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2010

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Articles 31 - 60 of 117

Full-Text Articles in Physical Chemistry

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

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

Journal of Electrochemistry

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


Phenomena Characterization Of Energy Materials By X-Ray Absorption Spectroscopy, Ming-Yao Cheng, Chun-Jen Pan, Ju-Hsiang Cheng, Bing-Joe Hwang Aug 2010

Phenomena Characterization Of Energy Materials By X-Ray Absorption Spectroscopy, Ming-Yao Cheng, Chun-Jen Pan, Ju-Hsiang Cheng, Bing-Joe Hwang

Journal of Electrochemistry

The aim of this review is to introduce the characterization of energy materials by X-ray absorption spectroscopy (XAS) . This technique allows us to probe changes in the valance state and the local environment of the targeted element in the active material; thereby,leading to a better understanding of its electrochemical behavior,and hopefully showing the way to improved performance. Here,electrocatalysts for fuel cells and active electrode materials for Li-ion batteries are taken as the examples that illustrate the capability of XAS and allow observation and theory to be correlated with electrochemical phenomena.


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

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

Journal of Electrochemistry

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


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

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

Journal of Electrochemistry

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


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

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

Journal of Electrochemistry

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


The Sers Effect Of AuCore@PtShelL Nanoparticles With Different Pt Shell Thicknesses, Yan Zhong, Liang-Liang Yan, Gui-Shi Rao, Xiao-Cong Deng, Fei-Peng Wen, Jin-Long Xu, Qi-Ling Zhong Aug 2010

The Sers Effect Of AuCore@PtShelL Nanoparticles With Different Pt Shell Thicknesses, Yan Zhong, Liang-Liang Yan, Gui-Shi Rao, Xiao-Cong Deng, Fei-Peng Wen, Jin-Long Xu, Qi-Ling Zhong

Journal of Electrochemistry

By using Au nanoparticles with a diameter of 55 nm as the core and ascorbic acid as the reductant, Aucore@ Ptshell nanoparticles of controllable Pt shell thickness (0.3 ~ 6 nm) were synthesized by controlling the concentration of [PtCl6]2- ions. The ultraviolet-visible absorption spectrometry,scanning electron microscope (SEM), transmission electron microscope (TEM) ,high resolution transmission electron microscope (HRTEM) , and electrochemical cyclic voltammetry were employed to determine surface morphology and structure of  Aucore@Ptshell. With SCN- ion as a probe,the effect of the thickness of the Pt shell on the SERS …


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

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

Journal of Electrochemistry

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


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

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

Journal of Electrochemistry

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


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

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

Journal of Electrochemistry

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


Preliminary Investigation Of Iron Protoporphyrin Sams On Platinum Electrodes By Surface Enhanced Vibrational Spectroscopies, Min Ma, Yao-Yue Yang, Han-Xuan Zhang, Wen-Bin Cai Aug 2010

Preliminary Investigation Of Iron Protoporphyrin Sams On Platinum Electrodes By Surface Enhanced Vibrational Spectroscopies, Min Ma, Yao-Yue Yang, Han-Xuan Zhang, Wen-Bin Cai

Journal of Electrochemistry

In situ SERS and ATR-SEIRAS were applied to investigate the electrochemical and structural properties of iron protoporphyrin IX (FePP) self-assembled monolayers (SAMs) on Pt electrodes in 0. 1 mol· L -1 HClO4. The potential dependent SERS spectra of the FePP SAM on a roughened Pt electrode with the enhancement factor of ca. 40 were acquired with the excitation line of 514 nm. Analyses of SERS data over the potential region from 0. 5 to -0. 3 V enabled to obtain potential dependent adsorption isotherms,from which the formal redox potential could be estimated to be ca. -0. 2 V. …


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

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

Journal of Electrochemistry

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


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

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

Journal of Electrochemistry

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


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

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

Journal of Electrochemistry

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


New C1 Geometries For Free 12-Crown-4 In Aqueous Solution And The Absolute Selectivity Of 12-Crown-4 On Alkali Metal Ions In Aqueous Solution: A Theoretical Study, Tanika Arora Aug 2010

New C1 Geometries For Free 12-Crown-4 In Aqueous Solution And The Absolute Selectivity Of 12-Crown-4 On Alkali Metal Ions In Aqueous Solution: A Theoretical Study, Tanika Arora

Student Theses and Dissertations

The IEFPCM conformational study of 12c4 in aqueous phase with B3LYP/6-31+G* and metal ion complex, M+(12c4), M= Li, Na and K withB3LYP, B3P86, B3PW91 and mPW3PBE using 6-31+G* basis sets are performed. Our result shows that the ground state conformer of 12c4 in gas phase, 1(S4) has population of no more than 2% in aqueous solution. The conformer 11(C1) structure was diagnosed to be the most populated conformer while B3LYP method predicts the conformer 6(Ci) has the lowest energy. The metal ion (Li+, Na+, K+) selectivity of 12c4 in aqueous phase is determined by the isodesmic reaction. The ensemble averaged …


Full Multiple Scattering Analysis Of Xanes At The Cd L 3- And O K- Edges In Cdo Films Combined With A Soft-X-Ray Emission Investigation, I. N. Demchenko, J. D. Denlinger, M. Chernyshova, K. M. Yu, D. T. Speaks, P. Olalde-Velasco, Oliver Hemmers, W. Walukiewicz, A. Derkachova, K. Lawniczak-Jablonska Aug 2010

Full Multiple Scattering Analysis Of Xanes At The Cd L 3- And O K- Edges In Cdo Films Combined With A Soft-X-Ray Emission Investigation, I. N. Demchenko, J. D. Denlinger, M. Chernyshova, K. M. Yu, D. T. Speaks, P. Olalde-Velasco, Oliver Hemmers, W. Walukiewicz, A. Derkachova, K. Lawniczak-Jablonska

Environmental Studies Faculty Publications

X-ray absorption near edge structure (XANES) at the cadmium L3 and oxygen K edges for CdO thin films grown by pulsed laser deposition method, is interpreted within the real-space multiple scattering formalism, FEFF code. The features in the experimental spectra are well reproduced by calculations for a cluster of about six and ten coordination shells around the absorber for L3 edge of Cd and K edge of O, respectively. The calculated projected electronic density of states is found to be in good agreement with unoccupied electronic states in experimental data and allows to conclude that the orbital character of the …


Theoretical And Experimental Studies In Nuclear Magnetic Resonance, Adrienne M. Roehrich Aug 2010

Theoretical And Experimental Studies In Nuclear Magnetic Resonance, Adrienne M. Roehrich

Department of Chemistry: Dissertations, Theses, and Student Research

Nuclear magnetic resonance (NMR) is a tool used to probe the physical and chemical environments of specific atoms in molecules. This research explored small molecule analogues to biological materials to determine NMR parameters using ab initio computations, comparing the results with solid-state NMR measurements. Models, such as dimethyl phosphate (DMP) for oligonucleotides or CuCl for the active site of the protein azurin, represented computationally unwieldy macromolecules. 31P chemical shielding tensors were calculated for DMP as a function of torsion angles, as well as for the phosphate salts, ammonium dihydrogen phosphate (ADHP), diammonium hydrogen phosphate, and magnesium dihydrogen phosphate. The …


Chemical Reasoning Based On An Invariance Property: Bond And Lone Pair Pictures In Quantum Structural Formulas, Joseph D. Alia Jul 2010

Chemical Reasoning Based On An Invariance Property: Bond And Lone Pair Pictures In Quantum Structural Formulas, Joseph D. Alia

Chemistry Publications

Chemists use one set of orbitals when comparing to a structural formula, hybridized AOs or NBOs for example, and another for reasoning in terms of frontier orbitals, MOs usually. Chemical arguments can frequently be made in terms of energy and/or electron density without the consideration of orbitals at all. All orbital representations, orthogonal or not, within a given function space are related by linear transformation. Chemical arguments based on orbitals are really energy or electron density arguments; orbitals are linked to these observables through the use of operators. The Valency Interaction Formula, VIF, offers a system of chemical reasoning based …


Quantitative Structure-Property Relationships For Predicting Group Iib Metal Binding By Organic Ligands, Aliyar Mousavi Jun 2010

Quantitative Structure-Property Relationships For Predicting Group Iib Metal Binding By Organic Ligands, Aliyar Mousavi

Chemistry and Chemical Biology ETDs

Mercury (Hg), cadmium (Cd), and zinc (Zn) in the environment are all of toxicological and environmental concern, and the pollution of natural waters by any of these three elements is most serious. Mercury is the most environmentally concerning of the three because of the neurotoxin species monomethylmercury produced in aquatic systems through the methylation of Hg2+ by aquatic microorganisms. An important chemical process in natural waters that limits the availability of mercury for methylation is the binding of Hg(II) by natural organic matter (NOM). These associations are exceptionally strong, and as NOM is ubiquitous in aquatic environments, estimating equilibrium …


A Surface Femtosecond Two-Photon Photoemission Spectrometer For Excited Electron Dynamics And Time-Dependent Photochemical Kinetics, Zefeng Ren, Chuanyao Zhou, Zhibo Ma, Chun-Lei Xhao, Xinchun Mao, Dongxu Dai, Jerry L. Larue, Russell Cooper, Alec M. Wodtke, Xueming Yang Jun 2010

A Surface Femtosecond Two-Photon Photoemission Spectrometer For Excited Electron Dynamics And Time-Dependent Photochemical Kinetics, Zefeng Ren, Chuanyao Zhou, Zhibo Ma, Chun-Lei Xhao, Xinchun Mao, Dongxu Dai, Jerry L. Larue, Russell Cooper, Alec M. Wodtke, Xueming Yang

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

A surface femtosecond two-photon photoemission (2PPE) spectrometer devoted to the study of ultrafast excited electron dynamics and photochemical kinetics on metal and metal oxide surfaces has been constructed. Low energy photoelectrons are measured using a hemispheri- cal electron energy analyzer with an imaging detector that allows us to detect the energy and the angular distributions of the photoelectrons simultaneously. A Mach-Zehnder interferom- eter was built for the time-resolved 2PPE (TR-2PPE) measurement to study ultrafast surface excited electron dynamics, which was demonstrated on the Cu(111) surface. A scheme for measuring time-dependent 2PPE (TD-2PPE) spectra has also been developed for studies of …


A Systematic Study Of The Effect Of Silver On The Chelation Of Formic Acid To A Titanium Precursor And The Resulting Effect On The Anatase To Rutile Transformation Of Tio2, Nicholas Nolan, Michael Seery, Steve Hinder, Linda Healy, Suresh Pillai Jun 2010

A Systematic Study Of The Effect Of Silver On The Chelation Of Formic Acid To A Titanium Precursor And The Resulting Effect On The Anatase To Rutile Transformation Of Tio2, Nicholas Nolan, Michael Seery, Steve Hinder, Linda Healy, Suresh Pillai

Articles

Anatase to rutile transition in an unmodified synthetic titania usually occurs at a temperature range of 600 – 700 °C. Various methods such as addition of metallic and non-metallic dopants and modifying the precursor have previously been reported to influence the anatase to rutile transition temperature. In the current study, the effect of addition of increasing amounts of silver to the extent of chelation of a formate group to a titanium precursor and the resulting effects on the transformation of anatase to rutile has been studied. The addition of silver (0, 1, 3 and 5 mol %) on the anatase …


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

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

Journal of Electrochemistry

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


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

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

Journal of Electrochemistry

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


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

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

Journal of Electrochemistry

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


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

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

Journal of Electrochemistry

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


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

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

Journal of Electrochemistry

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


Blocking Method In Enzyme-Amplified Amperometric Dna Biosensor, Miao He, Wei Chen, Xiong-Wei Xu, Ai-Lin Liu, Xin-Hua Lin May 2010

Blocking Method In Enzyme-Amplified Amperometric Dna Biosensor, Miao He, Wei Chen, Xiong-Wei Xu, Ai-Lin Liu, Xin-Hua Lin

Journal of Electrochemistry

Non-specific absorption of enzyme and nucleotide is a main source leading to the background staining in enzyme-amplified amperometric detection of DNA. To eliminate the background staining in this system, the blocking procedure by mercapto-hexanol (MCH) and bovine serum albumin (BSA) was studied systematically. The results show that the anti-fouling effect of BSA is better than that of MCH. A simple and efficient blocking strategy employing BSA as the sole blocking reagent was established and applied in the detection of PMLRARα fusion gene in acute promyelocytic leukemia. It can effectively eliminate the background staining,shorten the pre-processing time,and achieve strong signal amplification.


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

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

Journal of Electrochemistry

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


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

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

Journal of Electrochemistry

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


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

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

Journal of Electrochemistry

Electrochemical noise (ECN) measurement can provide information about both corrosion rate and corrosion type while inflicting no perturbation on the studied system. The ECN data of steel rebar in SPS with different amount of Cl-were collected and treated by discrete wavelet transformation to evaluate the contribution from transients in different frequency in the overall signals. Energy distribution plot (EDP) indicated in SPS with 0.0001 mol/L NaCl, the transients with time constant between 16 ~ 32 s were found to be predominant over other processes; while in SPS with higher Cl-concentration, the trend toward active corrosion became the main process. It …


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

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

Journal of Electrochemistry

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