Hydrogen evolution reaction （HER） at polycrystalline silver electrode in 0.1 mol/L HClO4 solution is investigated by cyclic voltammetry in the temperature range of 278-333 K. We found that at electrode potential φa...Hydrogen evolution reaction （HER） at polycrystalline silver electrode in 0.1 mol/L HClO4 solution is investigated by cyclic voltammetry in the temperature range of 278-333 K. We found that at electrode potential φa,app decreases with φ, while pre-exponential factor A remains nearly unchanged,which conforms well the prediction from Butler-Volmer equation. In contrast, with φ nega-tive shifts from the onset potential for HER to the potential of zero charge （PZC≈-0.4 V）, both Ea,app and A for HER increase （e.g., Ea,app increases from 24 kJ/mol to 32 kJ/mol）. The increase in Ea,app and A with negative shift in φ from -0.25 V to PZC is explained by the increases of both internal energy change and entropy change from reactants to the transition states, which is correlated with the change in the hydrogen bond network during HER. The positive entropy effects overcompensate the adverse effect from the increase in the activation energy, which leads to a net increase in HER current with the activation energy negative shift from the onset potential of HER to PZC. It is pointed out that entropy change may contribute greatly to the kinetics for electrode reaction which involves the transfer of electron and proton, such as HER.展开更多
Ag/AgCl electrode has been prepared using pressed powder techniques. In order to verify the feasibility of this type of electrode used as detecting electric field generated by vessels in seawater, its characteristics ...Ag/AgCl electrode has been prepared using pressed powder techniques. In order to verify the feasibility of this type of electrode used as detecting electric field generated by vessels in seawater, its characteristics of DC resistance, low frequency AC impedance, and receiving impedance in artificial seawater have been studied by polarization measurements, low frequency electrochemical impedance spectra, the open and short circuit cell conditions. The results show that the electrode can keep a low resistance when it responses the weak electrostatic field in seawater. The AC impedance of the electrode decreases as the frequency of the signal increasing. The receiving impedance decreases when the frequency of external field increases too. The valid detection bandwidth is determined by the properties of the impedance and the reactions occurring on the surface of the electrode.展开更多
Reference electrodes are a key part for corrosion monitoring and measurement of rebars in concrete. A reference electrode that can be buried in concrete is fabricated by using Ag/Ag Cl electrode and methyl cellulose g...Reference electrodes are a key part for corrosion monitoring and measurement of rebars in concrete. A reference electrode that can be buried in concrete is fabricated by using Ag/Ag Cl electrode and methyl cellulose gelling electrolyte. The stability, repeatability and anti-polarization of the reference electrode are investigated; the influences of the inner electrolyte loss, exterior OH- contamination, and temperature on the potential of the reference electrode are also investigated in this paper. The results show that the reference electrode has good stability, repeatability, and antipolarization. The influences of inner electrolyte loss, exterior OH- contamination, and temperature on the potential of the reference electrode are minimal. Therefore, it can be used for corrosion monitoring and measurement of rebars in concrete.展开更多
A novel nano crystalline Ag2O2-PbO2 film chemically modified electrode (CME) was prepared and the CME was characterized by X-ray diffractometer (XRD) and atomic force microscope (AFM). By chronoamperometry, the nano A...A novel nano crystalline Ag2O2-PbO2 film chemically modified electrode (CME) was prepared and the CME was characterized by X-ray diffractometer (XRD) and atomic force microscope (AFM). By chronoamperometry, the nano Ag2O2-PbO2 CME was used as bioelectro- chemical sensor to determine the population of Escherichia coli (E. coli) in water. Compared with conventional methods, it is found that the technique we used is fast and convenient in counting E. coli.展开更多
We put forward a method of rapid preparation of chloride selective electrode（Ag/AgCl electrode） by dipping silver wire into sodium hypochlorite solution. The electrodes were prepared through different immersion time...We put forward a method of rapid preparation of chloride selective electrode（Ag/AgCl electrode） by dipping silver wire into sodium hypochlorite solution. The electrodes were prepared through different immersion time. The properties of the electrodes, such as Nernst response, response time and longterm stability, were tested in simulated concrete pore solutions（SCPS）. Moreover, the surface morphology of the electrodes was also detected after immersion in solutions over three months. The experimental results reveal that the Ag/AgCl electrode with the fabrication time of 20 minutes（E-20） which is recommended to work as the chloride ion selective electrode has the best performance. Compared to that fabricated by the electrolytic process（E-EP）, E-20 can be manufactured in mass. The method has almost the same good performance of Nernst response as E-EP, and has a better response time which is less than 25 seconds. The method also shows a better good long-term stability in SCPS containing chloride ions over three months.展开更多
The tremendous potential of triboelectric generators-TENGs for converting mechanical energy into electrical energy places them as one of the most promising energy harvesting technologies. In this work, the fabrication...The tremendous potential of triboelectric generators-TENGs for converting mechanical energy into electrical energy places them as one of the most promising energy harvesting technologies. In this work, the fabrication of enhanced performance TENGs using Ag octahedron nano-assemblies on ITO as electrodes significantly increases the electric charge collection of the induced tribocharges. Thereby, nanostructured electrical contacts coated with Ag macroscale nano-assemblies with octahedral features were obtained by the electrodeposition technique on flexible PET/ITO substrates. Consequently, the nanostructured triboelectric generator-TENG exhibited 65 times more maximum output power, and almost 10 times more open circuit output voltage than that of a TENG with non-nanostructured contacts passing from μW to m W capabilities, which was attributed to the increment of intrinsic interface states due to a higher effective contact area in the former. Likewise, output performances of TENGs also displayed an asymptotic behavior on the output voltage as the operating frequency of the mechanical oscillations increased, which is attributed to a decrement in the internal impedance of the device with frequency. Furthermore, it is shown that the resulting electrical output power can successfully drive low power consumption electronic devices. On that account, the present research establishes a promising platform which contributes in an original way to the development of the TENGs technology.展开更多
The recent rapid growth in electronics has reached the point where there is a need for solid-state devices with excellent physical flexibility, which will be a significant advantage in modern electronic devices. In ...The recent rapid growth in electronics has reached the point where there is a need for solid-state devices with excellent physical flexibility, which will be a significant advantage in modern electronic devices. In particular, metal nanowires and nano-particles are chosen for electrodes because of their low resistance and high mechanical stability. Among the various alternatives, Ag nanomaterials have recently garnered increasing attention due to the high intrinsic conductivity, a transparency with a low sheet resistance and relatively low cost. We herein summarize recent developments toward flexible electronics on the basis of Ag nanomaterials , which show promising performance and outperform the commonly used. The typical fabrication techniques along with the promising applications for flexible devices, are thoroughly discussed.展开更多
The most common reference electrode (RE) which is used in electrochemical measurements is the Ag/AgCl electrode. In this study, we present a novel solid-state Ag/AgCl planar electrode that was coated with a thin layer...The most common reference electrode (RE) which is used in electrochemical measurements is the Ag/AgCl electrode. In this study, we present a novel solid-state Ag/AgCl planar electrode that was coated with a thin layer of Graphite Oxide (GO) as a protective layer. The Ag/AgCl planar electrode was fabricated by using the photolithography and lift-off method combined with the Ag[NH3]2Cl complex. The GO was produced by Hummer’s method and was deposited on top of the Ag/AgCl layer by drop-casting method. The layers of the fabricated reference electrode were characterized by micro Raman spectroscopy, Scanning Electron Microscopy (SEM) and Energy-dispersive X-ray spectroscopy (EDX). The responding time of the planar electrode was short and the signal was more stable in comparison to the plainAg/AgCl electrode. The Open Circuit Potential (OCP) measurement with the fabricated electrode as the RE and the platinum electrode as the working electrode in electrolyte solutions which had various pH values was performed with a linear response in pH ranges from pH 5 to pH 8 and the linear correlation coefficient (R^2 = 0.9899). Moreover, the coating of the GO layers also enhanced the durability of the modified electrode. The results showed that the modified Ag/AgCl electrode with a thin layer GO as the protective layer could be used as plana REs for the potentiometric sensors.展开更多
The behavior of chloride adsorbed on Ag(100) electrode has been studied using chronoamperometric technique, and the structural transition of chloride layer has been confirmed.
In this paper,the voltammetric behaviours of Ag cylinder electrode in 1 mol/dm(3) KOH solution have been investigated in the presence of ultrasound irradiation. The results based on the CV, EIS and polarization measur...In this paper,the voltammetric behaviours of Ag cylinder electrode in 1 mol/dm(3) KOH solution have been investigated in the presence of ultrasound irradiation. The results based on the CV, EIS and polarization measurements showed that ultrasound could enhance the mass transport, inhibit the oxygen evolution and increase the exchange current.展开更多
Polytetrafluoroethylene films are treated by room temperature helium atmospheric pressure plasma plumes, which are generated with a home-made single liquid electrode plasma device. After plasma treatment, the water co...Polytetrafluoroethylene films are treated by room temperature helium atmospheric pressure plasma plumes, which are generated with a home-made single liquid electrode plasma device. After plasma treatment, the water contact angle of polytetrafiuoroethylene fihn drops from 114° to 46° and the surface free energy increases from 22.0 mJ/m2 to 59.1 mJ/m2. The optical emission spectrum indicates that there are reactive species such as O2＋, O and He in the plasma plume. After plasma treatment, a highly crosslinking structure is formed on the fihn surface and the oxygen element is incorporated into the film surface in the forms of C O-C-, -C=O, and O C=O groups. Over a period of 10 days, the contact angle of the treated film is recovered by only about 10°, which indicates that the plasma surface modification is stable with time.展开更多
This paper summarizes the production of the platinum electrode of tantalum clad silver. Ta(Ag). It clarifies the determination of the design parameters for the composite electrode, the technological process, the tensi...This paper summarizes the production of the platinum electrode of tantalum clad silver. Ta(Ag). It clarifies the determination of the design parameters for the composite electrode, the technological process, the tensile test of the composite Ta(Ag) wire, the spotwelding of the electrode seal. the examination for leakage of the electrode. the prcess for winding the platinum foil and spotwelding, and the process parameter for obtaining high-quality electrodes during the production of 1,000 and more electrodes. The electrode produced satisfied the needs of the engineering design. It was demonstrated that the electrode had a long life-span and property stability, and fulfilled the norms for saving electricity and increasing production.展开更多
We report the fabrication of disposable and flexible Screen-Printed Electrodes (SPEs). This new type of screen-printed electrochemical platform consists of Ag nanoparticles (AgNPs) and graphite composite. For this pur...We report the fabrication of disposable and flexible Screen-Printed Electrodes (SPEs). This new type of screen-printed electrochemical platform consists of Ag nanoparticles (AgNPs) and graphite composite. For this purpose, silver nanoparticles were first synthesized by a chemical reduction method. The morphology and structure of the AgNPs were analyzed using a Scanning Electron Microscope (SEM) and UV-Visible spectroscopy. Graphite was chosen as the working electrode material for the fabrication of a thick-film. The fabrication of a screen-printed hydrogen peroxide biosensor consisting of three electrodes on a polyethylene terephthalate (PET) substrate was performed with a spraying approach (working, counter and reference: enzyme electrode, graphite, pseudo reference: Ag/AgCl). This biosensor was fabricated by immobilizing the peroxidase enzyme (HRP) in a Titania sol-gel membrane which was obtained through a vapor deposition method. The biosensor had electrocatalytic activity in the reduction of H2O2 with linear dependence on H2O2 concentration in the range of 10-5 to 10-3 M;the detection limit was 4.5 × 10-6 M.展开更多
基金ACKNOWLEDGMENTS This work was supported by the One Hundred Talents＇ Program of the Chinese Academy of Science, the National Natural Science Foundation of China （No.21073176）, and the National Basic Research Program of China National Science and Technology （No.2010CB923302）.
文摘Hydrogen evolution reaction （HER） at polycrystalline silver electrode in 0.1 mol/L HClO4 solution is investigated by cyclic voltammetry in the temperature range of 278-333 K. We found that at electrode potential φa,app decreases with φ, while pre-exponential factor A remains nearly unchanged,which conforms well the prediction from Butler-Volmer equation. In contrast, with φ nega-tive shifts from the onset potential for HER to the potential of zero charge （PZC≈-0.4 V）, both Ea,app and A for HER increase （e.g., Ea,app increases from 24 kJ/mol to 32 kJ/mol）. The increase in Ea,app and A with negative shift in φ from -0.25 V to PZC is explained by the increases of both internal energy change and entropy change from reactants to the transition states, which is correlated with the change in the hydrogen bond network during HER. The positive entropy effects overcompensate the adverse effect from the increase in the activation energy, which leads to a net increase in HER current with the activation energy negative shift from the onset potential of HER to PZC. It is pointed out that entropy change may contribute greatly to the kinetics for electrode reaction which involves the transfer of electron and proton, such as HER.
文摘Ag/AgCl electrode has been prepared using pressed powder techniques. In order to verify the feasibility of this type of electrode used as detecting electric field generated by vessels in seawater, its characteristics of DC resistance, low frequency AC impedance, and receiving impedance in artificial seawater have been studied by polarization measurements, low frequency electrochemical impedance spectra, the open and short circuit cell conditions. The results show that the electrode can keep a low resistance when it responses the weak electrostatic field in seawater. The AC impedance of the electrode decreases as the frequency of the signal increasing. The receiving impedance decreases when the frequency of external field increases too. The valid detection bandwidth is determined by the properties of the impedance and the reactions occurring on the surface of the electrode.
基金financially supported by the National Science and Technology Support Program of China(Grant No.2011BAG07B04)
文摘Reference electrodes are a key part for corrosion monitoring and measurement of rebars in concrete. A reference electrode that can be buried in concrete is fabricated by using Ag/Ag Cl electrode and methyl cellulose gelling electrolyte. The stability, repeatability and anti-polarization of the reference electrode are investigated; the influences of the inner electrolyte loss, exterior OH- contamination, and temperature on the potential of the reference electrode are also investigated in this paper. The results show that the reference electrode has good stability, repeatability, and antipolarization. The influences of inner electrolyte loss, exterior OH- contamination, and temperature on the potential of the reference electrode are minimal. Therefore, it can be used for corrosion monitoring and measurement of rebars in concrete.
基金We are greateful to the National Narural Science Foundation of China(No.20455017)Science and Technology Committee of Shanghai Municipal(No.0452nm084).
文摘A novel nano crystalline Ag2O2-PbO2 film chemically modified electrode (CME) was prepared and the CME was characterized by X-ray diffractometer (XRD) and atomic force microscope (AFM). By chronoamperometry, the nano Ag2O2-PbO2 CME was used as bioelectro- chemical sensor to determine the population of Escherichia coli (E. coli) in water. Compared with conventional methods, it is found that the technique we used is fast and convenient in counting E. coli.
基金the National Key Technology Research and Development Program of the Ministry of Science and Technology of China(2015BAB07B04)the Natural Science Foundation of China(51278167)the Fundamental Research Funds for the Central Universities(2016B04514)
文摘We put forward a method of rapid preparation of chloride selective electrode（Ag/AgCl electrode） by dipping silver wire into sodium hypochlorite solution. The electrodes were prepared through different immersion time. The properties of the electrodes, such as Nernst response, response time and longterm stability, were tested in simulated concrete pore solutions（SCPS）. Moreover, the surface morphology of the electrodes was also detected after immersion in solutions over three months. The experimental results reveal that the Ag/AgCl electrode with the fabrication time of 20 minutes（E-20） which is recommended to work as the chloride ion selective electrode has the best performance. Compared to that fabricated by the electrolytic process（E-EP）, E-20 can be manufactured in mass. The method has almost the same good performance of Nernst response as E-EP, and has a better response time which is less than 25 seconds. The method also shows a better good long-term stability in SCPS containing chloride ions over three months.
基金Consejo Nacional de Ciencia y Tecnología of México (CONACYT) for her Doctoral scholarshippostgraduate studies department at CIMAVMonterrey for fellowship support。
文摘The tremendous potential of triboelectric generators-TENGs for converting mechanical energy into electrical energy places them as one of the most promising energy harvesting technologies. In this work, the fabrication of enhanced performance TENGs using Ag octahedron nano-assemblies on ITO as electrodes significantly increases the electric charge collection of the induced tribocharges. Thereby, nanostructured electrical contacts coated with Ag macroscale nano-assemblies with octahedral features were obtained by the electrodeposition technique on flexible PET/ITO substrates. Consequently, the nanostructured triboelectric generator-TENG exhibited 65 times more maximum output power, and almost 10 times more open circuit output voltage than that of a TENG with non-nanostructured contacts passing from μW to m W capabilities, which was attributed to the increment of intrinsic interface states due to a higher effective contact area in the former. Likewise, output performances of TENGs also displayed an asymptotic behavior on the output voltage as the operating frequency of the mechanical oscillations increased, which is attributed to a decrement in the internal impedance of the device with frequency. Furthermore, it is shown that the resulting electrical output power can successfully drive low power consumption electronic devices. On that account, the present research establishes a promising platform which contributes in an original way to the development of the TENGs technology.
基金Program for the Top Young Academic Leaders of Higher Learning Institutions of Shanxi,100 Persons Program of Shanxithe Project Supported by Science Foundation of North University of China(No.110248-28140)The Project Supported by Science and Technology on Electronic Test & Measurement Laboratory(No.110103112113)
文摘The recent rapid growth in electronics has reached the point where there is a need for solid-state devices with excellent physical flexibility, which will be a significant advantage in modern electronic devices. In particular, metal nanowires and nano-particles are chosen for electrodes because of their low resistance and high mechanical stability. Among the various alternatives, Ag nanomaterials have recently garnered increasing attention due to the high intrinsic conductivity, a transparency with a low sheet resistance and relatively low cost. We herein summarize recent developments toward flexible electronics on the basis of Ag nanomaterials , which show promising performance and outperform the commonly used. The typical fabrication techniques along with the promising applications for flexible devices, are thoroughly discussed.
文摘The most common reference electrode (RE) which is used in electrochemical measurements is the Ag/AgCl electrode. In this study, we present a novel solid-state Ag/AgCl planar electrode that was coated with a thin layer of Graphite Oxide (GO) as a protective layer. The Ag/AgCl planar electrode was fabricated by using the photolithography and lift-off method combined with the Ag[NH3]2Cl complex. The GO was produced by Hummer’s method and was deposited on top of the Ag/AgCl layer by drop-casting method. The layers of the fabricated reference electrode were characterized by micro Raman spectroscopy, Scanning Electron Microscopy (SEM) and Energy-dispersive X-ray spectroscopy (EDX). The responding time of the planar electrode was short and the signal was more stable in comparison to the plainAg/AgCl electrode. The Open Circuit Potential (OCP) measurement with the fabricated electrode as the RE and the platinum electrode as the working electrode in electrolyte solutions which had various pH values was performed with a linear response in pH ranges from pH 5 to pH 8 and the linear correlation coefficient (R^2 = 0.9899). Moreover, the coating of the GO layers also enhanced the durability of the modified electrode. The results showed that the modified Ag/AgCl electrode with a thin layer GO as the protective layer could be used as plana REs for the potentiometric sensors.
文摘The behavior of chloride adsorbed on Ag(100) electrode has been studied using chronoamperometric technique, and the structural transition of chloride layer has been confirmed.
文摘In this paper,the voltammetric behaviours of Ag cylinder electrode in 1 mol/dm(3) KOH solution have been investigated in the presence of ultrasound irradiation. The results based on the CV, EIS and polarization measurements showed that ultrasound could enhance the mass transport, inhibit the oxygen evolution and increase the exchange current.
基金Project supported by the State Key Program of National Natural Science Foundation of China (Grant No. 10735090)the Young Scientist Fund of the National Natural Science Foundation of China (Grant No. 11005151)
文摘Polytetrafluoroethylene films are treated by room temperature helium atmospheric pressure plasma plumes, which are generated with a home-made single liquid electrode plasma device. After plasma treatment, the water contact angle of polytetrafiuoroethylene fihn drops from 114° to 46° and the surface free energy increases from 22.0 mJ/m2 to 59.1 mJ/m2. The optical emission spectrum indicates that there are reactive species such as O2＋, O and He in the plasma plume. After plasma treatment, a highly crosslinking structure is formed on the fihn surface and the oxygen element is incorporated into the film surface in the forms of C O-C-, -C=O, and O C=O groups. Over a period of 10 days, the contact angle of the treated film is recovered by only about 10°, which indicates that the plasma surface modification is stable with time.
文摘This paper summarizes the production of the platinum electrode of tantalum clad silver. Ta(Ag). It clarifies the determination of the design parameters for the composite electrode, the technological process, the tensile test of the composite Ta(Ag) wire, the spotwelding of the electrode seal. the examination for leakage of the electrode. the prcess for winding the platinum foil and spotwelding, and the process parameter for obtaining high-quality electrodes during the production of 1,000 and more electrodes. The electrode produced satisfied the needs of the engineering design. It was demonstrated that the electrode had a long life-span and property stability, and fulfilled the norms for saving electricity and increasing production.
文摘We report the fabrication of disposable and flexible Screen-Printed Electrodes (SPEs). This new type of screen-printed electrochemical platform consists of Ag nanoparticles (AgNPs) and graphite composite. For this purpose, silver nanoparticles were first synthesized by a chemical reduction method. The morphology and structure of the AgNPs were analyzed using a Scanning Electron Microscope (SEM) and UV-Visible spectroscopy. Graphite was chosen as the working electrode material for the fabrication of a thick-film. The fabrication of a screen-printed hydrogen peroxide biosensor consisting of three electrodes on a polyethylene terephthalate (PET) substrate was performed with a spraying approach (working, counter and reference: enzyme electrode, graphite, pseudo reference: Ag/AgCl). This biosensor was fabricated by immobilizing the peroxidase enzyme (HRP) in a Titania sol-gel membrane which was obtained through a vapor deposition method. The biosensor had electrocatalytic activity in the reduction of H2O2 with linear dependence on H2O2 concentration in the range of 10-5 to 10-3 M;the detection limit was 4.5 × 10-6 M.
