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Full-Text Articles in Physical Sciences and Mathematics

The Mechanism Of ~(13)Co_(Ad)/~(12)Co Isotope Exchange At Pt Electrode,A Combined Study By Electrochemical In-Situ Infrared Spectroscopy And Dipole-Dipole Coupling Analysis, Sang-Zi Liang, Shao-Xiong Liu, Ling-Wen Liao, Qian Tao, Jing Kang, Yan-Xia Chen Aug 2010

The Mechanism Of ~(13)Co_(Ad)/~(12)Co Isotope Exchange At Pt Electrode,A Combined Study By Electrochemical In-Situ Infrared Spectroscopy And Dipole-Dipole Coupling Analysis, Sang-Zi Liang, Shao-Xiong Liu, Ling-Wen Liao, Qian Tao, Jing Kang, Yan-Xia Chen

Journal of Electrochemistry

In this contribution,we have analyzed the IR spectra of saturated CO adlayer at rough Pt film electrode as a function of fractional surface coverage of 13COad/12COad recorded during 13COad /12CO isotope exchange process according to dipole-dipole coupling theory and coherent potential approximation. By properly choosing the parameters of adlayer structure and dipole-dipole coupling interaction under coherent potential approximation, we demonstrated that we can successfully simulate the IR spectra as a function of the surface coverage of CO adlayer at rough Pt film electrodes by assuming that COad molecules with low C—O stretching frequencies are dis- placed preferentially during the 13COad/12CO …


In-Situ Surface Enhanced Raman Scattering Electrochemical Investigation Of 4-Aminoantipyrine On Silver Electrode, Li-Jun Zhang, Wei Song, Ling Chen, Zong-Rang Zhang, Hai-Feng Yang Aug 2010

In-Situ Surface Enhanced Raman Scattering Electrochemical Investigation Of 4-Aminoantipyrine On Silver Electrode, Li-Jun Zhang, Wei Song, Ling Chen, Zong-Rang Zhang, Hai-Feng Yang

Journal of Electrochemistry

In this paper,4-AAP was self-assembled on silver surface to form monolayers. Surface-enhanced Raman Spectroscopy ( SERS) was used to in-situ investigate the adsorption mechanism of the 4-aminoantipyrine( 4-AAP) on silver surface dependent on shifting potentials and the effect of solution pH. Based on density functional theory( DFT) calculation of vibration modes,approximate assignment of 4-AAP SERS spectrum was conducted. In situ SERS spectral electrochemical experiments indicated that the 4-AAP monolayers experience a dynamic adsorption process from a tilted fashion to a more vertical mode for benzene ring and more parallel for pyrine ring with the potential applied toward more negative voltages. …


Electrooxidation Of Carbon Monoxide On Pd Thin Film-Coated Au Electrodes:Film Thickness Dependence, Yuqing Yang, Shouzhong Zou Aug 2010

Electrooxidation Of Carbon Monoxide On Pd Thin Film-Coated Au Electrodes:Film Thickness Dependence, Yuqing Yang, Shouzhong Zou

Journal of Electrochemistry

The adsorption and electrooxidation of CO on Pd-coated Au electrodes were studied by cyclic voltammetry and surface-enhanced Raman spectroscopy (SERS) . It is found that CO oxidation activity is film thickness dependent. Cyclic voltammograms (CVs) showed that CO oxidation peak potential shifted positively with the increase of the Pd thickness. SERS showed a redshift of the C—O stretching frequency with increasing Pd film thickness. These observations were explained by the dband theory. The strain effect strengthens CO adsorption and stabilizes adsorbed CO,while the ligand effect weakens CO adsorption and eases its oxidation. The ligand effect overpowers the strain effect.


In Situ Surface-Enhanced Raman Scattering Spectroscopic Study Of Sulfur Adsorption On Polycrystalline Platinum Electrode Surface, Bolian Xu-, In-Su Park, Ying Li, De-Jun Chen, Yuye J. Tong Aug 2010

In Situ Surface-Enhanced Raman Scattering Spectroscopic Study Of Sulfur Adsorption On Polycrystalline Platinum Electrode Surface, Bolian Xu-, In-Su Park, Ying Li, De-Jun Chen, Yuye J. Tong

Journal of Electrochemistry

The paper reports the first in situ surface enhanced Raman scattering (SERS) spectroelectrochemistry study of sulfur adsorption and electro-oxidation on highly roughened polycrystalline Pt surface in both acidic and basic supporting electrolytes. The SERS spectra were taken at a constant electrode potential after accumulative electro-oxidation CVs of the Pt electrode with pre-adsorbed sulfur species and at different electrode potentials that were varied stepwise of the Pt electrode immersed in sulfur-containing electrolytes without pre-adsorbed sulfur species. In both cases,a dominant vibrational band at 299 cm -1 in acidic electrolyte but at 310 cm-1 in basic electrolyte was observed,which was assigned to …


Studies Of Oxidation Processes Of Adsorbed And Solution Co On Pt(110) Electrode By Cyclic Voltammetry And In Situ Ftirs, Li Tian, Jun-Tao Li, Jin-Yu Ye, Chun-Hua Zhen, Shi-Gang Sun Aug 2010

Studies Of Oxidation Processes Of Adsorbed And Solution Co On Pt(110) Electrode By Cyclic Voltammetry And In Situ Ftirs, Li Tian, Jun-Tao Li, Jin-Yu Ye, Chun-Hua Zhen, Shi-Gang Sun

Journal of Electrochemistry

The oxidation processes of adsorbed CO (COad) and solution phase CO (COsol) on Pt(110) electrode were investigated by cyclic voltammetry and in-situ FTIR spectroscopy. It has revealed that in comparison with COad on Pt(110) in a CO-free solution,the oxidation current peak of COsol in a CO-saturated solution is positively shifted ca. 168 mV,and the peak current density has been increased by 6. 70 times. Linear adsorbed CO (COL) is determined by in-situ FTIR spectroscopy as the main species,which is uniformly distributed on Pt (110) surface. In a CO-free solution,the onset potential of COL is measured by in-situ FTIRS ca. 0. …


Electrochemical Sers Studies On The Adsorption Of Benzoimidazole And Derivative In Nonaqueous Solution, Ya-Xian Yuan, Feng-Zhu Yang, Wei Liu, Ping-Jie Wei, Jian-Lin Yao, Ren-Ao Gu Aug 2010

Electrochemical Sers Studies On The Adsorption Of Benzoimidazole And Derivative In Nonaqueous Solution, Ya-Xian Yuan, Feng-Zhu Yang, Wei Liu, Ping-Jie Wei, Jian-Lin Yao, Ren-Ao Gu

Journal of Electrochemistry

The surface adsorption of benzoimidazole (BIMH) and 2-mercaptobenzimidazole( MBI) was investigated by electrochemical in-situ surface enhanced Raman spectroscopy (SERS) and direct electrochemical synthesis on Cu electrode. The influence of the neutral ligand of triphenylphosphine (pph3) on the adsorption and surface coordination of BIMH and MBI were investigated respectively. BIMH interacted with metal surface by the neutral molecule to form chemical adlayer in the extremely negative potential,while it adsorbed onto metal surface through the N atoms to form a polymer film which may suppress the corrosion of the metal. The introduction of pph3 destroyed the film formation of BIMH on Cu …


Solid State Nmr Studies Of Lithium Manganese Silicate As Positive Electrode Materials For Li-Ion Batteries, Hu Cheng, Zi-Geng Liu, Yi-Xiao Li, Zhong Chen, Yong Yang Aug 2010

Solid State Nmr Studies Of Lithium Manganese Silicate As Positive Electrode Materials For Li-Ion Batteries, Hu Cheng, Zi-Geng Liu, Yi-Xiao Li, Zhong Chen, Yong Yang

Journal of Electrochemistry

The Li2MnSiO4 cathode material for lithium ion batteries was synthesized by sol-gel assisted hydrothermal method. XRD,FTIR and SS-NMR were used to study the phase,structure and morphology of obtained samples. Electrochemical performance of cathode material was tested. The results show that the main phase of sample prepared was Li2MnSiO4,whereas a small amount of impurities ( Li2CO3) were existed. The Li2MnSiO4 cathode material gave an initial discharging capacity of about 190 mAh·g -1. But this capacity faded rapidly during the cycling process due to the decomposition of Li2MnSiO4.


Density Functional Theory Studies Of Surface-Enhanced Raman Spectroscopy In Electrochemical Interfaces, Liu-Bin Zhao, De-Yin Wu, Bin Ren, Zhong-Qun Tian Aug 2010

Density Functional Theory Studies Of Surface-Enhanced Raman Spectroscopy In Electrochemical Interfaces, Liu-Bin Zhao, De-Yin Wu, Bin Ren, Zhong-Qun Tian

Journal of Electrochemistry

Quantum chemical density functional theory and Raman scattering theory were used to study the bonding mechanism and surface-enhanced Raman spectroscopy of pyridine adsorbed on transition metals (Ⅷ group) and coinage metals (IB group) . SERS studies of pyridine-metal systems have been reviewed. Chemical bonding mechanism as well as photo-driven charge transfer mechanism was considered to investigate the vibrational frequency shift and the enhancement of SERS intensity in electrochemical interfaces. Our theoretical results can be used to interpret the SERS phenomena dependent on metals,excitation wavelengths,and applied potentials.


Multi-Electron Redox Materials For High Energy Density Electrodes, Xin-Ping Ai, Han-Xi Yang Aug 2010

Multi-Electron Redox Materials For High Energy Density Electrodes, Xin-Ping Ai, Han-Xi Yang

Journal of Electrochemistry

Various new energy technologies being developed require electrochemical energy batteries to have a real breakthrough in energy density and rate capability,which imposes a great challenge for electrochemists and materials chemists. Multi-electron redox reactions seem to open a promising avenue to create new batteries with dramatically enhanced energy densities. This paper describes simply our research works on the multi-electron redox systems,including metal boride anode,lithium alloying compounds and electrochemical conversion materials, and also discusses the problems hindering these systems for battery applications.


Comparative Study Of Nanoporous Pt,Ptru And Ptruir Catalysts Using Electrochemical Ftir Spectroscopy, M. Amussen Robert, Holt-Hindle Peter, Nigro Samantha, Chen Aicheng Aug 2010

Comparative Study Of Nanoporous Pt,Ptru And Ptruir Catalysts Using Electrochemical Ftir Spectroscopy, M. Amussen Robert, Holt-Hindle Peter, Nigro Samantha, Chen Aicheng

Journal of Electrochemistry

In recent years much effort has been put towards developing efficient Pt-based electrocatalysts for applications in fuel cells. With the rising cost of precious metals such as Pt,the need to enhance the activity and to decrease the load of catalysts is prominent. Herein we report on the synthesis and comparative study of nanoporous Pt,PtRu and PtRuIr electrocatalysts. The nanoporous electrodes were fabricated using a hydrothermal method and characterized by scanning electron microscopy (SEM) ,energy dispersive spectroscopy (EDS) ,X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) . The electrocatalytic activity of the fabricated nanopo- rous materials was evaluated using both CO …


Electrochemical Surface-Enhanced Raman Spectroscopy—Current Status And Perspective, Bin Ren, Jian-Feng Li, Yi-Fan Huang, Zhi-Cong Zeng, Zhong-Qun Tian Aug 2010

Electrochemical Surface-Enhanced Raman Spectroscopy—Current Status And Perspective, Bin Ren, Jian-Feng Li, Yi-Fan Huang, Zhi-Cong Zeng, Zhong-Qun Tian

Journal of Electrochemistry

Electrochemical interface is a very important interface closely related to various energy and life processes. Surface-enhanced Raman scattering was widely used in electrochemistry soon after its discovery to understand the surface bonding,configuration,and orientation of the surface species. In recent 10 years,the fast development of nanoscience and nanotechnology has offered SERS with abundant substrates and characterization methods,which has allowed impressive development of electrochemical SERS. This articles will follow the time line to make systematically overview of SERS on Au and Ag,thin-layer transition-metal SERS,pure transition metal SERS,core-shell SERS and those methods for studying single crystal surfaces,including gap-mode SERS, TERS and SHINERS. Emphasis …


A High Performance Sulfur/Carbon Xerogel Composite In Lithium Sulfur Battery Application, Chong Wang, Jia-Jia Chen, Qiu-Jie She, Qian Zhang, Yi-Ning Shi, Ming-Sen Zheng, Quan-Feng Dong May 2010

A High Performance Sulfur/Carbon Xerogel Composite In Lithium Sulfur Battery Application, Chong Wang, Jia-Jia Chen, Qiu-Jie She, Qian Zhang, Yi-Ning Shi, Ming-Sen Zheng, Quan-Feng Dong

Journal of Electrochemistry

Sulfur/carbon composite was synthesized by the thermal method with the carbon xerogel as the conductive framework. The property of composite was characterd by XRD and SEM. It shown that the composite with the particle size below 10 μm had the same morphology as the carbon xerogel and the sulfur was absorbed in the pores in non-crystalline. The discharge capacity of the composites were 1311 mAh/g and 1107. 1 mAh/g at 0. 1C and 0. 2 C rates,respetively. And a retention capacity was about 800 mAh/g after 30 cylcyes.


Measurement And Wavelet Analysis Of The Electrochemical Noise Of Rebar Steel In Simulated Concrete Pore Solution, Rong-Gang Hu, Chen-Qing Ye, Shi-Gang Dong, Chang-Jian Lin May 2010

Measurement And Wavelet Analysis Of The Electrochemical Noise Of Rebar Steel In Simulated Concrete Pore Solution, Rong-Gang Hu, Chen-Qing Ye, Shi-Gang Dong, Chang-Jian Lin

Journal of Electrochemistry

Electrochemical noise ( ECN) measurement can provide information about both corrosion rate and corrosion type while inflicting no perturbation on the studied system. The ECN data of steel rebar in SPS with different amount of Cl-were collected and treated by discrete wavelet transformation to evaluate the contribution from transients in different frequency in the overall signals. Energy distribution plot( EDP) indicated in SPS with 0. 0001 mol/L NaCl,the transients with time constant between 16 ~ 32 s were found to be predominant over other processes; while in SPS with higher Cl-concentration,the trend toward active corrosion became the main process. It …


High-Rate Cyclic Properties Of Hollow Carbon Hemisphere As Anode Materials For Lithium Ion Batteries, Guang-Hui Zhang, Zao-Xue Yan, Hong-Li Zou, Pei-Kang Shen May 2010

High-Rate Cyclic Properties Of Hollow Carbon Hemisphere As Anode Materials For Lithium Ion Batteries, Guang-Hui Zhang, Zao-Xue Yan, Hong-Li Zou, Pei-Kang Shen

Journal of Electrochemistry

High surface area hollow carbon hemispheres ( HCHs) covered with hard carbon layers have been synthesized by using polystyrene spheres ( PSs) as templates under hydrothermal method combined with the intermittent microwave heating ( IMH) method. The morphologies of the materials are characterized by SEM and TEM. The electrochemical properties of the HCHs are tested. Comparing with graphite and mesocarbon microbeads ( MCMB) ,the HCHs show higher capacity and excellent cyclic life performance.


Research On Electrochemical Performance Of Lithium-Ion Battery Cathode Material Lini_(1/3)Co_(1/3)Mn_(1/3)O_2 In Aqueous Lino_3 Solution, Jun Zheng, Xin Jia, Chong Wang, Ming-Sen Zheng, Quan-Feng Dong May 2010

Research On Electrochemical Performance Of Lithium-Ion Battery Cathode Material Lini_(1/3)Co_(1/3)Mn_(1/3)O_2 In Aqueous Lino_3 Solution, Jun Zheng, Xin Jia, Chong Wang, Ming-Sen Zheng, Quan-Feng Dong

Journal of Electrochemistry

The cathode material of LiNi1/3Co1/3Mn1/3O2 synthesized by sol-gel method shows excellent high rate performance,and high output power density during discharge process. A well-ordered layered α-NaFeO2 structure was confirmed by XRD and a primary particle size of about 500 nm was indicated by SEM. Galvanostatic charge-discharge test indicates that LiNi1/3Co1/3Mn1/3O2 in 2 mol·L-1 LiNO3 aqueous solution with pH 12 reached a ca-pacity of 147 mAh/g while charged and discharged at 2C. The capacities were 64、33、16 mAh/g with 80C ( 14. 4 A/g) 、150C( 27 A/g) and 220C ( 39. 6 A/g) charge/discharge rates,while the power densities of the battery were 2574 …


Preparation And Application Of Ti/Ceo_2-F-Pbo_2 Electrode In Electrochemical Degradation Of Organics, Xun-Hua Wang, Tie-Ming Zhang, Shao-Ping Tong, Chun-An Ma May 2010

Preparation And Application Of Ti/Ceo_2-F-Pbo_2 Electrode In Electrochemical Degradation Of Organics, Xun-Hua Wang, Tie-Ming Zhang, Shao-Ping Tong, Chun-An Ma

Journal of Electrochemistry

The CeO2-modified PbO2 on Ti plate ( Ti/CeO2-F-PbO2) was prepared by electrodeposition. The SEM and XRD analyses indicated that the CeO2 particle could be beuniformly co-deposited in the film of PbO2. The results of electrochemical test showed that the Ti/CeO2-F-PbO2 anode had higher potential ( 1. 83 V. vs. SCE) for oxygen evolution ( OE) than the Ti/F-PbO2 anode ( 1. 78 V,vs. SCE) . The degradation of 4-chlorophenol was carried out to test electrocatalytic performance of this novel electrode,which indicated that Ti/CeO2-F-PbO2 anode had high COD removal rate and instantaneous current efficiencies ( ICE) .


Hydrogen Evolution Reaction Activtity Of Ni-Ru-Ir Oxide Cathode Coating, Yin-Hui Fu, Xue-Ming Li, Wu-Lin Li, Jun Zhang May 2010

Hydrogen Evolution Reaction Activtity Of Ni-Ru-Ir Oxide Cathode Coating, Yin-Hui Fu, Xue-Ming Li, Wu-Lin Li, Jun Zhang

Journal of Electrochemistry

The Ni-Ru-Ir electrode coating was fabricated by thermal decomposition and oxidation. Electrochemical properties of Ni-Ru-Ir electrode coating and pure nickel cathode in the 30% NaOH solutions at 90 ℃( conditions of the industrial electrolysis) ,have been investigated by cyclic voltammetry,Tafel curves and chronoamperometry. The results show that the Ni-Ru-Ir oxide electrode coating exhibited high catalytic activity. At the current density of 0. 3 A·cm-2,the lowest hydrogen evolution overpotential of Ni-Ru-Ir oxide electrode coating was about 300 mV lower than Ni. The roughness and excharge current density of Ni-Ru-Ir electrode coating were 32 and 4 times,respectively,larger than those of pure nickel …


Study On Electrocatalytic Properties For Oxygen Evolution Of Ti/Iro_2-Ta_2o_5 Anodes With Different Ir Contents, Yong-Lei Xin, Li-Kun Xu, Jun-Tao Wang May 2010

Study On Electrocatalytic Properties For Oxygen Evolution Of Ti/Iro_2-Ta_2o_5 Anodes With Different Ir Contents, Yong-Lei Xin, Li-Kun Xu, Jun-Tao Wang

Journal of Electrochemistry

The anodes of Ti/IrO2-Ta2O5 were prepared by Pechini method. The effects of coating loading on the surface morphology and electrochemical properties of the anodes were characterized by scanning electron microscope ( SEM) ,energy dispersive X-ray detector ( EDX) ,potentiodynamic polarization,cyclic voltammetry and accelerated life test. The results indicate that with the increase of the coating loading,the oxide anode presents evident IrO2 crystallite segregation,and cracks become narrow and shallow. Moreover,it has larger electrochemically active surface area,better electrocatalytic activity for oxygen evolution and higher stability. It was observed that for an iridium content of 1. 98 ~ 9. 08 g/m2 the service …


Synthesis And Electrochemical Properties Of Li_3v_2(Po_4)_3/C Cathode Materials For Lithium Ion Battery, Li-Ying Liu, Hai-Yan Zhang, Lian Chen, Yu-Chun Zhai May 2010

Synthesis And Electrochemical Properties Of Li_3v_2(Po_4)_3/C Cathode Materials For Lithium Ion Battery, Li-Ying Liu, Hai-Yan Zhang, Lian Chen, Yu-Chun Zhai

Journal of Electrochemistry

Cathode material Li3V2( PO4) 3 /C for Lithium-ion battery was synthesized by combination of ball milling and baking. Physical and electrochemical performances of as-prepared materials were characterized through XRD,EIS and galvanostatic cell cycling. The results show that the products were monoclinic Li3 V2 ( PO4) 3 with well-developed crystal structure. At 0. 1C,0. 25C and 0. 5C,the initial discharge capacities were 150. 6,134. 1 and 107. 1 mAh·g-1 ,respectively. Capacity retention rates were 87. 3% after 130 cycles at 0. 25C and 87. 2% after 105 cycles at 0. 5C. Charge-discharge efficiencies were all above 80% and the average discharge …


Electrochemical Behavior Of Kaempferide Interaction With Protein, Li-Qing Lin, Xin-Hua Lin, Jing-Hua Chen, Li-Ying Huang, Yin-Huan Liu, Guang-Wen Li May 2010

Electrochemical Behavior Of Kaempferide Interaction With Protein, Li-Qing Lin, Xin-Hua Lin, Jing-Hua Chen, Li-Ying Huang, Yin-Huan Liu, Guang-Wen Li

Journal of Electrochemistry

The electrochemical behavior of kaempferide at activated GCE and the interaction of kaempferide with human serum albumin( HSA) were investigated by cyclic voltammetry. A differential pulse voltammetric method has been proposed for the determination of the HSA with kaempferide. In pH 4. 5 phosphate buffer solutions ( PBS) kaempferide can react with HSA to form an electrochemically non-active supermolecular complex at activated GCE,resulting in the decrease of oxidation peak ( at 0. 468 V) without the change of peak potential. The decrease of the peak current is proportional to HSA concentration in the range of 0. 05 ~ 0. 25 …


Nano-Sized Au On Nickel Foam As Cathode Of Alkaline Al-H_2o_2 Semi Fuel Cell, Shu-Li Chen, Bang-An Lu, Yao Liu, Gui-Ling Wang, Dian-Xue Cao May 2010

Nano-Sized Au On Nickel Foam As Cathode Of Alkaline Al-H_2o_2 Semi Fuel Cell, Shu-Li Chen, Bang-An Lu, Yao Liu, Gui-Ling Wang, Dian-Xue Cao

Journal of Electrochemistry

Nano-sized Au particles were deposited on a nickel foam substrate by a fast spontaneous deposition method using AuCl3 as the source of Au. The effects of AuCl3 concentration and deposition time on the size and distribution of Au particles,and the performance of the obtained Au/Ni electrode as the cathode of Al-H2O2 semi fuel cell were investigated. It was found that after the nickel foam was immersed in a 2 mmol·L-1 AuCl3 solution for 60 s,Au particles with diameters smaller than 100 nm were deposited on its surfaces and cover the surface completely. The Al-H2O2 semi fuel cell with Au/Ni cathode …


Prerapation And Supercapacitor Property Of Mesoporous Carbon Nanofibers, Yong-Wen Wang, Ming-Bo Zheng, Jian Cao, Jie-Ming Cao, Guang-Bin Ji, Jie Tao May 2010

Prerapation And Supercapacitor Property Of Mesoporous Carbon Nanofibers, Yong-Wen Wang, Ming-Bo Zheng, Jian Cao, Jie-Ming Cao, Guang-Bin Ji, Jie Tao

Journal of Electrochemistry

Two different mesoporous carbon nanofibers with large mesopore or core-shell structure were prepared by using the resol/F127 mixture to fill the AAO template. The morphology and structural parameters of the samples were characterized by SEM,TEM,and N2 adsorption-desorption analysis. The supercapacitive behaviors of the electrodes were tested by cyclic voltammetry and galvanostatic charge-discharge. The results show that the specific capacitances of mesoporous carbon nanofibers increased obviously and the fine supercapacitive performances were achieved at high scan rate or large current density.


Optimization Of Membrane Electrode Assembly In Air-Breathing Direct Methanol Fuel Cell, Liang Ma, Wei-Wei Cai, Jing Zhang, Liang Liang, Jian-Hui Liao, Chang-Peng Liu, Wei Xing May 2010

Optimization Of Membrane Electrode Assembly In Air-Breathing Direct Methanol Fuel Cell, Liang Ma, Wei-Wei Cai, Jing Zhang, Liang Liang, Jian-Hui Liao, Chang-Peng Liu, Wei Xing

Journal of Electrochemistry

The structure and performance of MEA were optimized by tailoring the catalyst layer,cathodic microporous layer ( MPL) ,anodic MPL and membrane,with the considerations of unique characteristics of airbreathing direct methanol fuel cell ( DMFC) such as methanol crossover and cathode flooding. It was found that high catalyst loading could suppress the methanol crossover effectively,but too high catalyst loading can lead to high mass transport resistance. Hydrophobic anodic MPL with 30% ( by mass) PTFE could facilitate the CO2 bubble detachment,which decreased the methanol concentration gradient and suppressed the methanol crossover accordingly. When Nafion 115 was used as membrane,methanol crossover was …


Preparation And Electrochemical Performance Of Three-Dimensional Porous Snco Alloy Electrode, Lian-Jie Xue, Ling Huang, Fu-Sheng Ke, Guo-Zhen Wei, Xiao-Mei Zheng, Jun-Tao Li, Xiao-Yong Fan, Shi-Gang Sun May 2010

Preparation And Electrochemical Performance Of Three-Dimensional Porous Snco Alloy Electrode, Lian-Jie Xue, Ling Huang, Fu-Sheng Ke, Guo-Zhen Wei, Xiao-Mei Zheng, Jun-Tao Li, Xiao-Yong Fan, Shi-Gang Sun

Journal of Electrochemistry

Three-dimensional porous Cu film was prepared by electroless plating,and used as a current collector for preparation of three-dimensional structured SnCo alloy electrode,which was mainly prepared by an electrodeposition method,and composed of pure Sn and CoSn2 phases. Electrochemical experimental results show that three-dimensional structured SnCo alloy electrode exhibits much better cycleability than planar SnCo alloy electrode,with first discharge capacity and charge capacity of 636. 3 and 528. 7 mAh·g-1,respectively. After 70th cycling,capacity retention is 83. 1% with 529. 5 mAh·g-1. The lithiation process during first discharge was investigated by electrochemical impedance spectroscopy


Fabrication Of Electrochemically Activated Glassy Carbon/Bismuth Film Electrodes For Sensitive Analysis Of Pb~(2+) And Cd~(2+), Kang Shi, Wen-Jing Wang, Kun Hu May 2010

Fabrication Of Electrochemically Activated Glassy Carbon/Bismuth Film Electrodes For Sensitive Analysis Of Pb~(2+) And Cd~(2+), Kang Shi, Wen-Jing Wang, Kun Hu

Journal of Electrochemistry

The application of electrochemically activated glassy carbon ( GC) in the in-situ preparing of bismuth film electrodes ( BiFEs) to analyze Pb2 + and Cd2 + was investigated. The glassy carbon electrodes were electrochemically activated by either potentiostic or cyclic polarization in 1 mol·L-1 NaOH solution. Experimental results show that employment of HCl solution as the analytical solution not only can reproducibly renew the electrochemically activated GC electrode surface with an electrochemical clear procedure,but also can greatly enhance the sensitivity of BiFes method for analysis of Pb2 + and Cd2 + . The test range thus was extended to the …


Synthesis Of Cosalen Composite In Apo-5 And Its Electrocatalytic Behaviour For Reaction Of Dioxygen Reduction, Rong Zhang, Li-Hua Tang, Bin-Bin Fan, Jing-Hong Ma, Rui-Feng Li May 2010

Synthesis Of Cosalen Composite In Apo-5 And Its Electrocatalytic Behaviour For Reaction Of Dioxygen Reduction, Rong Zhang, Li-Hua Tang, Bin-Bin Fan, Jing-Hong Ma, Rui-Feng Li

Journal of Electrochemistry

CoAPO-5 molecular sieve was hydrothermally synthesized. The Cobalt ions in CoAPO-5 were coordinated with the SALEN ligend diffusing into the channels of the molecular sieve to form CoSALEN complexes. The electrochemical behaviors and electrocatalysis for dioxygen reduction of the CoSALEN complex immobilized in APO-5 modified glassy carbon electrodes ( GCEs) have been investigated by cyclic voltammetry( CV) and chronoamperometry ( CA) in differrent pH aqueous solutions. The results showed that the PS/CoSALEN/APO-5 /GC modified electrode is of the high electrocatalytic activity towards dioxygen reduction in pH 6. 86 buffer solution with a reduced overpotential of 447 mV lower than bare …


Electrocatalytic Oxidation Of Hcooh At Au_(Core)-Pd_(Shell)-Pt_(Cluster) Nanocubes, Qing-Ning Jiang, Huan Li, Ning Yang, Ping-Ping Fang, Feng-Ru Fan, Zhong-Qun Tian May 2010

Electrocatalytic Oxidation Of Hcooh At Au_(Core)-Pd_(Shell)-Pt_(Cluster) Nanocubes, Qing-Ning Jiang, Huan Li, Ning Yang, Ping-Ping Fang, Feng-Ru Fan, Zhong-Qun Tian

Journal of Electrochemistry

Gold nanocubes were synthesized by a two-step seed-mediated growth method. The Aucore-Pdshell and Aucore-Pdshell-Ptcluster nanocubes with controllable shell thickness of Pd and cluster coverage of Pt were synthesized by simply changing the amount ratio of H2PdCl4 or H2PtCl6. The samples were characterized by scanning electron microscope ( SEM) 、transmission electron microscopc ( TEM) and cyclic voltammetry ( CV) . CV was then used to make a systematic study on the dependence of the electrocatalytic properties on the shell thickness of Aucore-Pdshell and Pt coverage of Aucore-Pdshell-Ptcluster,respectively. The results indicated that the Au nanocube core coated by three atomic layers of …


Nano/Micro-Structured Electrode Materials For Lithium-Ion Batteries, Yu-Guo Guo, Zhong-Li Wang, Xing-Long Wu, Wei-Ming Zhang, Li-Jun Wan May 2010

Nano/Micro-Structured Electrode Materials For Lithium-Ion Batteries, Yu-Guo Guo, Zhong-Li Wang, Xing-Long Wu, Wei-Ming Zhang, Li-Jun Wan

Journal of Electrochemistry

Nanostructured materials are currently of interest as high performance anodes and cathodes for rechargeable lithium-ion batteries because of their novel nano-size effects and significantly enhanced kinetics. This review paper describes some recent developments in this field,addressing the size effects,morphology effects,as well as the functions of carbon coating layers toward lithium storage. Several"kinetically stabilized"nano/microstructured electrode materials and high-rate electrode materials with mixed-conducting networks based on the work of the authors are highlighted for illustration.


Failure Reaction Mechanism Of Internal Short-Circuit For Lithium-Ion Batteries, He Li, Shen-Jun Yu, Zhi-Kui Chen, Guang-Chuan Liang May 2010

Failure Reaction Mechanism Of Internal Short-Circuit For Lithium-Ion Batteries, He Li, Shen-Jun Yu, Zhi-Kui Chen, Guang-Chuan Liang

Journal of Electrochemistry

In this work,the battery impact testing machine has been used to study the failure progress of internal short-circuit ( ISC) for lithium ion batteries. The reaction mechanisms between cathode/anode and electrolyte in the battery at different temperatures were characterized by differential scanning calorimetry ( DSC) ,gas chromatography/mass spectrometry ( GC/MS) and X-ray diffraction ( XRD) . The experimental results show that the ISC failure of the battery was mainly due to the reaction between cathode Li0.5CoO2 and electrolyte. The decomposition and oxygen evolution reactions of cathode occurred when the temperature reached a certain value. At the same time a fierce …


Influence Of Ions Dimension On The Electric Field Activation Of Micro-Crystallite Carbon, Gang-Wei Sun, Wen-Hua Song, Guo Cheng, Wen-Ming Qiao, Li-Cheng Ling May 2010

Influence Of Ions Dimension On The Electric Field Activation Of Micro-Crystallite Carbon, Gang-Wei Sun, Wen-Hua Song, Guo Cheng, Wen-Ming Qiao, Li-Cheng Ling

Journal of Electrochemistry

Micro-crystallite carbon ( CC) was synthesized by KOH activation of carbonized petroleum coke precursors. The porous properties structure and crystallite structure were characterized by N2 adsorption-desorption, X-ray diffraction ( XRD) measurements. The capacitive behavior of CC was investigated in the electrolyte of Et4NBF4 /PC,Et4NBF4 /AN,Bu4NBF4 /PC and Bu4NBF4 /AN,respectively. Results showed that the lower potential of electric field activation ( EFA) was obtained in the solvent of AN than in PC,which was ascribed to the fact that smaller solvated ions dimension in AN facilitating the intercalation of the solvated ions into micro-crystallite interlayer. The extent of EFA was more remarkable …