Materials Chemistry Commons^™

Electrosynthesis Of 2,2-Dimethylolpropionic Acid, Hong-Yan Sun, Zhen-Hai Liang

Journal of Electrochemistry

The Ti/SnO₂+Sb₂O₄/PbO₂ electrode was prepared.The structure phase and valent state were characterized by means of XRD and XPS.The 2,2-dimethylolpropionic acid was synthesized on the Ti/SnO₂+Sb₂O₄/PbO₂ anode by direct electro-oxidation of 2,2-dimethylolpropionaldehyde.The product and crude material were analyzed by HPLC,the effects of the concentration of 2,2-dimethylolpropionaldehyde,pH,potential and reaction temperature were studied.The results showed that the optimum conditions were anode potential 1.8 V,pH=1,reaction temperature 15 ℃ and 2,2-dimethylolpropionaldehyde concentration 0.10mol/L.Under the optimum conditions,the selectivity of 36%,the current efficiency of 28% and the conversion of 58% were reached.The reported …

The Electrochemical Behavior And Determination Of Carbendazim On Iron Montmorillonite Modified Electrode, Xiao-Li Jiang, Rong Li, Xiao-Ying He, Jiang Li, Ying Li

Journal of Electrochemistry

The FeCl₃ modified clay electrode was made.The electrochemical behavior of carbendazim(BCM) on the modified electrode was studied by cyclic voltammetry.The impacts of pH,scan rate and dosages of modifier were discussed and the important kinetic parameters of the electrochemical process were determined.The results indicated that the process was controlled by diffusion.The effective area of FeMM-CMC/GCE(A)=0.027 cm²,the transfer electron numbers(n)=2 and the diffusion coefficient(D)=5.115×10^-6cm²/s.Under the optimized conditions,a good linearity was found between the first order derivative of peak current and concentration of BCM in the range of 2.00×10^-5～8.00×10^-4mol/L,with i′p=-8.045×10^-7-0.0237c,correlation …

Synthesis,Characteristics And Electrochemical Performance Of Nano-Sized Snco/Graphite Composites As Anode For Lithium Ion Batteries, Jin-Shu Cai, Ling Huang, Fu-Sheng Ke, Shi-Gang Sun

Journal of Electrochemistry

The nano-structural Sn-Co/graphite composites were prepared by chemical reduction of the alloy electroless deposition solution in graphite suspensions, and the composites were annealed at 500 ℃. The phase structure and surface morphology of the composites were measured by XRD, SEM and Raman. The results indicate that there were high dispersions and high loadings of Sn-Co nanoparticles on graphite by thermal treatment. Electrochemical lithium storage performance was studied preliminarily on the obtained samples. The graphite modified with the Sn-Co nanoparticles possessed a higher electrochemical reversible capacity than that of graphite during the charge and discharge process. The appetency between the Sn-Co …

High Utilization Aupt Nanoparticles Supported On Mwcnts For Methanol Electro-Oxidation In Alkaline Medium, Xun Guo, Dao-Jun Guo, Xin-Ping Qiu, Li-Quan Chen, Wen-Tao Zhu

Journal of Electrochemistry

We synthesized gold-platinum electrocatalysts supported on multi-walled carbon nanotubes(MWCNTs) with high utilization by a simple one-step method.A high Pt loading series of bimetallic AuPt/MWCNTs catalysts were prepared by the improved ethylene glycol reduction method,and then were compared in terms of the electrocatalytic activity for methanol electro-oxidation using cyclic voltammetry(CV) and chronoamperometry in alkaline solutions.The structure of AuPt/MWCNTs was characterized by the transmission electron microscopy(TEM),X-ray diffraction(XRD) and energy-dispersive X-ray spectroscopy(EDS).The results showed that the AuPt/MWCNTs catalysts had high Pt utilization,uniform AuPt nanoparticles size and good electrocatalytic activity for methanol electro-oxidation.The effect of Au/Pt mass ratio on electrocatalytic activity was also investigated.The …

One-Pot Synthesis Of Anionic (Nitrogen) And Cationic (Sulfur) Codoped High-Temperature Stable, Visible Light Active, Anatase Photocatalysts, Suresh Pillai, Declan Mccormack, Steven Hinder, Pradeepan Periyat

Articles

No abstract provided.

Influence Of Magnesium Nitrate On The Corrosion Performance Of Sol-Gel Coated Aa2024-T3 Aluminium Alloy, Rajath Varma, Brendan Duffy, John Cassidy

Articles

Traditional anti-corrosion technology has relied heavily on using reducible metal species, predominantly hexavalent chromium (Cr(VI)), for protecting reactive metal alloys such as aluminium which is extensively used in the aerospace sector. However, the impending changes in the use of Cr(VI) in Europe and the United States have forced aerospace manufacturers to examine alternative materials for protecting aluminium. One of the most promising alternatives being investigated are organosilane based sol-gels containing anticorrosion additives. In this work the anti-corrosion properties of magnesium (II) nitrate (Mg(NO3)2) as a inhibitor was investigated at different concentrations (0.1% - 1.0 wt %) in a methyltriethoxysilane (MTEOS) …

One-Pot Synthesis Of Anionic (Nitrogen) And Cationic (Sulfur) Codoped High-Temperature Stable, Visible Light Active, Anatase Photocatalysts, Suresh Pillai, Declan Mccormack, Steven Hinder, Pradeepan Periyat

Articles

No abstract provided.

Nondestructive Evaluation Of Aircraft Composites Using Terahertz Time Domain Spectroscopy, Christopher D. Stoik

Theses and Dissertations

Terahertz (THz) time domain spectroscopy (TDS) was assessed as a nondestructive evaluation technique for aircraft composites. Material properties of glass fiber composite were measured using both transmission and reflection configuration. The interaction of THz with a glass fiber composite was then analyzed, including the effects of scattering, absorption, and the index of refraction, as well as effective medium approximations. THz TDS, in both transmission and reflection configuration, was used to study composite damage, including voids, delaminations, mechanical damage, and heat damage. Measurement of the material properties on samples with localized heat damage showed that burning did not change the refractive …

Behavior Of Copper Electrodeposition In Copper Electroplating Solution With Different Peg Molecular Weight, Lie Yin, Zeng-Lin Wang

Journal of Electrochemistry

The effect of the polyethylene glycol(PEG) molecular weight(MW) upon via-hole filling with diameter of 50 μm and aspect ratio of 1 in the acid copper plating solution was studied.The cathodic polarization in copper electroplating bath with PEG of different molecule weights was investigated by linear sweep voltammetry.The surface roughness,crystallography,and the resistivity of copper films were characterized by X-ray diffraction(XRD),atomic force microscopy(AFM) and the four-point probe measurements.The results showed that the polarization on the cathode and the hole-filling capability of electroplating copper bath were increased evidently with an increase of PEG molecular weight from 600 to 8000.When the PEG MW was …

Voltammetric Determination Of Iodate Ion In Table Salt By Carboxylic Carbon Nanotubes Modified Carbon Paste Electrode, Jun-Hua Li, Fu-Xing Zhang, Jian-Qiu Wang, Zhi-Feng Xu, Rong-Ying Zeng, Yan Yu

Journal of Electrochemistry

A highly-sensitive and mercury-free method of determining iodate ion in table salt was established based on carboxylic carbon nanotubes modified carbon paste electrode.In 0.1 mol/L NaOH solution,there was a sensitive cathodic stripping peak on voltammograms.The stripping peak potential was-0.52 V when accumulation time of IO-3 at the modified electrode was 60 s and the potential scan rate was 300 mV/s.There was a good liner relationship between the peak current and IO-3 concentration in the range of 8.0×10^-10 ～ 5.0×10^-8 mol/L and 1.0×10^-7 ～ 3.0×10^-6 mol/L with the correlation coefficient of 0.999 and 0.998,respectively.The detection limit was …

Primary Study Of Tiron As Active Materials For The Redox Flow Battery, Yan Xu, Yue-Hua Wen, Jie Cheng, Yu-Sheng Yang, Zi-Li Xie

Journal of Electrochemistry

Effects of solution pH on the electrochemical behavior of tiron(sodium 4,5-dihydroxy-1,3-benzendisulfonic) couple(on a graphite electrode) were studied by cyclic voltammetry in aqueous solutions.It is shown that at pH<4,tiron exhibited a redox process at a relatively high potential with a good reversibility.A redox flow battery was formed employing tiron as the positive active species and V(III)/V(II) as the negative redox couple.In sulfuric acid medium,the coulombic efficiency of the tiron-V redox flow cell was more than 90% with a good cycle life.The decay in the cycle performance was minimal.Therefore,the feasibility of tiron as active materials for redox flow battery application is demonstrated.

Combustion Product Characterization Of The Iron-Heated Powders In Thermal Batteries, Jin Chong, Xue-Ping Gao, Ji-Qiang Wang

Journal of Electrochemistry

The combustion products of thermal battery used iron-heated powders have been studied.It is identified by X-ray diffraction (XRD) analysis that the main compositions of the combustion products are Fe, FeO and KCl. The transmission electron microscopy(TEM) shows a typical core-shell structure with un-reacted Fe particle core coated by FeO shell with a shell thickness of around 200 nm. The combusted iron-heated powders exhibit no metal property, which is contrast to previous assumption. Further measurement indicates that at the ambient temperature the combustion products show semiconductor property of the p-type with conductivity in the order of 103 S·cm^-1, which …

Preparation And Electrocatalystic Performance Of Ir/C Catalyst For Ammonia Oxidation, Qing-Mei Kong, Yi-Ping Han, Ling-Juan Deng, Tian-Hong Lu, Ya-Wen Tang

Journal of Electrochemistry

The Ir/C catalyst with 30%(by mass) Ir was prepared in the CH₃CH₂OH and H₂O binary system.The X-ray diffraction(XRD) data showed that the average sizes of the Ir particles in the Ir/C catalyst was about 2.2 nm.The results of the electrochemical measurements indicated that the electrocatalytic activity of the Ir/C catalyst for the ammonia oxidation in the neutral NaClO₄ solution was similar to the Ir catalyst,while electrocatalytic stability was much better than that of the Ir catalyst.Furthermore,the peak current density of the ammonia oxidation at the Ir/C catalyst electrode showed a good linear relationship …

Direct Electrochemistry Of Chloroperoxidase At Gc Electrode Modified With Swnts, Hong-Xia Zhang, Xia-Qin Wu, Wen-Jing Hou, Wen Xie, Zhong-Qing Lu, Rong Wang, He-Xing Li

Journal of Electrochemistry

The chloroperoxidase(CPO) was immobilized onto the surface of SWNTs modified electrodes.The electrochemical behaviors of modified electrode have been investigated by cyclic voltammetry.The appearance of a pair of well-defined redox peaks in the CV curve indicated that SWNTs can promote the electron transfer reaction of CPO.The results of cyclic voltammetry in PBS of different pH,from 3~9,showed that the reaction of CPO on the modified electrode was with equal numbers of electron and protein.This readily prepared SWNTs modified electrode showed excellent stability and good catalysis to O₂.

Preparations Of Composite Electrodes Of Pt With HXWo3 And Catalytic Activity Toward Oxygen Reduction Reaction, Pan-Pan Guo, You-Ju Huang, Hong-Yan Yang, Wei Li, Qing-Long Zhang, Wei-Shan Li

Journal of Electrochemistry

Three composite electrodes of platinum with hydrogen tungsten bronze(H_xWO₃)were prepared by voltammetry: hydrogen tungsten bronze deposited on platinum(H_xWO₃/Pt);platinum deposited on hydrogen tungsten bronze(Pt/H_xWO₃) and codeposited platinum and hydrogen tungsten bronze(Pt-H_xWO₃).The eletro-catalytic activities of three electrodes toward oxygen reduction reaction were studied.It is found that the catalytic activity of platinum can be improved by introducing with hydrogen tungsten bronze.Among these composite electrodes Pt/H_xWO₃,and the electrode shows the best eletro-catalytic activity toward oxygen reduction reaction,hence,provides a new way for reducing loading of …

High Performance Fuel Cell Catalyst And 5kw Pemfc Stack Without Humidification At Room Temperature And Atmosphere, Xin-Fa Hu, Min Chen, Shi-Jun Liao

Journal of Electrochemistry

The Pt/C catalyst with high dispersion and high performance was prepared successfully by an organic colloidal method and small batch production(10g) of Pt/C catalyst has been realized.The particle sizes of the active components in the catalyst could be as small as 2.8 nm and the active surface area was up to 450 m²/g.A high performance membrane-electrode assembly(MEA) with surface area of 275 cm² has been prepared by using the home-made catalyst with a catalyst coated membrane method invented in the lab,and a 5 kW stack has been assembled.The stack showed working 10 h at room temperature,atmosphere and …

Ceo2/Pt Composite Electrodes And Their Catalytic Performance, Ying Fu, Zi-Dong Wei, Yong-Chao Feng, Xin-Li Ma, Ming-Jia Liao, Chao Liao, Jie Zhang, Huan Zhang

Journal of Electrochemistry

In this paper,the cerium oxide(CeO₂) nanoparticles were electrochemically deposited on a Pt electrode by potentiostatic deposition(psd) and potential pulse deposition(ppd) to form CeO₂/Pt composite electrodes,CeO₂/Pt(psd) and CeO₂/Pt(ppd).The properties of the CeO₂ were characterized by field emission scanning electron microscope(FESEM) and X-ray diffraction(XRD).The results showed that the CeO₂ nanoparticles prepared by psd and ppd were homogeneous and dense.The methanol oxidation reaction(MOR) and oxygen reduction reaction(ORR) on the Pt electrode were enhanced with the introduction of CeO₂ into Pt.In addition,the catalytic capability of the CeO₂/Pt electrode can be further …

Voltammetric Determination Of L-Cysteine At Bipyrine Bridged Copper(Ⅱ) Complex Modified Glassy Carbon Electrode, Ming-Yan Wang, Fan Yang, Sheng-Yu Zhang, Xing-You Xu, Xu-Jie Yang

Journal of Electrochemistry

A modified electrode has been constructed by depositing a novel copper(Ⅱ) complex 2biPy(ClO₄)₄ on the glassy carbon electrode through the method of cyclic voltammetry(CV).It was found that the modified electrode exhibited high electrocatalytic activity toward L-Cysteine oxidation with good reproducibility and high sensitivity.The peak current of semi-derivative linear scan was proportional to the concentration of L-cys in the range of 1×10^-6～3×10^-4 mol·L^-1.The detection limit was 5×10^-7 mol·L^-1.

The Hydrothemal Synthesis Of Nanoscale Lifepo4 And Its Electrochemical Performance, Si-Min Wang, Ming-Sen Zheng, Quan-Feng Dong

Journal of Electrochemistry

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

Studies Of Surface Diffusion In Pemfc Electrodes, Jiang-Shui Luo, Jian Chen, Bao-Lian Yi, Chuan-Sin Cha, Hua-Min Zhang

Journal of Electrochemistry

A PEMFC electrode consisting of dual-layer catalyst layer(CL) was fabricated in this work. The outer CL was Nafion-free,while the inner CL was Nafion-bonded. The effects of Pt/C catalyst in the outer CL that did not contact with Nafion on the current generation in PEMFC electrodes were investigated. Cyclic voltammetric studies indicated that the Pt/C catalyst in the outer CL without direct contact with Nafion was still electrochemically active in taking part in the adsorption/desorption of hydrogen and the electrochemical oxidation/reduction of the oxygen-containing species occurring at the interface of "Pt/Nafion" in the inner CL. The polarization curves showed that the …

Synthesis Of The Lifepo4 By Co Reduction: Reaction Mechanism And Kinetics, Yun-Hua Chen, Yong Yang

Journal of Electrochemistry

LiFePO₄ cathode material was synthesized by CO reducing FePO₄ and LiOH precursors.The structure,morphology and electrochemical performances of such LiFePO₄ material were characterized by XRD,SEM and charge-discharge tests.It was shown that the particle size of the LiFePO₄ synthesized with 5% excess of LiOH in the precursor was about 200 nm.By carbon coating,the LiFePO₄ electrode was able to deliver a reversible capacity of 158 mAh·g^-1 at 0.1C discharge rate.Temperature-programmed X-ray diffraction was employed to monitor the reaction during the formation of LiFePO₄,and Li₃Fe₂(PO₄)₃ was found to be …

Ec-Pt/Cnts Glucose Oxidative Electrode, Jia-Hua Liang, Chun-Mei Zhou, Hong-Juan Wang

Journal of Electrochemistry

A glucose oxidative electrode(GOD),EC-Pt/CNTs glucose oxidative electrode,was constructed by ethyl cellulose(EC) and Pt/CNTs.The sensitivity of the EC-Pt/CNTs GOD is 0.85 μA/mM in the concentration range of 0～4 mmol/L of glucose.After dipped in PBS(4℃) for 18 days,the activity of the EC-Pt/CNTs GOD can reach 80%.It is promising for the EC-Pt/CNTs GOD to be used to construct glucose biosensor.

Corrosion Inhibition Of Magnesium Alloy In 3.5% Nacl Medium By Tungstate, Ling-Jie Li, Zhi-Ming Yao, Jing-Lei Lei, Dong-Hai He, Sheng-Tao Zhang, Fu-Sheng Pan

Journal of Electrochemistry

Electrochemical impedance spectroscopy(EIS),Tafel polarization curves and scanning electron microscopy(SEM) were used to study the corrosion inhibition of AZ61 magnesium alloy in 3.5% NaCl medium with tungstate.Results showed that tungstate demonstrates strong inhibition to the corrosion of AZ61 magnesium alloy.At the concentration of 0.01 mol/L,tungstate has a high inhibition efficiency 75.5%.Tungstate is an anodic inhibitor that mainly inhibited the anodic reactions of magnesium alloy through forming a compact protective layer that covered the magnesium alloy surface active sites.

Electrochemical Behavior And Determination Of Paracetamol On Activated Glassy Carbon Electrode, Bao-Yu Tan, Fang Liao, Xiao-Ying He, Qing-Tao Zhu, Jun Hua, Xiao-Li Jiang

Journal of Electrochemistry

The electrochemical behavior of paracetamol(PCT) was studied at glassy carbon electrode activated by cyclic voltammetry.In HAc-NaAc buffer solution(pH=4.00),a couple of sensitive redox peaks were recorded about 0.54 V in the cyclic voltammograms.The result indicated that the process was controlled by adsorption and nearly reversible.The reaction electron and proton numbers were estimated,respectively,to be two.Excllent linearity was observed in the correlation between the oxidation peak current and the concentration of PCT in the range of 8.00×10^-6～2.00×10^-4 mol·L-1.The correlative coefficient was-0.999 18.The detection limit was 6.34×10^-6 mol·L^-1.This method can be used for the determination of PCT real …

Fabrication Of Superhydrophilic Aluminum Oxide Through Single-Step Anodic Oxidation, Qin Zhang, Qi-Ming Yin, Jia-Ming Ye, Yuan-Rong Zhu

Journal of Electrochemistry

Hydrophilic aluminum oxide is popularly used for heat exchanger of air-condition.Herein,we developed a simple method to prepare superhydrophilic aluminum oxide on the surface of aluminum through single-step electrochemical oxidization.The morphologies and water contact angles on surfaces of alumina fabricated under different electrochemical conditions were investgated.Superhydrophilic surfaces fabricated by this method have good stability and high mechanical strength with water contact angle almost 0°.Coated with low surface energy materials,superhydrophilc alumina will be converted to superhydrophobic.

Localised Galvanic Corrosion Processes In Thermal Spray Coated/Cast Aluminium Alloy Systems, David Culliton, Tony Betts, David Kennedy

Conference Papers

Cast Aluminium Alloys, because of the propensity of aluminium to react with impurities and alloying elements, are prone to developing IM impurities during the solidification process. These IM phases can act, in some fluids, as initiation sites for localised corrosion processes, resulting in degradation phenomena, such as pitting. Whilst Thermal Spray coatings can improve the wear resistance of Cast Aluminium Alloys, their corrosion performance may be hampered by the presence of through porosity within the coating.

The present work details some preliminary studies of the localised corrosion processes occurring at the interface area between a Thermal Spray coating and a …

Electrochemical Synthesis, Characterization And Fluorescence Property Of Nano Na2Sif6, Guo-Xu Qin, Xin-Jun Wan, Xi-Mei Yuan, Dao-Bao Chu

Journal of Electrochemistry

The nano TiO₂ film was prepared by sol-gel process and characterized with X-ray diffraction(XRD) and scanning electron microscope(SEM).It was found that the average size of pore diameter was about 80 nm for the nano TiO₂ film.The Nano Na₂SiF₆ was synthesized by electrochemical deposition on the nanoporous film electrode and characterized with XRD and transmission electron microscope(TEM).The result showed that the average size of nanoparticle was 20 nm for the nano Na₂SiF₆.The fluorescence property of nano Na₂SiF₆ was also studied briefly.The result indicated that the nano Na₂SiF …

Electricity Generation In Microbial Fuel Cells Catalyzed By Mixed Culture And Pure Culture, Chen-Dong Shuang, En-Ren Zhang, Guo-Wang Diao, Fang-Fang Fan, Jie Yuan

Journal of Electrochemistry

Microbial fuel cells(MFCs) were constructed by inoculating fresh sedimentary microorganisms.Effect of phenol on performance of MFCs was investigated.The results showed that the generation of electrical current was induced by bacteria attached on the surface of the anode.Presence of phenol reduced the rate of glucose consumption and extended the duration of electricity generation with the same addition of glucose.In addition,the electricity generation by a single strain(belonging to pseudomonas species) separated from the sedimentary MFC was also investigated.The experimental results indicated that the presence of metabolic intermediates which exhibited electrochemical activity was necessary for the electricity production.Analysis of GC-MS showed that the …

Electrocatalytic Performance Of Carbon Supported Au-Ir Catalyst As Cathodic Catalyst In Direct Formic Acid Fuel Cell, Wei Chen, Ya-Wen Tang, Tain-Hong Lu

Journal of Electrochemistry

In this paper,it is reported for the first time that the electrocatalytic activities of the carbon supported Au(Au/C),carbon supported Ir(Ir/C) and the carbon supported Au-Ir(Au-Ir/C) catalysts prepared in the aqueous solution with tetrahydrofuran(THF) for the oxidation of formic acid and for the oxygen reduction were compared.It was found that all three catalysts showed no electrocatalytic activity for the oxidation of formic acid,but the electrocatalytic activity of the Au-Ir/C catalyst for oxygen reduction was much better than those of Au/C and Ir/C.Thus,the Au-Ir/C catalyst is suitable to be used as the cathodic catalyst in Direct formic acid fuel cell(DFAFC).

Hydrolysis Of Sodium Borohydride By Ru-Ni Foam Catalyst, Jie Cheng, Feng Ye, Tong-Tao Wang, Jing-Jing Li, Yong-Liang Wang, Xin-Dong Wang

Journal of Electrochemistry

This paper presented a method of hydrogen generation from sodium borohydride solution for fuel cells.The Ru-Ni foam catalyst which was prepared by chemical plating showed strong activity and stability.The pretreatment of Ni foam before chemical plating was very important for the catalyst's strong activity and stability.This easy-to-prepared catalyst exhibited a good activity after being used several times.The effects of NaBH₄ concentration,temperature and used times on the hydrogen generation rate were investigated.The results showed that the rate was remarkablely increased with the temperature rising and the rate increased more than ten times when the temperature of reaction rised from 15 …