Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 61 - 68 of 68

Full-Text Articles in Engineering

Simultaneous Determinations Of Ascorbic Acid, Dopamine And Uric Acid At Ca/Gc Electrode, Ying Zhang, Wang Ren, Min-Jiao Li Feb 2012

Simultaneous Determinations Of Ascorbic Acid, Dopamine And Uric Acid At Ca/Gc Electrode, Ying Zhang, Wang Ren, Min-Jiao Li

Journal of Electrochemistry

The citric acid modified glassy carbon electrode (CA/GC) was constructed by potentiostatic technique and used for simultaneous determinations of ascorbic acid (AA), dopamine (DA) and uric acid (UA) by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The CA/GC electrode exhibits excellent electrocatalytic activity towards AA, DA and UA. The oxidation peaks are well separated with the potential differences between AA and DA, DA and UA, and AA and UA being 170, 130 and 300 mV, respectively, which is large enough to determine AA, DA and UA simultaneously. The catalytic peak currents obtained were linearly dependent on the concentrations of …


Cycle Lifetime Investigation Of Nickel Electrode Prepared By Electrochemical Impregnation For Applications In Aerospace Nickel Hydrogen Cells, Hai-Chang Zhang, Li-Xin Tan, Cheng Guo, Wen-Cheng Ming, Xue-Ying Ren Feb 2012

Cycle Lifetime Investigation Of Nickel Electrode Prepared By Electrochemical Impregnation For Applications In Aerospace Nickel Hydrogen Cells, Hai-Chang Zhang, Li-Xin Tan, Cheng Guo, Wen-Cheng Ming, Xue-Ying Ren

Journal of Electrochemistry

In this paper, the effects of overcharge, charge-discharge C rate and pore size on cycle lifetime of 4.5’ electrochemical impregnated nickel electrode were investigated. In the case of the electrode was overcharged to 170% of nominal capacity, the initial capacity of the electrode could be maintained 2.7 Ah up to 150 cycles without deterioration and a discharge capacity of 1.7 Ah (remaining 63% of 2.7 Ah ) could be delivered after 300 cycles. Without overcharge, more than 300 charge-discharge cycles could be realized without loss of capacity and a discharge capacity of electrode could be maintained about 76% of initial …


Ag Nanoparticles Self-Assembled Films On Iron Surface And Their Inhibition Properties, Zhang Zhe, Jia Ming-Zi, Ruan Le Feb 2012

Ag Nanoparticles Self-Assembled Films On Iron Surface And Their Inhibition Properties, Zhang Zhe, Jia Ming-Zi, Ruan Le

Journal of Electrochemistry

The Ag nanoparticles were prepared in aqueous solutions through a chemical reduction method and transferred from water phase to toluene phase with the protection of 1-dodecanethiol (DDT). The polished iron electrode was immersed in the DDT-protected metal nanoparticles toluene solutions to form DDT/Ag nanoparticles self-assembled mixed films. Electrochemical methods such as electrochemical impedance spectroscopy and polarization curve measurement were used to study the inhibition properties of the self-assembled films in the 0.5 mol?L-1 H2SO4 solution. The appearance of elements such as S and Ag from the XPS data identified the presences of DDT and Ag nanoparticles.


Progress And Perspective Of Fuel Cell Technology, Ming Hou, Bao-Lian Yi Feb 2012

Progress And Perspective Of Fuel Cell Technology, Ming Hou, Bao-Lian Yi

Journal of Electrochemistry

Fuel cell, a clean and high-efficiency electrochemical power source, has being paid much attention worldwide recent years. In this paper, the progress and perspective of fuel cell technology are elucidated in detail. Fuel cells have been applied in some special fields such as spacecraft, shuttle and submarines. However, in the areas of transportation, stationary station and portable power source, fuel cells are still under demonstration due to the durability and cost problems. The reliability and surrounding survivability of fuel cells should be enhanced in the special application. Meanwhile, the durability and cost of fuel cells are the main issues to …


The Electrocatalytic Study Of Licoo2 In Air Electrode For Lithium-Air, Jun Gao, Wei Wu, Yan-Yan Tian, Yong Yang Feb 2012

The Electrocatalytic Study Of Licoo2 In Air Electrode For Lithium-Air, Jun Gao, Wei Wu, Yan-Yan Tian, Yong Yang

Journal of Electrochemistry

The LiCoO2 has been investigated as a new electrocatalyst for air electrodes using homemade lithium-air battery. The electrochemical performance and structural changes of the LiCoO2 based composite air electrodes have been studied. The results of CV, XRD and charge-discharge tests show that the composite air electrodes composed of LiCoO2 can greatly improve the discharge performance of lithium-air batteries. In particular when the composite air electrodes are charged to 4.1 V before further discharging, the obvious catalytic effects of LiCoO2 are attributed to higher valence state of the Co element in LiCoO2, esp. at charged state.


Preparation And Electrochemical Performance Of Lifepo4/C By Spray Drying Method Assisted With Organic Template, Quan-Bing Liu, Yang-Mei Jiang, Hui-Yu Song, Shi-Jun Liao Feb 2012

Preparation And Electrochemical Performance Of Lifepo4/C By Spray Drying Method Assisted With Organic Template, Quan-Bing Liu, Yang-Mei Jiang, Hui-Yu Song, Shi-Jun Liao

Journal of Electrochemistry

In this work, the LiFePO4/C composites were prepared by the spray drying and carbothermal method, and were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge-discharge measurements. The effects of the organic assisted templates on the morphologies and electrochemical properties of the LiFePO4/C composites were investigated. The results showed that the morphology and microstructure of the composites could be tuned by incorporating with the different templates. The morphology of the composite appeared to be solid microspheres if no organic template was added, while porous microspheres, nest-like aggregation, and uniform nano-micro …


Dissolved Oxygen Seawater Battery With Electrochemical Capacitance, Hai-Bo Xu, Yong-Hong Lu, Wei Zhang, Yan-Ting Yu, Chuan-Wei Yan, Ya-Ping Sun, Lian Zhong, Jian-Guo Liu, Yi Zheng, Bing Han, Yong-Liang Wang Feb 2012

Dissolved Oxygen Seawater Battery With Electrochemical Capacitance, Hai-Bo Xu, Yong-Hong Lu, Wei Zhang, Yan-Ting Yu, Chuan-Wei Yan, Ya-Ping Sun, Lian Zhong, Jian-Guo Liu, Yi Zheng, Bing Han, Yong-Liang Wang

Journal of Electrochemistry

A new concept of seawater battery with electrochemical capacitance (SWB-EC) has been proposed using carbon fibre brush (CFB) as the cathode material, and three testing prototypes have been made accordingly. The discharge performances of the CFB before- and after-oxidation and Mg alloy sacrifice anode were studied by cyclic voltammetry and constant current discharge tests under steady state conditions. Results show that the oxidized CFB exhibits the pseudo-capacitive characteristic and its activity of oxygen reduction reaction (ORR) in stirred seawater highly increases, comparing with the non-oxidized CFB. The open circuit potential of Mg alloy sacrifice anode is -1.74 V, having the …


Preparation And Hydrogen Evolution Properties Of Ni/Ag2o/Ruo2-Pt Cathodes, Shu Huang, Xue-Ming Li, Wu-Lin Li, Wen Wang Feb 2012

Preparation And Hydrogen Evolution Properties Of Ni/Ag2o/Ruo2-Pt Cathodes, Shu Huang, Xue-Ming Li, Wu-Lin Li, Wen Wang

Journal of Electrochemistry

The Ni/Ag2O/RuO2-Pt composite cathode was prepared by sol-gel method using RuCl3 and H2PtCl6 as raw materials. The effects of heat treatment conditions and AgNO3 concentrations on hydrogen evolution properties were investigated. The morphology and composition of Ni/Ag2O/RuO2-Pt composite cathode have been characterized by XRD, XPS and SEM-EDS. It is demonstrated that the surface structure of Ni/Ag2O/RuO2-Pt composite cathode is more compact, with fewer cracks and larger surface roughness than pure nickel. At the conditions of 0.3 A?cm-2, 90 oC, and 11 mol?L-1 NaOH solution, the hydrogen evolution overpotential of Ni/Ag2O/RuO2-Pt composite cathode increases 484 mV with respect to pure nickel …