMULINK software. The undershoot of the voltage is observed from the simulation results, and the response time of the voltage is basically the same as that of the fuel cell temperature, which indicates that the temperature has great influence on the dynamic performance of the fuel cell. From the perspective of the temperature, the dynamic responses of the thermodynamic potential, the activation overvoltage, …

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Interaction Between Energy And Electrocatalysis —— A Review On The 1st Young Scientist Forum On Energy Electrocatalysis, Hong Li, Wen-Bin Cai Apr 2018

Interaction Between Energy And Electrocatalysis —— A Review On The 1st Young Scientist Forum On Energy Electrocatalysis, Hong Li, Wen-Bin Cai

Journal of Electrochemistry

No abstract provided.

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Effects Of Rotating Magnetic Fields On Pem Fuel Cell Performance, Mao-Liang Wu, En-Ze Wang, Guang-De Pan, Zhong-Jun Liu, Fei Xie Apr 2018

Effects Of Rotating Magnetic Fields On Pem Fuel Cell Performance, Mao-Liang Wu, En-Ze Wang, Guang-De Pan, Zhong-Jun Liu, Fei Xie

Journal of Electrochemistry

Proton Exchange Membrane (PEM) fuel cell performance may be improved by application of additional magnetic fields. In this work, one square permanent magnet, made of either 16 combination cylinder magnets with homopolarity or 16 combination cylinder magnets with heteropolarity, was exerted on the fuel cell surface to produce additional magnetic field affecting PEM fuel cell performance. The influences of magnetic field status (rotating, static and none) on polarization and power density curves measured in a PEM fuel cell were investigated. The results verified the benefit of magnetic field, proving that the magnetic field distribution could improve the fuel cell output. …

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Superhydrophobic Surface On Aluminum Alloy By Hydrothermal Method And Its Electrochemical Performance, Xiao-Hang Chen, Mo-Jing Chen, Yu-Lin Min, Qun-Jie Xu Feb 2018

Superhydrophobic Surface On Aluminum Alloy By Hydrothermal Method And Its Electrochemical Performance, Xiao-Hang Chen, Mo-Jing Chen, Yu-Lin Min, Qun-Jie Xu

Journal of Electrochemistry

Superhydrophobic film formed on a metal surface is an effective way for corrosion protection. In this paper, the superhydrophobic film was prepared on the surfaces of aluminum alloy by hydrothermally treating with a solution containing CeCl3·7H2O and CO(NH2)2 , and a self-assemble process. The electrochemical measurements and surface morphology results confirmed that the best superhydrophobicity and electrochemical performance could be achieved with the contact angle of 155.5o after six hours of hydrothermal reaction. Furthermore, the inhibition efficiency of 99.6% was obtained in 3.5 wt% NaCl aqueous solution, indicating the excellent corrosion resistance …

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Preparation And Characterization Of Titanate-Phosphate Passivation Film On Tinplate, Zi-Yu Wang, Ming-Hao Wang, De-Yu Li, Ning Li Feb 2018

Preparation And Characterization Of Titanate-Phosphate Passivation Film On Tinplate, Zi-Yu Wang, Ming-Hao Wang, De-Yu Li, Ning Li

Journal of Electrochemistry

A passivation film was prepared on tinplate surface with a composite passivating agent made of titanate and phosphate. The surface morphologies, chemical compositions and corrosion resistances of the passivation films were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), salt spray test, Tafel polarization measurement and electrochemical impedance spectroscopy (EIS). The results were compared with those films untreated and treated with titanate or phosphate passivation. It was shown that the titanate and phosphate passivation film was mainly composed of Ti3(PO4)4·nH2O and TiO2. The finely crystallized surface could seal …

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Preparation And Properties Of Nanocrystalline Nickel By Pulse Electrodeposition On Glassy Carbon, Ya-Li Zhang, Ming-Xian Zhang, Teng-Da Guo, Yan-Jie Zhao, Sheng-Xue Yu Feb 2018

Preparation And Properties Of Nanocrystalline Nickel By Pulse Electrodeposition On Glassy Carbon, Ya-Li Zhang, Ming-Xian Zhang, Teng-Da Guo, Yan-Jie Zhao, Sheng-Xue Yu

Journal of Electrochemistry

Nanocrystalline nickel exhibits electrocatalytic activity for methanol. In this work, nanocrystalline nickel coating has been obtained by using the double pulse method on glassy carbon materials surface. The influence of pulse conditions on the grain size of nanocrystalline nicke was studied. The concentrations and compositions of the plating bath were  300 g·L-1 NiSO4·6H2O,45 g·L-1 NiCl2·6H2O,40 g·L-1 H3BO3,5 g·L-1 C7H5NO3S,and 0.05 g·L-1 C12H25NaO4S. The optimal pulse process parameters including the average pulse …

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Synthesis And Electrochemical Properties Of Nickel-Rich Cathode Material Lini0.6Co0.2Mn0.2O2 With High Initial Coulombic Efficiency, Xiao-Yun Guan, Chao-Yu Hong, Jian-Ping Zhu, Wei-Li Wang, Yi-Xiao Li, Yong Yang Feb 2018

Synthesis And Electrochemical Properties Of Nickel-Rich Cathode Material Lini0.6Co0.2Mn0.2O2 With High Initial Coulombic Efficiency, Xiao-Yun Guan, Chao-Yu Hong, Jian-Ping Zhu, Wei-Li Wang, Yi-Xiao Li, Yong Yang

Journal of Electrochemistry

Nickel-rich cathode materials LiNi0.6Co0.2Mn0.2O2(NCM622)were synthesized by a co-precipitation-solid state sintering method at different temperatures. The structure, morphology and electrochemical performance of the as-prepared materials were investigated by X-ray powder diffraction (XRD) /Rietveld refinement, scanning electron microscope (SEM) and electrochemical experiments. It is found that NCM622 calcined at 800 ℃ showed the lowest degree of cation disorder (~1.97%) with a high initial Coulombic effiency of 92.2% and the capacity retention of 81.4% after 100 cycles.

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Electrodeposition Of Cigs Thin Film With Special Structure Using Laser Etching Template, Jin-Zhi Yu, Ye Lian, Jin-Qiu Zhang, Pei-Xia Yang, Mao-Zhong An Feb 2018

Electrodeposition Of Cigs Thin Film With Special Structure Using Laser Etching Template, Jin-Zhi Yu, Ye Lian, Jin-Qiu Zhang, Pei-Xia Yang, Mao-Zhong An

Journal of Electrochemistry

Copper indium gallium selenide (Cu1.00InxGa1-xSe2.00, CIGS) thin film solar cells have a wide application in semiconductor thin film batteries. The CIGS absorbing layer is the key of the thin film solar cell material. Therefore, it is of theoretical and practical significance to carry out researches in CIGS thin films. In this work, the CIGS thin films with special structures were prepared by using laser etching template. The copper thin film was firstly electrodeposited in aqueous solution with Laser etching template. The influences of temperature, current and concentration of copper sulfate on morphology …

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Preparation And Electrocatalytic Activity Of Nitrogen-Doping Tungsten Carbide Catalyst, Pian-Pian Yang, Li-Zhen Huang, Ying-Ying Li, Mei-Qin Shi, Chun-An Ma Feb 2018

Preparation And Electrocatalytic Activity Of Nitrogen-Doping Tungsten Carbide Catalyst, Pian-Pian Yang, Li-Zhen Huang, Ying-Ying Li, Mei-Qin Shi, Chun-An Ma

Journal of Electrochemistry

Tungsten carbide (WC) is a promising electrocatalyst, however, its electrocatalytic activity is far inferior to Pt and Pt-group metal. In this work, nitrogen-doping tungsten carbide (WN|WC) catalysts with a nanoplate morphology were prepared via the tungsten nitride (WN) as the precursor and sodium tungstate as the tungsten source. The SEM and TEM results indicated that carbon atoms entered into the WN lattice to form the hexagonal close packed WC phase. In this way, an atomic scale heterostructure involving the closely linked interfaces between WN and WC was created . The XRD data confirmed that the cubic crystal structure of WN …

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Intrinsic Kinetic Properties Of Ternary Material For Lithium Ion Batteries Assessed By Single Particle Microelectrode, Yi-Min Wei Feb 2018

Intrinsic Kinetic Properties Of Ternary Material For Lithium Ion Batteries Assessed By Single Particle Microelectrode, Yi-Min Wei

Journal of Electrochemistry

Electrochemical performances such as capacity, rate, cycle and thermal stability of the nickel (Ni), cobalt (Co) and manganese (Mn) ternary cathode material, LiNixCoyMnzO2 (x + y + z = 1), are significantly influenced by the proportion of Ni, Co, and Mn elements. To obtain higher specific capacity, LiNi0.6Co0.2Mn 0.2O2 (NCM622) and LiNi0.8Co0.1Mn0.1O2 (NCM811) with high amounts of Ni element were employed for the lithium ion batteries. By now, many studies have been focusing on the thermal and cycling stabilities of …

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An Electrochemical Investigation In The Anticorrosive Properties Of Silver Nanoparticles For The Acidic Corrosion Of Aluminium, H. A. Fetouh, B. A. Abd-El-Nabey, Y. M. Goher, M. S. Karam Feb 2018

An Electrochemical Investigation In The Anticorrosive Properties Of Silver Nanoparticles For The Acidic Corrosion Of Aluminium, H. A. Fetouh, B. A. Abd-El-Nabey, Y. M. Goher, M. S. Karam

Journal of Electrochemistry

The mass loss, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques were used for the determinations of the corrosion rates for aluminium in 1.0 mol·L-1 hydrochloric acid (HCl) solutions both in the absence and presence of silver nanoparticles (SNPs) at 30 ℃. The protection efficiency was evaluated to be 96.4% for 0.014 g·L-1 of the SNPs. It has been found that the capacity of the electrical double layer at the aluminium/solution interface was decreased with increasing the concentration of the SNPs, indicating that the SNPs were adsorbed at the aluminium surface. The Langmuir adsorption isotherm and the kinetic-thermodynamic …

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Deposition Mechanism And Coating Characterization For The Trivalent Chromium Electrodeposition In Sulphate Electrolyte, Hui Yan, Shuai-Shuai Huang, Fang-Zu Yang, Zhong-Qun Tian, Shao-Min Zhou Feb 2018

Deposition Mechanism And Coating Characterization For The Trivalent Chromium Electrodeposition In Sulphate Electrolyte, Hui Yan, Shuai-Shuai Huang, Fang-Zu Yang, Zhong-Qun Tian, Shao-Min Zhou

Journal of Electrochemistry

Linear sweep voltammetry (LSV) and cyclic voltammetry (CV) were used to study the electrodeposition mechanism of trivalent chromium on a copper electrode in the novel sulphate electrolyte for thick trivalent chromium plating. The thickness, morphology, composition, microhardness, and structure, as well as the corrosion resistance in 3.5wt% NaCl solution of the trivalent chromium coatings were investigated by X-ray fluorescence gage, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), microhardness tester, X-ray diffraction (XRD) and Tafel curve measurements. The results showed that the electrodeposition of trivalent chromium involved two consecutive one electron reduction steps. The first step, Cr3+ + e …

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Applications Of Electrospinning In Lithium-Air Batteries, Yue Fu, Jin Wang, Hai-Yang Yu, Jing-Hua Tian, Rui-Zhi Yang Feb 2018

Applications Of Electrospinning In Lithium-Air Batteries, Yue Fu, Jin Wang, Hai-Yang Yu, Jing-Hua Tian, Rui-Zhi Yang

Journal of Electrochemistry

Lithium-air batteries have received increasing attention as the “ultimate batteries” due to their extremely high theoretical capacity and environment friendly. However, there are still many obstacles hindering the wide applications of the lithium-air batteries owing to the limitations of large charge-discharge over-potentials, poor Columbic efficiency and cycling performance. Exploring of high-efficiency, low-cost and eco-friendly catalysts is one of the vital issues for lithium-air batteries. Meanwhile, electrospinning techniques have been under substantial developments due to its simple fabrication process, high efficiency and production. This paper reviews the recent progresses in fabrications of various novel catalysts for lithium-air batteries with electrospinning techniques, …

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Solvent And Concentration Effects Governing The Hierarchical Organization Of Asphaltenes: A Small-Angle X-Ray Scattering Study, Hasan Rejoanur Rahman Jan 2018

Solvent And Concentration Effects Governing The Hierarchical Organization Of Asphaltenes: A Small-Angle X-Ray Scattering Study, Hasan Rejoanur Rahman

Open Access Theses & Dissertations

Asphaltenes are a group of planar molecules found in crude oil and are prone to aggregation which often causes blockage of pipes along the oil production stream resulting a huge economic downside. In an effort to understand the hierarchical organization of asphaltene in different solvents and concentrations, the solution structure of various asphaltene solutions were studied using small-angle x-ray scattering (SAXS). Solvents were chosen based on miscibility maps. Such maps are generated on the critical value of the solubility parameter difference between asphaltenes or asphaltene components, and a range of solvents. The critical factors that affect asphaltene and asphaltene component …

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Effect Of Allyl Thiourea On Nickel Electrodeposition From Solution Containing Ammonia And Chloride, Ya-Ning He, Liang Yuan, Zhi-Ying Ding, Shi-Jun Liu Dec 2017

Effect Of Allyl Thiourea On Nickel Electrodeposition From Solution Containing Ammonia And Chloride, Ya-Ning He, Liang Yuan, Zhi-Ying Ding, Shi-Jun Liu

Journal of Electrochemistry

The effects of allylthiourea (ATU) concentration on the cathodic polarization behaviour, nucleation and surface morphology of nickel electrodeposited on the glassy carbon electrode from ammonia-ammonium chloride-water (NH3-NH4Cl-H2O) solutions were investigated by cyclic voltammogry, cathodic polarization and current transient methods. The results revealed that the addition of ATU inhibited nickel deposition, which was enhanced with an increase in ATU concentration from 5 to 50 mg•L-1. The initial deposition kinetics corresponded to a model including instantaneous nucleation and diffusion controlled growth. In the presence of ATU, the initial nucleation of nickel electrocrystallisation remained unchanged. …

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Preparation Of Nis2 Nanosheet And Its Application In Asymmetric Supercapacitor, Yuan-You Wang, Ya-Nan Liu, Dang-Qin Jin Dec 2017

Preparation Of Nis2 Nanosheet And Its Application In Asymmetric Supercapacitor, Yuan-You Wang, Ya-Nan Liu, Dang-Qin Jin

Journal of Electrochemistry

In this work, the NiS2 nanosheets have been synthesized using Ni(OH)2  as a precursor through a sacrificial template method. The microstructure and chemical composition of as-prepared NiS2 were characterized by XRD, EDS, BET, SEM and TEM techniques. The results showed that both Ni(OH)2  and NiS2  were composed of nanoplates. The electrochemical tests revealed that NiS2 exhibited the high specific capacitance of 1067.3 F•g-1 at a current density of 1 A•g-1 and excellent rate performance. Furthermore, in order to evaluate the practical application of NiS2, an asymmetric supercapacitor, NiS2 as …

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Engineering The Electrochemical Capacitive Properties Of Activated Carbon By Correct Selection Of Ionic-Liquid Electrolytes, Qiu-Hong Zhang, Bao-Shou Shen, Song-Lin Zuo, Xin-Yu Wei Dec 2017

Engineering The Electrochemical Capacitive Properties Of Activated Carbon By Correct Selection Of Ionic-Liquid Electrolytes, Qiu-Hong Zhang, Bao-Shou Shen, Song-Lin Zuo, Xin-Yu Wei

Journal of Electrochemistry

In order to improve the electrochemical capacitive properties and to apply coconut shell activated carbon (AC) serving as electrode materials in ionic liquid (IL)-based supercapacitor (SC), the coconut shell AC material was re-activated using a steam as an activating agent in this work, forming a secondary AC (W-AC). The results showed that the specific capacitance of the W-AC electrode was much larger than that of the raw activated carbon electrode (R-AC) in 1-ethyl-3-methylimidazolium tetrafluoroborate ([EMIM]BF4). The electrochemical techniques including cyclic voltammetry (CV), galvanostatic charge/discharge (GCD) measurement, and electrochemical impedance spectroscopy (EIS) were used to systematically study the capacitive …

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