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Articles 601 - 630 of 860

Full-Text Articles in Physical Chemistry

Electricity Generation In Microbial Fuel Cells Catalyzed By Mixed Culture And Pure Culture, Chen-Dong Shuang, En-Ren Zhang, Guo-Wang Diao, Fang-Fang Fan, Jie Yuan Aug 2008

Electricity Generation In Microbial Fuel Cells Catalyzed By Mixed Culture And Pure Culture, Chen-Dong Shuang, En-Ren Zhang, Guo-Wang Diao, Fang-Fang Fan, Jie Yuan

Journal of Electrochemistry

Microbial fuel cells(MFCs) were constructed by inoculating fresh sedimentary microorganisms.Effect of phenol on performance of MFCs was investigated.The results showed that the generation of electrical current was induced by bacteria attached on the surface of the anode.Presence of phenol reduced the rate of glucose consumption and extended the duration of electricity generation with the same addition of glucose.In addition,the electricity generation by a single strain(belonging to pseudomonas species) separated from the sedimentary MFC was also investigated.The experimental results indicated that the presence of metabolic intermediates which exhibited electrochemical activity was necessary for the electricity production.Analysis of GC-MS showed that the …

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Electrocatalytic Performance Of Carbon Supported Au-Ir Catalyst As Cathodic Catalyst In Direct Formic Acid Fuel Cell, Wei Chen, Ya-Wen Tang, Tain-Hong Lu Aug 2008

Electrocatalytic Performance Of Carbon Supported Au-Ir Catalyst As Cathodic Catalyst In Direct Formic Acid Fuel Cell, Wei Chen, Ya-Wen Tang, Tain-Hong Lu

Journal of Electrochemistry

In this paper,it is reported for the first time that the electrocatalytic activities of the carbon supported Au(Au/C),carbon supported Ir(Ir/C) and the carbon supported Au-Ir(Au-Ir/C) catalysts prepared in the aqueous solution with tetrahydrofuran(THF) for the oxidation of formic acid and for the oxygen reduction were compared.It was found that all three catalysts showed no electrocatalytic activity for the oxidation of formic acid,but the electrocatalytic activity of the Au-Ir/C catalyst for oxygen reduction was much better than those of Au/C and Ir/C.Thus,the Au-Ir/C catalyst is suitable to be used as the cathodic catalyst in Direct formic acid fuel cell(DFAFC).

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The Effect Of Ru: Sn On Properties Of Ru-Ir-Sn Oxide Anode Coatings, Lei Ji, Jun-Tao Wang, Wen-Bin Liu, Li-Kun Xu, Gui-Lin Xue Aug 2008

The Effect Of Ru: Sn On Properties Of Ru-Ir-Sn Oxide Anode Coatings, Lei Ji, Jun-Tao Wang, Wen-Bin Liu, Li-Kun Xu, Gui-Lin Xue

Journal of Electrochemistry

The anode coatings of Ru-Ir-Sn oxide with different Ru/Sn ratios were prepared by sol-gel method.The influences of Ru/Sn ratio on properties of anode coatings were studied by scanning electron microscope(SEM),energy dispersive X-ray detector(EDX),X-ray diffraction(XRD).The potential of chlorine evolution,current efficiency,accelerated life,cyclic vohammetry and electrochemical impedance spectroscopy(EIS) tests were carried out.The results showed that there was an obvious effect of Ru/Sn ratio on the morphology of the coatings.The cyclic voltammogram,double layer capacitances and accelerated life of anode coatings had a tendency to fall down firstly then increased as the Ru% increased,the current effency and potential of chlorine evolution had a tendency to …

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Hydrolysis Of Sodium Borohydride By Ru-Ni Foam Catalyst, Jie Cheng, Feng Ye, Tong-Tao Wang, Jing-Jing Li, Yong-Liang Wang, Xin-Dong Wang Aug 2008

Hydrolysis Of Sodium Borohydride By Ru-Ni Foam Catalyst, Jie Cheng, Feng Ye, Tong-Tao Wang, Jing-Jing Li, Yong-Liang Wang, Xin-Dong Wang

Journal of Electrochemistry

This paper presented a method of hydrogen generation from sodium borohydride solution for fuel cells.The Ru-Ni foam catalyst which was prepared by chemical plating showed strong activity and stability.The pretreatment of Ni foam before chemical plating was very important for the catalyst's strong activity and stability.This easy-to-prepared catalyst exhibited a good activity after being used several times.The effects of NaBH4 concentration,temperature and used times on the hydrogen generation rate were investigated.The results showed that the rate was remarkablely increased with the temperature rising and the rate increased more than ten times when the temperature of reaction rised from 15 …

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Design And Fabrication Of The High Efficient Platinum-Nanoporous Gold Catalysts, Zhao-Na Liu, Jin-Tao Zhang, Fang Tian, Peng-Peng Liu, Hou-Yi Ma, Yi Ding Aug 2008

Design And Fabrication Of The High Efficient Platinum-Nanoporous Gold Catalysts, Zhao-Na Liu, Jin-Tao Zhang, Fang Tian, Peng-Peng Liu, Hou-Yi Ma, Yi Ding

Journal of Electrochemistry

The nanoporous gold(NPG) electrodes with uniform pore sizes and ligaments were prepared by using a simple dealloying method.The as-prepared NPG showed high catalytic activity towards the oxidation of formic acid and formaldehyde.After tiny amount of platinum was deposited onto the NPG substrate,not only the structure stability of NPG was greatly improved,but also the Pt-Au bimetallic catalysts displayed the better catalytic activity and the stronger poison resistance towards the electrooxidation of small organic molecules than the bulk platinum due to synergistic effect between Au and Pt compositions.

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Study On Electrocatalytic Oxidation Of Salbutamol At Carbon Nanotubes Modified Electrode, Ying-Liang Wei, Lu-Ping Zhang, Chen Shao, Hui Feng, Xian-Li Li Aug 2008

Study On Electrocatalytic Oxidation Of Salbutamol At Carbon Nanotubes Modified Electrode, Ying-Liang Wei, Lu-Ping Zhang, Chen Shao, Hui Feng, Xian-Li Li

Journal of Electrochemistry

The multi-wall carbon nanotubes(MWNT) were dispersed successfully into water in the presence of dihexadecyl hydrogen phosphate(DHP) and a stable well-distributed suspension.A was formed sensor based on the multi-carbon nanotubes film coated glassy carbon electrode was developed.The electrochemical response of salbutamol was studied by square wave voltammetry.The oxidation peak potential of salbutamol at the modified electrode was observed at 0.604 V,which shifted about 40 mV negatively.The peak current increased 4.5 folds,in contrast to that at a bare electrode.Under optimal measurement conditions,there was a good linear relationship between the peak current(Ipa) and salbutamol concentration(C) in the range from 8.3 × 1 0 …

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A Study Of Pd-Ir On Nickel Foam Cathode For Aluminum-Hydrogen Peroxide Semi-Fuel Cells, Ding-Wang Zhu, Dan-Dan Chen, Bi-Jin Li, Gui-Ling Wang, Dian-Xue Cao Aug 2008

A Study Of Pd-Ir On Nickel Foam Cathode For Aluminum-Hydrogen Peroxide Semi-Fuel Cells, Ding-Wang Zhu, Dan-Dan Chen, Bi-Jin Li, Gui-Ling Wang, Dian-Xue Cao

Journal of Electrochemistry

The Pd-Ir/Ni electrodes were prepared by electrodeposition of Pd and Ir on the porous nickel foam surface.The structure,composition and state of the Pd-Ir catalyst were analyzed using SEM and XPS.The catalytic performance of Pd-Ir/Ni for H2O2 electroveduction at different concentrations of H2O2 were investigated.A limiting current density of 318 mA/cm2 was obtained with 0.4 mol/L H2O2.The aluminum-hydrogen peroxide semi-fuel cells using different aluminum alloys as anode and Pd-Ir/Ni as cathode were assembled and tested.It was found that the fuel cell with aluminum-manganese alloy anode demonstrated a maximum power density …

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Electrocatalytic Oxidation Of Salicylic Acid At Novel Gold Nanoparticle-Modified Glassy Carbon Electrode, Yan-Ping Cui, Chang-Zhu Yang, Jian Huang, Wen-Hong Pu, Jing-Dong Zhang Aug 2008

Electrocatalytic Oxidation Of Salicylic Acid At Novel Gold Nanoparticle-Modified Glassy Carbon Electrode, Yan-Ping Cui, Chang-Zhu Yang, Jian Huang, Wen-Hong Pu, Jing-Dong Zhang

Journal of Electrochemistry

A gold nano-particles modified glassy carbon electrode(GNP/GCE) was prepared by the"seed-mediated gold nano-particles growth method".Field emission scanning electron microscopy,ultraviolet-visible(UV-vis) spectroscopy analysis and electroalaylsis were employed to study the morphology and electrochemical performances.The resulting electrode showed excellent electro-catalytic activity toward the oxidation of salicylic acid and the response sensitivity was 1.8 fold than that obtained on GCE.Good linear relationship was obtained between response current and salicylic acid concentration in the range of 5.0 × 10-7 ~8.0 × 10-5 mol/L,which could be used in the detection of trace salicylic acid.

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Synthesis And Electrochemical Characteristics Of Li[Li(0.167)Mn(0.583)Ni(0.25)]O2 Cathode Material, Ling-Yan Yu, Wei-Hua Qiu, Fang Lian, Jia-Yuan Huang, Xao-Li Kang, Wei Liu May 2008

Synthesis And Electrochemical Characteristics Of Li[Li(0.167)Mn(0.583)Ni(0.25)]O2 Cathode Material, Ling-Yan Yu, Wei-Hua Qiu, Fang Lian, Jia-Yuan Huang, Xao-Li Kang, Wei Liu

Journal of Electrochemistry

The cathode material of Li[Li0.167Mn0.583Ni0.25]O2 was synthesized by low-heat solid state reaction.The results of XRD and FESEM indicated that the powders of the material were well crystallized with the uniform diameters ranging from 60 nm to 100 nm and could be indexed as α-NaFeO2 structure(R3-m space). Galvanostatic charge-discharge tests showed that the electrode delivered the capacity of about 120 mAh/g with good cyclability when cycled in 2.5~4.4V at 0.5C. When the cut-off potential was set up to 4.6V, the cathode delivered much larger capacities with the maximum of 234 mAh/g. It was …

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Performance Of Air Breathing Direct Methanol Fuel Cell Under Ambient Condition, Jian-Guo Liu, Jun Gu, Tao Yu, Zhi-Gang Zou, T.S Zhao May 2008

Performance Of Air Breathing Direct Methanol Fuel Cell Under Ambient Condition, Jian-Guo Liu, Jun Gu, Tao Yu, Zhi-Gang Zou, T.S Zhao

Journal of Electrochemistry

The performance of the passive DMFC was systematically investigated under an ambient condition by simulating a wide range of temperature and humidity in a high-quality environmentally controlled room.The results indicated that the performance of the passive DMFC was nearly independent of ambient humidity from 30% to 90% RH and water produced in the cathode was expelled mostly from the cell in a liquid state.Compared with the humidity,the ambient temperature has a significant effect on the performance of the passive DMFC.The power density of 30 mW·cm-2 were obtained at 40℃,while only 10 mW·cm-2 at 10 ℃.

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Electroless-Deposition Synthesis Of Highly Active Ptru/C And Ptrusn/C As Anode Catalysts For Defc, Jing Zhu, Yi Su, Hua Ma, Fang-Yi Cheng, Zhan-Liang Tao, Jing Liang, Jun Chen May 2008

Electroless-Deposition Synthesis Of Highly Active Ptru/C And Ptrusn/C As Anode Catalysts For Defc, Jing Zhu, Yi Su, Hua Ma, Fang-Yi Cheng, Zhan-Liang Tao, Jing Liang, Jun Chen

Journal of Electrochemistry

In this paper,the preparation,characterization,and ethanol electrocatalytic oxidation of Pt0.5Ru0.5/C and Pt0.5Ru0.15Sn0.35/C electrocatalysts were reported.The electroless-deposition with sensitization-activation pretreatment was applied to prepare Pt0.5Ru0.5/C and Pt0.5Ru0.15Sn0.35/C electrocatalysts. The XRD and TEM analyses showed that the as-prepared catalysts were composed of well-dispersed PtRu or PtRuSn nanoparticles with an average particle size of about 3 nm.The electrochemical measurements demonstrated that the as-prepared Pt0.5Ru0.5/C and Pt0.5Ru0.15Sn0.35/C catalysts exhibited much enhanced peak current density for …

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Electrocatalytic Performance Of Pt/C And Pt/Wo3/C Catalysts For Methanol Oxidation, Yuan-Yuan Chu, Bing Wu, Ya-Wen Tang, Tian-Hong Lu, Ying Gao May 2008

Electrocatalytic Performance Of Pt/C And Pt/Wo3/C Catalysts For Methanol Oxidation, Yuan-Yuan Chu, Bing Wu, Ya-Wen Tang, Tian-Hong Lu, Ying Gao

Journal of Electrochemistry

The catalysts of Carbon supported Pt(Pt/C) and carbon supported Pt/WO3(Pt/WO3/C) were prepared with liquid phase reduction method.It was found that the catalytic activity and stability of the Pt/WO3/C catalysts were increased with the addition of WO3.When the atomic ratio of Pt and W was 1∶1,the best electrocatalytic performance of the Pt/WO3/C catalyst for the methanol oxidation was obtained.This is attributed to the larger electrochemical surface area of Pt/WO3/C and the weeker adsorption of CO towards the catalyst.

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Synthesis Of Agv3O8 As High-Capacity Of Cathode Materials For Lithium Secondary Batteries Via A Soft Chemistry Technique, Xiao-Yu Cao, Tao Li, Ling-Ling Xie, Xiang-Yang Yan, Chi-Wei Wang May 2008

Synthesis Of Agv3O8 As High-Capacity Of Cathode Materials For Lithium Secondary Batteries Via A Soft Chemistry Technique, Xiao-Yu Cao, Tao Li, Ling-Ling Xie, Xiang-Yang Yan, Chi-Wei Wang

Journal of Electrochemistry

The layered cathode material of AgV3O8 has been prepared for the lithium secondary batteries via the soft chemistry technique. The so-synthesized powders were characterized by XRD(powder X-ray diffraction), SEM(scanning electron microscope) and LPSA(laser particle size analysis). The electrochemical property was investigated by the galvanostatic discharge-charge technique. The results indicated that the particale sizes of AgV3O8 prepared were small in the distribution of narrow range, which leads to high discharge capacity. Among them, the material synthesized at 400 ℃ displayed the first discharge capacity of 760.5 mAh/g.

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The Effect Of Annealed Temperature On Properties Of Ru-Ir-Sn Oxide Anode Coatings, Lei Ji, Jun-Tao Wang, Li-Kun Xu, Wen-Bin Liu, Gui-Lin Xue May 2008

The Effect Of Annealed Temperature On Properties Of Ru-Ir-Sn Oxide Anode Coatings, Lei Ji, Jun-Tao Wang, Li-Kun Xu, Wen-Bin Liu, Gui-Lin Xue

Journal of Electrochemistry

The anode coatings of Ru-Ir-Sn oxide were prepared by sol-gel method with different annealed temperatures.The influences of annealed temperature in properties of anode coatings were characterized by scanning electron microscope(SEM),energy dispersive X-ray detector(EDX),X-ray diffraction(XRD),potential of chlorine evolution,accelerated life,cyclic voltammetry and electrochemical impedance spectroscopy(EIS) tests.The results showed that the annealed temperature affected the morphology of coatings,while the electric quantities of cyclic voltammetry and double layer capacitances of anode coatings had a tendency to fall down and the potential of chlorine evolution and accelerated life had a tendency to increase as the annealed temperature increased.

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Synthesis Of Adipic Acid From Cyclohexanol By Electrochemical Oxidation Using Cr2O72-/Cr3+ As Indirect Oxidant, Zhen-Hai Liang, Yu-Qing Cui, Hong-Yan Sun Feb 2008

Synthesis Of Adipic Acid From Cyclohexanol By Electrochemical Oxidation Using Cr2O72-/Cr3+ As Indirect Oxidant, Zhen-Hai Liang, Yu-Qing Cui, Hong-Yan Sun

Journal of Electrochemistry

Adipic acid was synthesized by electro-oxidation of cyclohexanol taking Cr2O72-/Cr3+ as indirect oxidant.The best technological conditions were optimized by orthogonal experiment.The optimum condition are as follows: the temperature is 35 ℃,ratio of crude material is n(cyclohexanol)∶n(Cr2O72-)=0.4∶1 and concentration of H2SO4 is 4 mol·L-1.Under these conditions,the yield of adipic acid can reach 70.29%.Moreover,The effects of concentration of Ag2SO4,(NH4)2SO4,H2SO4and current density on the formation of Cr2O72-were also …

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Mechanism Of The Cathode Reduction Of Ti(Ⅳ) In Molten Na3Alf6-Alf3, Hai-Bin Sun, Xiu-Rong Zuo, Zhi-Guo Zhong, Xue-Hui Hu Feb 2008

Mechanism Of The Cathode Reduction Of Ti(Ⅳ) In Molten Na3Alf6-Alf3, Hai-Bin Sun, Xiu-Rong Zuo, Zhi-Guo Zhong, Xue-Hui Hu

Journal of Electrochemistry

The mechanism of TiO2 electrode process has been investigated by cyclic voltammetry and chronopotentiometry on the tungsten filament in molten Na3AlF6-AlF3 salts at 990 ℃.The experimental results showed that electrochemical reduction of Ti(Ⅳ) precede were two steps,firstly Ti(Ⅳ) was reduced to Ti(Ⅱ),then Ti(Ⅱ) was reduced to Ti,namely: Ti(Ⅳ)→Ti(Ⅱ)→Ti.

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Effects Of Oxidation Methods On The Stability Of Coooh Conductive Network In Foam Nickel Electrodes, Xiao-Feng Li, Yan-Wei Wei, Hui-Chao Dong Feb 2008

Effects Of Oxidation Methods On The Stability Of Coooh Conductive Network In Foam Nickel Electrodes, Xiao-Feng Li, Yan-Wei Wei, Hui-Chao Dong

Journal of Electrochemistry

Two kinds of the cobalt oxyhydroxide conductive networks in foam nickel electrodes were prepared by different methods i.e.the electrochemical-oxidation(EO) and chemical-oxidation(CO) and which redox behaviors were studied by using cyclic voltammetry and X-ray diffraction measurements.The results show that the CoOOH(CO) has better redox reversibility than CoOOH(EO) and the structure of the former can be kept when nickel electrodes are subjected to a negative potential.Thus,98.7% capacity retention is demonstrated on nickel/metal-hydride batteries with CoOOH(CO) conductive network after being imposed over-discharge state storage;on the contrary,only 83.3% capacity retention is found on the batteries with CoOOH(EO) conductive network.

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The Influence Of The Sputtering Power On The Structural And Electrochemical Properties Of Tin Oxide Films, Min-Zhen Cai, Jie Song, Ming-Sen Zheng, Qi-Hui Wu, Sun-Tao Wu, Quan-Feng Dong Feb 2008

The Influence Of The Sputtering Power On The Structural And Electrochemical Properties Of Tin Oxide Films, Min-Zhen Cai, Jie Song, Ming-Sen Zheng, Qi-Hui Wu, Sun-Tao Wu, Quan-Feng Dong

Journal of Electrochemistry

Tin oxide films were deposited on silicon substrates at room temperature using the radio frequency(RF) magnetron sputtering with different sputtering power.The influence of sputtering power upon the crystal structure,surface morphology and electrochemical properties of tin oxide films were then investigated.The XRD and SEM results illustrate that the phase of tin oxide thin films changed from amorphous to crystalline and the grain size augments with the increase of the sputtering power.The constant current charge and discharge cycle tests imply that the initial irreversible capacity loss of Li/tin oxide batteries increase and which capacity decrease as the sputtering power increases.The sputtering power …

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Effect Of Au At Different States On Electrocatalytic Performance Of Pd Catalyst For Oxidation Of Formic Acid, Xin Wang, Ya-Wen Tang, Tian-Hong Lu Feb 2008

Effect Of Au At Different States On Electrocatalytic Performance Of Pd Catalyst For Oxidation Of Formic Acid, Xin Wang, Ya-Wen Tang, Tian-Hong Lu

Journal of Electrochemistry

Using liquid-reduction or complex-redution method,four catalysts,i.e,the Au/C,Pd/C,Pd-Au/C-T and Pd-Au/C-H were preparated and which electroanalytic activities and stabilities for the oxidation of formic acid were compares.It was found that the Au/C catalyst has no electrocatalytic activity,and the Pd/C catalyst possesses the good electrocatalytic performance for the oxidation of formic acid.The addition of Au into the Pd/C catalyst can increase the electrocatalytic activity and stability.Especially,the electrocatalytic activity and stability of the Pd-Au/C-T catalyst with the alloy of Pd and Au are better than that of the of the Pd-Au/C-H catalyst,in which,Pd and Au do not form the alloy.The investigation of its reason …

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Synthesis Of 2,2′-Dichlorohydrazobenzene Using An Ion Exchange Membrane, Chao Zhang, Pei-Jin Li Feb 2008

Synthesis Of 2,2′-Dichlorohydrazobenzene Using An Ion Exchange Membrane, Chao Zhang, Pei-Jin Li

Journal of Electrochemistry

Using an ion exchange membrane as a separator,the 2,2′-Dichlorohydrazobenzene is synthesized by the electrolytic reduction of o-chloronetrobenzene.The effects of electrode activation condition,current density,electrolyte temperature on electrolytic reduction are discussed.It was found that the optimum reaction temperature is 80 ℃.When the electrolyte concentration was 30% NaOH at the anode and 10% NaOH at the cathode,current density is 4.2A/dm2,the current efficiency reached 73% and yield is 83%.

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Emulsification And Dispersant Properties Of Sugar Ester Glycolipid In Water In Oil And Oil In Water Emulsion., Azrah Abdul Aziz Jan 2008

Emulsification And Dispersant Properties Of Sugar Ester Glycolipid In Water In Oil And Oil In Water Emulsion., Azrah Abdul Aziz

Student Works (2010-2019)

The influence of different dispersing agent on the rheological behaviors of paraffin oil-water emulsion with addition of TiO2 for uv-protect and moisturizing active ingredient was studied. While making creams with minimal structural defects and longer storage stability, it is important that preparation conditions be optimized. Settle volume properties, Zeta potential, effective diameter and settle volume of TiO2 suspension were studied in the presence of glycolipid (DDM and Carrageenan), nonionic (PEG 10,000 and Brij 35P) as well as anionic surfactants (sodium dodecyl sulfate, SDS). In the experiments, the higher concentration of dispersing agents shows higher settle volume percentage, higher zeta potential …

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Electrochemical Oxidization Of Herring Sperm Dna And Its Interaction With Histone, Juan Xu, Gui-Ping Huang, Hong Li, Wei Zhu Nov 2007

Electrochemical Oxidization Of Herring Sperm Dna And Its Interaction With Histone, Juan Xu, Gui-Ping Huang, Hong Li, Wei Zhu

Journal of Electrochemistry

The voltammetric behavior of herring sperm DNA at glassy carbon electrode and its interaction with histone have been investigated by using cyclic voltammetry,differential pulse voltammetry,and fluorescence measurement.In the potential range of 0.20 V to 1.25 V,it is found that an irreversible oxidative peak is exhibited in acid solution,but in the neutral or alkaline solution two oxidative peaks are observed.Oxidative peak potential values show a negative shift with increasing pH via a slope of-57 mV·pH-1 and a linear relation with DNA concentration in the range of 0.45 to 8.20 mmol·L-1.In the presence of histone,the oxidative peak current of DNA …

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Eiectro-Oxidation Of Methanol On Pdnio/C Catalyst In Alkaline Medium, Mei-Li Wang, Lin Sang, Cheng-De Huang Nov 2007

Eiectro-Oxidation Of Methanol On Pdnio/C Catalyst In Alkaline Medium, Mei-Li Wang, Lin Sang, Cheng-De Huang

Journal of Electrochemistry

The electro-oxidation of methanol in alkaline electrolyte at in-house synthesized PdNiO/C and Pd/C catalysts and the effect of heat treatment on the structure and performance of catalysts were studied by cyclic voltammetry,chronoamperometry,chronopotentiometry and X-ray diffraction methods.It is shown that when the reduction temperature is 70℃ and the ratio between Pd and Ni is 8∶2,The PdNiO/C catalyst presents a highest activity for methanol electrooxidation.Calcining can increase the particle size and crystallinity of catalysts,but decrease the dispersion and activity of catalysts, too.Besides,the NiO is disengaged from Pd lattice by heat-treatment.The optimal PdNiO/C catalyst shows higher catalytic activity and much better poisoning resistance …

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Ion-Implanting Modification Of Layered Manganese Dioxide And Its Electrochemical Performance, He-Ning Huang, Dong-Ping Lv, Xing-Kang Huang, Qi-Wei Zhang, Yong Yang Nov 2007

Ion-Implanting Modification Of Layered Manganese Dioxide And Its Electrochemical Performance, He-Ning Huang, Dong-Ping Lv, Xing-Kang Huang, Qi-Wei Zhang, Yong Yang

Journal of Electrochemistry

Layered MnO2(δ-MnO2) was prepared by thermal decomposition of potassium permanganate.Ti was ion-implanted into such δ-MnO2 by physical techniques,forming a composite(δ-MnO2-Ti).These materials were characterized by XRD,SEM,XPS techniques and their electrochemical proprieties were investigated.The results showed that the layered structure of δ-MnO2 did not been destroyed after Ti ion implantation,and the implanted Ti element was mainly Ti4+ as indicated by XPS.Both of the first and the highest discharge specific capacities of the ion-implanted layered MnO2(δ-MnO2-Ti),compared to those of δ-MnO2,were improved significantly.

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Selection Of Additions In The Process Of Electrochemical Synthesizing Of K2Feo4, Wei-Hua Yang, Dong-Qin Bi, Yan Zhou, Hong-Hui Wang, Xin-Ren Lan Nov 2007

Selection Of Additions In The Process Of Electrochemical Synthesizing Of K2Feo4, Wei-Hua Yang, Dong-Qin Bi, Yan Zhou, Hong-Hui Wang, Xin-Ren Lan

Journal of Electrochemistry

Some of different additions including KIO4 was added to the anodic electrolyte for electrochemical synthesizing of K2FeO4,the effects of these additions on current yield were investigated.XRD and SEM were used to characterize the structure and image of K2FeO4.The results show that KIO4 is a preferable addition.When the mass dosage of KIO4 is 0.02%,electrolysis time is 1 h,the current yield is enhanced by 31.6% and the corresponding purity of the product is improved by 3.85 %.

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Oxygen Enrichment Effect Of Mno2-Pt/C Compound Catalyst To The Cathode Of Pemfc, Hong-Feng Xu, Mao-Feng Zhang, Quan-Quan Gan, Cai-Sheng Huang Aug 2007

Oxygen Enrichment Effect Of Mno2-Pt/C Compound Catalyst To The Cathode Of Pemfc, Hong-Feng Xu, Mao-Feng Zhang, Quan-Quan Gan, Cai-Sheng Huang

Journal of Electrochemistry

TO study of the oxygen storage material of air cathode is crucial for increasing performance of proton exchange membrane fuel cell.Using the MnO2 as oxygen storage materials,a MnO2-Pt/C catalysts were prepared and is used to replace the conventional Pt/C in air cathode.The electrochemical performance of air cathode composed of MnO2 supported on Pt/C and the properties of fuel cell composed of MnO2-Pt/C were investigated by using the CV,galvanostatic dischange method and TEM.

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Electro-Chemical Oxidation Kinetics Of The V(Iv) In The Sulfuric Acid Solution, Yong-Lian Qiao, Qian Xu, Jie Zhang, Yu-Chun Zhai Aug 2007

Electro-Chemical Oxidation Kinetics Of The V(Iv) In The Sulfuric Acid Solution, Yong-Lian Qiao, Qian Xu, Jie Zhang, Yu-Chun Zhai

Journal of Electrochemistry

The electro-chemical oxidation kinetics for V(IV) in the sulfuric acid solution were investigated by cyclic voltammetry and steady state polarization curves at a graphite,platinum or conducting polymer electrode.Some kinetics parameters for the electrochemical reaction of V(IV) were calculated according to the Tafel curves.The results showed that the exchange current density and reversibility of V(V)/V(IV) redox reaction at the graphite electrode is largest among the three electrodes.There is the broadest extent of water stability and large oxidgen evolution potential when the conducting polymer was used as a working electrode in the solution of VOSO4(0.5 mol/L) and H2SO …

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Preparation, Structure, And Cv Study Of The Supported Ptruir/Tic Electrocatalysts For Oxygen Electrodes, Sheng Sui, Li-Rong Ma Aug 2007

Preparation, Structure, And Cv Study Of The Supported Ptruir/Tic Electrocatalysts For Oxygen Electrodes, Sheng Sui, Li-Rong Ma

Journal of Electrochemistry

The PtRuIr/TiC electrocatalysts were prepared by method of reduction and deposition on TiC powders as supports together with ultrasonic wave dispersion.The sampls were characterized by BET surface area,scanning electron microscope,X-ray diffraction,and cyclic voltammetry techniques.The active components of Pt,Ru,and Ir particles(2.6%Pt,1.3%Ru,16%Ir,and 80%TiC,by mass) were mainly dispersed on the outer surface of the TiC supports,which structures were in favor of fine variable crystallites.It was found that the electrochemical performance of the PtRuIr/TiC electrodes was about three times as that of the unsupported electrocatalysts with the same active compositions for oxygen evolution reaction.After 120 times of CV cycles,there was almost no PtRuIr/TiC dissolving …

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Electrocatalytic Oxidation Of Methanol At The Nano Ni-B Amorphous Alloy Powdermicroelectrode, Yi-Xiong Zheng, Shi-Bing Yao, Shao-Min Zhou Aug 2007

Electrocatalytic Oxidation Of Methanol At The Nano Ni-B Amorphous Alloy Powdermicroelectrode, Yi-Xiong Zheng, Shi-Bing Yao, Shao-Min Zhou

Journal of Electrochemistry

Electrocatalytic oxidation of methanol at the nano Ni-B amorphous alloy powder-microelectrode in alkaline media was studied by using cyclic voltammetry.Compared to the highly preferred orientation(220) nickel electrode,The onset potential of methanol electrooxidation at the nano Ni-B microelectrode is negatively shifted about 0.04V,and the current density is increased approximately by 2 orders of magnitude.Thus,the nano Ni-B microelectrode has very strong electrocatalytic activity for the oxidation of methanol.The kinetic parameters were determined with the steady polarization curves.The results show that the rate constants for both the oxidation of Ni(Ⅱ) to Ni(Ⅲ) and the reduction of Ni(Ⅲ) to Ni(Ⅱ) at the nano Ni-B …

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The Syntheses And Electrochemical Performance Of Nano-Mno2 For Supercapacitor, Jun Ma, Ming-Sen Zheng, Quan-Feng Dong Aug 2007

The Syntheses And Electrochemical Performance Of Nano-Mno2 For Supercapacitor, Jun Ma, Ming-Sen Zheng, Quan-Feng Dong

Journal of Electrochemistry

Nano-manganese dioxide were prepared by two different methods which are low temperature solid reaction and chemical deposition.The products were characterized by XRD,SEM,BET and constant current charge-discharge tests.The result shows that there is a close relationship between specific capacitance and BET surface areas.Meanwhile the specific capacitance was impacted little by the structure of the nano-manganese dioxides.However,the product performance of high rates,was influenced by structure,the higher rate can be obtained with the more perfect crystal structure.

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