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Full-Text Articles in Physical Sciences and Mathematics

Electrochemical Catalysis: A Dft Study, Li Li, Zi-Dong Wei Aug 2014

Electrochemical Catalysis: A Dft Study, Li Li, Zi-Dong Wei

Journal of Electrochemistry

In this review, we focus on achievements in electro-catalysis based on the density function theory study. The relationships among the electrode potential, electronic structure of catalysts and electro-catalytic activity are summarized in three parts: the adsorption and desorption of species, electron transfer, and stability of catalysts. The electrode potential and the electronic structure (d-band center or Fermi (HOMO) energy) of catalysts significantly influence the formation, adsorption and desorption of surface species on electrode. The electro-catalytic activity can be improved by modulating the electrode potential and electronic structure of catalysts.


Investigation Of The Dynamics Of Photocarriers During Photoelectrochemical Water Splitting By Combination Of Photoelectrochemistry And Transient Absorption Spectroscopy, Wen-Hua Leng Aug 2014

Investigation Of The Dynamics Of Photocarriers During Photoelectrochemical Water Splitting By Combination Of Photoelectrochemistry And Transient Absorption Spectroscopy, Wen-Hua Leng

Journal of Electrochemistry

Semiconductor photoelectrochemical hydrogen production is an important and promising technology for utilizing solar energy. The efficiency of hydrogen production depends on the efficiencies of separation and transport of photo-generated carriers. A deep understanding of the behavior of these processes has guiding significance for designing efficient solar hydrogen device. photoelectrochemical and transient absorption spectroscopy methods are powerful tool for studying the microscopic dynamics and mechanism of photocatalytic reaction. This review describes the part of the latest results of the author regarding the semiconductor photoelectrochemical hydrogen production obtained by these methods,and the problems and future research priorities in this field are proposed.


Room Temperature Ionic Liquid Templated Meso-Macroporous Material By Self-Assembled Giant Gold Nanoparticles And Its Enhancement On The Direct Electrochemistry Of Cytochrome C, Pei Li, Dong-Ping Zhan, Yuan-Hua Shao Aug 2014

Room Temperature Ionic Liquid Templated Meso-Macroporous Material By Self-Assembled Giant Gold Nanoparticles And Its Enhancement On The Direct Electrochemistry Of Cytochrome C, Pei Li, Dong-Ping Zhan, Yuan-Hua Shao

Journal of Electrochemistry

Room temperature ionic liquid (RTIL) is used as a soft-template to organize a meso-macroporous material constructed by self-assembled giant gold nanoparticles which are capped by L-cysteine. First, L-cysteine capped gold nanoparticles can self-assembly to form nanowires and sub-micrometer spherical giant particles due to the static interaction and/or the condensation reaction between the carboxyl and amino groups at the outer terminal of the ligand. Second, the spherical assembled particles can form a quasi-solid gel when grinding with a hydrophobic RTIL, 1-octyl-3-metyllimidazolium hexafluorophosphate. Finally, when the composite gel is coated on a glassy carbon electrode and then polarized by using cyclic voltammetry …


Recent Progress In The Mechanistic Understanding Of Formic Acid Oxidation On Pt Electrode, Jie Xu, Dao-Chuan Jiang, Dong Mei, Zheng-Da He, Yan-Xia Chen Aug 2014

Recent Progress In The Mechanistic Understanding Of Formic Acid Oxidation On Pt Electrode, Jie Xu, Dao-Chuan Jiang, Dong Mei, Zheng-Da He, Yan-Xia Chen

Journal of Electrochemistry

This article reviews the recent progress in understanding of the mechanisms for formic acid oxidation on Pt electrode. There are two pathways for formic acid oxidation on Pt electrode: (1) Indirect Pathway through which HCOOH is oxidized to CO2 through COad intermediate. This pathway contributes only 1% of the total current; (2) Direct Pathway where HCOOH is oxidized directly to CO2. The results from IR Spectroscopy, single-crystal electrochemistry and DFT calculation all support that the bridge-bonded formate is neither the intermediate of direct pathway nor the precursor for COad formation in indirect pathway. Possible mechanism …


Electrochemical And Surface Enhanced Raman Spectroscopic Studies Of Benzimidazole On Nickel Electrode, Ping-Jie Wei, Ya-Xian Yuan, Min-Min Xu, Jian-Lin Yao, Ren-Ao Gu Aug 2014

Electrochemical And Surface Enhanced Raman Spectroscopic Studies Of Benzimidazole On Nickel Electrode, Ping-Jie Wei, Ya-Xian Yuan, Min-Min Xu, Jian-Lin Yao, Ren-Ao Gu

Journal of Electrochemistry

By measuring cyclic voltammograms and polarization curves, the inhibition effects of benzimidazole (BMIH) concentration in acetonitrile system on a nickel electrode were investigated. It was found that the oxidation and the corrosion potentials shifted positively, and the oxidation current decreased with the increase in the concentration of BIMH. Potential dependent adsorption and film formation behavior of BMIH on the nickel electrode were investigated by in situ SERS spectroscopy. With the potential moving from negative direction to positive direction, the complexes made of BIMH and nickel were formed, preventing the nickel electrode from corrosion. In addition, the 0.001 mol·L-1 of …


Synthesis Of Silver Nanoparticles Supported On Graphene Quantum Dots For Oxygen Reduction Reaction, Jian Ju, Wei Chen Aug 2014

Synthesis Of Silver Nanoparticles Supported On Graphene Quantum Dots For Oxygen Reduction Reaction, Jian Ju, Wei Chen

Journal of Electrochemistry

Silver-based catalysts have been extensively investigated as the platinum substituted catalysts due to their high catalytic efficiency, low cost and long-term durability. In this study, the surfactant-free silver nanoparticles supported on graphene quantum dots were synthesized through a facile approach without addition of any other protecting ligands and reducing agents. The “surface-clean” silver nanoparticles had remarkable electrocatalytic performance towards oxygen reduction reaction (ORR) with the most efficient four-electron transfer process. Compared with commercial Pt/C catalyst, the hybrid nanoparticles showed comparable catalytic performance for ORR but much higher tolerance to methanol. Such silver nanoparticles supported on graphene quantum dots may have …


Preparation And Lithium Storage Performance Of Sn-Snsb Nanoparticles, Yao Xiao, Jiao-Hong Wu, Qi Wang, Ling Huang, Jun-Tao Li, Shi-Gang Sun Aug 2014

Preparation And Lithium Storage Performance Of Sn-Snsb Nanoparticles, Yao Xiao, Jiao-Hong Wu, Qi Wang, Ling Huang, Jun-Tao Li, Shi-Gang Sun

Journal of Electrochemistry

Tin was widely studied as alternative anode material to carbon for lithium-ion batteries thanks to its much higher theoretical capacity. However, a pure tin electrode suffers severely from its poor cycleability due to mechanical fatigue caused by volume change during lithium insertion and extraction processes. Tin-based alloy may improve the cycleability property of tin electrode. In this article, we report facile synthesis of spherical Sn-SnSb nanopartciles using a simple solvent-thermal approach. It is amazing to find that the spherical Sn-SnSb nanoparticles can circumvent volume changes effectively during charge-discharge process. Electrochemical discharge/charge results show that the spherical Sn-SnSb nanoparticles electrode exhibits …


Electrochemical Fabrication Of Two-Dimensional Flower-Like Pt Nanostructures For Methanol Electrocatalytic Oxidation, Xia Wang, Jun Hu, Yong-Jun Li Aug 2014

Electrochemical Fabrication Of Two-Dimensional Flower-Like Pt Nanostructures For Methanol Electrocatalytic Oxidation, Xia Wang, Jun Hu, Yong-Jun Li

Journal of Electrochemistry

Two-dimensional flower-like Pt nanostructures (2D FPNs) were fabricated on glassy carbon substrates by galvanostatical electrochemical technique. The electrolyte was the HAuCl4 + HClO4 aqueous solution without addition of any structure-directing organic reagent, which made as-prepared Pt nanostructures cleaner, exhibiting much higher reactivity. Scanning electron microscopic images revealed that 2D FPNs were spherical Pt nano-flowers constructed by the smallest building blocks, nano-leaves. The number density of spherical Pt nano-flowers can be tuned by controlling the electrodeposition time. High resolution transmission electron microscopic images indicated that each nano-leaf was formed by growing along Pt(111) direction. Electrocatalytic activities of as-prepared 2D …


Effecting Of Dissolved Oxygen On Microbial Fuel Cells Based On Pseudomonas Aeruginosa, Chang-Li Cao, Li-Xiang Chen, Ran-Ran Wu, Ken-Lin Chang, Feng Zhao Aug 2014

Effecting Of Dissolved Oxygen On Microbial Fuel Cells Based On Pseudomonas Aeruginosa, Chang-Li Cao, Li-Xiang Chen, Ran-Ran Wu, Ken-Lin Chang, Feng Zhao

Journal of Electrochemistry

In this work, the reaction between the electron shuttle secreted by Pseudomonas aeruginosa and anode was studied by measuring cyclic voltammogram and open circuit potential. The effect of dissolved oxygen on the oxidation reaction of anode was explored. It was demonstrated that the reaction was a diffusion-controlled and reversible process. The anode was a little affected when the dissolved oxygen of inocula was low (0 ~ 1.6 mg·L-1). The polarization curves showed that the current output of microbial fuel cells decreased 7% with the impact of dissolved oxygen.


A Sensitive And Label-Free Electrochemical Aptasensor Based On Signal Amplification Of Carbon Nanotubes, Chun-Yan Deng, Hui-Min Fan, Juan Xiang, Yuan-Jian Li Aug 2014

A Sensitive And Label-Free Electrochemical Aptasensor Based On Signal Amplification Of Carbon Nanotubes, Chun-Yan Deng, Hui-Min Fan, Juan Xiang, Yuan-Jian Li

Journal of Electrochemistry

A label-free electrochemical sensing electrode for highly sensitive detection of adenosine was constructed based on the signal amplification of carbon nanotubes (CNTs). The change in the interfacial feature of the modified electrode was characterized by electrochemical impedance spectroscopy. Using [Ru(NH3)6]3+ as the signaling moiety, adenosine with concentrations as low as 0.027 nmol·L-1 can be selectively detected. Additionally, the fabrication of this present aptasensor was simple, time-saving and cost-effective. Compared with other reported aptasensors, the proposed aptasensor had advantages of excellent sensitivity, selectivity and simplicity, which plays a potential role in development of aptasensor.


Electrocatalytic Oxidation Of Formate On Pd-Cu/C - Effect Of Dealloying Pretreatment, Jiang Kun, Wang Ye, Lin Tao, Cai Wen-Bin Aug 2014

Electrocatalytic Oxidation Of Formate On Pd-Cu/C - Effect Of Dealloying Pretreatment, Jiang Kun, Wang Ye, Lin Tao, Cai Wen-Bin

Journal of Electrochemistry

Carbon supported highly dispersed Pd-Cu nanoalloy catalyst toward formate electrooxidation is prepared via one-pot synthesis by using ethylene glycol as the reducing agent and sodium citrate as the stabilizer. The as-prepared catalyst is structurally characterized by TEM and XRD. The Cu dealloyment is carried out through repetitive potential cycling of the Pd-Cu/C catalyst in an acidic solution. The dealloying effect on the performance of the Pd-Cu/C is investigated by using cyclic voltammetry and chronoamperometry, and the surface structural change of Pd-Cu/C is probed by in situ ATR-IR measurement. The results show that the as-prepared Pd-Cu/C processes a better long-term stability …


High Sensitive Detection Of Cd(Ii) And Pb(Ii) Based On Antimony-Film Covered Pencil Core Electrodes, Shan Chen, Zhao-Yan Zheng, Yi-Min Fang, Li-Qing Zheng, Jian-Jun Sun Aug 2014

High Sensitive Detection Of Cd(Ii) And Pb(Ii) Based On Antimony-Film Covered Pencil Core Electrodes, Shan Chen, Zhao-Yan Zheng, Yi-Min Fang, Li-Qing Zheng, Jian-Jun Sun

Journal of Electrochemistry

In this paper, a pencil core was used as the substrate for an antimony-film electrode for simultaneous detection of Cd(II) and Pb(II) by square-wave anodic stripping voltammetry (SWASV). With the deposition time of 180 s, the low limit of detection (LOD) for the electrode was determined to be 0.075 ?g?L-1 for Cd(II), while 0.13 ?g?L-1 for Pb(II) with good reproducibility in low pH solutions (pH = 2). The results show a much lower LOD than that of bismuth-film pencil core electrode. Finally, this antimony-film electrode was successfully applied to determine Cd(II) and Pb(II) in tap water.


Preparation Of Pt-Tio2/Graphene Composites With High Catalytic Activity Towards Methanol Oxidation And Oxygen Reduction Reaction, Li Qi, Ying Yin, Wen-Guang Tu, Bing-Bing Wu, Zhao-Sheng Wang, Jian-Guo Liu, Jun Gu, Zhi-Gang Zou Aug 2014

Preparation Of Pt-Tio2/Graphene Composites With High Catalytic Activity Towards Methanol Oxidation And Oxygen Reduction Reaction, Li Qi, Ying Yin, Wen-Guang Tu, Bing-Bing Wu, Zhao-Sheng Wang, Jian-Guo Liu, Jun Gu, Zhi-Gang Zou

Journal of Electrochemistry

A series of graphene-supported TiO2 nanoparticles (TiO2/G) with different TiO2 contents were prepared by a facile hydrothermal method, and then the Pt-TiO2/G catalysts were successfully prepared by reducing Pt-precursor with microwave technique. Compared with Pt-G catalysts, the catalytic performance toward oxygen reduction reaction (ORR) and methanol oxidation reaction (MOR) of Pt-TiO2/G catalysts was improved due to the addition of TiO2. However, the excessive TiO2 would lead to a poor catalytic performance of Pt-TiO2/G catalysts because of the low electrical conductivity of TiO2.


23Na Mas Nmr Spectroscopic Study Of Na2Mnpo4F As Cathode Material For Sodium-Ion Battery, Xu Hou, Gui-Ming Zhong, Xiao-Chen Lin, Zi-Geng Liu, Xiao-Biao Wu, Yong Yang Jun 2014

23Na Mas Nmr Spectroscopic Study Of Na2Mnpo4F As Cathode Material For Sodium-Ion Battery, Xu Hou, Gui-Ming Zhong, Xiao-Chen Lin, Zi-Geng Liu, Xiao-Biao Wu, Yong Yang

Journal of Electrochemistry

The Na2MnPO4F is one of the promising cathode materials for the sodium ion batteries. In the paper, we employed the ex situ X-ray diffraction and solid state NMR techniques to study the charge and discharge processes of this material, including the crystal structure and sodium sites changes. The ex situ x-ray diffraction patterns showed that two new diffraction peaks could be observed at 31o and 36o indicating an intermediate phase formed with the extraction of Na+. From the 23Na MAS NMR spectrum of the material, three peaks were seen at -209 ppm,-258 ppm …


Effects Of Oxygen Coverage And Hydrated Proton Model On The Dft Calculation Of Oxygen Reduction Pathways On The Pt(111) Surface, Li-Hui Ou, Sheng-Li Chen Jun 2014

Effects Of Oxygen Coverage And Hydrated Proton Model On The Dft Calculation Of Oxygen Reduction Pathways On The Pt(111) Surface, Li-Hui Ou, Sheng-Li Chen

Journal of Electrochemistry

DFT calculation is used to study various possible steps in the oxygen reduction reaction (ORR), including the adsorption and dissociation process of O2 and the serial protonation process of dissociated products to form H2O on the Pt(111) surface. By using slabs of different sizes, and different numbers of pre-adsorbed oxygen atoms, the coverage effects on the pathways are investigated. The calculated results using different hydrated proton models are also compared. It is shown that the initial step of the ORR is the formation of a protonated end-on chemisorbed state of OOH*, which can transform to an unprotonated …


Electrochemistry At Liquid/Liquid Interfaces And Its Recent Progresses, Jing Gu, Yong-Hui Qiao, Xin-Yu Zhu, Xiao-Hong Yin, Xin Zhang, Ye Chen, Zhi-Wei Zhu, Yuan-Hua Shao Jun 2014

Electrochemistry At Liquid/Liquid Interfaces And Its Recent Progresses, Jing Gu, Yong-Hui Qiao, Xin-Yu Zhu, Xiao-Hong Yin, Xin Zhang, Ye Chen, Zhi-Wei Zhu, Yuan-Hua Shao

Journal of Electrochemistry

Electrochemistry and electroanalytical chemistry at a liquid/liquid interface have attracted much attention in the past few decades since they have been closely related to many applications including exploration in mechanisms of extraction processes and chemical sensing, as well as investigations in phase transfer catalysis, drug release and mimicking the function of biological membranes. In this review, recent progresses in this field in the last decade, especially the investigations in microstructure of liquid/liquid interface, charge (ion and electron) transfer reactions and functionalization of liquid/liquid interfaces, are reviewed.


Surface Enhanced Raman Spectroscopic Studies Of Pyridine Adsorbed On Ti/Au@Sio2 Film Electrode, Min-Min Xu, Ke Liu, Qing-Hua Guo, Jian-Lin Yao Jun 2014

Surface Enhanced Raman Spectroscopic Studies Of Pyridine Adsorbed On Ti/Au@Sio2 Film Electrode, Min-Min Xu, Ke Liu, Qing-Hua Guo, Jian-Lin Yao

Journal of Electrochemistry

This study was performed based on shell-isolated nanoparticles-enhanced Raman spectroscopy (SHINERS) technology. The Au@SiO2 nanoparticles were prepared and characterized by TEM and cyclic voltammetry. It was shown that the shell of SiO2 was compact. The high quality signal measured by surface enhanced Raman spectroscopy (SERS) was obtained from the adsorbed pyridine on Ti/Au@SiO2 electrode. The origin of the SERS signals was further confirmed by testing Pt and Ni electrodes. In addition, potential dependent adsorption behavior was investigated. It was found that pyridine was adsorbed parallel on the surface from -0.1 V to -0.6 V, and converted to …


The Ionic Diffusion Model For The Solid Oxide Cathode And Its Verification By The Electrolysis Of Ta2O5 In Molten Cacl2, Hua-Lin Chen, Zhi-Yong Wang, Xian-Bo Jin, George Z. Chen Jun 2014

The Ionic Diffusion Model For The Solid Oxide Cathode And Its Verification By The Electrolysis Of Ta2O5 In Molten Cacl2, Hua-Lin Chen, Zhi-Yong Wang, Xian-Bo Jin, George Z. Chen

Journal of Electrochemistry

The deoxidation speed of a solid oxide cathode in molten CaCl2 can be estimated by the PRS steady diffusion model of O2-, which correlates the deoxidation speed with the precursor porosity, P, the metal-to-oxide molar volume ratio, R, and the cathode volume shrinkage S. The PRS model indicates that the porosity of the oxide cathode has important influence on the deoxidation speed, and provides a very simple equation for the prediction of the optimal cathode porosity. For the electrolysis of Ta2O5, the porosity of the cathode is better to be …


Effects Of Conformational Transformations On Electronic Transport Properties Of Optical Molecular Switches: An Ab Initio Study, Yuan-Yuan He, Jian-Wei Zhao Jun 2014

Effects Of Conformational Transformations On Electronic Transport Properties Of Optical Molecular Switches: An Ab Initio Study, Yuan-Yuan He, Jian-Wei Zhao

Journal of Electrochemistry

A series of model molecules with 4 kinds of conformational transformations have been investigated as optical molecular switches by using density functional theory combined with nonequilibrium Green’s function method. The theoretical calculations show that molecules after conformational transformations have photoswitching characteristics. We find that the photochromic molecules with the same conformational transformation usually have a similar current on/off state when they are applied as photoshwitches. Among these transformations, the molecular switch with E(“trans”)/Z(“cis”)-isomerisation of the NN double bond has the highest current on-off ratio. The influences of the energy gap (HLG) between the highest occupied molecular orbital …


Preparation And Photocatalytic Properties Of Zno Nanorod Arrays On Ti Substrates, Jia-Ming Yang, Ling-Jun Han, Li-Ping Zhong, Zhen-Hai Liang Jun 2014

Preparation And Photocatalytic Properties Of Zno Nanorod Arrays On Ti Substrates, Jia-Ming Yang, Ling-Jun Han, Li-Ping Zhong, Zhen-Hai Liang

Journal of Electrochemistry

In this paper, the uniform ZnO nanorod arrays were prepared by galvanostatic electrodeposition on Ti Substrates. The morphology and structure of samples were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The effects of the concentration of Zn(NO3)2 and the deposition current on the morphology of the ZnO nanorod arrays were investigated. Photocatalytic properties of ZnO nanorod arrays were investigated by degradation of methyl orange (MO) under UV-light irradiation. The analysis revealed that the concentration of Zn(NO3)2 and the deposition current strongly influenced the morphology of the ZnO nanorod arrays. Compared with …


Key Factors And Techno-Economic Analyses Of Manganese Electrolysis Process, Gui-Mei Han, Fu-Yuan Xu, Lin-Hua Jiang, Zhi-Gang Dan, Xiao-Juan Gao, Ning Duan Jun 2014

Key Factors And Techno-Economic Analyses Of Manganese Electrolysis Process, Gui-Mei Han, Fu-Yuan Xu, Lin-Hua Jiang, Zhi-Gang Dan, Xiao-Juan Gao, Ning Duan

Journal of Electrochemistry

This paper first studied the key factors affecting the initial manganese electrolysis process, including concentration of Mn2+, electrolysis time, overpotential, and then optimized these processing parameters with the chronocoulometry method under a three-electrode system. The results showed that, during the initial manganese electrolysis process, hydrogen evolution occurred more significantly on the stainless steel surface. As electrolysis process continued, manganese covered the stainless steel surface gradually, and hydrogen evolution reaction restrained which all contributed to the higher current efficiency. Besides, the limiting current density appeared at high overpotential region, and the reaction was controlled by diffusion process. In 0.02 …


A New Silver Electrode Based On The Composite Silver Sulfide/Attapulgite As Ionophore, Wen-Zhuo Li, Ding-Jia Xu, Jun Wang, Jian-Long Wang Jun 2014

A New Silver Electrode Based On The Composite Silver Sulfide/Attapulgite As Ionophore, Wen-Zhuo Li, Ding-Jia Xu, Jun Wang, Jian-Long Wang

Journal of Electrochemistry

A novel silver ion selective electrode with its ionophore being a kind of organic/inorganic composite composed of silver sulfide and attapulgite has been prepared. Attapulgite is a type of natural inorganic polymer which has some properties similar to zeolite, such as a higher specific surface area and plenty of intercrystalline cavities. In this work, the silver ions were firstly adosrbed in the micropores of the attapulgite, then thioacetamidetiny was selected to mix with the prepared silver ions/ attapulgite composite. Owning to the existence of sulfur atoms in the structure of thioacetamide molecules, thioacetamide molecules can react with the silver ions/attapulgite …


Novel Electrochemical Interfaces Based On Functional Nanomaterials And Their Related Applications, Cheng-Zhou Zhu, Lei Han, Shao-Jun Dong Jun 2014

Novel Electrochemical Interfaces Based On Functional Nanomaterials And Their Related Applications, Cheng-Zhou Zhu, Lei Han, Shao-Jun Dong

Journal of Electrochemistry

Due to the unique optical, electronic, magnetic and catalytic properties, functional nanomaterials provide new opportunities for the rapid development in a variety of disciplines and show considerable promise in different fields. Specifically, constructions of the novel electrochemical interface using various nanomaterials and exploring their advanced electrochemical properties have received great attention to develop electrochemical devices with potential applications. In this account, we focus on our up-to-date progress in the construction of novel electrochemical interfaces based on nanomaterials, mainly highlighting our research advances on electrochemical sensors, fuel cells and fluorescence spectroelectrochemistry. These novel advanced nanomaterials endow them excellent performances and open …


Horseradish Peroxidase-Attapulgite Clay Nanocomposites: Fabrication And Application To Sensing The Extracellular H2O2 Released From Cells, Ping Wu, Chen-Xin Cai Jun 2014

Horseradish Peroxidase-Attapulgite Clay Nanocomposites: Fabrication And Application To Sensing The Extracellular H2O2 Released From Cells, Ping Wu, Chen-Xin Cai

Journal of Electrochemistry

The nanostructured attapulgite clay was employed as a support matrix for immobilizing horseradish peroxidase (HRP). FTIR and electrochemical methods demonstrated that HRP had been effectively assembled on attapulgite surface with the formation of HRP-attapulgite nanocomposites. The HRP-attapulgite hybrid was deposited on the glassy carbon (GC) electrode forming the HRP-attapulgite/GC electrode. Cyclic voltammetric results showed a pair of well-defined redox peaks, which were ascribed to direct electron transfer (DET) of HRP, with the formal potential E0′ = -335 mV (vs. SCE) in the phosphate buffer solution (PBS, pH 7.0). The dependence of E0′ on solution pH indicated …


Microfabrication And Redox Properties Of The Single Microcrystal Of Na3Co(Cn)6/Nacl Solid Solution, Yi-Liang Zhu, De-Zhi Yang, Ya-Qiong Su, De-Yin Wu, Zhong-Qun Tian, Dong-Ping Zhan Jun 2014

Microfabrication And Redox Properties Of The Single Microcrystal Of Na3Co(Cn)6/Nacl Solid Solution, Yi-Liang Zhu, De-Zhi Yang, Ya-Qiong Su, De-Yin Wu, Zhong-Qun Tian, Dong-Ping Zhan

Journal of Electrochemistry

Although the molecular structures are similar to each other, the redox property of Co(CN)63- at solid/liquid interface is not so good as Fe(CN)63-. In this paper, scanning electrochemical microscopy (SECM) was adopted to construct an electrochemical microsystem with a volume of fL~pL, in which a micropipette with micrometer-sized orifice was employed as the scanning tip. Due to the evaporation of water, the NaCl electrolyte is concentrated to form a microcrystal. During the crystallization, the redox species Co(CN)63- replaced the sites of NaCl65- unit due to their matching lattice parameters, i.e., the …


Detection Of Glucosamine Hydrochloride By Ion Chromatography With Integrated Pulsed Amperometric Detector, Yan-Qun Fan, Qing-Yang Chen, Jin-Mei Xia, Jian-Zhong Xu, Xun Xu, Chen Xu Apr 2014

Detection Of Glucosamine Hydrochloride By Ion Chromatography With Integrated Pulsed Amperometric Detector, Yan-Qun Fan, Qing-Yang Chen, Jin-Mei Xia, Jian-Zhong Xu, Xun Xu, Chen Xu

Journal of Electrochemistry

Factors (integral potential, concentration of NaOH and flow rate) affecting detection of Glucosamine hydrochloride by ion chromatography with integrated pulsed amperometric detector were studied. As the integral potential increased, the detection signal first increased and then decreased, while the detection background and noise increased directly. The suitable integral potential should be 0.1 V. With the concentration of NaOH increased, the retention time descended sharply, while the integral area increased quickly before they are coming back into balance. The number of theoretical plates increased firstly and then decreased. The optimum concentration of NaOH was 50 mmol·L-1. As the flow …


In Situ Detection On Electrochemical Chloride Removal Of Reinforcement In Concrete By Combined Ph/Cl- Probes, Jing-Jing Wang, Shi-Gang Dong, Xiao-Juan Zhang, Hong-Wei Lv, Yun-Chang Wu, Rong-Gui Du, Chang-Jian Lin Apr 2014

In Situ Detection On Electrochemical Chloride Removal Of Reinforcement In Concrete By Combined Ph/Cl- Probes, Jing-Jing Wang, Shi-Gang Dong, Xiao-Juan Zhang, Hong-Wei Lv, Yun-Chang Wu, Rong-Gui Du, Chang-Jian Lin

Journal of Electrochemistry

In this work, the concrete samples polluted by chloride ion were electrochemically treated using galvanostatic technique, and the distributions of chloride ion concentration and pH value in the polluted concretes were in-situ monitored by embedding a combined pH/Cl- probe during the electrochemical chloride removal. The corrosion behaviors of reinforcing steel in the concrete were simultaneously studied by using linear polarization and electrochemical impedance spectroscopy techniques (EIS). The micro environment of the concrete and corrosion rate of steel were explored during the electrochemical chloride removal. It was indicated that the Cl- concentration in the concrete pore solution decreased with …


Preparation And Electrochemical Performances Of Cofe2O4/Gns Nanocomposites As Anode Material For Lithium Ion Battery, Mo-Chao Cai, Sen-Rong Cai, Ming-Sen Zheng, Quan-Feng Dong Apr 2014

Preparation And Electrochemical Performances Of Cofe2O4/Gns Nanocomposites As Anode Material For Lithium Ion Battery, Mo-Chao Cai, Sen-Rong Cai, Ming-Sen Zheng, Quan-Feng Dong

Journal of Electrochemistry

The CoFe2O4/GNS was synthesized by a simple one-pot solvothermal method. The results obtained by X-ray diffraction (XRD) and transmission electron microscopy (TEM) showed that the CoFe2O4 particles with sizes of 15 nm dispersed on the surface of graphene uniformly. Electrochemical tests indicated that the CoFe2O4/GNS nanocomposite exhibited excellent cyclic stability with almost 95.8% capacity retention after 100 cycles at the current density of 500 mA·g-1 and delivered a high reversible capacity of 482 mAh·g-1 at the current density of 2 A·g-1.


Effects Of Carbon Interlayer On Electrochemical Performance Of Lithium-Sulfur Cell, Jin-Peng Yu, Ming Zhang, Fei Ding, Zhi-Yuan Tang, Xing-Jiang Liu Apr 2014

Effects Of Carbon Interlayer On Electrochemical Performance Of Lithium-Sulfur Cell, Jin-Peng Yu, Ming Zhang, Fei Ding, Zhi-Yuan Tang, Xing-Jiang Liu

Journal of Electrochemistry

Three kinds of conductive carbon films were prepared with Super-P (SP), KB and MWCNTs, and then the as-prepared carbon films were applied as an interlayer between a sulfur electrode and a separator for constructing a coin-type lithium-sulfur (Li-S) cell, respectively. The assessment results show that all the cells delivered the reversible capacities higher than 800 mAh·g-1 after 40 cycles when the sulfur loading was up to 80% (by mass) in the sulfur electrode. Due to significant differences of physical properties among the carbon materials,the cell with a KB interlayer exhibited higher electrochemical polarization; the cycling performance of the cell …


Electrochemical Behavior Of Ionic Liquid Confined Into Nanopores Of Silica Gel Matrix, Zuo-Peng Li, Ya-Qiong Wen, Mei-Xia Wu, Yong Guo Apr 2014

Electrochemical Behavior Of Ionic Liquid Confined Into Nanopores Of Silica Gel Matrix, Zuo-Peng Li, Ya-Qiong Wen, Mei-Xia Wu, Yong Guo

Journal of Electrochemistry

Imidazolium Ionic liquids (ILs) nano aggregates confined into nanopores of silica gel matrices (ILs-sg) modified electrodes were prepared by sol-gel process and characterized by cyclic voltammetry. Furthermore, the amounts of 15% ~ 28% ILs-sg and nano aggregates coated with ILs silica gel (ILs/sg) were prepared and their conductivities were evaluated by performing electrochemical AC impedance measurements from 20 oC to 80 oC. The abnormal results showed that, 1) comparing with the bulk IL, the confined IL had a positive shift effect of Fc/Fc+ redox potential; 2) when IL confined into a nanospace, the electrochemical stability became poor; 3) …