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Articles 1051 - 1080 of 1823

Full-Text Articles in Chemistry

Electrochemical Properties Of Ru-P/Mwcnts-Dhp/Gc Electrode, Miao-Jing Chen, Bao-Yi Lu, Wen-Jie Mei, Hong Li Aug 2009

Electrochemical Properties Of Ru-P/Mwcnts-Dhp/Gc Electrode, Miao-Jing Chen, Bao-Yi Lu, Wen-Jie Mei, Hong Li

Journal of Electrochemistry

Electrochemical properties of a novel monoruthenated porphyrin [Ru(phen)2(MPyTMPP)Cl]+ (where phen =1,10-phenanthroline,MPyTMPP =5-(3-pyridyl)-10,15,20-tris-(4-methylphenyl) porphyrin) on a multi-walled carbon nanotubes (MWCNTs) modified glassy carbon (GC) electrode with the participation of dihexadecyl phosphate (DHP) have been investigated by using cyclic voltammetry,differential pulse voltammetry,UV-Visible spectroscopy and fluorescence spectroscopy. It is found that [Ru(phen)2(MPyTMPP)Cl]+ has the ability to adsorb strongly onto the MWCNTs-DHP modified GC electrode and exhibits a pair of redox waves controlled by surface electrochemical process. DHP dispersed on the MWCNTs/GC electrode can facilitate the ruthenium complex to adsorb onto the MWCNTs-DHP surface. A new complex is generated by the …


Ellipsometric Study On Colored Electroplating Of Cuprous Oxide On Ni Substrate, Xue-Song Feng, Jing-Lei Lei, Ai-Xiang Chen, Wan-Shan Yin, Ling-Jie Li, Sha Zheng, Hui Zhao, Shao-Yan Pan Aug 2009

Ellipsometric Study On Colored Electroplating Of Cuprous Oxide On Ni Substrate, Xue-Song Feng, Jing-Lei Lei, Ai-Xiang Chen, Wan-Shan Yin, Ling-Jie Li, Sha Zheng, Hui Zhao, Shao-Yan Pan

Journal of Electrochemistry

The colored Cu2O coating was electroplated on Ni substrate to meet the decorative requirements. Results of X-ray photoelectron spectroscopy (XPS) indicate the coating consisting of Cu2O. Images of scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) show that the Cu2O coating is smooth and uniform,and covers the Ni substrate wholly. Ellipsomtric measurements for Cu2O coatings with various electroplating time were carried out. Using a 4-layer model of "Air-Cu2O layer-interphase-Ni" ,the interphase was modeled with the graded effective medium approximation (EMA),the ellipsomtric data were deconvoluted and the Cu2O …


Effect Of Liquid Dispersion On Corrosion Behavior Of Metals In Gas/Liquid/Solid Multiphase Corrosion Systems, Jing Jiang, Jia Wang May 2009

Effect Of Liquid Dispersion On Corrosion Behavior Of Metals In Gas/Liquid/Solid Multiphase Corrosion Systems, Jing Jiang, Jia Wang

Journal of Electrochemistry

Liquid dispersion,described by the parameters of gas/liquid/solid three-phase boundary(TPB) zone of dispersed liquid on a metal surface,is an important property of liquid state influencing corrosion behavior of metals in gas/liquid/solid multiphase corrosion systems.In our paper,the characterisation of cathodic oxygen reduction process in TPB zone was discussed,and a model describing the cathodic process of TPB zone was developed.On this basis,the relationship between the cathodic limiting current and the TPB parameters was studied,and the simulation results were in good agreement with the experimental data.The role of liquid dispersion in atmospheric and sandy soil corrosion systems was also simulated.


Electrodeposition Of Al On Magnesium Alloy In Ionic Liquid, Wen-Ta Tsai, Shu-You Chen, Mu-Huan Zhuang, Jeng-Kuei Chang, Yi-Wen Sun May 2009

Electrodeposition Of Al On Magnesium Alloy In Ionic Liquid, Wen-Ta Tsai, Shu-You Chen, Mu-Huan Zhuang, Jeng-Kuei Chang, Yi-Wen Sun

Journal of Electrochemistry

Electrodeposition of a metallic aluminum on a magnesium alloy in acidic aluminum chloride-1-ethyl-3-methylimidazolium chloride ionic liquids(AlCl3-EMIC) was investigated.The effects of current density and AlCl3 content in the ionic liquid on the electrodeposition behavior were studied.The results showed that aluminum could be successfully electrodeposited on the AZ91D substrate.At-0.2 V,the ionic liquid containing 60 m/o AlCl3 was optimum for Al electrodeposition.The current efficiency was higher if electrodeposition was performed at a lower applied current density.The existence of Al coating could caused a substantial increase in open circuit potential,reducing the susceptibility of Mg alloy to corrosion.The results of electrochemical …


Electrochemical Characteristics Of Vitaminb6 At Polybromocresol Green Modified Electrode, Jun Yao, Jiang-Yuan Li, Yang Luo May 2009

Electrochemical Characteristics Of Vitaminb6 At Polybromocresol Green Modified Electrode, Jun Yao, Jiang-Yuan Li, Yang Luo

Journal of Electrochemistry

Electrochemical characteristics of VB6 were investigated at PBG modified electrode by Cyclic voltammetry and linear sweep voltammetry.The VB6 produced an irreversible oxidation peak at 0.978 V(Vs.SCE) in HAc-NaAc(pH=4.0) buffer solution over the potential range of 0.7 to 1.2 V.The electron number,the proton number,the transfer coefficient were determined to be 1,1 and 0.37,respectively.The oxidation peak currents of VB6 versus its concentration showed a linear relationship in the concentration range of 1×10-3~2×10-5mol/L with the correlation coefficient of 0.9967 and the detection limit of 2×10-6mol/L.The recovery was 100.06%.


Corrosion Performance Of Epoxy Coatings By Chemical Modification With Silanes, Liang Liu, Wei-Gang Ji, Ji-Ming Hu, Jian-Qing Zhang, Chu-Nan Cao May 2009

Corrosion Performance Of Epoxy Coatings By Chemical Modification With Silanes, Liang Liu, Wei-Gang Ji, Ji-Ming Hu, Jian-Qing Zhang, Chu-Nan Cao

Journal of Electrochemistry

The improvement of corrosion performance of epoxy coatings by modification with "active" and "non-active" silanes is presented."Active" silanes are defined as ones having functional groups that can react with the epoxy groups in the epoxy resin,usually amino-silanes."Non-active" silanes are defined as ones not reacting with the epoxy groups,but can react with the hydroxyl groups in the epoxy backbone by the condensation reactions under the catalysis of organic tin compounds.The FTIR results showed that both the "active" and "non-active" silanes had been successfully grafted onto the epoxy resin.Electrochemical impedance spectroscopy(EIS) and accelerated corrosion test(Machu test) showed that the corrosion performance of …


Complex Of 3-Amino-1,2,4-Triazole And Na2Wo4 As An Inhibitor For Brass Corrosion, Qun-Jie Xu, Chun-Xiang Li, Yu-Hong Ni, Guo-Ding Zhou May 2009

Complex Of 3-Amino-1,2,4-Triazole And Na2Wo4 As An Inhibitor For Brass Corrosion, Qun-Jie Xu, Chun-Xiang Li, Yu-Hong Ni, Guo-Ding Zhou

Journal of Electrochemistry

AC impedance and polarization methods were used to study the inhibition effect of ATA and the complex of ATA and Na2WO4 for brass corrosion in 3% NaCl solution.The results indicated that ATA had inhibition effect for brass corrosion.ATA showed the best inhibition effect for brass corrosion at the ATA concentration of 7.5 mg·L-1,and the inhibition efficiency was 87.46%.At the ATA concentration of 7.5 mg·L-1 and at the Na2WO4 concentration of 0.15 mg·L-1,the complex showed optimum inhibition effect for brass corrosion,and also showed synergistic effect and the inhibition efficiency reached …


Electrode Of Metallic Oxides Coated Titanium With Interlayer, Yi Tang, Li-Kun Xu, Yong-Lei Xin, Jun-Tao Wang, Ping Long May 2009

Electrode Of Metallic Oxides Coated Titanium With Interlayer, Yi Tang, Li-Kun Xu, Yong-Lei Xin, Jun-Tao Wang, Ping Long

Journal of Electrochemistry

Various Ti/IrRuSn,Ti/IrTa/IrRuSn and Ti/IrTaSn/IrRuSn oxide electrodes were prepared by sol-gel method.The surface morphology and microstructure were analysed with FESEM and XRD.The electrochemical activity and stability were investigated using electrochemical technologies including chlorine and oxygen evolving potential measurements,cyclic voltammetry,accelerated life test,and alternative electrolysis.The results indicate that the electrodes with interlayers present more cracks on the surface and a little bigger average grain size,with particles of different shapes precipitated in the cracks.The electroactive sites are increased and the selectivity for the chlorine evolving reaction is enhanced,but the current efficiency for the chlorine production is somewhat lowered by the addition of different interlayers.The …


The Accelerated Test Of Simulated Atmospheric Corrosion And The Rust Evolution Of Low Carbon Steel, Jun-Hua Dong, Wei Ke May 2009

The Accelerated Test Of Simulated Atmospheric Corrosion And The Rust Evolution Of Low Carbon Steel, Jun-Hua Dong, Wei Ke

Journal of Electrochemistry

It has been set up an accelerated method of simulating to atmospheric corrosion by using wet/dry alternate test.The rust evolution rule of mass change vs time(in logarithmic coordinate) of low carbon steel under this test shows two linear sections with different slopes,in which the rust evolution transition in weight change corresponds to the compactness transition and crystallization transition during the rust layer growth.It has found that the rust evolution rule of low carbon steel in Wanning exposure site correlates to the rust evolution rule obtained by simulating the coastal atmospheric corrosion test,and the rust evolution rule of low carbon steel …


Investigation Of Electrochemical Noise In The Crevice Corrosion Of Q235 Carbon Cteel, Qian Hu, Yu-Bing Qiu, Xing-Peng Guo May 2009

Investigation Of Electrochemical Noise In The Crevice Corrosion Of Q235 Carbon Cteel, Qian Hu, Yu-Bing Qiu, Xing-Peng Guo

Journal of Electrochemistry

The crevice corrosion behavior of Q235 carbon steels in a NaHCO3+NaCl solution was investigated by electrochemical noise(EN) and electrochemical impedance spectroscopy(EIS).Three stages of crevice corrosion including the induction,the rapid transform and the stable development could be clearly distinguished.The characteristics of the electrochemical noise and the noise resistance Rn showed remarkable differences at each stage.The electrode area ratio(r) of outside to inside the crevice had a significant influence in the development of crevice corrosion.The time of the induction stage increased with increasing r.However,under the stable development stage of the crevice corrosion,the surface outside the crevice was at an active …


Effect Of Naphthalene Water Reducer On Corrosion Behavior Of Reinforcing Steel In Concrete, Yu-Ming Tang, Jie Zhang, Yu Zuo May 2009

Effect Of Naphthalene Water Reducer On Corrosion Behavior Of Reinforcing Steel In Concrete, Yu-Ming Tang, Jie Zhang, Yu Zuo

Journal of Electrochemistry

The influence of naphthalene water reducer on corrosion behavior of reinforcing steel in concrete was studied by the methods of corrosion potential measurement,linear polarization and EIS test.The values of concrete resistance(Rc) and polarization resistance(Rp) of the samples with naphthalene water reducer were higher than those without naphthalene water reducer,especially in the concrete with 0.2 percent naphthalene water reducer.A suitable amount of water reducer can improve the pore structures of concrete,increase the concrete compactness and impermeability,and decrease corrosion rate of rebars in concrete.


Effect Of Electrochemical Property Of Uns J91450 Stainless Steel On Stress Corrosion Cracking In Hydrogen Sulfide Solutions, Zhi-Yong Liu, Chao-Fang Dong, Xiao-Gang Li, Li-Xian Wang May 2009

Effect Of Electrochemical Property Of Uns J91450 Stainless Steel On Stress Corrosion Cracking In Hydrogen Sulfide Solutions, Zhi-Yong Liu, Chao-Fang Dong, Xiao-Gang Li, Li-Xian Wang

Journal of Electrochemistry

Effect of electrochemical behaviours on stress corrosion cracking(SCC) of UNS J91450 stainless steel in hydrogen sulfide environment was investigated using slow-strain-rate test(SSRT) and electchemial techniques.Results show that UNS J91540 stainless steel was susceptible to SCC in varying H2S solutions,and the SCC susceptibility reduced with the increase of pH value.The electrochemical property plays an important role in the SCC occurrence,as a combined effect of hydrogen embritlement and anodic dissolution at SCC cracktip at open circuit potential.In the solution with a lower pH the hydrogen revolution was intensive and the cracktip anodic dissolution was weaker,however,in the higher pH solution the …


Developments Of Scanning Electrochemical Probes And Their Applications In Studying Of Localized Corrosions, Chang-Jian Lin, Yan Li, Bin Lin, Rong-Gang Hu, Min Zhang, Xiang-Dong Zhuo, Rong-Gui Du May 2009

Developments Of Scanning Electrochemical Probes And Their Applications In Studying Of Localized Corrosions, Chang-Jian Lin, Yan Li, Bin Lin, Rong-Gang Hu, Min Zhang, Xiang-Dong Zhuo, Rong-Gui Du

Journal of Electrochemistry

The electrochemical inhomogeneities always exist at the interface of metal/solution,and play an important and often controlling role in localized corrosion of metals in a given environment.It is necessary to develop in situ imaging techniques for further studying the electrochemical and environmental inhomogeneities at the interface of metal/solution for the localized corrosion system.In this paper,various techniques with spatial resolution,such as scanning micro reference electrode(SMET),scanning electrochemical microscope(SECM),atomic force microscope(AFM),and scanning Kelvin probe(SKP),and their applications in corrosion studies were briefly reviewed.The chemical probes and array electrode have been developed.It was concentrated to describe our newly developed techniques of the scanning electrochemical probes,including SMET …


Preparation And Electrochemical Properties Of Layered Manganese Oxide(Li-Birnessite Type), Xing-Kang Huang, Hai-Tao Chang, Jian-Long Gan, Qing-Shun Zhang, Hong-Jun Yue, Dong-Ping Lv, Yong Yang May 2009

Preparation And Electrochemical Properties Of Layered Manganese Oxide(Li-Birnessite Type), Xing-Kang Huang, Hai-Tao Chang, Jian-Long Gan, Qing-Shun Zhang, Hong-Jun Yue, Dong-Ping Lv, Yong Yang

Journal of Electrochemistry

Layered Li-birnessite was prepared by means of oxidizing Mn2+ with O2 gas in alkaline media.The as-prepared sample was characterized by scanning electron microscopy(SEM), X-ray diffraction(XRD), BET and thermogravimetric/diffenential thermal analysis(TG/DTA) techniques. The electrochemical properties of the material were also investigated. The results show that such a Li-birnessite consists of well-crystallized spherical particles with an interlayer distance of 0.70 nm. The Li-birnessite delivered a high discharge capacity of 203 mAh/g at a rate of 0.2 C(40 mA/g), and had good rate capability as well.


Electrochemical Behavior Of Mg-Li Electrodes In Nacl Solution, Lin Wu, Yan-Zhuo Lv, Xue Cao, Gui-Ling Wang, Dian-Xue Cao May 2009

Electrochemical Behavior Of Mg-Li Electrodes In Nacl Solution, Lin Wu, Yan-Zhuo Lv, Xue Cao, Gui-Ling Wang, Dian-Xue Cao

Journal of Electrochemistry

The Mg-Li electrodes containing 8.5% and 14% Li were prepared using an induction melting method. Their electrochemical behavior in NaCl solution was investigated by means of potentiodynamic polarization, potentiostatic oxidation,electrochemical impedance technique and mass-loss measurements. The morphology of the electrodes after discharge was examined using scanning electron microscopy. The Mg-14Li electrode showed more negative open circuit potential and higher discharge current density than Mg-8.5Li electrode. The oxidation products of Mg-14Li loosely attached on the electrode surface and peeled off easily. The Mg-8.5Li exhibited higher utilization efficiency. Both electrodes gave higher utilization efficiencies when discharged at lower anodic potential.


Electrochemical Performance Of The Exfoliated Graphite Containing Sulfur Cathode Material For Lithium Sulfur Battery, Ke-Guo Yuan, Wei-Kun Wang, Zhong-Bao Yu, An-Bang Wang May 2009

Electrochemical Performance Of The Exfoliated Graphite Containing Sulfur Cathode Material For Lithium Sulfur Battery, Ke-Guo Yuan, Wei-Kun Wang, Zhong-Bao Yu, An-Bang Wang

Journal of Electrochemistry

The exfoliated graphite containing sulfur cathode material was prepared by the high temperature sulfur gas diffusion adsorption method.This cathode material could obtain an initial discharge specific capacity 972 mAh·g-1,capacity retention ratio 78% and cycling efficiency above 80%,respectively.The exfoliated graphite containing sulfur cathode could decrease the reaction interphase charge transfer impedance,and restrain the sulfur or polysulfide shuttle phenomenon during the charge-discharge process through improving the diffusion impedance.


Effects Of Kscn On Kinetic Characters Of The Positive Couple And Performance For Vanadium Redox Flow Battery, Jian-Guo Liu, Dong Shi, Yue Men, Chuan-Wei Yan May 2009

Effects Of Kscn On Kinetic Characters Of The Positive Couple And Performance For Vanadium Redox Flow Battery, Jian-Guo Liu, Dong Shi, Yue Men, Chuan-Wei Yan

Journal of Electrochemistry

In order to improve the reaction activity of VO2+/VO2+ and the battery performance of Vanadium redox flow battery,different concentration of potassium sulfocyanates KSCN were added into 0.1mol/L VOSO4/ H2SO4 solution,and the kinetic characters of electrochemical reaction of VO2+/VO2+ was studied by CV and EIS.The results showed that the addition of KSCN could improve the oxidative peak current value of positive couple VO2+/VO2+ reaction,but had little influence in the reductive peak.The addition of KSCN decreased the impedance at 1.0 V.And the value of standard rate constant k0 …


Effect Of Impurity Cu(2+) On Oxygen Electrode In Pemfc, Xiao Jie, Jun-Bo Hou, Zhi-Gang Shao, Bao-Lian Yi May 2009

Effect Of Impurity Cu(2+) On Oxygen Electrode In Pemfc, Xiao Jie, Jun-Bo Hou, Zhi-Gang Shao, Bao-Lian Yi

Journal of Electrochemistry

Rotating disk electrode was adopted in this paper to simulate the cathode in PEMFC.In the Cu2+ electrolyte,the influence of impurity Cu2+ on Carbon-Supported Pt Catalysts was investigated by using electrochemical measurements such as chronocoulometry,cyclic voltammetry and linear sweep.Experimental results showed that,after constant voltage at 0.49 V,the ECA of Pt/C decreased dramatically,it's perhaps under potential deposition of Cu might occur on the substrate.Meanwhile the change of ORR Tafel scope reaction is very large.It might be because oxygen adsorption sites are occupied by Cu atoms after they under potential deposit on surface of Pt/C catalyst,and the adsorption of oxygen on …


Electro-Oxidation Of Methanol On Fe-Doped Pt-Zro2/C Catalyst, Mao-Cai Lin, Dong-Dong Liu, Qing-Chun Yu, Ming-Ruo Hu, Heng-Yong Tu May 2009

Electro-Oxidation Of Methanol On Fe-Doped Pt-Zro2/C Catalyst, Mao-Cai Lin, Dong-Dong Liu, Qing-Chun Yu, Ming-Ruo Hu, Heng-Yong Tu

Journal of Electrochemistry

The Fe-doped ZrO2 powders were prepared by so-gel method.After that,Pt-Zr1-xFexO2/C catalysts were made by reducing platinum salts with ethylene glycol.The physical property of the catalyst was characterized by XRD and TEM.It was found that the distribution of the catalyst was narrow,the particle sizes of Pt and ZrO2 particles were 2~4 nm and 3~7 nm,respectively.The Cyclic Voltammetry and Chronoamperometry testing indicated that the electro-catalytic activity for methanol electro-oxidation on Pt-ZrO2/C catalyst increased when ZrO2 was doped with Fe.And Pt-Zr0.95Fe0.05O2/C catalyst showed the highest activity …


Preparation And Performance Of Co And La Co-Doped Li-Rich Lithium Manganate, Da-Qiao Zhou Feb 2009

Preparation And Performance Of Co And La Co-Doped Li-Rich Lithium Manganate, Da-Qiao Zhou

Journal of Electrochemistry

The cathode material of Li1.1Co0.02La0.01Mn2O4 was successfully synthesized by the method of co-precipitation followed by a solid state reaction.In the sintering temperature range of 700~850 ℃,X-ray diffraction(XRD) results showed a single phase of each material and the increase of crystallization degree,and scanning electron microscopic(SEM) images indicated that the particle size increased and the specific surface area decreased,respectively,with increasing the sintering temperature.Due to its lower polarization resistance,the Co and La co-doped lithium-rich lithium manganate(sintered at 800 ℃) positive electrodes showed the most promising electrochemical performance.The capacity retention after 50 cycles reached 98.5%.


Electrochemical Properties Of Functionalized Carbon Nanotubes And Their Applications In Analysis Of 6-Mercaptopurine, Bao-Yi Lu, Yan-Yan Lai, Hong Li Feb 2009

Electrochemical Properties Of Functionalized Carbon Nanotubes And Their Applications In Analysis Of 6-Mercaptopurine, Bao-Yi Lu, Yan-Yan Lai, Hong Li

Journal of Electrochemistry

The electrochemical behaviors and adsorption properties of single-walled carbon nanotubes such as SWNT,SWNT-COOH,and SWNT-OH and multi-walled carbon nanotubes including MWNT,MWNT-COOH,and MWNT-OH modified at a graphite electrode have been investigated by using [Fe(CN)6]3-anion and [Co(phen)3]3+ cation.It was shown that shows good redox reversibility of [Fe(CN)6]3-/4-reactions on the existed carbon nanotubes(CNT) modified electrode.Based on the strong adsorptive property of [Co(phen)3]3+ on the CNT surface,the [Co(phen)3]3+/CNT modified graphite electrode can be obtained by progressive potential sweeping and developed to monitor quantitatively 6-mercaptopurine(6-MP).The adsorption capacity of …


High Utilization Aupt Nanoparticles Supported On Mwcnts For Methanol Electro-Oxidation In Alkaline Medium, Xun Guo, Dao-Jun Guo, Xin-Ping Qiu, Li-Quan Chen, Wen-Tao Zhu Feb 2009

High Utilization Aupt Nanoparticles Supported On Mwcnts For Methanol Electro-Oxidation In Alkaline Medium, Xun Guo, Dao-Jun Guo, Xin-Ping Qiu, Li-Quan Chen, Wen-Tao Zhu

Journal of Electrochemistry

We synthesized gold-platinum electrocatalysts supported on multi-walled carbon nanotubes(MWCNTs) with high utilization by a simple one-step method.A high Pt loading series of bimetallic AuPt/MWCNTs catalysts were prepared by the improved ethylene glycol reduction method,and then were compared in terms of the electrocatalytic activity for methanol electro-oxidation using cyclic voltammetry(CV) and chronoamperometry in alkaline solutions.The structure of AuPt/MWCNTs was characterized by the transmission electron microscopy(TEM),X-ray diffraction(XRD) and energy-dispersive X-ray spectroscopy(EDS).The results showed that the AuPt/MWCNTs catalysts had high Pt utilization,uniform AuPt nanoparticles size and good electrocatalytic activity for methanol electro-oxidation.The effect of Au/Pt mass ratio on electrocatalytic activity was also investigated.The …


Preparation And Electrochemical Performance Of Li3V2(Po4)3, Hou-Gang Fan, Tao Jiang, Chun-Zhong Wang, Gang Chen, Ying-Jin Wei Feb 2009

Preparation And Electrochemical Performance Of Li3V2(Po4)3, Hou-Gang Fan, Tao Jiang, Chun-Zhong Wang, Gang Chen, Ying-Jin Wei

Journal of Electrochemistry

The carbon coating Li3V2(PO4)3 powder samples were synthesized by carbon incorporation solid state reaction.The structure,morphology and electrochemical properties have been studied by X-ray powder diffraction,scanning electron microscopy and automatic battery tester system,respectively.Carbon coating on Li3V2(PO4)3 would prevent the particles from agglomerating,reduce the particle size,raise the conductivity and improve the samples′ electrochemical performance.


Silicon Nanowires As Anode Materials For Lithium Ion Batteries, Yan-Peng Fu, Hui-Xin Chen, Yong Yang Feb 2009

Silicon Nanowires As Anode Materials For Lithium Ion Batteries, Yan-Peng Fu, Hui-Xin Chen, Yong Yang

Journal of Electrochemistry

The SiNWs electrodes were fabricated by coating and direct growth methods,respectively.The structure,morphology and electrochemical performance of such materials were characterized by XRD,SEM and charge-discharge tests.The results show that the electrodes prepared by direct growth method had higher capacity,better battery life and also displayed and excellent cyclability at higher currents.During the process of lithiation,the initial crystalline Si transformed to amorphous LixSi,and the average diameter of the SiNWs increased.Despite the large volume changed,the SiNWs remained intact and did not break into smaller particles.


Electrocatalytic Reduction Of Oxygen On Tungsten Carbide Electrode, Chun-An Ma, Yun Huang, Ying-Hong Zhu, Zhao-Yang Chen Feb 2009

Electrocatalytic Reduction Of Oxygen On Tungsten Carbide Electrode, Chun-An Ma, Yun Huang, Ying-Hong Zhu, Zhao-Yang Chen

Journal of Electrochemistry

Tungsten carbide(WC) catalysts were prepared by gas-solid reaction using ammonium metatungstate as precursors which were pretreated with spray drying sphere miniaturation,carbon monoxide as carrier gas and hydrogen as deoxidizing gas.The WC electrode was fabricated using WC catalyst powders and PTFE as binding agent,and characterized by XRD and SEM.Electrocatalyst behavior of WC for oxygen reduction reaction in the sulphuric acid solution was studied by steady-state voltammetry and cyclic voltammetry.The results show that the WC powders obtained were in spheric particles and the prepared WC electrode had a good electrocatalyst activity to the oxygen reduction reaction.The electrode reaction was controlled by adsorption.The …


Nano-Sn/Hard Carbon Composite As Anode Material For Lithium Ion Batteries, Bing-Kun Guo, Jie Shu, Kun Tang, Ying Bai, Zhao-Xiang Wang, Li-Quan Chen Feb 2009

Nano-Sn/Hard Carbon Composite As Anode Material For Lithium Ion Batteries, Bing-Kun Guo, Jie Shu, Kun Tang, Ying Bai, Zhao-Xiang Wang, Li-Quan Chen

Journal of Electrochemistry

The tin(Sn) nano particles were embedded into the mesopores of hard carbon spherules(HCS) to form a composite anode material for lithium ion batteries.The structure of the obtained composite was characterized by X-ray diffraction(XRD) while its electrochemical performances were evaluated with galvanostatic cycling.It is found that the embedding Sn nanoparticles into porous HCS not only result in a composite material with high lithium storage capacity and capacity retention,but also increase the initial coulombic efficiency of the composite.Based on the infrared spectroscopic analysis,the enhanced initial coulombic efficiency is attributed to the inductive decomposition of the ROCO2Li species in the solid …


19th International Symposium Of Fine Chemistry And Functional Polymers (Fcfp-Xix) & Iupac 5th Internaitonal Symoposium On Novel Materials And Synthesis (Nms-V), Editorial Office Of J.Electrochem. Feb 2009

19th International Symposium Of Fine Chemistry And Functional Polymers (Fcfp-Xix) & Iupac 5th Internaitonal Symoposium On Novel Materials And Synthesis (Nms-V), Editorial Office Of J.Electrochem.

Journal of Electrochemistry

No abstract provided.


Preparation Of The Protic Ionic Liquid/Pvdf-Hfp Composite Membranes And Its Performance For Dmfc, Rui-Ying Miao, Jian-Ling Li, Yong Fang, Xin-Dong Wang Feb 2009

Preparation Of The Protic Ionic Liquid/Pvdf-Hfp Composite Membranes And Its Performance For Dmfc, Rui-Ying Miao, Jian-Ling Li, Yong Fang, Xin-Dong Wang

Journal of Electrochemistry

The protic ionic liquid(PIL) α-methyl pyridinium trifluoroacetate([α-MPyH]Tfa) was synthesized by acid & alkali neutralization.Then PIL/PVDF-HFP composite membranes were prepared by means of phase inversion method using acetone as solvent.The conductivities of the composite membrane increased with the temperature and reached 8×10-3 S/cm,1×10-2 S/cm and 3×10-2 S/cm at room-temperature,30 ℃ and 80 ℃,respectively,by electrochemical impedance method.The properties of the methanol-rejecting of the membranes were measured by chronoamperometry as well.The results indicate that the properties of methanol-resistance of the membranes before and after IL combination were equivalent approximately.


Mesoporous Carbon For High Power Supercapacitors, Bin Xu, Lu Peng, Guo-Qing Wang, Gao-Ping Cao, Feng Wu, Yu-Sheng Yang Feb 2009

Mesoporous Carbon For High Power Supercapacitors, Bin Xu, Lu Peng, Guo-Qing Wang, Gao-Ping Cao, Feng Wu, Yu-Sheng Yang

Journal of Electrochemistry

Mesoporous carbon for supercapacitors was prepared from sucrose using nano-CaCO3 as template.The microstructure of the carbon was characterized with N2 adsorption and transmission electron microscopy(TEM) observation.The electrochemical performances were evaluated in 6mol·L-1 KOH aqueous electrolyte with galvanostatic charge/discharge,cyclic voltammetry,and ac impedance spectroscopy.The sucrose-based mesoporous carbon had a surface area of 606 m2/g and enriched mesopores in the range of 10~30 nm.The mesoporous carbon presented a specific capacitance of 125 F/g at a current density of 50 mA/g and outstanding excellent rate performance.As the current density increased to 20 000 mA/g,its capacitance remained at 88 F/g,much …


Preparation And Performance Of The Thin-Film Libpon Electrolyte, Feng Wu, Ya-Dong Liu, Ren-Jie Chen, Shi Chen Feb 2009

Preparation And Performance Of The Thin-Film Libpon Electrolyte, Feng Wu, Ya-Dong Liu, Ren-Jie Chen, Shi Chen

Journal of Electrochemistry

The LiBPON thin-film electrolyte was prepared by magnetron sputtering,and the relationship between the performance and the deposition condition was investigated.As seen in the SEM images,the thin films are dense and uniform without cracks,and according to the XRD patterns they have an amorphous structure.The electrochemical performance of the electrolyte was characterized by electrochemical impedance spectroscopy(EIS).The ionic conductivities of the thin film decreased with the RF power,but increased with the N2 pressure.The an ionic conductivity of 3.5×10-6 S/cm at room temperature was found from the electrochemical measurement.While the deposition rate increased with the RF power,but decreased with the N2 …