The deoxidization reaction at the interface between slag and metal is one of the most important reactions in the iron and steel making.The interface reaction and transport characteristics of Molten Ultra-low Carbon St...The deoxidization reaction at the interface between slag and metal is one of the most important reactions in the iron and steel making.The interface reaction and transport characteristics of Molten Ultra-low Carbon Steel with CaO-MgO-Al2O3slag system under different over potential conditions of the system was studied.The electrochemical reduction mechanism at the interface between the molten slag and molten steel was investigated.The results showed that Chronoamperometry method is very useful for the study of interfacial reaction in the slag-metal system.The current of interfacial reaction decreases approximately linearly with t-1/2,and the diffusion coefficient of oxygen in molten slag calculated by Cottrell equation increased dramatically with over potential.In the open circuit potential,the diffusion coefficient of oxygen in the slag is about 10-8m2/s.展开更多
Hydrogen diffusion coefficients in MlNi 3.75 Co 0.65 Mn 0.4 Al 0.2 alloy electrode as a function of state of charge (SOC) or temperature were determined by chronoamperometry. It is found that hydrogen diffusion coeffi...Hydrogen diffusion coefficients in MlNi 3.75 Co 0.65 Mn 0.4 Al 0.2 alloy electrode as a function of state of charge (SOC) or temperature were determined by chronoamperometry. It is found that hydrogen diffusion coefficient decreases with the increase of SOC or the decrease of temperature. The activation energy for hydrogen diffusion in the alloy electrode with 50%SOC is evaluated to be 19.9?kJ/mol.展开更多
Glutamate dehydrogenase occupies a pivotal position in the metabolism of most organisms. The reductive amination of α-ketoglutarate catalyzed by the enzyme is one of the most important reactions in the nitrogen assim...Glutamate dehydrogenase occupies a pivotal position in the metabolism of most organisms. The reductive amination of α-ketoglutarate catalyzed by the enzyme is one of the most important reactions in the nitrogen assimilation with NADH as coenzyme.展开更多
The electrodeposition of lead in alkaline solutions containing xylitol （1, 2, 3, 4, 5-pentahydroxypentane） was studied. The lead electrodeposition and the chemical stability of xylitol in alkaline solutions were inv...The electrodeposition of lead in alkaline solutions containing xylitol （1, 2, 3, 4, 5-pentahydroxypentane） was studied. The lead electrodeposition and the chemical stability of xylitol in alkaline solutions were investigated by cyclic voltammetry. Apparent activation energy, apparent transfer coefficient and exchange current density were obtained by linear sweep voltammetry. Initial stages of lead electrocrystallization were determined by chronoamperometry. Voltammograms of a AISI 316 stainless steel electrode in xylitol solution exhibit no current in the potential range of-1.3 V to 0.75 V （vs Hg/HgO）, implying that xylitol is stable to oxidation and reduction. The apparent activation energy, apparent transfer coefficient and exchange current density were calculated to be 35.15 kJ/mol, 1.56 and 9.65x10^-5 A/m^2. Analysis of the chronoamperometric responses implies three-dimensional growth of nuclei, with the type of nucleation depending on overpotential.展开更多
The electrodeposition of antimony in alkaline solutions containing xylitol was investigated using cyclic voltammetry,linear sweep voltammetry and chronoamperometry.The antimony electrodeposition and the chemical stabi...The electrodeposition of antimony in alkaline solutions containing xylitol was investigated using cyclic voltammetry,linear sweep voltammetry and chronoamperometry.The antimony electrodeposition and the chemical stability of xylitol in alkaline solutions were studied by cyclic voltammetric technique.Apparent activation energy,apparent transfer coefficient and exchange current density were obtained by linear sweep voltammetric technique.Initial stages of antimony electrocrystallization were determined by chronoamperometry.Xylitol in alkaline solutions exhibits high chemical stability and there is no redox in solutions when the potential ranges from-1.20 V to ＋0.60 V（vs Hg/HgO）.There is no other redox reaction but hydrolysis occurring on stainless steel in the potential range of-1.75 V to 1.25 V（vs Hg/HgO） while the xylitol decomposition maybe take place on antimony electrode when potential is more negative than-1.70 V（vs Hg/HgO）.Cyclic voltammograms with different scan rates indicate that the antimony electrodeposition process is an electrocrystallization which is a completely irreversible electrode process.The apparent activation energy,apparent transfer coefficient and exchange current density were calculated to be 46.33 kJ/mol,0.64 and 4.40×10-6 A/m2,respectively.The analyses of the chronoamperometric responses support the view of a three-dimensional growth under progressive nucleation.The average diffusion coefficient of antimony was calculated to be 1.53×10-6 cm2/s.展开更多
The processes of nucleation and growth of lead from the dilute electrolytes on copper substrates were investigated bychronoamperometry and by scanning electron microscopic (SEM) analysis of the deposits obtained in th...The processes of nucleation and growth of lead from the dilute electrolytes on copper substrates were investigated bychronoamperometry and by scanning electron microscopic (SEM) analysis of the deposits obtained in the potentiostatic regime ofelectrolysis. In the dependence of electrodeposition conditions, the nucleation of Pb followed either progressive or instantaneoustype. The type of nucleation changed from progressive to instantaneous one with increasing the concentration of Pb(II) ions and theoverpotential of electrodeposition. Regardless of the type nucleation, a novel type of Pb particles like cobweb was formed by thepotentiostatic electrodeposition in the moment of nucleation and at the early stages of growth. On the basis of the shape ofcobweb-like particles and the electrodeposition conditions leading to their formation, these particles were situated in the group ofspongy-like ones. Also, comparative morphological analysis of Pb deposits obtained in the conditions of progressive andinstantaneous nucleation confirmed the existence of two limiting types of nucleation.展开更多
We prepared a novel nickel（II）hydroxide-modified carbon paste electrode（Ni（OH）2-X/CPE）for the electrocatalytic oxidation of formaldehyde.The electrode was prepared by a simple method without the use of linking c...We prepared a novel nickel（II）hydroxide-modified carbon paste electrode（Ni（OH）2-X/CPE）for the electrocatalytic oxidation of formaldehyde.The electrode was prepared by a simple method without the use of linking chemicals.The prepared Ni（OH）2-X/CPE material was characterized by scanning electron microscopy and energy dispersive X-ray spectrometry.The electrochemical performance of the proposed electrode was investigated using cyclic voltammetry,electrochemical impedance spectroscopy,and chronoamperometry.The results indicate that Ni（OH）2-X/CPE exhibits good electrocatalytic activity with regards to formaldehyde oxidation owing to its nanoporous structure and the large surface area of zeolite X.The values of the electron transfer coefficient and the catalytic rate constant were 0.7 and 6.1 × 104 cm3/（mol·s）,respectively.Therefore,the proposed electrode,which showed remarkable electroactivity with regards to formaldehyde oxidation with long-term stability and good reproducibility,could be useful in fuel cells.展开更多
The electrochemical quartz crystal microbalance (EQCM) is used to investigate the characteristics of the thiolated self-assembled monolayer(SAM) on gold surface.A 5MHz QCM element serves as both the mass-sensitive sen...The electrochemical quartz crystal microbalance (EQCM) is used to investigate the characteristics of the thiolated self-assembled monolayer(SAM) on gold surface.A 5MHz QCM element serves as both the mass-sensitive sensor and the working electrode of the electrochemical system.The 6-mecapto-1-hexanol and and the 16-mer oligonucleotide with a mercaptohexyl group at the 5'-phosphate end are utilized to form the SAM on the gold electrode.The frequency response of the QCM during cyclic voltammetry (CV) scanning and cbronoamperometry are recorded together with the electrochemical current.The experimental results indicates that the frequency response is more sensitive to the surface coverage.Therefore,the response of the EQCM reveals more details of the SAM on gold electrode.It is especially useful for analysing the immobilization quality,such as probe orientation and coverage,of the SAM.展开更多
One of the thrust areas of research is to find an alternative fuel to meet the increasing demand for energy.Glucose is a good source of alternative fuel for clean energy and is easily available in abundance from both ...One of the thrust areas of research is to find an alternative fuel to meet the increasing demand for energy.Glucose is a good source of alternative fuel for clean energy and is easily available in abundance from both naturally occurring plants and industrial processes.Electrochemical oxidation of glucose in fuel cell requires high electro-catalytic surface of the electrode to produce the clean electrical energy w ith minimum energy losses in the cell.Pt and Pt based alloys exhibit high electro-catalytic properties but they are expensive.For energy synthesis at economically cheap price,non Pt based inexpensive high electro catalytic material is required.Electro synthesized Zn O-Al2O3composite is found to exhibit high electro-catalytic properties for glucose oxidation.The Cyclic Voltammetry and Chronoamperometry curves reflect that the material is very much comparable to Pt as far as the maximum current and the steady state current delivered from the glucose oxidation are concerned.XRD image confirms the mixed oxide composite.SEM images morphology show increased 3D surface areas at higher magnification.This attributed high current delivered from electrochemical oxidation of glucose on this electrode surface.展开更多
An extensive analysis of iron-nitrogen-carbon(Fe-N-C)electrocatalysts synthesis and activity is presented concerning synthesis conditions such as initial Fe content,pyrolysis temperature and atmosphere(inert N_(2),red...An extensive analysis of iron-nitrogen-carbon(Fe-N-C)electrocatalysts synthesis and activity is presented concerning synthesis conditions such as initial Fe content,pyrolysis temperature and atmosphere(inert N_(2),reducing NH_(3),oxidizing Cl_(2) and their sequential combinations)and the influence of an external magnetic field on their performance in oxygen reduction reaction(ORR).Thermosetting porous polymers doped with FeCl_(3) were utilized as the Fe-N-C catalysts precursors.The pyrolysis temperature was varied within a 700-900℃range.The temperature and atmosphere of pyrolysis strongly affect the porosity and compositi on of the resultant Fe-N-C catalysts,while the in itial amount of Fe precursor shows much weaker impact.Pyrolysis under NH_(3) yields materials similar to those pyrolyzed under an inert atmosphere(N_(2)).In contrast,pyrolysis under Cl_(2) yields carbon of peculiar character with highly disordered structure and extensive microporosity.The application of a static external magnetic field strongly enhances the ORR process(herein studied in an alkaline environment)and the enhancement correlates with the Fe content in the Fe-N-C catalysts.The Fe-N-C materials containing ferromagnetic iron phase embedded in N-doped microporous carbon constitute attractive catalysts for magnetic field-aided anion exchange membrane fuel cell technology.展开更多
[Objective] The study aimed to discuss the application of boron-doped diamond （BDD） film electrode in fast detection of samonella in water. [ Method] Boron-doped diamond film electrode was prepared and used as the w...[Objective] The study aimed to discuss the application of boron-doped diamond （BDD） film electrode in fast detection of samonella in water. [ Method] Boron-doped diamond film electrode was prepared and used as the working electrode in fast detection of salmonella in water using chronoamberometry, and the oxidation mechanism of the electrode acting on salmonella was discussed. [ Result] Compared with traditional biologi- cal methods, chronoamperometry could detect the number of salmonellae in water more simply, rapidly and sensitively. [ Conclusion] The method of using BDD electrode to detect salmonella quantity will be widely applied in future.展开更多
A copper hexacyanoferrate modified ceramic carbon electrode （CuHCF/CCE） had been prepared by two-step sol-gel technique and characterized using electrochemical methods. The resulting modified electrode showed a pair...A copper hexacyanoferrate modified ceramic carbon electrode （CuHCF/CCE） had been prepared by two-step sol-gel technique and characterized using electrochemical methods. The resulting modified electrode showed a pair of well-defined surface waves in the potential range of 0.40 to 1.0 V with the formal potential of 0.682 V （vs. SCE） in 0.050 mol·dm^-3 HOAc-NaOAc buffer containing 0.30 mol·dm^-3 KCl. The charge transfer coefficient （a） and charge transfer rate constant （ks） for the modified electrode were calculated. The electrocatalytic activity of this modified electrode to hydrazine was also investigated, and chronoamperometry was exploited to conveniently determine the diffusion coefficient （D） of hydrazine in solution and the catalytic rate constant （kcat）. Finally, hydrazine was determined with amperometry using the resulting modified electrode. The calibration plot for hydrazine determination was linear in 3.0 × 10^-6--7.5 × 10^-4 mol·dm^-3 with the detection limit of 8.0 × 10^-7 molodm^-3. This modified electrode had some advantages over the modified film electrodes constructed by the conventional methods, such as renewable surface, good long-term stability, excellent catalytic activity and short response time to hydrazine.展开更多
基金Item Sponsored by National Natural Science Foundation of China[No.50874072]
文摘The deoxidization reaction at the interface between slag and metal is one of the most important reactions in the iron and steel making.The interface reaction and transport characteristics of Molten Ultra-low Carbon Steel with CaO-MgO-Al2O3slag system under different over potential conditions of the system was studied.The electrochemical reduction mechanism at the interface between the molten slag and molten steel was investigated.The results showed that Chronoamperometry method is very useful for the study of interfacial reaction in the slag-metal system.The current of interfacial reaction decreases approximately linearly with t-1/2,and the diffusion coefficient of oxygen in molten slag calculated by Cottrell equation increased dramatically with over potential.In the open circuit potential,the diffusion coefficient of oxygen in the slag is about 10-8m2/s.
文摘Hydrogen diffusion coefficients in MlNi 3.75 Co 0.65 Mn 0.4 Al 0.2 alloy electrode as a function of state of charge (SOC) or temperature were determined by chronoamperometry. It is found that hydrogen diffusion coefficient decreases with the increase of SOC or the decrease of temperature. The activation energy for hydrogen diffusion in the alloy electrode with 50%SOC is evaluated to be 19.9?kJ/mol.
文摘Glutamate dehydrogenase occupies a pivotal position in the metabolism of most organisms. The reductive amination of α-ketoglutarate catalyzed by the enzyme is one of the most important reactions in the nitrogen assimilation with NADH as coenzyme.
基金Project(2007CB613604)supported by the National Basic Research Program of China
文摘The electrodeposition of lead in alkaline solutions containing xylitol （1, 2, 3, 4, 5-pentahydroxypentane） was studied. The lead electrodeposition and the chemical stability of xylitol in alkaline solutions were investigated by cyclic voltammetry. Apparent activation energy, apparent transfer coefficient and exchange current density were obtained by linear sweep voltammetry. Initial stages of lead electrocrystallization were determined by chronoamperometry. Voltammograms of a AISI 316 stainless steel electrode in xylitol solution exhibit no current in the potential range of-1.3 V to 0.75 V （vs Hg/HgO）, implying that xylitol is stable to oxidation and reduction. The apparent activation energy, apparent transfer coefficient and exchange current density were calculated to be 35.15 kJ/mol, 1.56 and 9.65x10^-5 A/m^2. Analysis of the chronoamperometric responses implies three-dimensional growth of nuclei, with the type of nucleation depending on overpotential.
文摘The electrodeposition of antimony in alkaline solutions containing xylitol was investigated using cyclic voltammetry,linear sweep voltammetry and chronoamperometry.The antimony electrodeposition and the chemical stability of xylitol in alkaline solutions were studied by cyclic voltammetric technique.Apparent activation energy,apparent transfer coefficient and exchange current density were obtained by linear sweep voltammetric technique.Initial stages of antimony electrocrystallization were determined by chronoamperometry.Xylitol in alkaline solutions exhibits high chemical stability and there is no redox in solutions when the potential ranges from-1.20 V to ＋0.60 V（vs Hg/HgO）.There is no other redox reaction but hydrolysis occurring on stainless steel in the potential range of-1.75 V to 1.25 V（vs Hg/HgO） while the xylitol decomposition maybe take place on antimony electrode when potential is more negative than-1.70 V（vs Hg/HgO）.Cyclic voltammograms with different scan rates indicate that the antimony electrodeposition process is an electrocrystallization which is a completely irreversible electrode process.The apparent activation energy,apparent transfer coefficient and exchange current density were calculated to be 46.33 kJ/mol,0.64 and 4.40×10-6 A/m2,respectively.The analyses of the chronoamperometric responses support the view of a three-dimensional growth under progressive nucleation.The average diffusion coefficient of antimony was calculated to be 1.53×10-6 cm2/s.
基金supported by the Ministry of Education,Science and Technological Development of the Republic of Serbia under the research project:“Electrochemical synthesis and characterization of nanostructured functional materials for application in new technologies”(Project No.172046)
文摘The processes of nucleation and growth of lead from the dilute electrolytes on copper substrates were investigated bychronoamperometry and by scanning electron microscopic (SEM) analysis of the deposits obtained in the potentiostatic regime ofelectrolysis. In the dependence of electrodeposition conditions, the nucleation of Pb followed either progressive or instantaneoustype. The type of nucleation changed from progressive to instantaneous one with increasing the concentration of Pb(II) ions and theoverpotential of electrodeposition. Regardless of the type nucleation, a novel type of Pb particles like cobweb was formed by thepotentiostatic electrodeposition in the moment of nucleation and at the early stages of growth. On the basis of the shape ofcobweb-like particles and the electrodeposition conditions leading to their formation, these particles were situated in the group ofspongy-like ones. Also, comparative morphological analysis of Pb deposits obtained in the conditions of progressive andinstantaneous nucleation confirmed the existence of two limiting types of nucleation.
基金support of this work by the University of Mazandaran Research Council
文摘We prepared a novel nickel（II）hydroxide-modified carbon paste electrode（Ni（OH）2-X/CPE）for the electrocatalytic oxidation of formaldehyde.The electrode was prepared by a simple method without the use of linking chemicals.The prepared Ni（OH）2-X/CPE material was characterized by scanning electron microscopy and energy dispersive X-ray spectrometry.The electrochemical performance of the proposed electrode was investigated using cyclic voltammetry,electrochemical impedance spectroscopy,and chronoamperometry.The results indicate that Ni（OH）2-X/CPE exhibits good electrocatalytic activity with regards to formaldehyde oxidation owing to its nanoporous structure and the large surface area of zeolite X.The values of the electron transfer coefficient and the catalytic rate constant were 0.7 and 6.1 × 104 cm3/（mol·s）,respectively.Therefore,the proposed electrode,which showed remarkable electroactivity with regards to formaldehyde oxidation with long-term stability and good reproducibility,could be useful in fuel cells.
文摘The electrochemical quartz crystal microbalance (EQCM) is used to investigate the characteristics of the thiolated self-assembled monolayer(SAM) on gold surface.A 5MHz QCM element serves as both the mass-sensitive sensor and the working electrode of the electrochemical system.The 6-mecapto-1-hexanol and and the 16-mer oligonucleotide with a mercaptohexyl group at the 5'-phosphate end are utilized to form the SAM on the gold electrode.The frequency response of the QCM during cyclic voltammetry (CV) scanning and cbronoamperometry are recorded together with the electrochemical current.The experimental results indicates that the frequency response is more sensitive to the surface coverage.Therefore,the response of the EQCM reveals more details of the SAM on gold electrode.It is especially useful for analysing the immobilization quality,such as probe orientation and coverage,of the SAM.
基金"TEQIP,COE Phase Ⅱ "in Jadavpur University for the support of this work
文摘One of the thrust areas of research is to find an alternative fuel to meet the increasing demand for energy.Glucose is a good source of alternative fuel for clean energy and is easily available in abundance from both naturally occurring plants and industrial processes.Electrochemical oxidation of glucose in fuel cell requires high electro-catalytic surface of the electrode to produce the clean electrical energy w ith minimum energy losses in the cell.Pt and Pt based alloys exhibit high electro-catalytic properties but they are expensive.For energy synthesis at economically cheap price,non Pt based inexpensive high electro catalytic material is required.Electro synthesized Zn O-Al2O3composite is found to exhibit high electro-catalytic properties for glucose oxidation.The Cyclic Voltammetry and Chronoamperometry curves reflect that the material is very much comparable to Pt as far as the maximum current and the steady state current delivered from the glucose oxidation are concerned.XRD image confirms the mixed oxide composite.SEM images morphology show increased 3D surface areas at higher magnification.This attributed high current delivered from electrochemical oxidation of glucose on this electrode surface.
基金supported by the National Science Centre,Poland,UMO-2016/23/B/ST5/00127。
文摘An extensive analysis of iron-nitrogen-carbon(Fe-N-C)electrocatalysts synthesis and activity is presented concerning synthesis conditions such as initial Fe content,pyrolysis temperature and atmosphere(inert N_(2),reducing NH_(3),oxidizing Cl_(2) and their sequential combinations)and the influence of an external magnetic field on their performance in oxygen reduction reaction(ORR).Thermosetting porous polymers doped with FeCl_(3) were utilized as the Fe-N-C catalysts precursors.The pyrolysis temperature was varied within a 700-900℃range.The temperature and atmosphere of pyrolysis strongly affect the porosity and compositi on of the resultant Fe-N-C catalysts,while the in itial amount of Fe precursor shows much weaker impact.Pyrolysis under NH_(3) yields materials similar to those pyrolyzed under an inert atmosphere(N_(2)).In contrast,pyrolysis under Cl_(2) yields carbon of peculiar character with highly disordered structure and extensive microporosity.The application of a static external magnetic field strongly enhances the ORR process(herein studied in an alkaline environment)and the enhancement correlates with the Fe content in the Fe-N-C catalysts.The Fe-N-C materials containing ferromagnetic iron phase embedded in N-doped microporous carbon constitute attractive catalysts for magnetic field-aided anion exchange membrane fuel cell technology.
基金sponsored by the National Basic Research Program of China(973 Program)under grant no.2015CB351905the National Natural Science Foundation of China(no.61504019)+3 种基金China Postdoctoral Science Foundation(no.2015M580783)Scientific Research Start-up Foundation of University of Electronic Science and Technology of China(Y02002010301082)the Technology Innovative Research Team of Sichuan Province of China(no.2015TD0005)the Fundamental Research Funds for the Central Universities of China(no.ZYGX2015J140)
基金the Project of General Administration of Quality Supervision,Inspection and Quarantine of the People's Republic of China(2011QK345)Natural Science Foundation of Guangxi,China(0728048)
文摘[Objective] The study aimed to discuss the application of boron-doped diamond （BDD） film electrode in fast detection of samonella in water. [ Method] Boron-doped diamond film electrode was prepared and used as the working electrode in fast detection of salmonella in water using chronoamberometry, and the oxidation mechanism of the electrode acting on salmonella was discussed. [ Result] Compared with traditional biologi- cal methods, chronoamperometry could detect the number of salmonellae in water more simply, rapidly and sensitively. [ Conclusion] The method of using BDD electrode to detect salmonella quantity will be widely applied in future.
基金Project supported by the National Natural Science Foundation of China （No. 20675062） and the Natural Science Foundation of Shaanxi Province in China （No. 2004B20）.
文摘A copper hexacyanoferrate modified ceramic carbon electrode （CuHCF/CCE） had been prepared by two-step sol-gel technique and characterized using electrochemical methods. The resulting modified electrode showed a pair of well-defined surface waves in the potential range of 0.40 to 1.0 V with the formal potential of 0.682 V （vs. SCE） in 0.050 mol·dm^-3 HOAc-NaOAc buffer containing 0.30 mol·dm^-3 KCl. The charge transfer coefficient （a） and charge transfer rate constant （ks） for the modified electrode were calculated. The electrocatalytic activity of this modified electrode to hydrazine was also investigated, and chronoamperometry was exploited to conveniently determine the diffusion coefficient （D） of hydrazine in solution and the catalytic rate constant （kcat）. Finally, hydrazine was determined with amperometry using the resulting modified electrode. The calibration plot for hydrazine determination was linear in 3.0 × 10^-6--7.5 × 10^-4 mol·dm^-3 with the detection limit of 8.0 × 10^-7 molodm^-3. This modified electrode had some advantages over the modified film electrodes constructed by the conventional methods, such as renewable surface, good long-term stability, excellent catalytic activity and short response time to hydrazine.
