In Situ Surface-Enhanced Raman Scattering Spectroscopic Study Of Sulfur Adsorption On Polycrystalline Platinum Electrode Surface,
2010
Department of Chemistry, Georgetown University, 37th & 0 Streets, NW, Washington, DC 20057, USA
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,
2010
Fudan University
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,
2010
Xiamen University
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,
2010
State Key Lab for Physical Chemistry of Solid Surface and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005,Fujian,China
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,
2010
Xiamen University
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,
2010
Arkansas State University
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,
2010
University of Nevada, Las Vegas
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,
2010
University of Nebraska-Lincoln
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,
2010
University of Minnesota - Morris
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,
2010
University of New Mexico
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,
2010
Dalian Institute of Chemical Physics
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,
2010
Technological University Dublin
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,
2010
State Key Lab of Physical Chemistry of Solid Surfaces,Department of Chemistry, College of Chemistry and Chemical Engineering,Xiamen University,Xiamen 361005,Fujian,China;
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,
2010
Institute of Chemistry,Chinese Academy of Sciences,Beijing 100190,China;
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,
2010
State Key Laboratory for Physical Chemistry of Solid Surfaces and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian, China;
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,
2010
Nanomaterials Research Institute, College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China;
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,
2010
Department of Pharmaceutical Analysis,Fujian Medical University, Fuzhou 350004, China;
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,
2010
Department of Pharmaceutical Analysis,Faculty of Pharmacy,Fujian Medical University, Fuzhou 350004, China;
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,
2010
Changchun Institute of Applied Chemistry, Clean Energy Department, Changchun 130022, China;
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,
2010
Department of Chemistry,College of Chemistry and Chemical Engneering,;
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.
