Three-electrode Mode Research Articles

Breaking barriers of CeO2 in energy storage: Hydrothermal energized preparation of mesoporous carbon added CeO2 nanohybrids as supercapacitor electrodes

Inspired by the excellent physio-chemical properties of nano-sized materials, this study details the hydrothermal preparation and electrochemical characterization of mesoporous carbon added CeO2 nanostructures towards the energy storage applications. Cubic CeO2 is observed for the crystal structure and phase of the prepared materials. The formation of nano-sized (∼ 7 nm) quasi spherical-like structure is found from the TEM analysis and it is mainly ascribed to the combined effect of mesoporous carbon and hydrothermal treatment. The charge storage performance of the prepared composites is examined using three-electrode mode. The capacitive behaviour of mesoporous carbon is additionally supported for electrochemical performance in addition to the battery-like behavior of the CeO2 electrodes resulting in an increase of specific capacity by 102.6 %. Hybrid supercapacitor cell is devised and it could yield a specific energy of 31 W h kg–1 (562 W kg–1) and retain 81 % capacity after 3000 continuous charge discharge cycles. With this efficient composite, the future of energy storage may pave the way for more sustainable and powerful energy solutions.

α-Bi2O3 tubular rods coated on Bi2O2CO3 nanosheets for high-performance asymmetric supercapacitor applications

Mixed phases of bismuth oxide nanostructures as an active electrode material in supercapacitor applications have recently gained huge research interest. In this study, the layered Bi2O2CO3 nanosheets and the secondary phase of α-Bi2O3 tubular rods named Bi2O2CO3/α-Bi2O3 heterostructure have been synthesized and utilized for supercapacitor applications. The crystal nature and microstructure of the Bi2O2CO3/α-Bi2O3 heterostructure were initially confirmed by powder X-ray diffraction (p-XRD), Raman, UV-Vis diffuse reflectance spectroscopy (UV-DRS, absorbance), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) studies. X-ray photoelectron spectroscopy (XPS) measurements have investigated the oxidation states and chemical binding energies. Regarding the electrochemical performances, the Bi2O2CO3/α-Bi2O3 heterostructure as electro-active material delivered a maximum specific capacitance (Cs) value of 635 F g−1 at the given current density value of 1 A g−1 in a conventional three-electrode mode. A coin cell type electrode has been fabricated using Bi2O2CO3/α-Bi2O3 heterostructure, resulting in an asymmetric supercapacitor device cell (ASC), which has a Cs of 112 F g− 1 (at 1 A g− 1) and a power density and energy density values of 515 W kg−1 and 22.5 Wh kg−1 respectively. The two supercapacitor electrodes in sequence effectively ignite the red-light-emitting diode (LED). Moreover, in the ASC type Bi2O2CO3 /α-Bi2O3 heterostructure, the specific capacitance value was slightly reduced to 12.3 % by 2000 cycles, showing favourable cyclic performance and stability during the electrochemical process. Based on the above-mentioned characterization, the appropriate electrochemical performances of Bi2O2CO3/α-Bi2O3 tubular rod heterostructures make them a promising candidate for future energy storage devices.

A Solid Electrolyte RHE for Electrode Diagnosis of Proton Exchange Membrane Water Electrolyzers.

Reference electrode is the foundation of electrochemical study; thus, most electrode materials are tested in a three-electrode mode to acquire potential-dependent kinetics. However, it is difficult to directly use conventional reference electrodes to detect potential information in solid electrolyte devices due to their compact assembly structure. Therefore, the kinetic study of an electrochemical device faces challenges in precise identification of specific problems originating from the anode or cathode. Here, focusing on proton exchange membrane water electrolysis, we design a solid electrolyte reversible hydrogen electrode (SE-RHE), which can be used for electrode diagnosis under various operating conditions. Compared to the reference electrodes reported in the literature, which are mainly based on liquid electrolyte, the SE-RHE is highly sensitive and compatible, as well as easy to assemble. The potential deviation is less than ±0.5 mV, and the cell voltage derived from the electrode potential well reproduces the value that was directly measured with a deviation less than 0.2%. The reference electrode developed in this work enables the kinetic study of a specific electrode rather than the entire cell. For instance, an interesting observation is that the cathode shows distinct stability under stable and fluctuating operations. Differing from the high stability under stable operation, the cathode degrades significantly under fluctuating operations.

Heteroatoms-doped hierarchically porous graphene as electrode material for supercapacitors with ultra-high capacitance

In this work, a dual-templating pyrolysis strategy is successfully developed to synthesize a highly crumpled graphene (N-TRPG-800). The achievement of the graphene is based on the carbonization of the d(+)-glucosamine hydrochloride and the spatial confinement effect of the graphitic carbon nitride (g-C3N4) in the presence of zinc nanoparticles (Zn NPs). During the pyrolysis process, the d(+)-glucosamine hydrochloride first polymerizes into the layers of g-C3N4, which is derived from melamine. Afterwards, a further increase in pyrolysis temperature leads to the decomposition of g-C3N4 and the generation of reducing NH3 gas, which eventually resulting in the formation of 2D ultrathin structure and high heteroatoms doping degree. Simultaneously, the volatilization of the Zn NPs also plays a key role in the pore formation and the hierarchical structure generation. As a result, the as-synthesized graphene sheets simultaneously possesses hierarchical porous structure, high heteroatoms-doped degree, and large specific surface area (506 m2 g−1). Electrochemical measurements show that the N-TRPG-800 exhibits an ultrahigh supercapacitance of 471 F g−1 at 0.2 A g−1 in a three-electrode mode, approaching the theoretical capacitance of 550 F g−1 of graphene, which is superior to that of the state-of-the-art heteroatom-doped porous carbons in literature.

Oxidation of Alloy 690 in Simulated Pressurized Water Reactor Primary Coolant – Experiments and Modeling

During normal operation of the primary loop of a water cooled-water moderated energy reactor (WWER), the associated water chemistry evolves from an initially high-boron high-potassium (beginning-of-cycle, 1200 ppm B and 8 ppm K) to significantly lower concentrations (ca. 400 ppm B and 3.5 ppm K) at the end of the respective campaign. In addition to that, the concentration of Li produced by transmutation of B reaches ca. 0.7 – 0.9 ppm. To the best of our knowledge, the effect of such water chemistry changes on pressurized water reactor (PWR) internals such as Alloy 690 have not been studied yet. Such a study appears relevant also within the frames of a discussion for a possible transition from B-Li to B-K water chemistry in PWRs.In the present paper, the effect of evolution of primary water chemistry during operation on the corrosion rate and conduction mechanism of oxide films on Alloy 690 is studied by in-situ impedance spectroscopy at 280 °C / 8 MPa during 1-week exposures in an autoclave connected to a re-circulation loop. Impedance measurements were performed in three-electrode mode featuring a Pt sheet counter electrode and a Pd electrode negatively polarized with a current of -10 µA vs. another Pt to approximate the reversible hydrogen electrode (RHE). Spectra were recorded at the corrosion potential in a frequency range 10 kHz – 0.1 mHz using an ac amplitude of 50 mV (rms). At the end of exposure, the samples were polarized in the range of potentials -0.1 to 0.5 V vs. RHE to evaluate the stability of the passive oxide. Separate samples of Alloy 690 were simultaneously exposed in the autoclave and subsequently analyzed by Glow-Discharge Optical Emission Spectroscopy (GDOES) in order to estimate the thickness and the in-depth composition of the formed oxides.Impedance data were quantitatively interpreted using the Mixed-Conduction Model for Oxide Films (MCM) to estimate the rates of metal oxidation at the alloy/oxide interface, oxide dissolution and restructuring at the film/coolant interface and ion transport in the protective layer. The effect of water chemistry evolution on corrosion rate and conduction mechanism in the oxide on Alloy 690 in primary coolant is discussed on the basis of the obtained parameters.Acknowledgments: This study is funded by the European Union-NextGenerationEU, through the National Recovery and Resilience Plan of the Republic of Bulgaria, project № BG-RRP-2.004-0002 (BiOrgaMCT).

Binder-free self-supporting electrodes formed by intercalation of RuO2 on wood-derived carbon for supercapacitor

The production of energy storage electrodes with excellent performance using pseudocapacitive materials and biomass carbon is tricky. To address this, a self-supporting electrode material with RuO2 intercalated in wood carbon was prepared using wood as a framework, and the materials exhibited good morphology stability. In the three-electrode mode, the prepared materials exhibited good electrochemical performance, among which the specific capacitance of SPWC15-800 reached 326.95 F/g (0.1 A/g). Moreover, SPWC15-800 maintained a capacitance retention of 91.25% when the CV curve runs to 12,450 cycles, exhibiting good stable characteristics. For the evaluation of two-electrode, under 0.1 A/g, the corresponding energy density was 3.765 Wh/kg, displaying the potential of wood-carbon based self-supporting materials.

Exploring the electrochemical properties of CuSe-decorated NiSe2 nanocubes for battery-supercapacitor hybrid devices

Chalcogenides, a promising class of electrode materials, attracted massive popularity owing to their exciting features of high conductive nature, high capacity, rich redox activities, and structural functionalities, making them the first choice for the electrochemical energy domain. This paper reported a new NiSe2–CuSe nanocomposite prepared via a wet-chemical synthesis followed by a low-cost and simple hydrothermal reaction. The physical characterization showed cubes and nanoparticles type morphological features of NiSe2 and CuSe products, while their composite reveals a combined morphological characteristic. The electrochemical properties were tested in an aqueous solution, demonstrating that the NiSe2–CuSe nanocomposite exhibits a high capacity of 376 C g−1, low resistance, good reversibility and rate capability in a three-electrode mode than bulk counterparts. For practical aspects, a battery-hybrid supercapacitor (BHSC) is developed with NiSe2–CuSe nanocomposite, and activated carbon (AC) serves as cathode and anode in two-cell mode operation. The built NiSe2–CuSe||AC/KOH BHSC expanded the voltage to 1.8 V and delivered the highest capacitance of 148 F g−1 and 55 F g−1 from 1 to 10 A g−1, suppressing most of the previously existing literature reports. Also, our built NiSe2–CuSe||AC/KOH BHSC displayed a high-power delivery of 8928 W kg−1 at a maximum energy density of 66.6 W h kg−1 and retained 91.7% capacitance after a long way of 10,000 cycles. These outstanding results demonstrate that metal selenides can be effectively utilized as alternative electrodes with high energy, rate performance, and long-term durability for advanced energy conversion and storage devices.

Integrated solar-rechargeable supercapacitors with a dual-functional-layered electrode

Early integrated solar-rechargeable supercapacitor (ISRS) systems with four physically distinguishable electrodes are cumbersome and require multistep manufacturing process with application disadvantages. Therefore, a stacked ISRS with a three-electrode mode that uses a dual-functional-layered (shared) electrode, which is particularly important to integrate two main active components, is one of the target configurations for a compact, safe and efficient power supplier in advanced soft electronics. This work reports the effect of various fabrication methods on the surface morphology profile of a graphene oxide-incorporated poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (m-PHGO) as a shared electrode; this process exhibited a significant impact on the charge/discharge rate and ISRS efficiency. By controlling the deposition method, the shared electrode fabricated by a modified spin/spray-coating technique using an m-PHGO dispersion features an interface that meets all of the requirements of a dual-functional layer. It is effective for hole charge filtration, transfer, and storage in the stacked ISRS. Under 1-sun illumination, the supercapacitor moiety is charged entirely by the organic solar cell unit within 5 s to build a fusion ISRS capable of approaching a high charging voltage of ∼0.6 V. The as-developed ISRS (with a thickness of ∼2.6 μm and the substrate) shows an impressive energy-storage efficiency of ∼81%. This study provides insights about fabricating high-performance and easy-to-use compact electronic devices.

A new ZnO-ZnS-CdS heterostructure on Ni substrate: A binder-free electrode for advanced asymmetric supercapacitors with improved performance

ZnO is an appealing electrode material for supercapacitors due to its high capacitance, low cost, environmental friendliness, and good electrochemical reversibility. In this paper, we present the synthesis of a newly designed ZnO covered with ZnS and paired with CdS to produce a ternary heterostructure. According to the morphological research, ZnO has an urchin-like shape coated with ZnS and CdS nanoparticles on the surface with no undesired by-product residues, which improves the surface functionalities. First, we combined ZnO and ZnS to make a binary nanocomposite that outperformed its bulk equivalent ZnO by 322 mAh g−1 at 175 mAh g−1 during the charge-discharge process when a low current flow of 1 A g−1 was used. Meanwhile, the synergistic effect of multiple components, a new class of ternary ZnO-ZnS-CdS heterostructure was developed which effectively improved the electrochemical properties of the individual constituents, e.g., a capacity of 434 mAh g−1, and charged transfer kinetics (over pristine ZnO, and ZnO-ZnS electrodes). Inspired from the good capacitive behavior in a three-electrode mode, we further assembled an ASC that exhibits exceptional energy-storage performance of 36 Wh kg−1, 5422 W kg−1 after adding an optimal voltage (1.8 V), and retain only ∼91% at a higher current response. Last but not least, compositing is a vital strategy to boost the overall capacitive performance of the nanomaterials.

Suppressing the oxygen-related parasitic reactions in NaTi2(PO4)3-based hybrid capacitive deionization with cation exchange membrane

The parasitic reactions leading to capacity fading and charge loss remain a serious issue for capacitive deionization (CDI). NaTi2(PO4)3 (NTP) has recently emerged as a promising faradaic cathode in hybrid CDI (HCDI) with high Na+ uptake capacity and good Na+ selectivity, but it is still challenged by serious parasitic reactions. Although the irreversible faradaic reactions on carbon electrode are raising growing attention in CDI research field, the parasitic reactions on faradaic materials are seldom studied in HCDI by now. In this work, we evaluated the parasitic reactions of NTP-reduced graphene oxide (rGO) electrode in both three-electrode mode and full-cell HCDI mode. By using deaired electrolyte, the coulombic efficiency of NTP-rGO is significantly enhanced from 75.0% to 98.2% in 3rd cycle, and the capacity retention rate is promoted from 37.5% to 80.3% at the low current density of 0.1 mA g−1 in 100 cycles, suggesting that electrochemical reduction of oxygen and its derived reactions are the main parasitic reactions in NTP-based HCDI. In full-cell HCDI desalination tests, by introducing cation exchange membrane to block the penetration of dissolved oxygen, the parasitic reactions and pH fluctuations are successfully suppressed. The study here provides an insight into understanding and suppressing the parasitic reactions in HCDI, and should be of value to the development of efficient and stable HCDI for practical applications.

Extraction of photosynthetic electron from mixed photosynthetic consortium of bacteria and algae towards sustainable bioelectrical energy harvesting

Extraction of photosynthetic electron for bioelectrical energy harvesting is an efficient approach to utilize solar energy harvested by photosynthetic microorganisms. To explore this approach in natural and artificial photosynthetic system in which alga and photosynthetic bacteria are usually coexisted, the intracellular electron extraction from mixed photosynthetic consortium of Chlorella vulgaris and Rhodopseudomonas palustris was investigated under three-electrode mode by holding working electrode at different potentials. The mixed-culture biofilm grown at 0 V exhibited a maximum Coulomb efficiency of 42.12% while the peak current (12.2 mA) was 8.07, 1.5, 2.97 and 4.65 fold higher than that produced at −0.4 (1.5 mA), −0.2 (8.06 mA), 0.2 (4.08 mA) and 0.4 V (2.6 mA), respectively. The electrode potential can regulate the dominant species within the biofilm. Large enrichment of Rhodopseudomonas palustris in the biofilm was responsible for the high photosynthetic electron extraction efficiency at 0 V since the photosynthetic electrons extracted by the electrode were mainly derived from photoheterotrophic metabolism of Rhodopseudomonas palustris. Extraction of equivalent amounts of intracellular electron from Chlorella vulgaris required higher potential than that from Rhodopseudomonas palustris and was highly dependent on the presence of exogenous electron mediator. As an electron sacrificer, photosynthetic oxygen released by Chlorella vulgaris could complete electron with electrode. Intracellular electrons can also be extracted from dark respiration, but the peak current (6.4 mA) was 47.54% lower than that produced under illumination (12.2 mA) due to low exoelectrogenic activity of biofilm.

Synergistic effect of Co3O4@C@MnO2 nanowire heterostructures for high-performance asymmetry supercapacitor with long cycle life

Heterostructures show excellent performance in energy and environment fields due to the unique interface structure and synergistic effect of multi-components. Here, we introduce a stepwise method to prepare multi-element Co3O4@C@MnO2 heterostructures on nickel foam as binder-free supercapacitor electrode material, where crystalline Co3O4 acts as intimal “core” and wrinkled ultrathin MnO2 nanosheets as the outer “shell”. In three-electrode mode, Co3O4@C@MnO2 shows excellent electrochemical performance with a high cyclic specific capacitance of 1335.3 F g−1 at a current density of 20 A g−1. Furthermore, the asymmetry supercapacitor device assembled with Co3O4@C@MnO2 heterostructures and active carbon exhibits high specific capacity (126.6 F g−1 at a current density of 0.5 A g−1) and long life (about 61 F g−1 at a relatively high current of 20 A g−1 after 40,000 cycles). Compared with Co3O4@MnO2 or C@MnO2, the improved performance of Co3O4@C@MnO2 heterostructures is proposed to be attributed to the synergistic effect in multi-components. Remarkably, the introduction of C between Co3O4 and MnO2 could promote the electron transfer, reduce the impedance and thus improve the electrochemical performance of the heterostructures.

Hierarchical NiCo layered double hydroxides nanosheets on carbonized CNT/cotton as a high-performance flexible supercapacitor

Layered double hydroxides (LDHs) are promising Faradaic materials for the construction of high-performance supercapacitors, due to their unique two-dimensional lamellar structures and remarkable stability. Herein, hierarchical porous NiCo LDHs integrated with flexible carbon nanotubes (CNT)/cotton fabric current collector, are realized by a facile method, which exhibits a high capacitance of 811 F g−1 at 0.1 A g−1 in a three-electrode mode. Moreover, the hybrid electrode has been assembled into a flexible supercapacitor device, where the mass capacitance reaches 47.25 F g−1 with a good cycling stability of 94% capacitance retention after 3000 cycles. The better flexibility and conductivity of the CNT, and highly intrinsic electrochemical activity of the NiCo LDHs as well as the superiority of the interwoven structure are responsible for the outstanding performance of the supercapacitor. The elaborate structural design can provide new insights into the construction of high-performance flexible supercapacitors.

MOF-derived N-doped carbon bubbles on carbon tube arrays for flexible high-rate supercapacitors

N-doped carbon bubbles homogenously dispersed on highly conductive carbon tube arrays scaffold are derived from ZnO@ZIF-8 nanoarrays template through in situ catalytic decomposition of ethanol and reduction-evaporation process. The as-obtained hierarchical carbon tube connected N-doped carbon bubbles arrays possess well interconnected micro-/mesopores and large specific surface area, which are expected to improve both the specific capacitance and rate capability of carbon-based electrochemical capacitors. The hierarchical porous N-doped carbon nanostructures yield a remarkable rate capability with 56.8% capacitance retention when the current density ranges from 1 to 200mAcm−2, and an excellent long-term cycle stability with 98.5% capacitance retention after 10,000 continuous cycles in 1M H2SO4 aqueous solution under three-electrode mode. The symmetric supercapacitor delivers an areal capacitance of 580 mF cm−2 at 1mAcm−2. Furthermore, the assembled symmetric device validates excellent mechanical stability and flexibility.

A Three-Electrode Gas Switch Triggered by Microhollow Cathode Discharge With Low Trigger Voltage

The trigger voltage is usually high in traditional three-electrode gas switch, which makes the trigger system large and complex in large-scale pulsed power system such as linear transformer driver. In this paper, a three-electrode gas switch triggered by microhollow cathode (MHC) discharge is put forward, which can be operated stably under low trigger voltage. MHC discharge is a kind of microplasma with the characteristics of low trigger voltage (several thousand volts), high electron density, and high gas pressure discharge. In this switch, three MHC triggers sharing the same cathode are designed as the third electrode of the switch in the middle. Positive and negative high voltages are applied to two main electrodes, respectively. The breakdown characteristics of MHC discharge triggered by pulse voltage are first studied. The trigger voltage can be as low as 8 kV at 0.3 MPa in pure N2 with the discharge peak current up to 80 A. A circuit simulation model describing breakdown process of MHC is also built. Then two operating modes of the switch, three-electrode mode (T-mode) and two-electrode mode (D-mode), are analyzed. The stable operation with the charging voltage from ±35 to ±50 kV is realized under different working coefficients from 64% to 92% and different trigger voltages from 8 to 15 kV. The turn-on parameters including delay time, jitter, and turn-on time are studied that the delay time and jitter of D-mode are longer than that of T-mode under the same condition. At last, the improvement of MHC trigger for the stable operation of D-mode with shorter delay time is described.

Resorcinol-formaldehyde carbon spheres/polyaniline composite with excellent electrochemical performance for supercapacitors

Well-dispersed resorcinol-formaldehyde-based carbon spheres (RFCs) have been prepared by the polycondensation of resorcinol and formaldehyde with ammonia as catalyst and subsequent carbonization of the obtained polymer. In situ polymerization of the aniline occurred in the suspension of the RFC, and RFC was surrounded by the polyaniline (PANI) wires. The PANI and RFC hybrid network (PRFC) formed gradually. In a three-electrode mode, the specific capacitance (C sp) of PRFC reaches 315 F g−1 at a current density of 1 A g−1 in 2 M H2SO4, much higher than that of pure PANI (225 F g−1) and RFC (121.7 F g−1). Furthermore, the C sp of PRFC retains 80.0 % after 1000 charge-discharge processes at a current density of 5 Ag−1. The enhanced electrochemical performance of the PRFC came from its homogeneous three-dimensional hierarchical network structure, good electric conductivity of the PANI around the RFC, and the synergistic effect between the RFC and PANI.

Electrodeposition and characterization of palladium nanostructures on stainless steel and application as hydrogen sensor

Palladium nanostructures have been deposited onto the stainless steel electrode by simple electrochemical deposition method in a buffer solution. The morphology of the synthesized Pd nanoparticles is controllable by deposition potentials because the driving force for various crystal growth mechanisms is merely dependent on applied potentials. The deposited Pd nanoparticles at higher applied potentials showed a cauliflower-like morphology with a nanoscale structure and large surface area. Then, an amperometric hydrogen sensor based on Pd nanoparticles can be constructed. This sensor is based on polymer electrolyte membrane fuel cell (PEMFC) and can be used at the ambient temperature. It is operated in the three-electrode mode that consists of three electrodes (working, counter and reference) and protonated Nafion membrane as proton conducting solid polymer electrolyte (SPE). The steady-state current response is obtained linearly to the concentrations of hydrogen from 50 to 2000 ppm, when a fixed potential of 0.2V is applied to the sensor. Typical factors that influence the performance of the sensor are analyzed and discussed. The simple and inexpensive hydrogen sensor fabricated shows low LOD (10 ppm, based on S/N = 3), wide linear range (50-2000 ppm) and short response time (10-40 s).

A simulation of current focusing and steering with penetrating optic nerve electrodes

Objective. Current focusing and steering are both widely used to shape the electric field and increase the number of distinct perceptual channels in neural stimulation, yet neither technique has been used for an optic nerve (ON)-based visual prosthesis. In order to evaluate the effects of current focusing and steering in penetrative stimulation, we built an integrated computational model to simulate and investigate the influence of stimulating parameters on ON fibre recruitment. Approach. Finite element models with extremely fine meshes were first established to compute the 3D electric potential distribution under different stimulating parameters. Then the external electric potential was fed to randomized multi-compartment cable models to predict the distribution of fibres generating an action potential. Finally a statistical process was conducted to quantify the recruitment region. Main results. The simulation results show that a two-electrode mode is superior to a three-electrode mode in current steering. The three-electrode mode performs poorly in current focusing, albeit the localized recruitment from both configurations implies that current focusing might be unnecessary in penetrative ON stimulation. Significance. This study provides useful information for the optimized design of penetrating ON electrodes and stimulating strategies. The Monte Carlo style computation paradigm is designed to simulate neural responses of an ensemble of ON fibres, which can be immediately transferred to other similar problems.

Light-induced electro-rotation: Microspheres spin in micro-manipulation using light-induced dielectrophoresis

According to the equivalent circuit model (ECM), finite element model (FEM) and physical experiment, the LIDEP force induced by the spatial variations of the phase of AC electric fields produced by the bright and dark regions on the photoconductive layer was demonstrated. Besides, the phenomenon of the light-induced electro-rotation (LIER) caused by the light-induced rotating electric field was confirmed numerically and experimentally for the first time. It may be helpful to go out of the dilemma that only the dipole moment model, based on the effect of light-induced partial potentials, can be used for LIDEP theoretical calculation currently. Through the FEM simulation and the electro-rotating experiment of yeast cells, it was found that the direction of yeast’s LIER is relevant to the distance between its location and the edge of optical electrode, and the spin velocity of LIER is inversely proportional to that distance. Nevertheless, the LIER torques in the three-electrode mode show a non-uniform distribution where the LIDEP forces are harmful for a particle spinning stably around a fixed axis. Moreover, a four-electrode double-layer mode was proposed for the first time and the finite element simulation results agreed with the expected design, suggesting a new way for the dielectric spectrum measurement based on LIER.

A new photoelectrochemical test cell and its use for a combined two-electrode and three-electrode approach to cell testing

This paper describes the design, assembly, and operation of a photoelectrochemical (PEC) test cell that is relatively easy to construct and well suited for testing photoelectrode/counterelectrode combinations in a reproducible manner. The design of the cell permits measurements to be made in both two-electrode and three-electrode arrangements. The benefits of conducting both two-electrode and three-electrode measurements are illustrated using data obtained from the new test cell for a PEC system based on a polysulfide electrolyte, CdSe(0.8)Te(0.2) photoanode, and tungsten monocarbide counterelectrode. It is shown that linear sweep voltammograms measured in three-electrode mode can be used to describe current transients recorded in a two-electrode cell modified by the addition of a reference electrode.