Physical Chemistry Commons^™

In Situ Measurement Of Chloride Concentration And Ph Distribution In The Crevice During The Crevice Corrosion Of Copper Electronic Board, Min Zhang, Xiang-Dong Zhuo, Chang-Jian Lin

Journal of Electrochemistry

Although the crevice corrosion of metals had been extensively studied in the past years,it remained lack of direct experimental information of the micro chemical environments and electrochemical conditions inside the corroding crevice.The distribution of chloride concentration and local pH in the occluded area are the most crucial factors in development of crevice corrosion.The array probes in one dimension of Ag/AgCl and IrO₂ array were developed in this work to in situ follow the distribution of chloride concentration and local pH in the occluded area during the crevice corrosion propagation.Based on a designed simulated crevice corrosion system in 0.5mol/L NaCl …

A Study On Supercapacitor Based On Aligned Carbon Nanotubes, Xiao-Yan Ye, Yan-Zhi Wang, Hai-Yan Song, Zhuo Sun, Pin-Gang He, Yu-Zhi Fang

Journal of Electrochemistry

Large scale vertically aligned carbon nanotubes(ACNTs) with uniform length and diameter were prepared by the pyrolysis of iron(Ⅱ) phthalocyanine at low pressure.The ACNTs were activated by electrolyte-activation,acid-activation or electrochemical activation.The performance of the capacitor based on activated ACNTs was characterized by cyclic voltammograms which was of rectangular shape,impedence spectroscopy in which the phase is above 80° and the result specific capacitance was 16～32 F/g,which suggest that the ACNTs are the promising material for the supercapacitor.

Preparation And Electrochemical Performance Of Ordered Mesoporous Titanium Phosphate As Cathode Material For Li-Ion Battery, Qiong Wang, Attia Adel, Zhi-Cong Shi, Yong Yang

Journal of Electrochemistry

Ordered porous titanium phosphate materials were prepared by using the surfactant template combined with the sol-gel method. The samples were characterized by small angle X-ray diffraction(SA-XRD) method, N₂ adsorption/desorption techniques,high resolution transmission electron microscopy(HRTEM) and element analysis. It is found that the calcination temperature is a big influence on the porous structure, and electrochemical performance of the titanium phosphate materials, and the mesoporous titanium phosphate showed good performance in the electrochemical test, the first discharge capacity is 94 mAh/g at the current density of 150 mA/g. On the other hand, the no porous material with a low capacity of …

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

Journal of Electrochemistry

Adipic acid was synthesized by electro-oxidation of cyclohexanol taking Cr₂O₇^2-/Cr³⁺ as indirect oxidant.The best technological conditions were optimized by orthogonal experiment.The optimum condition are as follows: the temperature is 35 ℃,ratio of crude material is n(cyclohexanol)∶n(Cr₂O₇^2-)=0.4∶1 and concentration of H₂SO₄ is 4 mol·L^-1.Under these conditions,the yield of adipic acid can reach 70.29%.Moreover,The effects of concentration of Ag₂SO₄,(NH₄)₂SO₄,H₂SO₄and current density on the formation of Cr₂O₇^2-were also …

Study Of Black Electromagnetic Shielding Fabric, Shao-Wen Lu, Wei Wang, Bin Sun

Journal of Electrochemistry

A soft electromagnetic shielding fabric was successfully prepared by electroplating black nickel on the Cu-plated PET fabric,preliminary thechnigue conditions were carried out as NiSO₄·6H₂O 40 g·L^-1,H₃BO₃ 30 g·L^-1,NiSO₄·(NH₄)SO₄·6H₂O 40 g·L^-1,ZnSO₄·7H₂O 50 g·L^-1,NH₄CNS 20 g·L^-1,pH=4,t=30 ℃.The expericments showed that the soft electromagnetic shielding fabric had good conductive and electromagnetic shielding effectiveness,great abrasion resistance and erosion resistance performance and excellent absorbency performance,all of these promote the fabric decoration,protection and absorbency property.

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

Journal of Electrochemistry

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

Interfacial Electrochemical Behavior Of Fibrinogen On Pt Electrode, Song-Mei Chen, Jian-Zhang Zhou, Zhong-Hua Lin, Dong-Mei Zeng, Nan Huang, Guo-Jiang Wan

Journal of Electrochemistry

The interfacial electrochemical behaviors of fibrinogen on Pt electrode in phosphate buffered solution(PBS) was investigated by using cyclic voltammetry and electrochemical in-situ FTIR spectroscopy.The cyclic voltammetry results demonstrated that the fibrinogen adsorb on Pt electrode and impede the interfacial charge transfer of hydrogen ion reaction process as well as of oxygen reduction process,which is increased with higher scan rate.The cyclic voltammetry spectra of platinum absorbed with fibrinogen in K₃[Fe(CN)₆] and K₄[Fe(CN)₆]·3H₂O solutions shows that the fibrinogen can partly decrease the oxidation and reduction current peaks.There is no specific anodic and …

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

Journal of Electrochemistry

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

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

Journal of Electrochemistry

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

A Quick Charge System For The Agv Automatic Guided Vehicle, Chun-Yuan Pian, Jun-Feng Liu

Journal of Electrochemistry

The quick charge system used for AGV automation guidance vehicle nickel hyarogen driving force battery,witch can test and compute parameter in real time during charging process,judge logically,control the charging process and adopt a depolarization to discharge in order to improve charging efficiency.

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

Journal of Electrochemistry

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

Quantized Capacitance Charging Of Self-Assembled Monolayer Protected Gold Clusters, Li Wen, Jian-Zhang Zhou, Qiao-Lin Chen, Guo-Liang Chen, Zhong-Hua Lin

Journal of Electrochemistry

Quantized capacitance charging was observed for the C₁₂Au monolayer-protected clusters self-assembled on a gold electrode surface in CH₂Cl₂ solution at room temperature.The result from differential pulse voltammetry(DPV) of C₁₂Au MPC with average core diameter of 2.0 nm showed that which appear nine entries well-defined quantized capacitance charging peaks within the potential range of-0.6 to +0.6 V.The change trend of MPC double-layer capacitances(CMPC) was that the value of CMPC was smallest near zero charge potential and increased with potential positive or negative transfer.In addition,the effect of Au core size on quantized capacitance charging of …

Inhibition Mechanism Of The Imidazoline Derivate In H2S Solution, Jing-Mao Zhao, He-Xia Liu, Chao Xiao, Yuan Lu

Journal of Electrochemistry

Weight-loss method and polarization curve measurement were employed to study the inhibition mechanism of imidazoline derivate for mild steel in acidic solution with H₂S. The results show that the derivate can retard the cathodic process,and belongs to the cathodic-type inhibitor. The adsorption of the derivate on the surface of mild steel accords with the amended Langmuir adsorption isothermal equation,and higher temperature will facilitate its adsorption. The changes in the apparent activation energy(E_a) and the pre-exponential factor(A) of the corrosion reaction before and after the addition of inhibitor were also discussed.

Electrochemical Behavior Of 6-Substituted Purines And Its Interaction With Dna, Bao-Yi Lu, You-Zhi Zheng, Hong Li

Journal of Electrochemistry

The electrochemical behavior of 6-furfurylaminopurine(6-KT) and 6-mercaptopurine(6-MP) on a mercury electrode has been investigated using cyclic voltammetry and differential pulse voltammetry.It is found that there are two pairs of redox waves for 6-KT and 6-MP on the mercury electrode controlled by diffusion and adsorption,respectively.The anodic peak currents of the diffusion-controlled wave increase with the adding concentration of 6-substituted purines.A good linear relationship for 6-KT and 6-MP is revealed in the concentration range from 0.1 to 50.0 μmol·L^-1.Based on the effects of accumulating time and pH values on the cathodic peak potentials and currents of adsorption-controlled waves,their adsorption mechanism …

Molten Salt Treatment Of Mno2 And Investigation On Supercapacitor Properties, Ye Chen, Zun-Bo Zhang, Wei Zhang, Liang Liu, Zhi-Min Liu

Journal of Electrochemistry

The MnO₂ prepared by solid phase method is treated by KCl-NaCl-LiCl molten salt system.The XRD patterns indicated that the crystal structures of MnO₂ sample have had the α-MnO₂ and γ-MnO₂ phase,the crystallinity of sample is increased after treated by molten salt.The electrochemical properties were tested by cyclic voltammetry,constant current charge/discharge and AC impedance.The result shows that the supercapacitor performance of the treated material has improved.The specific discharge capacitance of the treated sample are 129.07 F·g^-1,increased by 27.88% compared to 100.94 F·g^-1 of untreated sample.Long cycle life and high coulombic efficiency were also demonstrated …

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

Journal of Electrochemistry

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

Study On The Binding Mode Of In(Bpy)Cl3·H2O With Dna By The Methods Of Electrochemistry, Jun-Wei Wang, Jian-Guo Ren, Bao-Juan Zhou, Xiao-Ling Gao, Yan-Ni Tian

Journal of Electrochemistry

The complex In(bpy)Cl₃·H₂O was synthesized.The binding mode of the complex with DNA was studied by the methods of cyclic voltammetry(CV),differential pulse voltammetry and ac impedance in the buffer Tris-HCl(pH=7.2).A quasi-reversible redox wave for the central Indium ion from the cyclic voltammograms was shown at a PG electrode.It has been found that after the complex acted with DNA,The complex's formal potential negatively shifted from-0.696 V to-0.717 V,the values of the reduction peak current and apparent diffusion coefficient decreased significantly.The results of differential pulse voltammetry were the same as cyclic voltammetry,and the electrochemical reaction resistance values increased from …

Potentiometric Response Of Glucose On Mno2-GoX Carbon Paste Electrode, Cai-Juan Wang, Xiao-Ya Hu

Journal of Electrochemistry

A novel carbon paste electrode(CPE) modified with MnO₂ and glucose oxidase(GO_x), is reported. Different factors, such as the effect of supporting electrolyte, pH of solutions,various paste glues, the amount of MnO₂ and temperature, which may influence the determination of H₂O₂ and glucose were tested to optimize. Based on above, potentiometric determination of glucose was achieved in neutral solution and at 35 ℃, the electrode gave a response of 36.12～34.62 mV/pG lucose between 2.0×10^-5 mol·L-1 and 5.2×10^-3 mol·L^-1 with a detection limit of 3.3×10^-6 mol·L^-1. Moreover, this kind …

Square Wave Stripping Voltammetric Behaviors Of Rutin On Glassy Carbon Electrode And Its Application, Jun Hua, Xiao-Ying He, Fang Liao, Qing-Tao Zhu

Journal of Electrochemistry

The electrochemical behaviors of rutin(Rt) at glassy carbon electrode were studied by square wave stripping voltammeter in the presence of 0.1mol·L^-1HAc-NaAc buffer solution(pH=3.0).The sensitive oxidation peak of rutin was observed and which potential peak is 0.46V(vs.SCE).The experimental parameters,such as pH value,deposition potential and deposition time were investigated and selected.The peak currents were proportional to the concentration of rutin in range of 5.0×10^-8 mol·L^-1~1.0×10^-6mol·L^-1,and the linear regression coefficient equaled 0.99799,the detection limit was 1.1×10-8 mol·L^-1.This method was applied to the determination of rutin content in tablet with satisfactory results.

Corrosion Electrochemical Behavior Of Az31 And Az61 Magnesium Alloys In Simulated Sea Water, Ling-Jie Li, Sheng-Hai Yu, Jing-Lei Lei, Chuan-Pu Liu, Sheng-Tao Zhang, Fu-Sheng Pan

Journal of Electrochemistry

Tafel polarization curves and electrochemical impedance spectroscopy(EIS) techniques were employed to investigate the corrosion electrochemical behavior of AZ31 and AZ61 magnesium alloys.Scanning electron microscopy(SEM) was used to observe the alloy microstructure and corrosion morphology.The variation of the bulk corrosive medium pH with immersion time was recorded during the exposure of the alloys to simulated sea water.Results show that AZ61 magnesium alloy exhibits much better anti-corrosion ability than AZ31 magnesium alloy.The different corrosion behavior between the two magnesium alloys is correlated with their different content of Al alloying element.The higher content of Al in AZ61 alloy leads to the homogenerous microstructure …

The Determination Of Vitamin C By Bromophenol Blue Modified Glassy Carbon Electrode, Shu-Lin Zhang, Min-Jiao Li, Yi Luo, Xiao-Bo Wang

Journal of Electrochemistry

The content of ascorbic acid of(vitamin C) was analyzed by using fast cyclic voltamment with bromophenol blue(BPB) modififed GC-electrode,and which experimental conditions were optimiged.The results showed that the BPB modified GC-electrode had the good stability and anti-jamming faculty for analysing the content of ascorbic acid.A linear relationship between the peak current and concentration of vitamin C in the range of 0.0050~0.1500 g·L^-1 was obtained,which related coefficient and the detection limit are-0.9991 and 0.0010 g·L^-1,respeclively.The method has satisfactory results.

Dirubidium Digallium Oxide Bis(Orthoborate), Robert W. Smith, Chunhua Hu, Christopher D. Despain

Chemistry Faculty Publications

The title compound, Rb2Ga2O(BO3)2, is part of the homologous series A2Ga2O(BO3)2 (A = Na, K, Rb and Cs). The structure contains pairs of gallium-centered tetrahedra connected through a shared oxygen vertex. Orthoborate triangles connect the basal vertices of the tetrahedra, forming a three-dimensional network with voids occupied by rubidium ions.

C–N Bond Rotation And E–Z Isomerism In Some N-Benzyl-N-Methylcarbamoyl Chlorides: A Dft Study, Michael Horwath, Vladimir Benin

Chemistry Faculty Publications

The current report presents the first theoretical study of the restricted CN bond rotation in carbamoyl chlorides. Several N-benzyl-N-methylcarbamoyl chlorides were investigated, with varying pattern of substitution in the aromatic ring. Optimizations and frequency calculations were conducted employing DFT at the B3LYP/6-31+G(d) level of theory. Each of the studied structures exhibits a pair of rotamers (s-Z and s-E), generated upon rotation around the C(O)N bond. The s-E isomer is the global minimum in every case, but the preference for it is usually less than 1 kcal/mol. Two possible transition state structures were identified …

[Link Foundation Fellowship Final Report], Alex Martinson

Link Foundation Energy Fellowship Reports

Efficient conversion of solar radiation into electricity is a compelling scientific and economic goal. As the world’s energy demands continue to grow it has become clear that burning fossil fuels for energy is unsustainable and detrimental to global health and geopolitics. More than any other renewable resource, solar energy conversion has the potential to meet human energy needs with a total yearly insolation of 120,000 TW/year.1 While organic photovoltaics (PVs) are currently not as efficient as their inorganic counterparts, their efficiencies have been steadily increasing over the past decade. The most significant advances are attributable to greater control over the …

Parameterizing A Simple Potential Energy Function Appropriate For Vibrational Frequencies Using Molecular Dynamics, Carl W. David

Chemistry Education Materials

A Maple scheme for quickly parameterizing vibrational potential energy functions is presented. As an example, the potential energy function's parameters for the vibrational motions in H_2O_2 are obtained assuming the simplest potential energy function.

This paper was originally written as a research paper, but rejected by the referees. It is therefore being edited into an ``educational'' paper for student usage.

Singlet Oxygen Chemistry In Water:  A Porous Vycor Glasssupported Photosensitizer, David Aebisher, Nikolay S. Azar, Matibur Zamadar, Naveen Gandra, Harry D. Gafney, Roumei Gao, Alexander Greer

Faculty Publications

Singlet molecular oxygen [1O2 (1Δg)] is generated cleanly in aqueous solution upon irradiation of a heterogeneous complex, meso-tetra(N-methyl-4-pyridyl)porphine (1) adsorbed onto porous Vycor glass (PVG). The cationic photosensitizer 1 tightly binds onto PVG and gives a stable material, which does not dissociate 1 into the surrounding aqueous phase. The production of 1O2 was measured by monitoring the time-resolved 1O2 (1Δg) phosphorescence at 1270 nm. Indirect analysis of 1O2 generation was also carried out with the photooxidation oftrans-2-methyl-2-pentenoate anion, which afforded the corresponding hydroperoxide. Sensitizer-1-impregnated PVG gives rise to a new singlet …

Ua66/1/5 Icset - Institute For Combustion Science & Environmental Technology, Wku Ogden College Of Science & Engineering

WKU Administration Documents

History and overview of the work of the WKU Institute for Combustion Science & Environmental Technology through 2008.

Spectroscopy Is Applied Quantum Mechanics. Part 2: The Quantum Revolution, David W. Ball

Chemistry Faculty Publications

The article presents several theories relative to the nature of matter. The quantum theory of German theoretical physicist Max Planck proposes that the energy of a vibrating atom was related to its frequency. Albert Einstein's quantum theory of light hypothesizes that light itself had an energy that was directly proportional to its frequency. Danish physicist Niels Bohr develops an equation that could help explain the lines that appeared in the spectrum of the hydrogen atom.

Evaluation Of A Naive Model For Square Wave Voltammetry At A Microelectrode, Patrick Enright, John Cassidy, Tony Betts

Articles

A square wave voltammetric waveform ( SWV) was applied to an inlaid microdisk electrode in a solution of K4[Fe(CN)6]. A simple model relying on the assumption of steady state current throughout the scan was used to model the current potential behaviour. However, experimental peak current magnitudes were between 30% and 50% greater than those predicted by the model. The model predicts an increase of peak current and peak width at half height with pulse height Esw and no effect of the parameters frequency, f and step height, ΔEs. Experimental peak current magnitudes and peak current magnitudes predicted by the model …

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

Student Works (2010-2019)

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