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Chinese Chemical Society | Xiamen University

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Full-Text Articles in Physical Chemistry

A Comparative Study Of Charge-Discharge Behaviors Of α-Pbo2 And β-Pbo2 Cathodes, Cong-Ying Cui, Xue-Mei Ma, De-Long Kong, Hou-Yi Ma Feb 2013

A Comparative Study Of Charge-Discharge Behaviors Of α-Pbo2 And β-Pbo2 Cathodes, Cong-Ying Cui, Xue-Mei Ma, De-Long Kong, Hou-Yi Ma

Journal of Electrochemistry

The α-PbO2 and β-PbO2 powders were prepared using simple chemical synthetic methods, and their crystalline structures and surface morphologies were characterized with X-ray powder diffraction spectroscopy and scanning electron microscopy. Using the as-synthesized α-PbO2 and β-PbO2 powders as positive active materials, the electrochemical performance of the two PbO2 materials was investigated by means of cyclic voltammetry, galvanostatic charge-discharge tests, and electrochemical impedance spectroscopy. The results indicate that the discharge capacity of α-PbO2 electrode is larger than that of β-PbO2; moreover, the composite electrodes made by α-PbO2 and β-PbO2 mixtures with …


An In Situ Ftir Spectroelectrochemical Study On Methanol Oxidation At Pt-Mo2C/Gc Catalyst, Hai-Ping Huang, Xi-Yu Yao, Pei-Kang Shen Feb 2013

An In Situ Ftir Spectroelectrochemical Study On Methanol Oxidation At Pt-Mo2C/Gc Catalyst, Hai-Ping Huang, Xi-Yu Yao, Pei-Kang Shen

Journal of Electrochemistry

A 40% Pt on Mo2C/GC catalyst has been prepared by ion exchange method. The mechanism of methanol electrooxidation on Pt-Mo2C/GC and commercial Pt/C catalysts in acidic media was studied by cyclic voltammetry, XRD measurements and in-situ Fourier transform infrared spectroelectrochemistry. The results revealed that the Pt nanoparticles were uniformly dispersed on Mo2C/GC with an average particle size of 3 nm. The cyclic voltammetric and chronopotentiometric experiments indicated that Pt-Mo2C/GC catalyst exhibited a better performance for methanol oxidation than that of Pt/C in acid solution. A negative shift over 90 mV of the …


Recent Experimental Progresses On Electrochemical Atr-Seiras, Yao-Yue Yang, Han-Xuan Zhang, Wen-Bin Cai Feb 2013

Recent Experimental Progresses On Electrochemical Atr-Seiras, Yao-Yue Yang, Han-Xuan Zhang, Wen-Bin Cai

Journal of Electrochemistry

Technical aspects on developing electrochemical ATR surface-enhanced infrared absorption spectroscopy are briefly accounted mainly based on our recent investigations, including wet-fabrication of metallic film electrodes on Si prism, design and construction of a wide-frequency combination optical window and a spectroelectrochemical cell switchable for external and internal reflection modes.


Applications Of Ellipsometry In The Investigations Of Electrode-Solution Interface, Jing-Lei Lei, Liang-Liu Wu, Ling-Jie Li, Sheng-Mao Wu, Sheng-Tao Zhang Feb 2013

Applications Of Ellipsometry In The Investigations Of Electrode-Solution Interface, Jing-Lei Lei, Liang-Liu Wu, Ling-Jie Li, Sheng-Mao Wu, Sheng-Tao Zhang

Journal of Electrochemistry

Ellipsometry is an optical technique with high-sensitivity to quantitatively obtain surface/interface properties such as thickness andrefractive index by analyzing the changes in polarized light reflected from the surface/interface. Its noncontacting and nondestructivenature makes it possible to acquire thein situreal-time information of the change at the surface/interface. Therefore, ellipsometry has been used widely in the electrochemical investigations. In this paper, based on the brief introduction of the measurementprinciple of ellipsometry, the current progress and the future trends of ellipsometry in electrochemistry arediscussed. The applications of ellipsometry in the fields of conversion and storage of electrochemical energy, electrochemistry ofmaterials science,electroanalysisand bioelectrochemistry are …


Oxygen Reduction Reaction On Glycin Modified Pt(111) Electrode, Ming-Fang Li, Jing Kang, Ling-Wen Liao, Yan-Xia Chen, Shen Ye Feb 2013

Oxygen Reduction Reaction On Glycin Modified Pt(111) Electrode, Ming-Fang Li, Jing Kang, Ling-Wen Liao, Yan-Xia Chen, Shen Ye

Journal of Electrochemistry

O

xygen reduction reaction (ORR) on glycin (NH2CH2COOH) modified Pt(111) electrode has been investigated using hanging meniscus rotating disk electrode system (HMRD) in 0.05 mol•L-1 H2SO4 and 0.1 mol•L-1 HClO4 solutions, respectively. Cyclic voltammograms of the glycin modified Pt (111) electrode measured in 0.05 mol•L-1 H2SO4 solution similar to that of CN- modified Pt(111) electrodes, demonstrating that sulfate adsorption is strongly inhibited at the glycin modified Pt(111). From the polarization curve of ORR recorded in 0.05 mol•L-1 H2SO4 solution, it is …


Porous Electrodes With High Pt Utilization Obtained By Ion-Exchange/Electrodeposition, Si-Guo Chen, Wei Ding, Xue-Qiang Qi, Li Li, Zi-Hua Deng, Zi-Dong Wei Feb 2013

Porous Electrodes With High Pt Utilization Obtained By Ion-Exchange/Electrodeposition, Si-Guo Chen, Wei Ding, Xue-Qiang Qi, Li Li, Zi-Hua Deng, Zi-Dong Wei

Journal of Electrochemistry

We report a novel method based on ion-exchange/electrodeposition (IEE) for constructing high Pt utilization porous electrodes. The electrode prepared using IEE was assessed by linear sweep voltammetry (LSV), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and single cell test. The preliminary results show that the undesired ion-exchange between Pt anion and surface functional group in carbon black can be eliminated through the electrode preparation process, and every Pt particle prepared by IEE is expected to be deposited on the three-phase reaction zone and thus can be fully utilized in fuel cell reactions. The Pt particle size, shape and distribution …


Effect Of Ti/Pbo2 Electrodes Doped With Different Elements On Electrocatalytic Oxidation Characteristics Of Phenol, Xiao-Lei Liu, Yuan-Yuan Dan, Hai-Yan Lu, Hai-Bo Lin, Ming-Li Ouyang, Chuan-Jun Yun Feb 2013

Effect Of Ti/Pbo2 Electrodes Doped With Different Elements On Electrocatalytic Oxidation Characteristics Of Phenol, Xiao-Lei Liu, Yuan-Yuan Dan, Hai-Yan Lu, Hai-Bo Lin, Ming-Li Ouyang, Chuan-Jun Yun

Journal of Electrochemistry

Three types of electrodes, namely, Ti/PbO2, F-doped PbO2 (Ti/PbO2-F) and nano-Co3O4-doped PbO2 (Ti/PbO2+Nano-Co3O4) electrodes, were prepared by electro-deposition method on the Ti substrate with the interlayer of SnO2-Sb2O5. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to study the compositions, structures and film morphologies of the electrodes. Electrocatalytic oxidation characteristics to phenol on the prepared electrodes were investigated by electrochemical method. The experimental results showed that compared with the Ti/PbO2 electrode, the potentials of oxygen …


A Dft Calculation Screening Of Pt-Based Bimetallic Catalysts For Oxygen Reduction, Li-Hui Ou, Sheng-Li Chen Feb 2013

A Dft Calculation Screening Of Pt-Based Bimetallic Catalysts For Oxygen Reduction, Li-Hui Ou, Sheng-Li Chen

Journal of Electrochemistry

Developing Pt-lean catalysts for oxygen reduction reaction (ORR) is the key for large-scale application of proton exchange membrane fuel cell (PEMFC). In this paper, we have proposed a multiple-descriptor strategy for screening efficient and durable ORR alloy catalysts of low Pt content. We argue that an ideal Pt-based bimetallic alloy catalyst for ORR should possess simultaneously negative alloy formation energy, negative surface segregation energy of Pt and a lower oxygen binding ability than pure Pt. By performing detailed DFT calculations on the thermodynamics, surface chemistry and electronic properties of various Pt-M alloys (M refers to non-precious transition metals in the …


Sodium Carbonate Catalyzed Photoelectrochemical Water Splitting Over Tio2 Nanotubes Photoanode, De-Sheng Kong, Jing Wang, Xue-Di Zhang, Xi Zhao, Chao Wang, Yuan-Yuan Feng, Wen-Juan Li Feb 2013

Sodium Carbonate Catalyzed Photoelectrochemical Water Splitting Over Tio2 Nanotubes Photoanode, De-Sheng Kong, Jing Wang, Xue-Di Zhang, Xi Zhao, Chao Wang, Yuan-Yuan Feng, Wen-Juan Li

Journal of Electrochemistry

Surface recombination of the photogenerated electron-hole pairs at semiconductor/electrolyte interface is one of the most essential reasons responsible for lowering photoconversion efficiency (Φ) of light to chemical energy for photoelectrochemical (PEC) water splitting reaction. In this paper, the catalytic effect of sodium carbonate on the oxygen evolution reaction (OER) over TiO2 nanotubes photoanode during PEC water splitting was investigated by performing photocurrent and ac impedance measurements. It was demonstrated that the addiction of 1 mmol•L-1 Na2CO3 in 0.5 mol•L-1 NaClO4 electrolyte can effectively improve the charge transfer properties for the photogenerated holes across …


Advances And Challenges Of Intermediate Temperature Solid Oxide Fuel Cells: A Concise Review, Sanping Jiang Dec 2012

Advances And Challenges Of Intermediate Temperature Solid Oxide Fuel Cells: A Concise Review, Sanping Jiang

Journal of Electrochemistry

Fuel cell is an electrochemical energy conversion device to directly convert the chemical energy of fuels to electricity. Among all types of fuel cells, solid oxide fuel cells (SOFCs) operating at intermediate temperatures of 600~800 oC offer an attractive option that is much more fuel flexible than low temperature fuel cells such as proton exchange membrane fuel cells, and is suitable for a wide range of applications. However, two main challenges remain towards the commercial viability and acceptance of the SOFC technologies: the cost and durability. Both are critically dependent on the process, fabrication, performance, chemical and microstructural stability …


Ternary Alloy Electrocatalysts For Oxygen Reduction Reaction, Jin Luo, Lefu Yang, Binghui Chen, Chuanjian Zhong Dec 2012

Ternary Alloy Electrocatalysts For Oxygen Reduction Reaction, Jin Luo, Lefu Yang, Binghui Chen, Chuanjian Zhong

Journal of Electrochemistry

Proton exchange membrane fuel cell represents an important electrochemical energy conversion device with many attractive features in terms of efficiency of energy conversion and minimization of environmental pollution. However, the large overpotential for oxygen reduction reaction at the cathode and the low activity, poor durability and high cost of platinum-based catalysts in the fuel cells constitute a focal point of major barriers to the commercialization of fuel cells. The development of nanostructured catalysts shows promises to addresses some of the challenging problems. The ability to engineer the composition and nanostructure of nanoalloy catalysts is important for developing active, robust and …


Electrocatalytic Activity Of Palladium Nanocatalysts Supported On Carbon Nanoparticles In Formic Acid Oxidation, Jie Huang, Zhiyou Zhou, Yang Song, Xiongwu Kang, Ke Liu, Wancheng Zhou, Shaowei Chen Dec 2012

Electrocatalytic Activity Of Palladium Nanocatalysts Supported On Carbon Nanoparticles In Formic Acid Oxidation, Jie Huang, Zhiyou Zhou, Yang Song, Xiongwu Kang, Ke Liu, Wancheng Zhou, Shaowei Chen

Journal of Electrochemistry

Palladium nanostructures were deposited onto carbon nanoparticle surface by a chemical reduction method. Transmission electron microscopic studies showed that whereas the resulting metal-carbon (Pd-CNP) nanocomposites exhibited a diameter of 20 to 30 nm, the metal components actually showed a cauliflower-like surface morphology that consisted of numerous smaller Pd nanoparticles (3 to 8 nm). Electrochemical studies showed that the effective surface area of the Pd-CNP nanoparticles was about 40% less than that of Pd black, possibly because the Pd nanoparticles were coated with a layer of carbon nanoparticles; yet, the Pd-CNP nanocomposites exhibited marked enhancement of the electrocatalytic activity in formic …


Electrocatalytic Oxidation Of Formic Acid On Pd/Ni Heterostructured Catalyst, Mingjun Ren, Liangliang Zou, Ju Chen, Ting Yuan, Qinghong Huang, Haifeng Zhang, Hui Yang, Songlin Feng Dec 2012

Electrocatalytic Oxidation Of Formic Acid On Pd/Ni Heterostructured Catalyst, Mingjun Ren, Liangliang Zou, Ju Chen, Ting Yuan, Qinghong Huang, Haifeng Zhang, Hui Yang, Songlin Feng

Journal of Electrochemistry

A Pd/Ni bimetallic nanostructured electrocatalyst was fabricated via a two-step reduction route. Owing to an epitaxial growth of Pd atoms on the surface of Ni nanoparticles, heterostructured Pd/Ni nanocomposites were formed and verified by high resolution transmission electron microscopy combined with energy-dispersion X-ray spectroscopy. X-ray diffraction confirmed that the as-prepared Pd/Ni nanocomposites possessed a single face-centered-cubic (fcc) Pd structure, probably due to a weaker diffraction intensity of metallic Ni and/or overlapping by that of Pd. The intrinsic catalytic activity on the Pd/Ni is higher than that on the Pd. Moreover, the durability of formic acid oxidation on the Pd/Ni was …


Adsorption And Electrooxidation Of Carbon Monoxide On Platinum Surfaces Modified With Sulfur, A. Mattox Mathew, W. Henney Matthew, Johnson Adam, Zou Shouzhong Dec 2012

Adsorption And Electrooxidation Of Carbon Monoxide On Platinum Surfaces Modified With Sulfur, A. Mattox Mathew, W. Henney Matthew, Johnson Adam, Zou Shouzhong

Journal of Electrochemistry

Adsorbed sulfur is commonly considered as a reaction poison. However, small amounts of sulfur on platinum significantly increase the surface reactivity toward carbon monoxide (CO) electrooxidation. For the solution CO oxidation, the onset potential was shifted up to over 300 mV negative to that on S-free surface, and the extent of the negative potential shift increases with the sulfur coverage (Xs) up to about 0.6. The enhanced CO oxidation also depends on the solution pH. For the adsorbed CO, at low sulfur coverages (Xs < 0.3), the oxidation peak potential is about 40 mV negative to that of the corresponding clean Pt. However, at higher coverages, the peak potential is about 30 mV more positive. Surface-enhanced Raman spectra show that the adsorption of sulfur significantly redshifts the Pt-CO stretching frequency. These observations are explained by the weakening of the Pt-CO bond and the hindrance of CO diffusion by Sads.


Kinetic Study Of Photoelectrochemical Oxidation Of Lignin Model Compounds On Tio2 Nanotubes, Min Tian, Daniel Liba, Aicheng Chen Dec 2012

Kinetic Study Of Photoelectrochemical Oxidation Of Lignin Model Compounds On Tio2 Nanotubes, Min Tian, Daniel Liba, Aicheng Chen

Journal of Electrochemistry

In this study, TiO2 nanotubes were prepared via the electrochemical oxidation of titanium substrates in a non-aqueous electrolyte and their morphology and microstructures were examined by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The photoelectrochemical oxidation of two lignin model compounds, 1-(3,4-dimethoxyphenoxy)-2-(2-methoxyphenoxy)-1,3-propanediol (DMP) and 3-hydroxy-1-(3,4-dimethoxyphenoxy)-2-(2-methoxyphenoxy)-1,3-propanone (HDM), was investigated. A new band appeared at ~304 nm during the photoelectrochemical oxidation of DMP. The rate of DMP intermediate formation was amplified with the increase of initial concentrations, while it was diminished with increased temperature. Despite the similarity in structure between HDM and DMP, there are only small increases in absorbance …


Electrochemical Performance Of Screen-Printed Composite Coatings Of Conducting Polymers And Carbon Nanotubes On Titanium Bipolar Plates In Aqueous Asymmetrical Supercapacitors, Xiaohang Zhou, George Z. Chen Dec 2012

Electrochemical Performance Of Screen-Printed Composite Coatings Of Conducting Polymers And Carbon Nanotubes On Titanium Bipolar Plates In Aqueous Asymmetrical Supercapacitors, Xiaohang Zhou, George Z. Chen

Journal of Electrochemistry

Composites of conducting polymers (polypyrrole and polyaniline) with acid treated multi-walled carbon nanotubes were formulated into printable aqueous inks, with the aid of functional additives (benzethonium chloride as a surfactant with or without polyvinyl alcohol as a binder). The inks were screen-printed as fairly uniform coatings of various mass loading densities and areas (up to 75 mg cm-2 and 100 cm2) on thin titanium plates (0.1 mm in thickness). These screen-printed plates were used to fabricate both unit cell and multi-cell stack of asymmetrical supercapacitors with screen-printed negative electrodes of activated carbon (pigment black) in aqueous electrolytes …


In Situ Pm-Irras Studies Of A Floating Bilayer Lipid Membrane At Au(111) Electrode Surface, Su Zhangfei, Kycia Annia, Jay Leitch J., Lipkowski Jacek Oct 2012

In Situ Pm-Irras Studies Of A Floating Bilayer Lipid Membrane At Au(111) Electrode Surface, Su Zhangfei, Kycia Annia, Jay Leitch J., Lipkowski Jacek

Journal of Electrochemistry

In situ Polarization modulation infrared reflection absorption spectroscopy (PM-IRRAS) was used to study the structure of a DMPC + cholesterol + GM1 floating bilayer lipid membrane (fBLM) at a Au(111) surface. 1-thio-beta-D-glucose (beta-Tg) was self-assembled onto the Au electrode to increase the overall hydrophilicity of the surface. The fBLM was deposited on the beta-Tg self-assembled monolayer (SAM) using a combination of Langmuir-Blodgett/Langmuir-Schaefer (LB/LS) techniques. The carbohydrate headgroups of the GM1 molecules were physically adsorbed to the beta-Tg SAM forming a water rich cushion between the fBLM and the modified gold substrate. The PM-IRRAS spectra indicate that the DMPC molecules within …


Electrochemical Synthesis Of Silver-Tetracyanoquinodimethane Nanorods At Agar Supported Water/1,2-Dichloroethane Interface, Li Huang, Yixian Wang, Michael V. Mirkin, Bin Ren, Dongping Zhan Oct 2012

Electrochemical Synthesis Of Silver-Tetracyanoquinodimethane Nanorods At Agar Supported Water/1,2-Dichloroethane Interface, Li Huang, Yixian Wang, Michael V. Mirkin, Bin Ren, Dongping Zhan

Journal of Electrochemistry

Silver-tetracyanoquinodimethane (AgTCNQ) is an important charge transfer salt due to its high conductivity and other electronic properties. In this communication, we report the synthesis of AgTCNQ at the liquid/liquid interface. Agar was used as a gelling agent to support water/1,2-dichloroethane (DCE) interface. Silver ions were transferred from the hydrogel into DCE phase, where they combined with TCNQ- to form AgTCNQ nanorods. The developed method can provide a new route for synthesis of functional materials based on the electrochemistry at the liquid/liquid interface.


A New Random Walk Simulation Model For Study Of Diffusion Behavior Of Single Particle Within Two-Dimensional Space, Jianwei Zhao, Lili Chen, Yingqiang Fu, Shaohong Li, Tiannan Chen, Shijie Zhang Oct 2012

A New Random Walk Simulation Model For Study Of Diffusion Behavior Of Single Particle Within Two-Dimensional Space, Jianwei Zhao, Lili Chen, Yingqiang Fu, Shaohong Li, Tiannan Chen, Shijie Zhang

Journal of Electrochemistry

Research on diffusion behaviors is of significant value in that it is closely related to transport phenomena in micro-chemistry. However, the effects of variables on diffusion are still unclear. Here, we developed and programmed a simulation methodology along with data analysis, which was capable to simulate the diffusion of a particle within twodimensional heterogeneous space in large timescale; the effects of periodically arranged impenetrable barriers of specific shape and lateral drifting velocity on diffusion behavior were studied. As well as standard mean square displacement analysis, a new method, the appearance probability distribution method, was introduced, which revealed whether the particle …


Electrochemical Detection Of Ammonia In Aqueous Solution Using Fluorescamine: A Comparison Of Fluorometric Versus Voltammetric Analysis, Panchompoo Janjira, G. Compton Richard Oct 2012

Electrochemical Detection Of Ammonia In Aqueous Solution Using Fluorescamine: A Comparison Of Fluorometric Versus Voltammetric Analysis, Panchompoo Janjira, G. Compton Richard

Journal of Electrochemistry

Fluorescamine is a non-fluorescent reagent widely used for the quantitative determination of primary amines by fluorescence spectroscopy as it reacts readily with primary amines to form a fluorescent product. In this work, a new sensitive voltammetric method for the detection of ammonia in aqueous solution by the reaction with fluorescamine has been developed. First, the electrochemical behaviour of fluorescamine in the absence and presence of ammonia was investigated in 0.1 mol L-1 borate buffer solution (pH 9.0) by cyclic voltammetry using a glassy carbon (GC) electrode. As for fluorescamine itself, a well-defined irreversible oxidation peak could be observed at …


The Oxidation Of Hydrogen Peroxide On Nanostructured Rhodium Microelectrodes, N. Bartlett Philip, F. Esterle Thomas Oct 2012

The Oxidation Of Hydrogen Peroxide On Nanostructured Rhodium Microelectrodes, N. Bartlett Philip, F. Esterle Thomas

Journal of Electrochemistry

Mesoporous Rh films were deposited onto platinum microelectrodes from the H1 lyotropic liquid crystalline phase of C12EO8 (octaethyleneglycol monododecyl ether). The electrodes show well defined voltammetry for the oxidation and the reduction of hydrogen peroxide at low concentrations (<10 mmol•L-1) with excellent stability for operation at neutral pH. Based on the hysteresis in the current and the potential dependence the oxidation of hydrogen peroxide occurs through a CEE mechanism involving Rh(OH)3 on the mesoporous Rh electrode surface. At higher hydrogen peroxide concentrations the current reaches a plateau that is due to either saturation of the binding sites for hydrogen peroxide or limitation of the reaction due to acidification of the solution within the pores. For the thin films (below 200 nm) the hydrogen peroxide calibration curves we …


Foreword, Bin Ren Oct 2012

Foreword, Bin Ren

Journal of Electrochemistry

On the request of Prof. Shi-Gang Sun, Editor-in-Chief of Journal of Electrochemistry, I served as the guest editor for this International Special Issue on Current Electrochemistry. The Journal of Electrochemistry was founded in 1995 associated to the Chinese Chemical Society just before the 46th Annual meeting of the International Society of Electrochemistry (ISE). Prof. Zhao-Wu Tian was the founder of the journal and had been serving as the Editor-in-Chief until 2010. The journal is known for high quality scientific papers related to the electrochemical science, techniques and engineering, and is well-known in Electrochemistry Community in China. However, the journal …


Underpotential Deposition Of Copper On Pt(S)[N(100)X(110)] Stepped Surfaces, Gisbert Rubn, Climent Vctor, Herrero Enrique, M. Feliu Juan Oct 2012

Underpotential Deposition Of Copper On Pt(S)[N(100)X(110)] Stepped Surfaces, Gisbert Rubn, Climent Vctor, Herrero Enrique, M. Feliu Juan

Journal of Electrochemistry

The underpotential deposition of Cu on platinum stepped surfaces composed of (100) terraces and (110) monoatomic steps has been studied in different acidic solutions. It has been found that the initial stage of copper deposition on the surface takes place simultaneously on terrace and step sites, irrespective of the nature of the adsorbing anion. During the voltammetric deposition of a full monolayer, several peaks can be observed. The analysis of the dependence of the peak charge with the step density allows assigning the different peaks to different deposition sites. The peak appearing at most positive potentials corresponds to the deposition …


The Electrochemical Properties Of 1-Pyrenebutyric Acid/Graphene Composites And Their Application In Glucose Biosensors, Min Wang, Jiong Wang, Fengbin Wang, Xinghua Xia Oct 2012

The Electrochemical Properties Of 1-Pyrenebutyric Acid/Graphene Composites And Their Application In Glucose Biosensors, Min Wang, Jiong Wang, Fengbin Wang, Xinghua Xia

Journal of Electrochemistry

The electrochemical properties of 1-pyrenebutyric acid/graphene composites (PBA/G) obtained by one-step synthesis via π-π stacking was investigated. The electrochemical impedance titration curve shows the surface charge changes as function of solution pH by using ferricyanide/ferrocyanide redox couple as the probe. An apparent pKa value is estimated as 6.2 according to the impedance titration curve. In addition, a glucose biosensor was constructed by immobilizing glucose oxidase (GOD) on the surface of PBA/G via covalent interaction. This biosensor shows a linear response to glucose within the concentration up to 5 mmol L-1 with a detection limit of 0.085 mmol L …


Carbon Nanotubes With Ni2P Nanoparticles As A Counter Electrode In Dye-Sensitized Solar Cells, Yan-Ye Dou, Nan-Fu Yan, Guo-Ran Li, Xue-Ping Gao Aug 2012

Carbon Nanotubes With Ni2P Nanoparticles As A Counter Electrode In Dye-Sensitized Solar Cells, Yan-Ye Dou, Nan-Fu Yan, Guo-Ran Li, Xue-Ping Gao

Journal of Electrochemistry

Carbon nanotubes (CNTs) supported by Ni2P nanoparticles are prepared and used as a counter electrode in dye-sensitized solar cells (DSSCs) for the first time. The CNTs-Ni2P composite was prepared by the heat treatment of a mixed precursor including nickel chloride, sodium hypophosphite and CNTs in argon atmosphere. The X-Ray diffraction (XRD) results indicate that the as-prepared sample consists of hexagonal Ni2P and carbon nanotubes. No peaks of other nickel phosphides are observed in the XRD pattern. Microstructure of the Ni2P-CNTs composite was investigated using transmission electron microscopy (TEM). It is shown that the Ni …


Discharge Curve Fitting Of Lifepo4 Based On Impedance Model, Ming Wang, Jian-Jun Li, Xiang-Ming He, Peng Bai, Gan Wu, Chun-Rong Wan, Guang-Yu Tian Aug 2012

Discharge Curve Fitting Of Lifepo4 Based On Impedance Model, Ming Wang, Jian-Jun Li, Xiang-Ming He, Peng Bai, Gan Wu, Chun-Rong Wan, Guang-Yu Tian

Journal of Electrochemistry

In this paper, an impedance model is developed for simulating the discharge curve of LiFePO4 cathode material. The voltage drop is divided into three parts: the Ohm voltage drop, the charge transfer voltage drop and the diffusion voltage drop. A theoretical expression has been derived to predict the discharge curves at various discharge rates. The parameters of the equation have been obtained by fitting the results of EIS measurement, and a good agreement between the fitting and the experimental data has been found at all discharge rates.


Influences Of Particle Size And Sulfuric Acid Treatment On The Electrochemical Performance Of Bamboo Charcoal, Yu Yao, Ai-Shui Yu Aug 2012

Influences Of Particle Size And Sulfuric Acid Treatment On The Electrochemical Performance Of Bamboo Charcoal, Yu Yao, Ai-Shui Yu

Journal of Electrochemistry

The bamboo charcoal had been milled and treated by sulfuric acid. The influences of as-prepared material particle size and sulfuric acid treatment on the electrochemical performance had been studied. The result displays that the bamboo charcoal with mean particle size about 5 μm has the best first coulombic efficiency. Sulfuric acid treatment could raise the discharge capacity of bamboo charcoal, and the first discharge capacity of 328.2 mAh·g-1 was obtained with the bamboo charcoal treated by sulfuric acid for 18 h. Furthermore, the capacity of 302.3 mAh·g-1 could be maintained for 50 cycles, showing good cycle performance.


Electrochemical Performance Of Yf3-Coated Li(Li0.22Ni0.17Mn0.61)O2 Cathode Material For Li-Ion Batteries, Xin Feng, Guo-Ran Li, Shi-Hai Ye, Xue-Ping Gao Aug 2012

Electrochemical Performance Of Yf3-Coated Li(Li0.22Ni0.17Mn0.61)O2 Cathode Material For Li-Ion Batteries, Xin Feng, Guo-Ran Li, Shi-Hai Ye, Xue-Ping Gao

Journal of Electrochemistry

The Li(Li0.22Ni0.17Mn0.61)O2 was prepared with oxalic co-precipitation and coated with an YF3 layer by a chemical deposition method. The as-prepared and YF3-coated Li-rich materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). The results demonstrate that the as-prepared and YF3-coated Li(Li0.22Ni0.17Mn0.61)O2 materials have a typical layered structure and are composed of sphere-like particles with a diameter of 100~200 nm. Galvanostatic charge-discharge tests show that the discharge capacity of the YF3-coated Li(Li0.22 …


Preparation And Performance Of Sn-Co-M-C(M = Zn, Fe)Composites As An Anode Material, Guo-Qing Fang, Wei-Wei Liu, Shi-Ci He, Qian Zhang, Jun-Wei Zheng, De-Cheng Li Aug 2012

Preparation And Performance Of Sn-Co-M-C(M = Zn, Fe)Composites As An Anode Material, Guo-Qing Fang, Wei-Wei Liu, Shi-Ci He, Qian Zhang, Jun-Wei Zheng, De-Cheng Li

Journal of Electrochemistry

The anode materials of Sn-Co-M-C (M = Zn, Fe) composites were prepared by carbothermal reduction method from metal oxides and sucrose in N2 atmosphere. Their structural and electrochemical properties were studied by XRD, SEM and charge-discharge test. Among them, the Sn-Co-Zn-C composite showed higher specific capacity and good cycle performance. The initial specific discharge capacity of 571 mAh·g-1 could be obtained, while 369 mAh·g-1 was still kept after 45 cycles.


A Facile Approach To Prepare Lifepo4/C Composite With High-Rate Performance, Peng Zhang, Ling-Bin Kong, Yong-Chun Luo, Long Kang Aug 2012

A Facile Approach To Prepare Lifepo4/C Composite With High-Rate Performance, Peng Zhang, Ling-Bin Kong, Yong-Chun Luo, Long Kang

Journal of Electrochemistry

The LiFePO4/C composite electrode material was synthesized by a moderate in situ carbothermal reduction method at 600 °C using FeCl3·6H2O, LiOH·H2O, and NH4H2PO4 as starting materials, soluble starch sol as a carbon source and a reducing agent. This method is readily reproducible and possibly feasible to carry out large-scale synthesis. The structure and morphology of the LiFePO4/C samples were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The synthesized LiFePO4/C composite was in pure phase of olivine-type, …