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

Materials Chemistry Commons™

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

Physical Chemistry

Institution
Keyword
Publication Year
Publication
Publication Type

Articles 1321 - 1350 of 2394

Full-Text Articles in Materials Chemistry

Prepartion And Characterization Of Spr Au Substrate Using Wet Chemical Plating, You-Chen Zhou, Yan-Yan Wang, Zhi-Fang Ma, Yan-Xia Jiang, Jin Qiu, Shi-Gang Sun Feb 2011

Prepartion And Characterization Of Spr Au Substrate Using Wet Chemical Plating, You-Chen Zhou, Yan-Yan Wang, Zhi-Fang Ma, Yan-Xia Jiang, Jin Qiu, Shi-Gang Sun

Journal of Electrochemistry

The present study developed a preparation method of SPR gold substrate based on water phase operation.Firstly,on the glass modified by APTMS we self-assembed a gold colloid monolayer as the catalyst bed;Secondly,using the chemical plating technique,we made the gold film increase equably within the namometer range to obtain the proper shape and thinkness of the gold film required by the SPR.The analysis results of UV-vis and TEM demonstrated that the diameter of the monolayer formed from gold nanoparticles was 2.5 nm.Moreover,SEM showed that the nanoparticle prepared by electroless gold plating was uniformly distributed,whose diameter was 40 nm.The SPR flow injection experiment …

Go to article

Preparation And Electrochemical Properties Of Sn Thin Film As Anode Materials For Lithium-Ion Batteries, Hong-Mei Bai, Zhan-Liang Tao, Fang-Yi Cheng, Jun Chen Feb 2011

Preparation And Electrochemical Properties Of Sn Thin Film As Anode Materials For Lithium-Ion Batteries, Hong-Mei Bai, Zhan-Liang Tao, Fang-Yi Cheng, Jun Chen

Journal of Electrochemistry

Sn thin films as the anode materials of Li-ion batteries were prepared by vacuum-evaporation method on the copper foam substrate. The phase structure,surface morphology and electrochemical property of the as-prepared films were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM), and galvanostatic cycling. The results showed that three-dimensional structure of copper foam substrate enhanced the adhesion strength between the active material and the substrate, under the same substrate temperature, the particles became bigger with the increasing of evaporation time, while their electrochemical property decreased, under the same evaporation time, the particles didn′t changed obviously with the increasing of substrate temperature,while their cycle …

Go to article

Electrochemical Double-Layer Capacitors Using Phenolic Resin-Based Carbon Fibers, Rong Xue, Jing-Wang Yan, Ying Tian, Bao-Lian Yi Feb 2011

Electrochemical Double-Layer Capacitors Using Phenolic Resin-Based Carbon Fibers, Rong Xue, Jing-Wang Yan, Ying Tian, Bao-Lian Yi

Journal of Electrochemistry

Phenolic resin-based activated carbon fiber(ACF) was prepared by KOH activation.The electrochemical properties of pulverized phenolic resin-based carbon fiber(P-ACF) were examined in 6 mol·L-1 KOH compared with that of the original ACF.P-ACF exhibited a better capacitive behavior and showed a larger specific capacitance(200 F·g-1) as well as a lower capacitance decrease at high current densities.The pore resistance for ion migration(Rp) in P-ACF was lower(2.96 Ω) than that in ACF(4.65 Ω).Pulverization increased the exposure of the cross section,lowered the contact resistance between the carbon fibers and decreased the pore resistance for ion migration.

Go to article

Low-Temperature Performance Of Li-Ion Battery With Fluoroethylene Carbonate Electrolyte, Chun-Wei Yang, Feng Wu, Bo-Rong Wu, Yong-Huan Ren, Jing-Wen Yao Feb 2011

Low-Temperature Performance Of Li-Ion Battery With Fluoroethylene Carbonate Electrolyte, Chun-Wei Yang, Feng Wu, Bo-Rong Wu, Yong-Huan Ren, Jing-Wen Yao

Journal of Electrochemistry

The low temperature performance of electrolytes containing FEC including FEC+EMC, EC and PC, as well as the compatibility of electrolytes with LiFePO4 anode and with MCMB cathode were investigated.The electrolyte exhibits a high value of ionic conductivity at low temperature.The stability of cathode was enhanced by the formation of SEI film at 1.6 V as a result of FEC reaction. The infrared spectra showed that FEC can suppress decomposition of other solvents during SEI formation, and lower the resistance of SEI on MCMB cathode. The electrochemistry test indicates that Li-ion batteries with FEC electrolyte display high capacity at low …

Go to article

Influence Of Electric Field On The Adsorption And Bioactivity Of Hemoglobin On A Macroporous Gold Electrode, Cui-Hong Wang, Yi-Bing Kong, Xing-Hua Xia Feb 2011

Influence Of Electric Field On The Adsorption And Bioactivity Of Hemoglobin On A Macroporous Gold Electrode, Cui-Hong Wang, Yi-Bing Kong, Xing-Hua Xia

Journal of Electrochemistry

The adsorption and bioactivity of proteins at interfaces have been widely studied due to their important role in the construction of biosensors,bioelectronics and biofuel cells.Interfacial electric field is one of the important factors which could affect the adsorption and bioactivity of proteins at materials surfaces.It could dramatically change the adsorption density,molecular conformation and orientation at material surfaces.In this paper,the influence of interfacial electric field on the adsorption kinetics and bioactivity of hemoglobin(Hb) on a three-dimensional(3D) macroporous gold electrode surface has been studied using electrochemical methods and infrared spectroscopy.It was found that the interfacial electric field created excess surface charge which …

Go to article

Synthesis Of Mesoporous Nickel Oxide For Supercapacitor Application, Xuan-Xuan Chen, Zhen-Zhen Zhao, Deng-Chao Wang, Zhong-Jie Huang, Wen-Bin Ni, Li Yu, Jian-Wei Zhao Feb 2011

Synthesis Of Mesoporous Nickel Oxide For Supercapacitor Application, Xuan-Xuan Chen, Zhen-Zhen Zhao, Deng-Chao Wang, Zhong-Jie Huang, Wen-Bin Ni, Li Yu, Jian-Wei Zhao

Journal of Electrochemistry

Mesoporous nickel oxide has been synthesized by calcining metal-organic coordination precursor.Transmission electron microscopy and BET test showed that the prepared NiO had a regular morphology and displayed a narrow size distribution.Electrochemical tests revealed that such mesoporous NiO had a specific capacity of 72 F·g-1 at the current of 2.0 A·g-1.Futhermore,the material showed excellent cycle-life stability.There was no degradation of capacitance after 1000 cycles.

Go to article

A Titanium-Supported Nanoporous Pd Electrocatalyst For Methanol Oxidation, Feng-Juan Niu, Qing-Feng Yi Feb 2011

A Titanium-Supported Nanoporous Pd Electrocatalyst For Methanol Oxidation, Feng-Juan Niu, Qing-Feng Yi

Journal of Electrochemistry

Titanium-supported nanoporous palladium electrode(nanoPd /Ti) was prepared by a hydrothermal process in the presence of the ligand EDTA and using formaldehyde as reducing agent.SEM images showed that the size of Pd particles was about 60 nm and the Pd particles were connected with each other to form a three-dimensional network structure.Cyclic voltammetry(CV) and electrochemical impedance spectroscopy(EIS) were applied to evaluate the electrocatalytic activity of the nanoPd/Ti electrode towards methanol oxidation in alkaline solution.CV results showed that the nanoPd /Ti electrode presented high anodic peak densities and a low onset potential for methanol oxidation.Also nanoPd /Ti electrode showed excellent CO tolerance …

Go to article

Electrocatalytic Oxidation Of Hydrazine At Rutin Carbon Nanotubes Modified Electrode, Hong-Fang Zhang, Qing-Lin Sheng, Jian-Bin Zheng Feb 2011

Electrocatalytic Oxidation Of Hydrazine At Rutin Carbon Nanotubes Modified Electrode, Hong-Fang Zhang, Qing-Lin Sheng, Jian-Bin Zheng

Journal of Electrochemistry

The electrochemical behavior and electrocatalytic oxidation of hydrazine on rutin multiwall carbon nanotubes modified glassy carbon electrode were studied by cyclic voltammetry.The experimental results indicated that the electrode exhibits good electrocatalytic activity to hydrazine at a reduced oxidation potential of 262 mV.The amperometric response of the modified electrode showed linear increase after successive addition of hydrazine in the concentration range of 2.5×10-6~1.0×10-4 mol·L-1 with a detection limit of 5×10-7 mol·L-1.

Go to article

Applications Of Raman Spectroscopy Technique In Lithium Ion Batteries, Liang Zhao, Yong-Sheng Hu, Hong Li, Zhao-Xiang Wang, Hong-Xing Xu, Xue-Jie Huang, Li-Quan Chen Feb 2011

Applications Of Raman Spectroscopy Technique In Lithium Ion Batteries, Liang Zhao, Yong-Sheng Hu, Hong Li, Zhao-Xiang Wang, Hong-Xing Xu, Xue-Jie Huang, Li-Quan Chen

Journal of Electrochemistry

The Raman spectroscopy has been widely used in the study of lithium ion batteries.In this short review,we gave some examples of the applications of Raman spectroscopy in the study of electrode materials including carbonaceous materials,spinel LiMxMn2-x O4,LiFePO4,as well as polymer electrolytes,room temperaturemolten salt electrolytes and the solid-electrolyte interphase layers.The advantages and disadvantages of the ex-situ and in-situ Raman spectrum techniques are discussed.Using new Raman techniques to investigate Li-ion batteries are suggested.

Go to article

Electrochemical Performance Of Polytriphenylamine As A Novel Non-Aqueous Supercapcitor Cathode Material, Qiu-Jie She, Zhi-Kai Wei, Ming-Sen Zheng, Quan-Feng Dong Feb 2011

Electrochemical Performance Of Polytriphenylamine As A Novel Non-Aqueous Supercapcitor Cathode Material, Qiu-Jie She, Zhi-Kai Wei, Ming-Sen Zheng, Quan-Feng Dong

Journal of Electrochemistry

The PTPAn/active carbon compounds were synthesized by heterogeneous precipitation method.The SEM results show that the size of the PTPAn decreases from about 150 nm to few ten nanometers after being incorporated with active carbon.The PTPAn/active carbon compounds have excellent rate and cycling performance:the discharge capacity increases from 88.5 mAh/g to 105 mAh/g at 0.5 C charge/discharge rate and can reach to 70 mAh/g even at 40 C charge/discharge rate.And the capacity retention of the PTPAn/active carbon compounds remain almost unchanged after 1000 cycles at 40 C charge/discharge rate.

Go to article

Novel Anion Exchange Membranes Base On Copolymer Of 2-(Diethylamino) Ethyl Methacrylate And Fluoro-Polyacrylate For Alkaline Direct Methanol Fuel Cells, Yan-Mei Zhang, Jun Fang, Ge Yan, Yong-Ze Zhuang Feb 2011

Novel Anion Exchange Membranes Base On Copolymer Of 2-(Diethylamino) Ethyl Methacrylate And Fluoro-Polyacrylate For Alkaline Direct Methanol Fuel Cells, Yan-Mei Zhang, Jun Fang, Ge Yan, Yong-Ze Zhuang

Journal of Electrochemistry

Anion exchange membrane fuel cells,which use anion exchange membranes as polyelectrolytes,have attracted more and more research interests recently.In this work,a series of hydroxyl-conducting anion-exchange membranes based on the copolymer of 2-(Diethylamino)ethyl methacrylate and fluoro-polyacrylate were prepared by radical polymerization,and their potential applications in alkaline fuel cells were assessed.It was shown that the ionic conductivity of the membranes reached 10-2 S·cm-1 at room temperature,while the methanol permeability was lower than 10-7 cm2·s-1.The maximum power density of fuel cell assembled with this membrane was achieved to be 43.2 mW·cm-2 at room temperature,indicating possible application …

Go to article

Electrooxidation Of Methanol On Multilayer Films Of Polypyrrole-Platinum Electrode, Ling Zhang, Long-Zhen Zheng Feb 2011

Electrooxidation Of Methanol On Multilayer Films Of Polypyrrole-Platinum Electrode, Ling Zhang, Long-Zhen Zheng

Journal of Electrochemistry

Multilayer films of polypyrrole-platinum electrode were fabricated by cyclic voltammetric technique.Electro-oxidation of methanol on this electrode was investigated with the aid of cyclic voltammetry and chronoamperometry.Results demonstrated that the multilayer of polypyrrole-platinum electrode behaved better electrocatalytic performance for electro-oxidaton of methanol and better poison resistant.Furthermore,with the increase of deposited platinum loadings,the rate controlling step on electro-oxidation reaction of methanol was changed from CO oxidation to sorption-desorption of hydrogen.

Go to article

Electrochemical Capacitive Performance Of Polyaniline Electrode With Different Electrolytes, Yong-Tao Tan, Fen Ran, Ling-Ren Wang, Ji Liu, Ling-Bin Kong, Yong-Chun Luo, Long Kang Feb 2011

Electrochemical Capacitive Performance Of Polyaniline Electrode With Different Electrolytes, Yong-Tao Tan, Fen Ran, Ling-Ren Wang, Ji Liu, Ling-Bin Kong, Yong-Chun Luo, Long Kang

Journal of Electrochemistry

The polyaniline(PANi) for supercapacitor was prepared by chemical-oxidative polymerization.The SEM,FTIR data and electrochemical performance showed that,polyaniline nanoparticles were formed which were about 50 nm;the specific capacitances of PANi were 404 F/g,208 F/g and 279 F/g in 1 mol/L H2SO4,NaNO3 and KOH,respectively,when the current density was 5 mA/cm2.The concentrations of H2SO4 increased to 2 mol/L or 6 mol/L,the capacitances decreased to 330 F/g or 248 F/g.

Go to article

Electrochemical Deposition Of Zinc Oxide Crystal Whiskers, Peng-Zeng Lu, Su Li, Jin-Qian Jia, Zhen-Hai Liang Feb 2011

Electrochemical Deposition Of Zinc Oxide Crystal Whiskers, Peng-Zeng Lu, Su Li, Jin-Qian Jia, Zhen-Hai Liang

Journal of Electrochemistry

Pine needle ZnO crystal whiskers were electrodeposited by anodization of zinc foil.The crystal whiskers were characterized by scanning electron microscopy(SEM) and X-ray diffraction(XRD) spectroscopy.The results show that the lengths and diameters of ZnO crystal whiskers are 200~300 nm and 20~50 nm,respectively,with the ratio of the length to diameter ranging from 10~15.The whiskers belong to wurtzite ZnO(JCPDS 36-1451) with good crystallinity and high purity.The crystalization behavior of ZnO was studied by cyclic voltammetry.The effects of the surface oxide layer at the zinc substrates and the [Zn(OH)4]2-concentration of the aqueous electrolyte on the formation of zinc oxide whiskers …

Go to article

Elastic Properties Of Poly(Vinyldene Fluoride) (Pvdf) Crystals: A Density Functional Theory Study, Yong Pei, Xiao Cheng Zeng Jan 2011

Elastic Properties Of Poly(Vinyldene Fluoride) (Pvdf) Crystals: A Density Functional Theory Study, Yong Pei, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

We computed structural and elastic properties of totally nine phases of poly(vinyldene fluoride) (PVDF) crystals using the density-functional theory (DFT) method with and without inclusion of the dispersion corrections. In addition to the four known crystalline forms, mechanic properties of five theoretically predicted crystalline forms of PVDF are also investigated. The all-trans form Ip exhibits the largest cohesive energy, bulk, and Young’s modulus among the nine crystalline forms. The DFT calculations suggest that the δ crystalline forms (IIIau, IIIpu, IIIpd, and IIIad) possess poor chain rigidity among the nine PVDF …

Go to article

Structure Evolution Of Gold Cluster Anions Between The Planar And Cage Structures By Isoelectronic Substitution: AuN− (N = 13–15) And MauN− (N = 12–14; M = Ag, Cu), Rhitankar Pal, Lei-Ming Wang, Wei Huang, Lai-Sheng Wang, Xiao Cheng Zeng Jan 2011

Structure Evolution Of Gold Cluster Anions Between The Planar And Cage Structures By Isoelectronic Substitution: AuN− (N = 13–15) And MauN− (N = 12–14; M = Ag, Cu), Rhitankar Pal, Lei-Ming Wang, Wei Huang, Lai-Sheng Wang, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

The structural and electronic effects of isoelectronic substitution by Ag and Cu atoms on gold cluster anions in the size range between 13 and 15 atoms are studied using a combination of photoelectron spectroscopy and first-principles density functional calculations. The most stable structures of the doped clusters are compared with those of the undoped Au clusters in the same size range. The joint experimental and theoretical study reveals a new C3v symmetric isomer for Au13 −, which is present in the experiment, but has hitherto not been recognized. The global minima of Au14 − and Au …

Go to article

Study On Preparing Technology And Corrosion Resistance Of Ti/Zr Based Chromium-Free Chemical Conversion Coating On Zinc Electroplating Layer, Yong Guan, Jian-Guo Liu, Chuan-Wei Yan Nov 2010

Study On Preparing Technology And Corrosion Resistance Of Ti/Zr Based Chromium-Free Chemical Conversion Coating On Zinc Electroplating Layer, Yong Guan, Jian-Guo Liu, Chuan-Wei Yan

Journal of Electrochemistry

In this paper,we obtained environmental-friendly chromium-free chemical conversion coating on the non-cyanide alkaline zinc electroplating layer by employing the optimized Ti/Zr based conversion technique.At the same time,the performances of the Ti/Zr based conversion coating were compared with chromate colour passivation coating.The corrosion resistances of the conversion coatings were investigated by using neutral salt spray(NSS) test,potentiodynamic polarization and electrochemical impedance spectroscopy(EIS).The results showed that the white rust appeared after 96 hours when the NSS test was performed on the Ti/Zr based conversion coating,which was close to the corrosion resistance rating of chromate colour passivation coating.Compared with the chromate passivation coating,the Ti/Zr …

Go to article

The Sol-Gel Synthesis And Electrochemical Performance Of Li3V2(Po4)3/C Cathode Material For Lithium Ion Battery, Li-Ying Liu, Lian Chen, Hai-Yan Zhang, Yu-Chun Zhai Nov 2010

The Sol-Gel Synthesis And Electrochemical Performance Of Li3V2(Po4)3/C Cathode Material For Lithium Ion Battery, Li-Ying Liu, Lian Chen, Hai-Yan Zhang, Yu-Chun Zhai

Journal of Electrochemistry

Li3V2(PO4)3/C was synthesized by sol-gel method with citric acid as chelate and C sources. Physical and electrochemical performances of as-prepared materials were characterized through XRD, SEM and galvanostatic charge-discharge tests,etc. The results showed that products produced by calcining at 800 ℃ for 12 h had a single phase crystal structure and relatively small particle sizes with uniform distribution. At 0.1 C, 0.5 C and 1 C, the initial specific discharge capacities were 153.0, 143.1 and 130.6 mAh·g-1, respectively, and capacity efficiencies were 93.1%, 85.4% and 77.3% after 50 cycles, respectively. …

Go to article

The Roles Of The Width Of Gas/Liquid/Solid Three-Phase Boundary Zone Of Dispersion Water Films In Atmospheric Corrosion Of Metals, Jia Wang, Jing Jiang Nov 2010

The Roles Of The Width Of Gas/Liquid/Solid Three-Phase Boundary Zone Of Dispersion Water Films In Atmospheric Corrosion Of Metals, Jia Wang, Jing Jiang

Journal of Electrochemistry

The roles of TPB(Three-Phase Boundary) width in the corrosion processes of metals under dispersed water films were investigated by electrochemical techniques combined with contact angle measurement.It is found that both cathodic limiting current density and corrosion current density linearly increases with increasing the TPB width,confirming the important role of TPB width in gas/liquid/solid multiphase corrosion systems.Based on above results,the effect of water film thickness on atmospheric corrosion rate was quantitatively evaluated by the TPB width.

Go to article

Photoelectrochemical Properties Of N, S, And Cl Modified Nano Tio2 Thin Films, Hong Yun, Chang-Jian Lin, Jing Li, Rong-Gui Du Nov 2010

Photoelectrochemical Properties Of N, S, And Cl Modified Nano Tio2 Thin Films, Hong Yun, Chang-Jian Lin, Jing Li, Rong-Gui Du

Journal of Electrochemistry

The nitrogen(N),sulfur(S) and chlorine(Cl) modified nano TiO2 thin films were prepared by adding Ti(O-n-Bu)4 as the precursor into concentrated HNO3,H2SO4 and HCl Solutions,respectively,on different substrates in a sol-gel process.The photoelectrochemical performances of N,S and Cl modified nano TiO2 thin films have been studied by UV-vis(DRS),photocurrent curves,EIS and OCP-time curves.N-modified TiO2 nano films show better surface structure,which helps to improve the quantum efficiency of nano TiO2 thin films.

Go to article

Corrosion Electrochemical Behavior Of Am60 Magnesium Alloys In Automobile Engine Coolants, Ling-Jie Li, Sha Wang, Yin Xiao, Jun Lan, Jing-Lei Lei, Sheng-Tao Zhang, Fu-Sheng Pan Nov 2010

Corrosion Electrochemical Behavior Of Am60 Magnesium Alloys In Automobile Engine Coolants, Ling-Jie Li, Sha Wang, Yin Xiao, Jun Lan, Jing-Lei Lei, Sheng-Tao Zhang, Fu-Sheng Pan

Journal of Electrochemistry

The polarization measurements and electrochemical impedance spectroscopy(EIS) were used to study the corrosion electrochemical behavior of AM60 magnesium alloys in three kinds of commercial coolants for automobile engine.Results show that the tested commercial coolants are slightly corrosive to AM60 magnesium alloys and their corrosivity varies from coolant to coolant.The coolant C is the least corrosive among the studied commercial coolants and the coolant A is more corrosive than the coolant B and C.The coolant C appears to be the most promising coolant for automobile engine made by magnesium alloys.The coolant resistivity plays an important role in the corrosion of AM60 …

Go to article

Electroless Deposition And Characterization Of Nickel Coating In Lead-And Cadmium-Free Bath, Fang-Zu Yang, Ming-Hui Chen, Xia-Jing Huang, Zhong-Qun Tian, Shao-Min Zhou Nov 2010

Electroless Deposition And Characterization Of Nickel Coating In Lead-And Cadmium-Free Bath, Fang-Zu Yang, Ming-Hui Chen, Xia-Jing Huang, Zhong-Qun Tian, Shao-Min Zhou

Journal of Electrochemistry

Technology of electroless nickel deposition in lead-and cadmium-free bath was developed.Coating′s morphology,composition,structure and electrochemical activity were characterized by SEM,EDS,XRD and electrochemical methods.The results showed that,the deposition rate of nickel in self-catalysing was 22.4 μm·h-1,which was increased by the increase of bath temperature and pH value.The effect of sodium hypophosphite on deposition rate was much more remarkable compared with nickel sulfate.The obtained nickel coating was 7.8% in phosphor weight content,having compact and neat surface morphology,amorphous structure,and good electrochemical corrosion resistance in sodium chloride solution.

Go to article

Electrochemical Detection For The Corrosion Of Reinforcing Steel In Concrete During Immersion And Drying Cycles, Bing-Li Jia, Fa-He Cao, An-Na Chen, Jian-Qing Zhang Nov 2010

Electrochemical Detection For The Corrosion Of Reinforcing Steel In Concrete During Immersion And Drying Cycles, Bing-Li Jia, Fa-He Cao, An-Na Chen, Jian-Qing Zhang

Journal of Electrochemistry

The corrosion behavior of reinforcing steel in concrete under dry-wet cycle condition has been studied by electrochemical noise(EN) compared with the electrochemical impedance spectroscopy(EIS),SEM micrographs and EDS.The statistical method has been employed to analyze the EN data of reinforcing steel in concrete,which revealed three different corrosion stages of reinforcing steel in concrete,including the dissolution of the passive film,the active corrosion and the cumulation of corrosion product.The wavelet transform has also been employed,which indicated that steel in concrete with pH 1 is associated with uniform corrosion,while steel in concrete with pH 3 and pH 7 are associated with localized corrosion,such as …

Go to article

Preparation And Characterization Of The Silane-Phosphonic Acid Composite Passivation Coating For Electrogalvanized Steel, Yong Guan, Jian-Guo Liu, Chuan-Wei Yan Nov 2010

Preparation And Characterization Of The Silane-Phosphonic Acid Composite Passivation Coating For Electrogalvanized Steel, Yong Guan, Jian-Guo Liu, Chuan-Wei Yan

Journal of Electrochemistry

A new silane-phosphonic acid composite passivation coating process has been developed for the protection of electrogalvanized steel based on N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane(AAPTMS),γ-(2,3-epoxypropoxy)propyltrimethoxy-silane(GPTMS) and 1-hydroxy ethylidene-1,1-diphosphonic acid(HEDP).The results of X-ray photoelectron spectroscopy(XPS),Fourier transform infrared spectroscopy(FTIR),potentiodynamic polarization scan,electrochemical impedance spectroscopy(EIS) and neutral salt spray(NSS) tests indicated that the major structure of the prepared silane-phosphonic acid composite passivation coating consisted mainly of Si—O—Si and Si—O—P bonds.The area of white rust was not more than 5% of the total panal after 120 h NSS test,which could be compared favourably with the chromate colour passivation coating.However,the corrosion reaction on the anode of the silane-phosphonic acid composite passivation …

Go to article

Initial Stage Of Atmospheric Corrosion Of Ndfeb(M35) In A Simulated Marine Atmosphere, Chun-Ling Li, Yuan-Tai Ma, Ying Li, Fu-Hui Wang Nov 2010

Initial Stage Of Atmospheric Corrosion Of Ndfeb(M35) In A Simulated Marine Atmosphere, Chun-Ling Li, Yuan-Tai Ma, Ying Li, Fu-Hui Wang

Journal of Electrochemistry

This study detailed the atmospheric corrosion behaviour of sintered NdFeB(M35) in a simulated marine atmosphere with 80% relative humidity(RH).The dissolution and subsequent reaction of NaCl particles cause the attack of NdFeB.The corrosion presented three representative types:if the electrolyte covered magnetic phase and Nd-rich phase,the Nd-rich phase was corroded firstly due to galvanic effect;if the electrolyte covered magnetic phase,magnetic phase was corroded along the grain boundary;if the electrolyte located near the position of defects,corrosion progressed along with the defect because of low concentration of oxygen inside the defect.With corrosion progressing,local corrosion areas were mutually connected,with Nd-rich phase and grain boundary being …

Go to article

Hydrothermal Reduction Synthesis Of Lifepo4 And Its Electrochemical Performance, Hong-Li Zou, Guang-Hui Zhang, Pei-Kang Shen Nov 2010

Hydrothermal Reduction Synthesis Of Lifepo4 And Its Electrochemical Performance, Hong-Li Zou, Guang-Hui Zhang, Pei-Kang Shen

Journal of Electrochemistry

The cathode materials of LiFePO4 were prepared via a hydrothermal reduction method using FeCl3 as Fe source and iron as a reducing agent.The results showed that ferric salt could be reduced to ferrous salt completely under the hydrothermal condition and pure-phase LiFePO4 was obtained based on the test results of XRD and FTIR.Carbon-coated LiFePO4 was synthesized by pyrolysisng glucose at high temperature.The morphologies of pure LiFePO4 displayed cluster-like while the LiFePO4/C displayed sphere-like particles.The electrochemical test showed that the LiFePO4/C had good rate performance,while LiFePO4 delivered much lower discharge capacity.

Go to article

Effects Of Solvents And Electrolyte Salts On The Electrochemical Reduction Of Oxygen In Non-Aqueous Electrolytes, Yan-Yan Tian, Wei Wu, Jun Gao, Yong Yang Nov 2010

Effects Of Solvents And Electrolyte Salts On The Electrochemical Reduction Of Oxygen In Non-Aqueous Electrolytes, Yan-Yan Tian, Wei Wu, Jun Gao, Yong Yang

Journal of Electrochemistry

The electrochemical reduction processes of oxygen in different non-aqueous solvents such as acetonitrile(MeCN),propylene carbonate(PC) and their mixtures were investigated by cyclic voltammetry method.The results indicated a one electron reduction of oxygen to O2-occured in these systems as a first step reduction,no matter whether in tetrabutylammonium hexafluorophosphate(TBAPF6)/MeCN or TBAPF6/PC electrolyte.However,the CV curves in 0.1 mol·L-1 TBAPF6/MeCN showed a couple of reversible redox peaks,indicating that the reduction process of oxygen was irreversible in the 0.1 mol·L-1 TBAPF6/PC electrolyte.In the PC-based electrolyte,the reduction current peak reduced largely and the oxidation peak …

Go to article

Study Of The 11-Ferrocenylalkanethiol Redox-Induced Structure Changes By Flow-Injection Electrochemical Surface Plasmon Resonance, Xiu-Juan Xiao, Yong-Hui He, Juan Xiang, Bin Ren Nov 2010

Study Of The 11-Ferrocenylalkanethiol Redox-Induced Structure Changes By Flow-Injection Electrochemical Surface Plasmon Resonance, Xiu-Juan Xiao, Yong-Hui He, Juan Xiang, Bin Ren

Journal of Electrochemistry

Redox-induced orientation changes of self-assembled monolayers(SAMs) of 11-ferrocenylundecanethiol(FcC11SH) were studied by the flow-injection electrochemical surface plasmon resonance(FI-EC-SPR).Results indicated that there existed two mechanisms concerning the redox-induced structure change of the self-assembled monolayer of ferrocenylalkanethiols:the electrostatic repulsion between the positively charged surface and the ferricenium cation and that among the cations led to a decrease in the tilt angle of the alkanethiol chain;upon Fc oxidation,the Fc group rotated from a tilted conformation to a position where the cyclpentyldiene plane became perpendicular to the electrode.

Go to article

Electrodeposition Of Lead Dioxide From Dluoroborate Solutions, Chun-Mei Kong, Yong-Ming Tang, Wen-Zhong Yang, Xiao-Yuan Yang Nov 2010

Electrodeposition Of Lead Dioxide From Dluoroborate Solutions, Chun-Mei Kong, Yong-Ming Tang, Wen-Zhong Yang, Xiao-Yuan Yang

Journal of Electrochemistry

The PbO2 anodes were prepared on platinum from fluoroborate media and its doped solutions by electrodeposition technique.Elecchemical and pysicochemical properties of these PbO2 films were studied by cyclic voltammetry methods,XRD and SEM.The results showed that the presence of BF4-increased PbO2 electrodeposition rate;the prepared lead dioxide consisted of β-PbO2;the preferential orientation of crystals and surface morphology were affected a lot by doping F-and Fe3+.The FB/F-Fe-PbO2 electrode exhibited regular-shaped layers with compact morphology.Furthermore,increasing current density also change the preferential orientation of PbO2 crystals.

Go to article

Research On Nafion/Sio2 Composite Membrane In All Vanadium Redox Flow Battery, Dong-Dong Liu, Mao-Cai Lin, Tao Guan, Qing-Chun Yu Nov 2010

Research On Nafion/Sio2 Composite Membrane In All Vanadium Redox Flow Battery, Dong-Dong Liu, Mao-Cai Lin, Tao Guan, Qing-Chun Yu

Journal of Electrochemistry

The Nafion117/SiO2 composite membrane was prepared by sol-gel method.The results showed that,during composite membrane preparation process,the ratio of MeOH and TEOS did not affect the penetration rate of VO2+ basically,however,the lowest permeability of 427×10-9cm2/s in the membrane was achieved while hydrolysis time was 10 min and natural drying for 24 h after hydrolysis,which reduced by 52 times than that in Nafion117 membrane.The SEM tests proved that SiO2 grains grew bigger in the composite membrane during the natural drying,and most of the holes in Nafion117 were filled.Single cell test showed the battery power efficiency was improved …

Go to article

First Prev Next Last