Indium Electrodes Research Articles

Keggin-type P-W-Mo-V polyoxometalates in electrocatalyzed CO 2 reduction using indium electrodes

Keggin-type P-W-Mo-V polyoxometalates in electrocatalyzed CO ₂ reduction using indium electrodes

Study on microstructure and charge–discharge mechanism of all solid‐state indium‐graphite batteries

AbstractThis study centers on indium‐ion solid‐state batteries. Indium is a soft metal that provides excellent adhesion and does not generate dendrites during the charge–discharge process. The solid‐state electrolyte material, sodium‐based silicate, is an environmentally friendly material that offers better thermal stability compared to liquid electrolytes and reduces packaging requirements. The positive electrode material, a graphite film (GF), features a layered structure, enabling the stable insertion and extraction of ions. In this experiment, graphite film doped sodium phosphate (GFN) are used as positive electrodes, sodium‐based silicate powder through cloth deposition (battery cloth deposition [BCD]) is used as the electrolyte and indium is used as the negative electrode. To improve the low capacity of indium electrodes, indium is alloyed with silver and prepared by thermal evaporation method. The results show that the In‐30Ag with Cu substrate (weight ratio of In‐30 wt.% Ag) exhibits higher cycling capacity (61 mAhg−1). To further increase the capacity, the substrate of In‐30Ag is replaced from copper foil to aluminum foil. According to result, the capacity of In‐30Ag with Al substrate (91 mAhg−1) exhibits 1.6 times higher compared to In‐30Ag with Cu substrate. However, In‐30Ag with Al substrate after vacuum heat treatment, the thin film exhibits melting and agglomeration, leading to a decrease in capacity. Thus, the unheated In‐30Ag (Al substrate)/2×BCD/GFN system is subjected to large‐area module testing using an industrial fan as the load, confirming its practical applications.

Thermo-electrocatalytic reduction of potassium bicarbonate to formate on an indium electrode

Abstract In this work, we developed a thermo-electrochemical bicarbonate reduction (TEBR) process for the production of formate on a simple indium foil electrode. The TEBR process relies on the synergistic effect of thermochemical and electrochemical processes, which ensures the continuous redox of metals on the electrode surface. In the thermochemical environment, indium can interact with water to form InO(OH), which facilitates the absorption and hydrogenation of bicarbonate to form formate. In the electrochemical environment, the reduction of indium oxide to indium supports the maintenance of a dynamic interface of In3+/In. This study revealed that, when an indium electrode is employed in the reaction system, the Faraday efficiency and partial current density of formate can reach 86.2% and 86.5 mA cm−2, respectively, at 100 °C with a KHCO3 concentration of 3.0 mol L−1. Therefore, an indium electrode can be effectively employed for the direct reduction of bicarbonate to produce formate. This study provides an insight into the synergistic effect of thermochemical and electrochemical processes, and suggests a potential application of indium in the production of formate via a TEBR process.

Separation of lanthanides erbium and ytterbium on indium electrodes by modulated potential selective extraction in molten salts and a thermodynamic and kinetic analysis of the process

The main purpose of this paper is to study the extraction and separation of key fragment elements based on the electrolytic refining process of spent fuel dry reprocessing. Firstly, the electrochemical mechanisms of Er(III) and Yb(III) in LiCl-KCl molten salts were investigated on W and In film electrodes with applied cyclic voltammetry (CV), square wave voltammetry (SWV) and open circuit potential (OCP) at 773 K. The results indicated that the reduction behaviour of In(III) and Yb(III) ions were a two-step transfer process and Er(III) ions was a one-step transfer process. Then, the kinetic parameters in electrochemical processes were calculated on an In electrode with different temperatures. The OCP approach was used to determine the equilibrium potential of Er(III)/Er(0) in the temperature range of 773 K∼848 K, and thermodynamic parameters of the In3Er alloy were provided. Based on electrochemical behaviour results, the electrochemical extraction of Er(III) and Yb(III) from LiCl-KCl-ErCl3 molten salts and LiCl-KCl-YbCl3 molten salts at liquid In electrodes was performed by constant potential and constant current electrolysis, respectively. The electrolysis products were determined by X-ray diffraction (XRD), scanning electron microscopy and energy dispersive spectrometry (SEM-EDS), the primary intermetallic compounds generated in the alloys were In3Er and In3Yb. The average extraction rates for Er(III) and Yb(III) were 94.70% and 96.54%, respectively, according to inductively coupled plasma atomic emission spectroscopy (ICP-AES) analysis. Er(III) and Yb(III) were selectively extracted and separated from LiCl-KCl-ErCl3-YbCl3 molten salts by potentiostatic control on the basis of the previously studied Lns (Er and Yb) extraction on In electrodes. The separation rate of Er(III) and Yb(III) by electrochemical selective deposition was 94.21%.

Compositional effects of Ga incorporation on electrical and dielectric parameters in Ge-Se-Sb-Ga thin films

In this paper, the existence of new selenium-rich chalcogenide glassy systems i.e. (Ge20Se80)90-xSb10Gax (x = 2, 4, 6 and 10 at %) had been reported. (Ge20Se80)90-xSb10Gax glassy systems were prepared using melt-quenching technique. Thin films of (Ge20Se80)90-xSb10Gax were prepared on properly cleaned glass substrates using vacuum evaporation technique. Planar geometry of indium (In) electrodes (electrode spacing 0.08 cm) was used for electrical measurements. The physical parameters – average number of constraints, cohesive energy, mean bond energy, average coordination number, heat of atomization, glass transitition temperature and lone pair electrons had been estimated. The high values for the lone pair electrons proves the investigated system to be a good glass former. The increasing values of cohesive energy, glass transition temperature and mean bond energy with the incorporation of Ga, reveal that Ge-Se-Sb-Ga glassy systems are thermally stable glasses. The current transport mechanisms had been studied within the temperature range 173–363 K. Thermionic emission dominated in the high temperature region above 333 K. Within the intermediate temperature range 273–333 K, thermally-assisted tunneling of the charge carriers through grain boundary potential as well as thermionic emission over grain boundary potential contributed to the conduction mechanism. Below 273 K, Mott’s hopping process dominated the conduction mechanism. Dielectric measurements had been examined within the temperature range 173–363 K and the frequency range 50 Hz–1 MHz. Dielectric constant as well as dielectric loss decreased as the frequency was increased and increased as the temperature was increased. Orientation polarization described the temperature-dependence and frequency-dependence of dielectric constant. Temperature-dependence and frequency-dependence of dielectric loss was explained by conduction loss as well as hopping of charger carriers. The ac conductivity agrees with the power law: ωs where s < 1. The present investigation of dielectric parameters could be explained in terms of correlated barrier hopping (CBH) model. Profound analysis of the physical, electrical and dielectric properties and their variation as a function of Ga-content suggest the utilization of these glasses in optoelectronic devices.

Efficient electrocatalytic CO2 reduction to ethanol through the proton coupled electron transfer process of PVnMo(12-n) (n = 1, 2, 3) over indium electrode

The multistep proton-coupled electron transfer (PCET) processes are beneficial for products distribution and selectivity of the electrocatalytic CO2 reduction reaction (CO2RR), which are affected by the nature of the catalyst and electrolyte at electrode–electrolyte interface. Polyoxometalates (POMs) are electron regulators of PCET processes, which can catalyze CO2RR effectively. Accordingly, the commercial indium electrodes are combined in this work with a series of Keggin-type POMs (PVnMo(12-n)O40)(n+3)−, n = 1, 2, 3) to process CO2RR with Faradaic efficiency toward ethanol reaching 93.4% at −0.3 V (vs. RHE). The cyclic voltammetry and X-ray photoelectron spectroscopy results reveal the activation of CO2 molecules by the first PCET process of the VⅤ/Ⅳ in POM. Subsequently, the PCET process of MoⅥ/Ⅴ results the oxidation of the electrode, causing the loss of In0 active sites. Electrochemical in-situ infrared spectroscopy confirms the weak adsorption of *CO at the later stage of electrolysis due to the oxidation of the In0 active sites. The indium electrode in PV3Mo9 system retains more In0 active sites owing to the highest V-substitution ratio, thereby ensuring a high adsorption ratio of *CO and CC coupling. In sum, the regulation of the interface microenvironment by POM electrolyte additives can be used to boost the performance of CO2RR.

The behavior of indium in dilute sodium tetraborate containing bromide ions in the presence of some ethoxylated surfactants

The potentiometric technique was used to study the oxide film repair and destruction on indium electrodes in 0.01 M Na2B4O7 containing various amounts of Br- ions. Higher amounts of Br- ions, ≥5 × 10−2 M, reduces the oxide film growth and initiate the destruction of oxide film by inducing pitting corrosion. The initiation of pitting corrosion is raised with the addition of more concentrations of Br- ions and raising the temperature. Some freshly prepared ethoxylated surfactant molecules, ETO I, ETO II, and ETO III were utilized as inhibitors to resist the oxide film destruction and sustain the oxide film repair with the formation of a layer of surfactant molecules. The protection efficacy of such molecules is found to rely on the concentration of the surfactant besides the number of ethylene oxide monomers per molecule. The inhibition efficacy reaches 87.8 %, 83.1 %, and 79.5 % with ETO III, ETO II, and ETO I, successively, at 0.01 M inhibitor concentration and 25 ºC. The inhibition mechanism relies on an adsorption process obeying Langmuir's model. The thermodynamic adsorption functions. Viz, Kads, and ∆G°ads are computed and explained. The inhibition efficacy of such compounds decreases in the order, ETO III> ETO II> ETO I.

On the stability of electrochemical CO2 reduction reaction to formate at indium electrodes at biocompatible conditions

In a circular economy, carbon dioxide (CO2) has to serve as feedstock that can be utilized by electrochemical CO2 reduction reaction (eCO2RR). Using eCO2RR to C1-compounds such as formate (HCOO−) allows producing feed for microbial syntheses that generates value-added compounds. However, eCO2RR at biocompatible conditions is currently limited to short-term operation facing a gradual performance deterioration. Here, we evaluate the possible parameters affecting the stability of performance in terms of formate production rate (rHCOO−) and coulombic efficiency (CE) of eCO2RR at indium during 72 h batch mode operation. Formate accumulated over time affected catholyte conductivity, but statistical analysis showed this did not have an immediate influence on the performance. However, both are key factors altering the actual cathode potential over time that in turn is leading to changes in rHCOO− (maximum deviation of ± 0.03 mmol h−1 cm−2 at the stable performance at each condition) and CE (maximum deviation ± 40% at stable performance at each condition). These effects were more significant after reaching certain formate concentration and catholyte conductivity (ca. 70 mM and 21 mS cm−1, respectively). These results highlight the potential obstacles needed to be considered and tackled in order to achieve stable rHCOO− and CE over a long-term eCO2RR operation. This study discusses how to overcome these obstacles from different operational perspectives.

A Promising Crystalline KCl: Electrolyte Material for Studying the Electrochemical Properties of Cerium on Liquid Indium Electrodes

Potassium chloride crystals are good conductors in the UV to mid-infrared broadband and can be widely used as materials for high-power CO2 lasers. However, the most important use of potassium chloride crystals has been overlooked; their stable chemistry and wide electrochemical window allow them to form molten eutectic salts with other chlorides for the dry reprocessing of spent fuel. The aim of this work is to investigate the electrochemical properties of the actinide substitute cerium metal on liquid indium media in order to provide basic data for further realization of lanthanides (Ln)/actinides (An) separation. In this paper, we investigated the electrochemical behavior of 3LiCl-2KCl-CeCl3 melt at liquid metal media indium (In) electrode using various transient electrochemical analysis methods, such as cyclic voltammetry, square wave voltammetry and open circuit potential technique. The quasi-equilibrium potentials of Ce3+ at different temperatures on the liquid metal In electrode were determined. On the redox process, the reaction kinetics of the oxidation–reduction process in the 3LiCl-2KCl-CeCl3 system is studied. It was determined that the reduction of Ce3+ at the liquid metal In electrode is an irreversible single-step process with three electron transfers. The relationship between the diffusion coefficient and the reduction process of Ce3+ ions on liquid metal indium electrodes at different temperatures was determined. The expression for the diffusion coefficient and temperature of Ce3+ at the liquid metal indium electrode is: lnD = 1.43 − 7974.69/T.

Toward abiotic sugar synthesis from CO2 electrolysis

Toward abiotic sugar synthesis from CO2 electrolysis

Microbial | electrochemical CO2 reduction: To integrate or not to integrate?

Microbial | electrochemical CO2 reduction: To integrate or not to integrate?

Using Light and Electrons to Bend Carbon Dioxide: Developing and Understanding Catalysts for CO2 Conversion to Fuels and Feedstocks.

Our global society generates an unwieldy amount of CO2 per unit time. Therefore, the capture of this greenhouse gas must involve a diverse set of strategies. One solution to this problem is the conversion of CO2 into a more useful chemical species. Again, a multiplicity of syntheses and products will be necessary. No matter how elegant the chemistry is, commercial markets often have little use for a small set of compounds made in tremendous yield. Following this reasoning, the Bocarsly Research Group seeks to develop new electrochemical and photochemical processes that may be of utility in the conversion of CO2 to organic compounds. We focus on investigating proton-coupled charge transfer mechanisms that produce both C1 and carbon-carbon bonded products (C2+).In early work, we considered the reduction of CO2 to formate at electrocatalytic indium and tin electrodes. These studies demonstrated the key role of surface oxides in catalyzing the reduction of CO2. This work generated efficient systems for the formation of formate and paved the way to studies using non-copper, intermetallic electrocatalysts for the generation of C2+ species. Most notable is the efficient formation of oxalate at an oxidized Cr3Ga electrode. Oxalate has recently been suggested as a potential nonfossil, alternate organic feedstock.Separately, we have focused on the electrocatalytic effects of pyridine on the reduction of CO2 in aqueous electrolyte. These studies demonstrated that electrodes that normally yield a low hydrogen overpotential (Pd and Pt) show suppressed H2 evolution and strongly enhanced activity for CO2 reduction in the presence of pyridinium. Methanol was observed to form in high Faradaic yield at low overpotential using this system. The 6-electron, 6-proton reduction of CO2 in the presence of pyridinium was intriguing, and significant effort was placed on understanding the mechanism of this reaction both on metal electrodes and on semiconducting photocathodes. P-GaP electrodes were found to provide exceptional behavior for the formation of methanol using only light as the energy source.The pyridinium studies highlighted the role of protons in the overall reduction of CO2, stimulating our interest in the chemistry of MnBr(bpy)(CO)3 and related compounds. This complex was reported to electrochemically reduce CO2 to CO. We saw these reports as an opportunity to study the detailed nature of the proton-coupled electron transfer (PCET) mechanism associated with CO2 reduction. Our investigation of this system revealed the role of hydrogen-bonding in CO2 reduction and pointed the way for the construction of a photochemical process for CO generation using a [(bpy)(CO)3Mn(CN)Mn(bpy)(CO)3]+ photocatalyst.Based on our studies to date, it appears likely that heterogeneous systems can be assembled to convert CO2 into products that are "beyond C2 products." This may open up new practical chemistry in the area of fossil-based replacements for both synthesis and fuels. Systems with pragmatic efficiencies are close to reality. Electrochemical reactors using heterogeneous electrocatalysts show the stability and product selectivity needed to generate industrial opportunities. Continued growth of mechanistic understanding is expected to facilitate the chemical design of cogent systems for the taming of CO2.

Low-Temperature Annealing of CdZnTeSe under Bias.

We performed a gradual low-temperature annealing up to 360 K on a CdZnTeSe radiation detector equipped with gold and indium electrodes under bias at both polarities. We observed significant changes in the detector’s resistance and space-charge accumulation. This could potentially lead to the control and improvement of the electronic properties of the detector because the changes are accompanied with the reduction in the bulk dark current and surface leakage current. In this article, we present the results of a detailed study of the internal electric field and conductivity changes in CdZnTeSe detector for various annealing steps under bias taking into account different polarities during annealing and subsequent characterization. We observed that low-temperature annealing results in an increase in the barrier height at the contacts that, in general, reduces the dark current and decreases the positive space charge present in the sample compared to the pre-annealed condition.

Performance Improvement of Amorphous Ga2O3/P-Si Deep Ultraviolet Photodetector by Oxygen Plasma Treatment

Gallium oxide (Ga2O3) is an attractive semiconductor that is very suitable for deep ultraviolet (DUV) inspection. However, due to the existence of many types of oxygen vacancies in the amorphous Ga2O3 (a-Ga2O3) film, it greatly limits the performance of the a-Ga2O3-based photodetector. Here, we perform oxygen plasma treatment on the a-Ga2O3/p-Si photodetector to reduce the concentration of oxygen vacancies in the a-Ga2O3 film, so that the dark current is reduced by an order of magnitude (from 1.01 × 10−3 A to 1.04 × 10−4 A), and the responsivity is increased from 3.7 mA/W to 9.97 mA/W. In addition, oxygen plasma processing makes the photodetector operate well at 0 V bias. The response speed is that the rise time is 2.45 ms and the decay time is 1.83 ms, while it does not respond to the DUV illumination without oxygen plasma treating at a zero bias. These results are attributed to the fact that oxygen plasma treatment can reduce the Schottky barrier between a-Ga2O3 and the electrode indium tin oxide (ITO), which promotes the separation and collection efficiency of photo-generated carriers. Therefore, this work proposes a low-cost method to improve the performance of Ga2O3 film-based DUV photodetectors.

Designing a solution-processable electron transport layer for transparent organic light-emitting diode

In this work, the extensively used opaque metal cathodes of the conventionally structured OLEDs were replaced with the widely used transparent electrode indium tin oxide (ITO) for solution-processed transparent organic light-emitting diode (T-OLED). A new solution-processable electron transport layer (ETL), aside from facilitating the efficient injection of electrons into the T-OLED, protected the organic emission layer (EML) of the T-OLED against the plasma damage during top ITO cathode sputter deposition. The newly designed solution-processed ETL was the composite of the zinc oxide nanoparticles (ZnO-NPs), and cesium carbonate-doped ethoxylated polyethyleneimine (d-PEIE) with the semi-hydrophilic poly (methyl methacrylate) (PMMA) interlayer coated on the EML insured the good wettability and contact of the hydrophilic ETL with the hydrophobic EML. The solution-processed T-OLED emitted the total maximum luminance of about 2417 cd/m 2 (bottom side emission at 1455 cd/m 2 and top emission at 962 cd/m 2 ), total maximum current efficiency at 3.12 cd/A (bottom and top emissions at about 1.78 and 1.34 cd/A, respectively), and total maximum power efficiency at 1.64 l m/W (bottom and top emissions at about 0.95 and 0.69 l m/W, respectively) while having a very high optical transmittance of around 85% at 550 nm light wavelength. • The solution-processed T-OLED with newly designed composite ETL was fabricated. • The electrion injection efficiency and plasma barrier effect of the composite ETL was studied. • The composite ETL had the uniform morphology with even distribution of ZnO in the PEIE matrix. • The T-OLED with composite ETL showed excellent blue light emission.

Reliable and Reversible Contact of Eutectic Gallium Indium and Copper Electrodes

AbstractPhysically reconfigurable electronics provide a unique method to significantly increase the range of capabilities that a single component can possess. Room temperature liquid metal gallium alloys provide this function as a fluid that can be mobilized to drastically modify electrical performance in devices, such as tunable antennas, high isolation switches, and mechanically responsive stretchable electronics. One of the most critical limitations of using gallium alloys for reconfigurable electronics is the irreversible interactions at the interface between the liquid gallium alloy and a traditional solid electrode. In this work, the effect of repeated connection/disconnection cycles on the electrical performance of eutectic gallium indium, a common liquid gallium alloy, and a copper electrode is characterized. The effects of environment, surface treatment, and method of contact between the liquid metal and the solid surface are identified. The failure mechanisms which prevent the reversibility of the electrical interface of these contacts are determined and a mitigation strategy is provided which resulted in 1000 reversible contacts with no degradation in electrical performance.

Thermodynamics, Solubility and the Separation of Uranium from Cerium in Molten In/3LiCl-2KCl System

The purpose of this work is to study the electrochemical behavior of uranium and cerium in fused In/3LiCl-2KCl system in the temperature range of 723–823 K by open-circuit potentiometry. The apparent electrode potential of Ce3+/Ce (U4+/U) couples and apparent standard potential of Ce-In (U-In) alloys vs AgCl/Ag reference electrode were established. The principal thermodynamic properties, activity and solubility of cerium and uranium were determined. The separation factor of uranium/cerium couple on liquid indium electrode was calculated. The experimental results have been shown that a lower temperature should be more effective for the separation uranium from cerium.

Indium Diffusion Behavior and Application in HfO2‐Based Conductive Bridge Random Access Memory

This study proposes the design of conductive bridge random access memory (CBRAM) using an indium electrode, which diffuses into hafnium oxide. The device is found to exhibit good operating characteristics, maintaining a large operation window, low set and reset voltages, and advantageous operation speed, thereby reducing operating power consumption. Electrical experiments, transmission electron microscopy, and energy‐dispersive spectroscopy confirm that the device exhibits the characteristics of a CBRAM device. In addition, due to the large operation window of this In electrode device, a combination of two of these CBRAM can act as a complementary resistive switching (CRS) device with a large memory window.

3D hierarchical porous indium catalyst for highly efficient electroreduction of CO2

A highly porous indium electrode was prepared with a facile electrodeposition method, which delivers remarkable activity and selectivity towards electro reduction of Co2.

The Kinetics of Indium Electroreduction from Chloride Solutions

The electroreduction of indium on indium electrode (99.98%) in perchlorate-containing chloride electrolytes is studied by the methods of linear sweep and cyclic voltammetry, impedance spectroscopy, and chronoamperometry. The indium electroreduction is limited by diffusion, the reaction rate constant is 1.3 10–4 cm/s at the indium salt concentration of 0.1 M. The values of the apparent rate constant for the charge transfer stage found by linear sweep and cyclic voltammetry and also by impedance spectroscopy are 2.37 × 10–3, 3.62 × 10–3, 3.06 × 10–3 cm/s, respectively. The values of diffusion coefficient of indium(III) ions calculated according to the Cottrell equation based on chronoamperametric measurements and from the Warburg impedance found by impedance spectroscopy are in good agreement. The presence of the Gerischer impedance is stated, which suggests that a homogeneous reaction of formation of indium chloride complexes proceeds and its mechanism is chemical-electrochemical.