Two-dimensional analysis of progressive delamination in thin film electrodes

By employing the two-dimensional analysis, i.e.,plane strain and plane stress, a semi-analytical method is developed to investigate the interfacial delamination in electrodes. The key parameters are obtained from the governing equations, and their effects on the evolution of the delamination are evaluated. The impact of constraint perpendicular to the plane is also investigated by comparing the plane strain and plane stress. It is found that the delamination in the plane strain condition occurs easier, indicating that the constraint is harmful to maintain the structure stability. According to the obtained governing equations, a formula of the dimensionless critical size for delamination is provided, which is a function of the maximum volumetric strain and the Poisson’s ratio of the active layer.

Preparation of dendritic bismuth film electrodes and their application for detection of trace Pb(Ⅱ)and Cd(Ⅱ)

In this paper,dendritic Bi film electrodes with porous structure had successfully been prepared on glassy carbon electrode using a constant current electrolysis method based on hydrogen bubble dynamic templates.The electrode prepared using a large applied current density showed an increased internal electroactive area and a significantly improved electrochemical performance.The analytical utility of the prepared dendritic Bi film electrodes for the determination of Pb(Ⅱ)and Cd(Ⅱ)in the range of 5–50 μg·L^(-1)were presented in combination with square wave stripping voltammetry in model solution.Compared with non-porous Bi film electrode,the dendritic Bi film electrode exhibited higher sensitivity and lower detection limit.The prepared Bi film electrode with dendritic structure was also successfully applied to real water sample analysis.

Analysis of delamination in thin film electrodes under galvanostatic and potentiostatic operations with Li-ion diffusion from edge

Progressive delamination driven by Li-ion diffusion in elastic disk-like thin film electrodes of Li-ion batteries is modeled based on the cohesive model. Axisymmetric diffusion model is considered under both galvanostatic and potentiostatic operations. The effect of edge diffusion on the delamination process is evaluated. It is found that the diffusion from edge leads to an earlier delamination initiation. The edge effect is significant for active disks with a small aspect ratio, but negligible for the case of large aspect ratio. The edge diffusion is weaker in the potentiostatic operation than in the galvanostatic operation.

Study on water treatment effect of dispersion discharge plasma based on flowing water film electrode

To improve the utilization rate of plasma active species,in this study,a closed non-uniform air gap is formed by a flowing water film electrode and a sawtooth insulating dielectric layer to realize the diffuse glow discharge in the atmosphere.Firstly,the electric field distribution characteristics of non-uniform air gap in the sawtooth dielectric layer are studied,and the influence of aspect ratio on the characteristics of diffuse discharge plasma is discussed.Subsequently,the effects of wire mesh,the inclination angle of the dielectric plate,and liquid inlet velocity on the flow characteristics of the water film electrode are analyzed.The results show that the non-uniform electric field distribution formed in the sawtooth groove can effectively inhibit the filamentous discharge,and the 1 mm flowing water film is directly used as the electrode,and high-active plasma is formed directly on the lower surface of the water film.In addition,a plasma flowing water treatment device is built to treat the methyl orange solution and observe its decolorization effect.The experimental results show that after 50 min of treatment,the decolorization rate of the methyl orange solution reaches 96%,which provides a new idea for industrial applications of wastewater treatment.

Effect of Some Metal Ion Dopants on Electrochemical Properties of Ni(OH)_2 Film Electrode

The Ni(OH) 2 film electrodes doped respectively with alkali-earth metal aluminum, lead, partial transition metal and some rare-earth metal(altogether 17 kinds of metals) ions were prepared by cathode electrodeposition. The electrode reaction reversibility, the difficult extent of oxygen evolution, the proton diffusion coefficient, the discharge potential of middle value and the active material utilization of the Ni(OH) 2 film electrode were compared with those of the ones doped with the metal ions by means of cyclic voltammetry, potential step and constant current charge-discharge experiments. It was found that Ca 2+ , Co 2+ , Cd 2+ , Al 3+ etc. have obviously positive effect.

Electrically enhanced photodegradation of an azodye(Acid Orange II) using a Pt/TiO_2 film electrode irradiating with an UV lamp

A photoelectrochemical process in the degradation of an azodye (Acid Orange II) on a Pt/TiO 2 film electrode was investigated. By using the glass device and the voltage stabilized source of direct current, decolorization ratios higher than 78% were observed during a period of 5h. Comparing this value with the sum of the decolorization ratios obtained by a sole application of electrochemical(lower than 3%) and photochemical(about 23%) procedures, a significant synergic effect between both processes was observed. The effects of adscititious voltage and pH value on the decolorization ratios were obvious while the effect of the amount of aeration was minor.

A STUDY ON VOLTAMMETRIC BEHAVIOR OF INDIGO CARMINE AND ITS MIXTURE WITH AMARANTH AT MERCURY FILM ELECTRODE ON SILVER SUBSTRATE

The voltammetric behavior of indigo carmine at mercury film electrode on a silver substrate (MFES) was studied in this paper. It was found that indigo carmine gave a sensitive reduction peak at a potential (Vp) of -0.11 V at pH 4.0 in aqueous solution. The MFES gave good reproducibility and life time. The peak currents (ip) depended lipearly on the concentrations of indigo carmine free 0 to 100 ng/ml. The Vp and Ip of indigo carmine at MFES were independent of the concentrations of amaranth at pH 4.0, the Vp of amaranth was -0.24 V at this pH. The differences of Vp between both colorants enabled to distinguish indigo carmine free amaranth.

Preparation and Characterization of Gold Thin Film Electrode Modified by Microbe

A novel method based on microbe modification has been employed to prepare gold thin film electrode. The preparation method is simple and the electrode obtained is stable and very sensitive in determining heavy metal ions. The quantitation limit of Cu2+ is 0.05 ng/mL.

Application of Boron-doped Diamond Film Electrode in Fast Detection of Samonella in Water

[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.

IMPS STUDIES OF SEMICONDUCTOR CdSe THIN FILM ELECTRODE

The kinetics of interracial processes of CdSe thin film electrode before and after sur- face modification of 1,1'-di linolene ferrocenyl L-B films have been studied in K_4Fe(CN)_6 solution by Intensity Modulated Photocurrent Spectroscopy(IMPS).Potential dependence of surface state relaxation time(T_s),steady state photocurrent(I_s),collection coefficient of minority carriers(G_o), rate constant of photocorrosion(K_(cr)),and density of surface state(N_(ss))were determined in terms of frequency response analysis of IMPS plots.

Femtosecond laser fabrication of 3D vertically aligned micro-pore network on thick-film Li_(4)Ti_(5)O_(12)electrode for high-performance lithium storage

The development of energy storage devices with high energy density relies heavily on thick film electrodes,but it is challenging due to the limited ion transport kinetics inherent in thick electrodes.Here,we report on the preparation of a directional vertical array of micro-porous transport networks on LTO electrodes using a femtosecond laser processing strategy,enabling directional ion rapid transport and achieving good electrochemical performance in thick film electrodes.Various three-dimensional(3D)vertically aligned micro-pore networks are innovatively designed,and the structure,kinetics characteristics,and electrochemical performance of the prepared ion transport channels are analyzed and discussed by multiple characterization and testing methods.Furthermore,the rational mechanisms of electrode performance improvement are studied experimentally and simulated from two aspects of structural mechanics and transmission kinetics.The ion diffusion coefficient,rate performance at 60 C,and electrode interface area of the laser-optimized 60-15%micro-porous transport network electrodes increase by 25.2 times,2.2 times,and 2.15 times,respectively than those of untreated electrodes.Therefore,the preparation of 3D micro-porous transport networks by femtosecond laser on ultra-thick electrodes is a feasible way to develop high-energy batteries.In addition,the unique micro-porous transport network structure can be widely extended to design and explore other high-performance energy materials.

Electrochemical behavior of Dy(Ⅲ) on bismuth film electrode in eutectic LiCl-KCl melts

An electrochemical study of dysprosium（III） on Bi film electrode was carried out in eutectic LiCl-KCI melts by transient and steady state electrochemical techniques.The results of transient electrochemical techniques showed that the reduction of Dy（III） appears at a more positive value than the one detected on W electrode owing to the formation of Bi-Dy intermetallic compounds through electrochemical deposition of Dy on bismuth film electrode.The thermodynamic properties of the formation for Dy-Bi intermetallics were estimated by a steady state electrochemical method in a temperature range of 713-803 K.Furthermore,the electrochemical preparation of Bi-Dy alloys was conducted by galvanostatic electrolysis at different current intensities.The Bi-Dy alloys,characterized by scanning electron microscopy equipped with energy dispersive spectrometry and X-ray diffraction,are comprised of DyBi3/5 and DyBi phases

Electrochemical Characteristics and Applications of Boron-Doped Polycrystalline Diamond Film Electrodes

The elcetrochemical characteristics of boron doped polycrystalline diamond thin film (BDF) electrode 4×4 mm 2 in size were studied using cyclic voltammetry and potentiostatic method. The diamond electrode exhibits adequate electrochemical activity and its response current changes linearly with K 3Fe(CN) 6 concentrations. The response current is proportional to the square root of the scan rate, reflecting mass transport controlled by planar diffusion. Stable mass transport can be quickly established within 4s. The BDF electrode provides good resolving power for the determination of lead and cadmium and gives satisfactory results in the analysis of pure water sample.

Highly active porous nickel-film electrode via polystyrene microsphere template-assisted composite electrodeposition for hydrogen-evolution reaction in alkaline medium

A highly porous nickel-film electrode with satisfactory mechanical strength was prepared by a facile vertical template-assisted composite electrodeposition method using polystyrene(PS) microspheres templates, with the aim of improving the electrocatalytic activity for the hydrogen-evolution reaction(HER). During the composite electrodeposition process, the hydrophobic PS microspheres were highly dispersed in the electrolyte with the help of a surfactant, and then co-deposited with Ni to form the film electrode. After removing the PS templates by annealing, a porous Ni film containing large amount of uniformly dispersed pores with narrow size distribution was obtained, and then applied as the electrode for the HER in an alkaline medium. As evidenced by the electrochemical analysis, the porous Ni film electrode exhibits higher catalytic activity as compared to a dense Ni film electrode and is superior to a Ni/Ru O2/Ce O2 commercial electrode. The effect of temperature on the catalytic properties of the porous Ni film electrode was also investigated; the activation energy was calculated as 17.26 k J/mol. The enhanced activity toward the HER was attributed to the improved electrochemical surface area and mass transportation facilitated by the high porosity of the synthesized Ni film electrode.

A potential-responsive ion-pump system based on nickel hexacyanoferrate film for selective extraction of cesium ions

A nickel hexacyanoferrate(NiHCF)film electrode was prepared with NiHCF,conductive carbon black,and polyvinylidene difluoride,which was coated on graphite plate substrate for selective extraction of Cs^(+)ions by using electrochemically switched ion exchange(ESIX)technology.A potential-responsive ionpump system for efficient extraction of Cs+ions was designed,and the effect of wet film thicknesses,charging modes,flow rates,and chamber widths on Cs+ions extraction performance was investigated.In the system,the adsorption capacity and removal percentage of Cs^(+)ions on the NiHCF film electrode reached as high as 147.69 mg·g^(-1)and 92.47%,respectively.Furthermore,the NiHCF film electrode showed high selectivity for Cs^(+)ions and stability.After seven cycles of adsorption/desorption,the desorption percentage could reach about 100%.The excellent Cs^(+)extraction performance should be attributed to the strong driving force produced by the potential-responsive ion-pumping effect in the ESIX process,as well as the low ion transfer resistance of the film electrode which is caused by the special crystal structure of NiHCF.In addition,the NiHCF film electrode was implemented to work together with the bismuth oxybromide(BiOBr)film electrode to accomplish the simultaneous extraction of Cs^(+)and Br^(-).And the adsorption capacity and removal percentage of Br^(-)ions on the BiOBr film electrode reached 69.53 mg·g^(-1)and 77.32%,correspondingly.It is expected that such a potential-responsive ion-pump system based on NiHCF and BiOBr film electrodes could be used for the selective extraction and concentration of Cs^(+)and Br^(-)ions from salt lake brine.

Corrosion characteristics of single-phase Mg-3Zn alloy thin film for biodegradable electronics

Biodegradable metals as electrodes, interconnectors, and device conductors are essential components in the emergence of transient electronics, either for passive implants or active electronic devices, especially in the fields of biomedical electronics. Magnesium and its alloys are strong candidates for biodegradable and implantable conducting materials because of their high conductivity and biocompatibility, in addition to their well-understood dissolution behavior. One critical drawback of Mg and its alloys is their considerably high dissolution rates originating from their low anodic potential, which disturbs the compatibility to biomedical applications. Herein, we introduce a single-phase thin film of a Mg-Zn binary alloy formed by sputtering, which enhances the corrosion resistance of the device electrode, and verify its applicability in biodegradable electronics. The formation of a homogeneous solid solution of single-phase Mg-3Zn was confirmed through X-ray diffraction and transmission electron microscopy. In addition, the dissolution behavior and chemistry was also investigated in various biological fluids by considering the effect of different ion species. Micro-tensile tests showed that the Mg-3Zn alloy electrode exhibited an enhanced yield strain and elongation in relation to a pure Mg electrode. Cell viability test revealed the high biocompatibility rate of the Mg-3Zn binary alloy thin film. Finally, the fabrication of a wireless heater demonstrated the integrability of biodegradable electrodes and highlighted the ability to prolong the lifecycle of thermotherapy-relevant electronics by enhancing the dissolution resistance of the Mg alloy.

Study on electrode process of myoglobin at a polymerized Toluidine Blue film electrode

This paper reports the use of an electrochemically polymerized Toluidine Blue (TB) film electrode.The film on platinum electrode surface was analyzed with ESCA.The heterogeneous electron transfer processes of myoglobin at the polymerized TB film electrode have been investigated using in situ UV-visible spectroelectrochemistry.The formal potential(E°′)and electron transfer number(n)of myoglobin were calculated as E°′=0.045 V(vs.NHE)and n=0.99.The exhaustive reduction and oxidation electrolyses are achieved in 130 s and 110 s respectively,during a potential step between-0.4 V and+0.4 V.A formal heterogeneous electron transfer rate constant(ksh)of 1.09× 10^(-4) cm/s and a transfer coefficient(α)of 0.47 were obtained by cyclic voltabsorptometry,which indicated that myoglobin underwent a quasi-reversible electrode process at the polymerized TB film electrode.

THE PREPARATION OF ISOPOLYMOLYBDIC ACID-POLYANILINE FILM MODIFIED ELECTRODE AND ITS CATALYTIC EFFECTS ON CHLORATE IONS

The preparation method of H_4MoO_(26)-polyaniline film modified electrode and its voltammetric behaviour are described. The modified electrode has high electrocatalytic activity on chlorate ions.

PHOTOSPLITTING OF WATEM AT THIN FILM IRON OXIDE ELECTRODES

both theoretical and experimental findings of the photoresponse for water spliting of the pyrolytically prepared thin film iron oxide electrodes are given.Fur- ther,the spray time and the corresponding thickness of the Fe_2O_3 thin film were opti- mized to have maximum photoresponse.The effect of iodine doping on photoresponse of iron oxide was investigated.

Electrophoretic Deposition of TiO2/Nb2O5 Composite Electrode Thin Films for Photovoltaic Application

Nano sized powders of TiO2 （titanium dioxide） and Nb2O5 （Niobium （V） oxide） were used to fabricate TiO2/Nb2O5 composites thin films by EPD （electrophoretic deposition） technique. The metal oxide powders, together with magnesium nitrate hexahydrate pellets, were suspended in propan-2-ol inside an EPD cell. The electrodes, placed 1.2 cm apart, were partially immersed in the suspension and a DC potential applied across them. Key EPD process parameters, which include applied DC electric field, deposition time and solid concentration in suspension, were optimized through visual inspection and from UV-Vis-NIR spectrophotometer spectra. The highest （55%） transmittance was obtained for films with deposition time of 90 s, powder concentration of 0.01 g/40 mL, and 35 V DC （direct current） voltage. XRD micrographs confirmed that TiO2 and Nb2O5 particles were presented in the composite film. SEM （scanning electron microscope） micrographs of the composite electrode thin films showed that porous films of high quality with well controlled morphology were deposited by using the EPD technique.