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Full-Text Articles in Engineering Science and Materials

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

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

Journal of Electrochemistry

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


High Performance Membrane Electrode Assembly With Low Platinum Loadings Prepared By Atomic Layer Deposition For Pemfc Application, Ting Shu, Shi-Jun Liao, Chien-Te Hsieh, Ay Su Feb 2013

High Performance Membrane Electrode Assembly With Low Platinum Loadings Prepared By Atomic Layer Deposition For Pemfc Application, Ting Shu, Shi-Jun Liao, Chien-Te Hsieh, Ay Su

Journal of Electrochemistry

A high performance membrane electrode assembly (MEA) with low platinum loadings was successfully prepared with atomic layer deposition (ALD) technique. The anode of the MEA was prepared by depositing platinum on the carbon paper substrate, which was prepared by coating the slurry of carbon black (XC-72R) and Teflon, followed by drying and calcining at 350 °C. The MEAs consisted of the ALD anode or commercial catalyst anode, pretreated Nafion membrane (Nafion-117) and commercial cathode. Performances of MEAs were measured by single cell testing, and the anodes and MEAs were characterized by CV, SEM, TEM and XRD. The results revealed that …


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

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

Journal of Electrochemistry

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


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

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

Journal of Electrochemistry

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


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

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

Journal of Electrochemistry

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


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

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

Journal of Electrochemistry

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


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

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

Journal of Electrochemistry

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


An In Situ Ftir Spectroelectrochemical Study On Methanol Oxidation At Pt-Mo2c/Gc Catalyst, Hai-Ping Huang, Xi-Yu Yao, Pei-Kang Shen Feb 2013

An In Situ Ftir Spectroelectrochemical Study On Methanol Oxidation At Pt-Mo2c/Gc Catalyst, Hai-Ping Huang, Xi-Yu Yao, Pei-Kang Shen

Journal of Electrochemistry

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


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

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

Journal of Electrochemistry

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


Electrochemical Performance Of Fe3o4/C Composites As Negative Material For Lithium-Ion Batteries, Jun-Jie Cai, Shu Yao, Ze-Sheng Li, Hui Meng, Pei-Kang Shen Feb 2013

Electrochemical Performance Of Fe3o4/C Composites As Negative Material For Lithium-Ion Batteries, Jun-Jie Cai, Shu Yao, Ze-Sheng Li, Hui Meng, Pei-Kang Shen

Journal of Electrochemistry

The Fe3O4/Carbon composites have been synthesized through coprecipitation pathway and by insitu aniline polymerization as a carbon source. Structural characterization and morphological study of the composites were investigated by using XRD, SEM and TEM techniques. The results showed that the nanosized Fe3O4 particles (40 ~ 80 nm) were encapsulated in the amorphous carbon. During the electrochemical tests, the Fe3O4/C composites exhibited high capaticity and excellent cycle ability, the retention of capaticity was about 1000 mAh?g-1 after 30 cycles of charge/discharge tests at 50 mA?g-1.


Mechaniczny Rozdział Faz Proj., Wojciech M. Budzianowski Jan 2013

Mechaniczny Rozdział Faz Proj., Wojciech M. Budzianowski

Wojciech Budzianowski

No abstract provided.


Challenges And Prospects Of Processes Utilising Carbonic Anhydrase For Co2 Separation, Patrycja Szeligiewicz, Wojciech M. Budzianowski Jan 2013

Challenges And Prospects Of Processes Utilising Carbonic Anhydrase For Co2 Separation, Patrycja Szeligiewicz, Wojciech M. Budzianowski

Wojciech Budzianowski

This article provides an analysis of processes for separation CO2 by using carbonic anhydrase enzyme with particular emphasis on reactive-membrane solutions. Three available processes are characterised. Main challenges and prospects are given. It is found that in view of numerous challenges practical applications of these processes will be difficult in near future. Further research is therefore needed for improving existing processes through finding methods for eliminating their main drawbacks such as short lifetime of carbonic anhydrase or low resistance of reactive membrane systems to impurities contained in flue gases from power plants.


Determination Of Kinetic Parameters From The Thermogravimetric Data Set Of Biomass Samples, Karol Postawa, Wojciech M. Budzianowski Dec 2012

Determination Of Kinetic Parameters From The Thermogravimetric Data Set Of Biomass Samples, Karol Postawa, Wojciech M. Budzianowski

Wojciech Budzianowski

This article describes methods of the determination of kinetic parameters from the thermogravimetric data set of biomass samples. It presents the methodology of the research, description of the needed equipment, and the method of analysis of thermogravimetric data. It describes both methodology of obtaining quantitative data such as kinetic parameters as well as of obtaining qualitative data like the composition of biomass. The study is focused mainly on plant biomass because it is easy in harvesting and preparation. Methodology is shown on the sample containing corn stover which is subsequently pyrolysed. The investigated sample show the kinetic of first order …