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Articles 391 - 420 of 598

Full-Text Articles in Materials Chemistry

Applications Of Raman Spectroscopy Technique In Lithium Ion Batteries, Liang Zhao, Yong-Sheng Hu, Hong Li, Zhao-Xiang Wang, Hong-Xing Xu, Xue-Jie Huang, Li-Quan Chen Feb 2011

Applications Of Raman Spectroscopy Technique In Lithium Ion Batteries, Liang Zhao, Yong-Sheng Hu, Hong Li, Zhao-Xiang Wang, Hong-Xing Xu, Xue-Jie Huang, Li-Quan Chen

Journal of Electrochemistry

The Raman spectroscopy has been widely used in the study of lithium ion batteries.In this short review,we gave some examples of the applications of Raman spectroscopy in the study of electrode materials including carbonaceous materials,spinel LiMxMn2-x O4,LiFePO4,as well as polymer electrolytes,room temperaturemolten salt electrolytes and the solid-electrolyte interphase layers.The advantages and disadvantages of the ex-situ and in-situ Raman spectrum techniques are discussed.Using new Raman techniques to investigate Li-ion batteries are suggested.

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Electrocatalytic Oxidation Of Hydrazine At Rutin Carbon Nanotubes Modified Electrode, Hong-Fang Zhang, Qing-Lin Sheng, Jian-Bin Zheng Feb 2011

Electrocatalytic Oxidation Of Hydrazine At Rutin Carbon Nanotubes Modified Electrode, Hong-Fang Zhang, Qing-Lin Sheng, Jian-Bin Zheng

Journal of Electrochemistry

The electrochemical behavior and electrocatalytic oxidation of hydrazine on rutin multiwall carbon nanotubes modified glassy carbon electrode were studied by cyclic voltammetry.The experimental results indicated that the electrode exhibits good electrocatalytic activity to hydrazine at a reduced oxidation potential of 262 mV.The amperometric response of the modified electrode showed linear increase after successive addition of hydrazine in the concentration range of 2.5×10-6~1.0×10-4 mol·L-1 with a detection limit of 5×10-7 mol·L-1.

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Study Of The 11-Ferrocenylalkanethiol Redox-Induced Structure Changes By Flow-Injection Electrochemical Surface Plasmon Resonance, Xiu-Juan Xiao, Yong-Hui He, Juan Xiang, Bin Ren Nov 2010

Study Of The 11-Ferrocenylalkanethiol Redox-Induced Structure Changes By Flow-Injection Electrochemical Surface Plasmon Resonance, Xiu-Juan Xiao, Yong-Hui He, Juan Xiang, Bin Ren

Journal of Electrochemistry

Redox-induced orientation changes of self-assembled monolayers(SAMs) of 11-ferrocenylundecanethiol(FcC11SH) were studied by the flow-injection electrochemical surface plasmon resonance(FI-EC-SPR).Results indicated that there existed two mechanisms concerning the redox-induced structure change of the self-assembled monolayer of ferrocenylalkanethiols:the electrostatic repulsion between the positively charged surface and the ferricenium cation and that among the cations led to a decrease in the tilt angle of the alkanethiol chain;upon Fc oxidation,the Fc group rotated from a tilted conformation to a position where the cyclpentyldiene plane became perpendicular to the electrode.

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Photoelectrochemical Properties Of N, S, And Cl Modified Nano Tio2 Thin Films, Hong Yun, Chang-Jian Lin, Jing Li, Rong-Gui Du Nov 2010

Photoelectrochemical Properties Of N, S, And Cl Modified Nano Tio2 Thin Films, Hong Yun, Chang-Jian Lin, Jing Li, Rong-Gui Du

Journal of Electrochemistry

The nitrogen(N),sulfur(S) and chlorine(Cl) modified nano TiO2 thin films were prepared by adding Ti(O-n-Bu)4 as the precursor into concentrated HNO3,H2SO4 and HCl Solutions,respectively,on different substrates in a sol-gel process.The photoelectrochemical performances of N,S and Cl modified nano TiO2 thin films have been studied by UV-vis(DRS),photocurrent curves,EIS and OCP-time curves.N-modified TiO2 nano films show better surface structure,which helps to improve the quantum efficiency of nano TiO2 thin films.

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The Mechanism Of 13CoAd/12Co Isotope Exchange At Pt Electrode,A Combined Study By Electrochemical In-Situ Infrared Spectroscopy And Dipole-Dipole Coupling Analysis, Sang-Zi Liang, Shao-Xiong Liu, Ling-Wen Liao, Qian Tao, Jing Kang, Yan-Xia Chen Aug 2010

The Mechanism Of 13CoAd/12Co Isotope Exchange At Pt Electrode,A Combined Study By Electrochemical In-Situ Infrared Spectroscopy And Dipole-Dipole Coupling Analysis, Sang-Zi Liang, Shao-Xiong Liu, Ling-Wen Liao, Qian Tao, Jing Kang, Yan-Xia Chen

Journal of Electrochemistry

In this contribution,we have analyzed the IR spectra of saturated CO adlayer at rough Pt film electrode as a function of fractional surface coverage of 13COad /12CO recorded during 13COad /12CO isotope exchange process according to dipole-dipole coupling theory and coherent potential approximation. By properly choosing the parameters of adlayer structure and dipole-dipole coupling interaction under coherent potential approximation, we demonstrated that we can successfully simulate the IR spectra as a function of the surface coverage of CO adlayer at rough Pt film electrodes by assuming that COad molecules with low …

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An In Situ Fourier Transform Infrared Spectroelectrochemical Study On Alcohols Electrocatalytic Oxidation At Pd Electrode In Acidic Solution, Hai-Ping Huang, Lian-Qin Wang, Pei-Kang Shen Aug 2010

An In Situ Fourier Transform Infrared Spectroelectrochemical Study On Alcohols Electrocatalytic Oxidation At Pd Electrode In Acidic Solution, Hai-Ping Huang, Lian-Qin Wang, Pei-Kang Shen

Journal of Electrochemistry

The methanol and ethylene glycol electrooxidation on palladium electrode in acidic solution has been investigated by cyclic voltammetry and in situ Fourier transform infrared spectroelectrochemistry. It shows that the oxidation of methanol and ethylene glycol at Pd electrode cannot proceed until over 1.5 V in acidic and neutral media. The overpotential decreases and the peak current density increases with the reduction in pH values. The formation of the oxygen-containing species significantly affects the alcohol oxidation on Pd electrode. The in situ FTIR spectroscopic measurements show that the oxidation products of ethylene glycol on Pd electrode are CO2 and oxalic …

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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 …

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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.

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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 …

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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 …

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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 …

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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. …

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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. …

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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.

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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.

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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 …

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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.

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Nano-Sized Au On Nickel Foam As Cathode Of Alkaline Al-H2O2 Semi Fuel Cell, Shu-Li Chen, Bang-An Lu, Yao Liu, Gui-Ling Wang, Dian-Xue Cao May 2010

Nano-Sized Au On Nickel Foam As Cathode Of Alkaline Al-H2O2 Semi Fuel Cell, Shu-Li Chen, Bang-An Lu, Yao Liu, Gui-Ling Wang, Dian-Xue Cao

Journal of Electrochemistry

Nano-sized Au particles were deposited on a nickel foam substrate by a fast spontaneous deposition method using AuCl3 as the source of Au. The effects of AuCl3 concentration and deposition time on the size and distribution of Au particles,and the performance of the obtained Au/Ni electrode as the cathode of Al-H2O2 semi fuel cell were investigated. It was found that after the nickel foam was immersed in a 2 mmol·L-1 AuCl3 solution for 60 s,Au particles with diameters smaller than 100 nm were deposited on its surfaces and cover the surface completely. The …

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Preparation And Electrochemical Behavior Of Li4Ti5O12 Nanosheets As Anode Material For Lithium Ion Battery, Yi-Fei Wang, Yu-Feng Tang, Zheng Qiu, Li Yang Feb 2010

Preparation And Electrochemical Behavior Of Li4Ti5O12 Nanosheets As Anode Material For Lithium Ion Battery, Yi-Fei Wang, Yu-Feng Tang, Zheng Qiu, Li Yang

Journal of Electrochemistry

Spinel lithium titanate(Li4Ti5O12) nanosheets with a size range of 200 ～400 nm were synthesized by hydrothermal process from the amorphous hydrous titanium oxide precursors.The as-prepared products were characterized by X-ray powder diffraction(XRD),scanning electron microscopy(SEM) and transmission electron microscopy(TEM).The electrochemical behaviors of Li4Ti5O12 electrode in conventional organic electrolyte and ionic liquid electrolyte were investigated by using cyclic voltammetry,galvanostatic charge-discharge and AC impedance techniques.The experimental results indicate that the as-prepared nanostructured Li4Ti5O12,evaluated as anode material,exhibited good reversibility and cycle performance.It is expected to be a …

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Electrocatalytic Reduction Of L-Cystine At Pb/Nanotio2 Film Electrode, Dao-Bao Chu, Feng Wang, Ying Xiao, Xue-Jiao Zhang Feb 2010

Electrocatalytic Reduction Of L-Cystine At Pb/Nanotio2 Film Electrode, Dao-Bao Chu, Feng Wang, Ying Xiao, Xue-Jiao Zhang

Journal of Electrochemistry

The nanoporous Ti-based TiO2 films electrodes modified with Pb particles(Pb/nanoTiO2) were prepared by using anodization and potentiostatic electro-deposition.The optimum deposition conditions were determined by comparing with various deposition potentials and time.The SEM analyses indicated that the TiO2 films were homogeneous nanoporous structure,and the Pb particles well dispersed on the TiO2 films.The L-cystine electrocatalytic activity reduction on the Pb/nanoTiO2 film electrodes was investigated by cyclic voltammetry and Chronoamperometric curves.The results showed that this type of the electrode posseses high acticity and stability.

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Synthesis And Characterization Of Zinc Oxide Nanostructures., Khalifa Said Zahran Al-Azri Jan 2010

Synthesis And Characterization Of Zinc Oxide Nanostructures., Khalifa Said Zahran Al-Azri

Student Works (2010-2019)

The growth mechanism, morphology, structure and optical properties of the ZnO nanostructures grown on bare and gold-coated silicon substrates using carbothermal reaction at atmospheric pressure were investigated under different growth conditions. The ZnO nanostructures formed were studied as a function of substrate location, furnace temperature, Ar gas flow rate, deposition time and ZnO powder to carbon powder mass ratio. The morphology and structure of the samples were characterized using the fieldemission scanning electron microscopy (FESEM), energy dispersive x-ray spectroscopy(EDX) spectrum, x-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM). It was found that in both silicon and gold-coated silicon …

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Synthesis And Characterization Of Silicon Oxide And Silicon Carbide Nanostructures., Majid Salim Mohammed Al-Ruqieshi Jan 2010

Synthesis And Characterization Of Silicon Oxide And Silicon Carbide Nanostructures., Majid Salim Mohammed Al-Ruqieshi

Student Works (2010-2019)

Silicon oxide nanostructures have attracted extensive interests in recent years due to their physical and optical properties. SiOx nanostructures are synthesized by catalytic and non-catalytic approaches. With catalytic approach, long and uniform amorphous silicon oxide nanowires, nanofibers (comet and tree like), nanocakes and nanocages were synthesized on Si substrate by carbothermal evaporation reactions of TiO2 at high temperature. The SiOx nanowires were about 13 nm to 243 nm in diameters and 194 nm to several microns in length and the nanofibres with diameter between 8 nm to 30 nm and around 50 nm to 2.5μm in length. The diameter and …

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Production Of Multiwall Carbon Nanotube For Alcohol Sensor Application., Ebtehal Saleh Alshaqaq Jan 2010

Production Of Multiwall Carbon Nanotube For Alcohol Sensor Application., Ebtehal Saleh Alshaqaq

Student Works (2010-2019)

Multiwall carbon nanotube/polyethylene oxide (PEO), multiwall carbon nanoube/polyvinyl alcohol(PVA) and multiwall carbon nanotube/ polyvinyl alcohol(PVA)/zinc oxide(ZnO) have been tested as chemical sensors and detailed study on the effect of different gas concentration and material properties on gas sensitivity is presented. Initial composites were prepared by a simple solution casting and characterized by x-ray diffraction for ZnO, Fourier transform infra-red spectroscopy (FTIR) and scanning electron microscopy (SEM) to demonstrate crystallite size of ZnO, the morphology and surface area respectively. On the other hand, MWCNT/PEO , MWCNT/PVA , MWCNT/PVA/ZnO were prepared with different loading MWCNT and ZnO. The chemical sensing properties of …

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Preparation Of Pt Nanoflower/Zno Composites Arrays And Their Electrocatalysis For Methanol Oxidation, Li Gao, Yi-Feng E, Lou-Zhen Fan Nov 2009

Preparation Of Pt Nanoflower/Zno Composites Arrays And Their Electrocatalysis For Methanol Oxidation, Li Gao, Yi-Feng E, Lou-Zhen Fan

Journal of Electrochemistry

The Pt nanoflower/ZnO(PtNF/ZnO) nanorod composites arrays were electrochemically prepared by controlling the hydrophobicity and the hydrophilicity of ZnO nanorods arrays.The Pt nanoflowers grew on the tip of ZnO nanorods,which maintain the vertical array of Zno nanorods with a high degree of size uniformity and high surface area.Compared with Pt nanoparticle covered ZnO nanorod arrays,which were prepared by controlling the hydrophilicities of ZnO nanorods and Pt nanoparticles,the PtNF/ZnO displayed highest electrocatalytic activities for the oxidation of methanol.

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Progresses In Electrocatalysis Of Nanomaterials—Tuning The Surface Structure And Property Of Electrocatalysts, Yan-Xia Jiang, Na Tian, Zhi-You Zhou, Sheng-Pei Chen, Shi-Gang Sun Nov 2009

Progresses In Electrocatalysis Of Nanomaterials—Tuning The Surface Structure And Property Of Electrocatalysts, Yan-Xia Jiang, Na Tian, Zhi-You Zhou, Sheng-Pei Chen, Shi-Gang Sun

Journal of Electrochemistry

The property of an electrocatalyst depends strongly on its surface structure.The study of surface structure-catalytic functionality is the base of design and preparation of electrocatalysts of high activity,high stability and high selectivity at microstructure level.In this paper,based mainly on our results concering hydrogen and oxygen adsorption-desorption,ethylene glycol oxidation and CO2 reduction,the research progresses in tuning the surface structure and property of electrocatalysts are summarized.This paper overviews firstly the cyclic voltammetric characteristics,electrocatalytic properties of platinum single crystal planes lying on different crystallographic zones of the unit stereographic triangle of face-centered cubic(fcc) metals.Next,the innovation of electrochemical methods to control the surface …

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Synthesis And Electrocatalytic Properties Of Ni-Pd/C Catalysts With Pd-Enriched Surface, Yu-Mei Chen, Zhi-Xiu Liang, Sheng-Li Chen Nov 2009

Synthesis And Electrocatalytic Properties Of Ni-Pd/C Catalysts With Pd-Enriched Surface, Yu-Mei Chen, Zhi-Xiu Liang, Sheng-Li Chen

Journal of Electrochemistry

The Ni-Pd alloy catalysts with Pd-enriched surface were synthesized through a modified polyol process.The synthesized materials were investigated by XRD and electrochemical methods,and tested as electrocatalysts for CH3OH-tolerant oxygen reduction.The results indicated that the synthesized Ni-Pd nanoparticles possess multiple phases containing Pd-Ni alloy and pure Ni.Comparing with Pd/C,the prepared Ni-Pd/C nanoparticles exhibited better resolved voltammetric peaks between the hydrogen absorption and adsorption,and positively shifted current peaks for the reduction of Pd oxide.The prepared Ni-Pd alloys with Pd-enriched surface have significantly enhanced ORR activity and improved CH3OH tolerance as comparing with Pd/C catalysts.

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Complex Reduction Preparation Of Carbon Supported Pd Nanoparticle Catalyst And Its Electrocatalysis For Formic Acid Oxidation, Wei He, Yong-Yin Kang, Chong Du, Zhi-Qing Zou, Xiao-Gang Zhang, Hui Yang Nov 2009

Complex Reduction Preparation Of Carbon Supported Pd Nanoparticle Catalyst And Its Electrocatalysis For Formic Acid Oxidation, Wei He, Yong-Yin Kang, Chong Du, Zhi-Qing Zou, Xiao-Gang Zhang, Hui Yang

Journal of Electrochemistry

A simple procedure involved the complexing of PdCl2 with sodium citrate followed by ethylene glycol reduction has been employed for the preparation of carbon-supported Pd nanoparticles(Pd/C).The XRD and TEM characterizations indicate that Pd nanoparticles with a small particle size were well-dispersed on carbon support.The mean particle sizes of the Pd/C catalysts were found to be increased from 2.7 to 5.8 nm with heat-treatments at different temperature.The mass activity of the Pd/C catalyst for formic acid electrooxidation increased with the decrease in Pd particle size.However,the specific activity increased with Pd particle size.Furthermore,the Pd/C catalyst with a particle size of ca.3.6 …

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Cyclic Voltammetric And In-Situ Ftir Spectroscopic Studies Of Adsorption And Reduction Of No On Electrode Of Pt Nanoparticles, Qian Cheng, Yan-Xia Jiang, Dong-Mei Zeng, Shi-Gang Sun Nov 2009

Cyclic Voltammetric And In-Situ Ftir Spectroscopic Studies Of Adsorption And Reduction Of No On Electrode Of Pt Nanoparticles, Qian Cheng, Yan-Xia Jiang, Dong-Mei Zeng, Shi-Gang Sun

Journal of Electrochemistry

Adsorption and reduction of NO on electrode of Pt nanoparticles in acid solutions were studied by means of cyclic voltammetry(CV) and in-situ FTIR spectroscopy.The results indicated that the reduction of NO is a complicated process including the adsorption of NO on electrode surface.Two types of surface-bonded NO were determined on Pt nanoparticles.The weakly adsorbed NO was reduced between 0.6 V and-0.05 V,which yielded nitrous oxide(N2O) and ammonium(NH4+) as products;while the strongly bonded NO was reduced at more negative potentials between-0.05V and-0.15V,producing only NH4+ species.

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Enhanced Visible Light Photoelectrochemical Performances With Nitrogen Doped Tio2 Nanowire Arrays, Xiao-Jun Lv, Yue-Ming Li, Hao Zhang, Da Chen, Jennifer Hensel, Jin Z Zhang, Jing-Hong Li Nov 2009

Enhanced Visible Light Photoelectrochemical Performances With Nitrogen Doped Tio2 Nanowire Arrays, Xiao-Jun Lv, Yue-Ming Li, Hao Zhang, Da Chen, Jennifer Hensel, Jin Z Zhang, Jing-Hong Li

Journal of Electrochemistry

Self-organized anodic anatase TiO2 nanowire arrays doped with nitrogen have been successfully fabri-cated and their photoelectrochemical(PEC) properties have been characterized and found to be substantially im-proved compared to undoped nanowires or commercial P25 nanoparticles.Photocurrent measured with monochro-matic incident light showed that the incident photon-to-current efficiency(IPCE,%) values of nanowire arrayelectrodes with or without N-doping were obviously higher than that of commercial P25 nanoparticle electrodes,and nitrogen-doped TiO2 nanowire arrays(NTNA) had noticeable absorption in the visible region.The NTNAelectrodes showed the highest photocurrent density and power conversion efficiency under 100 mW/cm2 visiblelight illumination.A maximumolphotoconversion efficiency of 0.52% was achieved for the …

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Redox State Of Polyaniline Nanodot And Its Coulomb Staircase Effect, Jian-Zhang Zhou, Shao-Huang Weng, Zhong-Hua Lin Aug 2009

Redox State Of Polyaniline Nanodot And Its Coulomb Staircase Effect, Jian-Zhang Zhou, Shao-Huang Weng, Zhong-Hua Lin

Journal of Electrochemistry

Polyaniline nanodot array had been fabricated in AAO template with potentiostatic method and the I~V characteristics of nanodots with different redox states were measured by conducting atomic force microscope (C-AFM) in atmosphere at room temperature. We found that only nanodots in partial oxidation state exhibit coulomb staircase in the I~V curves,while those in the full oxidation state and reduced state do not. The above phenomena were discussed preliminarily.

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