Type Of Electrolyte Solution Research Articles

Comparative Characteristics of Electrolyte Solutions Using Electrical Impedance Spectroscopy Method

Electrolyte solutions can conduct electric current and help maintain balance in the human body. This study compares the electrical impedance characteristics of various electrolyte solutions using the Electrical Impedance Spectroscopy (EIS) method. Three types of electrolyte solutions were tested: NaCl solution, Ringer’s Lactate (RL) solution, and Simulated Body Fluid (SBF) solution with concentration variations of 20%, 40%, 60%, 80%, and 100%. Measurements were conducted over a frequency range from 1 Hz to 1 MHz to compare electrolyte solutions using a frequency of 10 kHz with an electric current of 50 μA. At a frequency of 10 kHz, a comparison of the three types of electrolyte solutions with concentration variations from 20% to 100% was made. The measurement result showed that the NaCl solution had an impedance value of 200Ω to 900Ω at high frequencies. The Ringer’s Lactate (RL) solution exhibited impedance variations with impedance values ranging from 800Ω to 300Ω, which is more complex due to the other hand, the Simulated Body Fluid (SBF) solution demonstrated impedance stability at high frequencies with impedance values ranging from 400Ω to 200Ω, indicating its electrical properties suitability with human body conditions. Each electrolyte solution has its characteristics in impedance values at a frequency of 10 kHz, which allows for comparing the three types of electrolyte solutions. For further research, additional studies could include impedance characteristics of electrolyte solutions to broaden understanding of their electrical properties, considering variations in frequency and current conditions to optimise impedance characteristic measurements for various electrolyte solutions.

Engineered CoFe2O4@NiFe LDH nanocomposite based electrochemical sensor for the detection of Cr, As, Sb and Tl in various supporting electrolytes

The early detection and timeous monitoring of trace metals within the environment is crucial, especially with the need to develop mitigating strategies that help reduce health challenges. In this context, the electrochemical detection of Cr(VI), Sb(V), As(III), As(V) and Tl(III) has been performed using differential pulse anodic stripping voltammetry (DPASV) on a glassy carbon electrode modified with CoFe2O4@NiFe LDH. The anticipated active sites, such as the surface hydroxyl and oxide groups on the highly mesoporous nanoflower-like CoFe2O4@NiFe LDH composite that can readily interact with trace metal ions, were identified through physiochemical characterisation. The electrochemical characterisation revealed that the electrical conductivity was improved upon modifying the glassy carbon electrode with the CoFe2O4@NiFe LDH modifier. Subsequently, the developed sensor demonstrated a remarkable response on the detection of Cr(VI), Sb(V), As(III), As(V) and Tl(III), with good linearity (0.13–50 µg/L), low limit of detection (0.14, 0.15, 0.09, 0.12 and 0.19, respectively), low limit of quantification and high sensitivity. Significant parameters critical to the sensor's performance, such as type of electrolyte solution, deposition potential, deposition time and pH, were optimised. The DPASV results suggested that the developed sensor was repeatable and reproducible with intra-day and interday precision below 5 %. The proposed electrochemical sensor performed very well in tap and river water samples and could, therefore, open new avenues for the selective detection of trace metals in various matrices.

SOLVENT EFFECTS ON THE ELECTRONIC AND IONIC CONDUCTIVITY IN POLYMERIC NICKEL(II) COMPLEX OF N,N′ BIS(3 METHOXYSALICYLIDENE)ETHYLENEDIAMINE

The electrochemical oxidation-reduction of polymeric nickel(II) complex of N,N′-bis(3-methoxysalicylidene)ethylenediamine was investigated in acetonitrile and 1,2-dichloroethane-based solutions by a combination of in situ conductance measurements, quartz crystal microbalance, and cyclic voltammetry. The type of electrolyte solution is shown to have a pronounced effect on the variations in the electrical conductance and ion and solvent transfer at the polymer/solution interface when the polymer is electrochemically switched between various oxidation states.

Innovative photoelectrocatalytic water remediation system for ammonia abatement

Ammonia, produced by human and animal activities, contributes to water and soil pollution because it is toxic for aquatic flora and fauna, and responsible for eutrophication. In this work, the photoelectrocatalytic (PEC) oxidation of ammonia is investigated employing a stainless-steel PEC reactor, consisting of a central UV Hg-vapor lamp surrounded by a metallic Ti mesh coated with a photoactive TiO2 film, directly grown by Plasma Electrolytic Oxidation (PEO). The so prepared TiO2 film is characterized by XRD, SEM, UV–vis DRS and IPCE. The PEC reactor operates at 4 V potential drop between the TiO2 coated mesh (photoanode) and the body of the reactor (cathode). The effect of the operating parameters (recirculation flowrate and air bubbling) and type of electrolyte solution (KCl or K2SO4) on the PEC performance are investigated in terms of ammonia conversion and selectivity to nitrite, nitrate and molecular nitrogen. Full ammonia conversion (XNH3) with a selectivity to molecular nitrogen up to 67 % are attained after 12 h in 5 mM KCl electrolyte solution. Nitrite is produced within the first 6 h irradiation and then fully converted into nitrate. By contrast, only a slight XNH3 (ca. 10 %) is observed in K2SO4 electrolyte solution. These results suggest that chlorine has a crucial role in the ammonia PEC oxidation process: photo-generated holes on the photoanode surface can oxidize Cl− to Cl• (electro-induced process), which is a reactive radical able to oxidase ammonia.

Nitrate pollution and its solutions with special emphasis on electrochemical reduction removal.

Nitrate pollution has become a serious environmental concern all over the world including in China due to the mismanagement of water resources and human activities. Agricultural runoff and industrial and nuclear waste are among the major sources of nitrate pollution. Consuming nitrate-rich water can cause many chronic diseases including digestive problems, which can lead to many types of cancer and other serious health issues. Denitrification is the natural process for nitrate reduction under aerobic conditions, but it cannot handle an excess of nitrate, so several methods have been adopted for nitrate removal, i.e., biological, chemical, physicochemical, and electrochemical reduction removal. Among all, electrochemical reduction removal is a cost-effective and environmental-friendly process. To obtain the maximal elimination efficiency ideal conditions of current intensity, pH, plate distance, initial nitrate concentration, and type of electrolyte solution should be studied for effective nitrate removal. Electrochemical reduction removal of nitrate involves the transfer of electrons and hydrogenation. Besides an efficient nitrate removal process, electrochemical reduction removal has some drawbacks like sludge formation, low selectivity for nitrogen, and production of brine that limit its long-term implementation. This review focused on nitrate pollution, previous nitrate removal strategies, and essential principles for understanding the mechanism of electrochemical reduction removal and controlling the products of the reaction.

Synergy of Mediator and LiNO3 in Electrolyte Solution and Analysis of Reaction Mechanisms on Li-Air Battery Performance

Li-air batteries (LAB) have a theoretical energy density of 3500 Wh kg− 1, overwhelming that of Li-ion batteries, due to the Li metal anode and atmospheric oxygen fed to the air electrode (AE). Therefore, they have been attracting much attention because of the potential longer cruising range of electric vehicles, although many problems are still left to be solved. The most serious one among them is large charge overvoltage of AE due to the low reactivity of discharge product Li2O2, which induces clogging of the air electrode during repeated discharge/charge cycles, decomposition of the electrolyte solution, and air electrode corrosion. Redox mediator (RM) to reduce the charge overvoltage is widely studied nowadays, while RM+ generated at AE diffuses and reacts with Li negative electrode to cause shuttle effect [1, 2]. In this study, we employed both RM to reduce the charge overvoltage and LiNO3 as an electrolyte salt in tetraglyme (G4)-based electrolyte solution to modify the Li surface into Li2O as a protector against shuttle effect [3]. We further applied RM-coating on AE to stabilize the cell performance and suppress the shuttle effect [4].AE consisted of Ketjen Black, PVDF binder, and MPT (10-methylphenothiazine) as an RM coated on a carbon paper substrate. Two types of electrolyte solutions were used: 1.0 M LiNO3/G4 with and without MPT. Three cell configurations with different combinations of AE and electrolyte solution were assembled: “RM-free” without MPT, “MPT-in-EL” containing MPT in the electrolyte solution, and “MPT-on-AE” with MPT coated on AE. The amount of RM dosed on AE was adjusted to be the same as that dissolved in the electrolyte solution of the MPT-in-EL cell. The cell components, AE of 2 cm2, a separator, a Li negative electrode and an electrolyte solution, were stacked and contained in an air-tight test cell, which was supplied with pure O2 gas of 1.0 mL s− 1 at 50 oC. The discharge/charge cycle test mode was constant current-constant capacity of 200 mA gKB − 1 and 500 mAh gKB − 1 between 2.0 V and 4.5 V. Figure 1 shows cross sections of discharge/charge voltage profiles at the midpoit of 250 mAh gKB − 1 of the three cells, RM-free, MPT-in-EL, and MPT-on-AE. MPT-on-AE revealed better performance with the less overvoltages in both charge and discharge than the others, although slight degradation was indicated even in MPT-on-AE by the 15th cycle. While we could conceive various causes for the degradation such as dissolution of the coated MPT, decomposition of MPT, and covering of AE with deposits, we started with the quantitative analysis of the dissolved MPT from the coated MPT. Figure 2 shows the results of colorimetric analysis of MPT on AE before discharge, which evaluates the dissolved amount of the coated MPT. A calibration line was obtained by dissolving MPT in 1.0 M LiNO3/G4 base solution. MPT sample was extracted from MPT-on-AE cell after 1 h rest following cell assembly by means of centrifugal separation. The results showed that half of the coated MPT eluted immediately. However, SEM-EDS analysis evidenced no trace of shuttle effect, suggesting local high concentration of the applied MPT near the AE. Other analytical results concerning degradation causes will be reported on the presentation.This study was supported by JST Project ALCA-SPRING (JPMLAL1301) and NIMS Joint Research Hub Program, Japan.[1] S. Ha et al., J. Mater. Chem. A, 5, 10609 (2017).[2] Y. Hayashi et al., J. Electrochem. Soc., 167, 020542 (2020).[3] M. Saito et al., J. Electrochem. Soc., 168, 010520 (2021).[4] Y. Hayashi, M. Saito et al., Electrochemistry, 89, 557-561 (2021). Figure 1

Electrochemical Synthesis of Ferrate (FeO4 2–) in Extreme Alkaline Medium and its Application in Dye Degradation

Synthesis of ferrate (FeO4 2−) from iron plate of transformer waste electrochemically in high alkaline medium and its application for dye degradation has been carried out. The effect of parameters such as time, NaOH concentration, type of electrolyte solution and ferrate stability were studied. The ferrate solution formed is dark purple in colour with a maximum wavelength of 505 nm. The ferrate was compacted by fresh drying to produce Na2FeO4 crystals and characterized by XRF, XRD and FT-IR techniques. The ferrate was applied to degrade methylene blue, methyl orange, rhodamine and remazol black B dyes. The results showed the highest degradation of dyestuff in methylene blue by 98% and COD reduction by 73.69% at pH 8, ferrate dose of 1.1 mg and contact time of 70 min. This shows that ferrate is an environmentally friendly material which can be used to degrade toxic dyes.

Cobalt nanoparticles introduced to activated carbon, CoNP/AC, as an effective electrocatalyst for oxidation and determination of methanol and ethanol

Addressed herein, a glassy carbon electrode was modified by cobalt nanoparticles stuck to the activated carbon (CoNP/AC/GCE). The electrocatalytic oxidation of methanol and ethanol on the surface of the modified electrode in acidic setting was investigated using cyclic voltammetry (CV), linear sweep voltammetry (LSV) and chronoamperometry as the first report. The effect of some parameters such as the potential scan rate, type of electrolyte solution and concentration effect of methanol and ethanol on the modified electrode was investigated. The kinetic parameters such as I0 (exchange current) and k0 (intrinsic heterogeneous rate constant) for methanol and ethanol were obtained through Tafel plots. By comparing the values obtained for I0 and K0, it would be clear that the effect of electrode modification on the electro-oxidation kinetics of ethanol and methanol is very significant. Finally, the response trends for electrooxidation of the alcohols by the CoNP/AC/GCE confirmed the quantitative application of the modified electrode.

Electrochemically Induced Bulk Nanobubbles

We describe the generation of bulk nanobubbles using electrolysis of aqueous alkaline, neutral, or acidic electrolytes. The technique can be used in either an undivided electrolytic cell to generate a mixture of bulk nanobubbles filled with different gases, for example, a hydrogen- and oxygen-filled bulk nanobubble suspension, or in a divided electrolytic cell to prepare separate hydrogen- and oxygen-filled bulk nanobubble suspensions. We systematically study the effects of the operating parameters on the characteristics of the nanobubbles formed and the effectiveness of their generation. A greater current input, longer operating time, higher electrolyte concentration, or lower water operating temperature enhance the production of nanobubbles. The type of electrolyte determines the colloidal stability of the nanobubbles formed. In all types of electrolyte solutions, the initial bubble size is of the order of 100 nm. Bulk nanobubbles in an alkaline electrolyte exist in a stable cluster form, but they dissociate into tiny primary nanobubbles of the order of 1 nm in neutral and acidic electrolytes, which is consistent with our previous findings on the clustering of bulk nanobubbles.

Analysis of Electrical Energy Contained in Vegetables

This study aims to determine the source of electrical energy in potatoes and lime. The method used is based on the principle that the salt content in potatoes is a solution, where salt is the solute and water is the solvent, so the ions can move freely. The movement of the ions in the potato can conduct electricity. For the contained acid lime affects the hardness of the composite, which affects the matrix and filler bonds. oxalic acid, which is in lime juice, is a type of electrolyte solution. In a voltaic cell, the electrolyte solution can function to deliver ions from the anode to the cathode so that it can produce electrical energy. Electrical energy is energy that is very important in life. Electrical energy is a basic human need so that potatoes and lime can be used as an alternative source of electrical energy.

Optimization of Voltammetric Determination of Dysprosium (III) Using Plackett-Burman and RSM-CCD Experimental Designs

This study was aimed to develop an optimized Dy determination method using differential pulse voltammetry (DPV). The Plackett-Burman (PB) experimental design was used to select significant factors that affect the electrical current response, which were further optimized using the response surface method-central composite design (RSM-CCD). The type of electrolyte solution and amplitude modulation were found as two most significant factors, among the nine factors tested, which enhance the current response based on PB design. Further optimization using RSM-CCD shows that the optimum values for the two factors were 0.1046 M and 0.1082 V respectively. When the optimum conditions were applied for Dy determination good recovery and precision were achieved with values of 91.58%, and 99.80%, respectively. The detection limit and quantification limit of the method were 1.4322 mg/L and of 4.7741 mg/L, respectively.

(Invited) Electrochemical Investigation of Hard Carbon Electrodes for Sodium-Ion Batteries Using a Coaxial Ring Reference Electrode

Sodium-ion batteries (NIBs) are an attractive alternative to lithium-ion batteries (LIBs) because of the natural abundance of sodium resources [1]. Owing to their similar working principles to LIBs, NIBs also offer the advantage of utilizing the same manufacturing protocols and methodology as LIBs, and as such minimal additional capital costs are required for existing LIB manufacturers to switch to NIB technology.Since the sodium storage mechanism of hard carbon (HC) was demonstrated by Stevens and Dahn in 2000 [2], it has become the state-of-the-art anode material for NIBs due to its good cycling stability, low working potentials, small voltage hysteresis and relatively low cost. However, the storage mechanism for high performance is not fully understood due to the complexity of the HC structure. The prevalent problem of under-estimated capacity of HC in half-cell tests indicates that this conventional test method requires improvement. Furthermore, half-cell studies are generally carried out in two-electrode configuration, where the counter electrode (CE) acts also as reference electrode (RE). This provides reliable results only if the passage of current does not significantly perturb the potential of the CE [3].In this study, we present an in-depth investigation of the electrochemical behavior of a range of HC-based working electrodes (WE) in three-electrode half-cell configuration, with a pure Na metal CE and a concentric Na metal coaxial ring RE. The use of a separate RE allows simultaneous data acquisition for both WE and CE, during galvanostatic cycling and electrochemical impedance spectroscopy measurements.Using this approach, the electrochemical performance, including cycling stability, rate capability and electrochemical impedance, is measured in a reliable manner to assess the capacity and cyclability of HC. In addition, the effect of four different types of electrolyte solution on the electrochemical behavior is analysed and discussed to inform electrolyte selection from a full-cell perspective (Figure 1). Reference s : [1] C. Vaalma, D. Buchholz, M. Weil, S. Passerini, Nat. Rev. Mat., 3 (2018) 18013.[2] J. R Dahn, D. A. Stevens, J. Electrochem. Soc., 4 (2000) 147.[3] R. Raccichini, M. Amores, G. Hinds, Batteries., 5 (2019) 12. Figure 1

Rapid synthesis of UiO-66 by means of electrochemical cathode method with electrochemical detection of 2,4,6-TCP

Electrochemical cathode methods were used to rapidly synthesize metal-organic frameworks (MOFs) UiO-66 and applied to electrochemical detection of 2,4,6-trichlorophenol (2,4,6-TCP). The effects of reaction voltage, time and temperature on the rapid synthesis of UiO-66 by means of electrochemical cathode method were systematically studied. It was confirmed that the UiO-66 synthesized by this method had small particle size with the diameter of 60 nm. Moreover, the UiO-66′s performance in electrochemical detection of 2,4,6-TCP was studied. The effect of the content for UiO-66 in the electrode, the types of electrolyte solution, and the pH value of the electrolyte solution on the electrochemical detection of 2,4,6-TCP were systematically investigated. The minimum detection limit of this experiment could reach 6.49 × 10−9 M (1.29 μg/L), which is significantly lower than the one specified by the national standard: 10 μg/L in drinking water. The limit of detection concentration is significantly lower than that of UiO-66-CPE prepared by conventional hydrothermal methods. Furthermore, in addition to 2,4-dichlorophenol (2,4-DCP) and phenol, some common cations and anions had only weak effect on the signals of 2,4,6-TCP with signal change less by 10%. This strategy provides specificity and sensitivity approach for the detection of 2,4,6-TCP and has promising applications in the water analysis field.

Highly Sensitive and Selective Detection of Arsenic Using Electrogenerated Nanotextured Gold Assemblage.

Arsenic is considered as a toxic heavy metal which is highly detrimental to ecological systems, and long-term exposure to it is highly dangerous to life as it can cause serious health effects. Timely detection of traces of active arsenic (As3+) is very crucial, and the development of simple, cost-effective methods is imperative to address the presence of arsenic in water and food chain. Herein, we present an extensive study on chemical-free electrogenerated nanotextured gold assemblage for the detection of ultralow levels of As3+ in water up to 0.08 ppb concentration. The gold nanotextured electrode (Au/GNE) is developed on simple Au foil via electrochemical oxidation–reduction sweeps in a metal-ion-free electrolyte solution. The ultrafine nanoscale morphological attributes of Au/GNE substrate are studied by scanning electron microscopy. Square wave anodic stripping voltammetry (ASV) response for different concentrations of arsenites is determined and directly correlated with As3+ detection regarding the type of electrolyte solution, deposition potential, and deposition time. The average of three standard curves are linear from 0.1 ppb up to 9 ppb (n = 15) with a linear regression coefficient R2 = 0.9932. Under optimized conditions, a superior sensitivity of 39.54 μA ppb–1 cm–2 is observed with a lower detection limit of 0.1 ppb (1.3 nM) (based on the visual analysis of calibration curve) and 0.08 ppb (1.06 nM) (based on the standard deviation of linear regression). Furthermore, the electrochemical Au/GNE is also applicable for arsenic detection in a complex system containing Cu2+, Ni2+, Fe2+, Pb2+, Hg2+, and other ions for the selective and sensitive analysis. Au/GNE substrate also possesses remarkable reproducibility and high stability for arsenic detection during repeated analysis and thus can be employed for prolonged applications and reiterating analyses. This electrochemically generated nanotextured electrode is also applicable for As3+ detection and analysis in a real water sample under optimized conditions. Therefore, fabrication conditions and analytical and electroanalytical performances justify that because of its low cost, easy preparation method and assembly, high reproducibility, and robustness, nanosensor Au/GNE can be scaled up for further applications.

Study on Transport Properties of Chitosan Membrane in Different Types of Electrolytes

In this study, the electrical properties of chitosan membrane in different types of electrolytes were investigated by analyzing the current-voltage (I‑V) curve. The membrane used was chitosan membrane 2%. The different electrolyte solutions used were KCl, HCl, MgCl 2 , CaCl 2 and AlCl 3 at concentrations of 0.025 M. The I-V experiments were done using a two-compartment cell, which contained two working electrodes made of platinum connected to a DC current source and two Ag/AgCl reference electrodes connected to a voltmeter. All experiments were conducted at an ambient temperature of 28.7 °C. Water uptake (hydrophilicity) and Fourier transform infrared (FTIR) measurements were also studied in this research. The I-V curves show the ohmic behavior of the membrane. The resistance of the membrane was higher in the electrolyte solutions with larger Stokes radii and lower in the electrolyte solutions with larger diffusion coefficients, except in the HCl solution. These results indicate that the I-V curve shapes are affected by the type of electrolyte solution used for the chitosan membrane transport. The hydrophilicity of the membrane was improved after exposure to the electrolyte solutions. The FTIR analysis revealed a new peak at about 677 cm -1 , which indicates the formation of C-Cl groups in the used membranes.

An experimental examination of the effect of the salt type on the chemo-osmotic, diffusive, and hydraulic parameters of Wakkanai mudstones

To better understand the groundwater flow and chemistry in argillaceous formations, the dependency of transport parameters such as permeability, diffusion coefficient, and chemical osmotic efficiency on each of the chemical species dominant in groundwater must also be understood. Despite its importance, however, little is known about the dependence of transport parameters on different types of groundwater. Thus, we investigated transport parameters of Wakkanai mudstones using three different types of electrolyte solutions. Here, we report the relationship among the solution salt type, solute concentration, transport parameters, and pore structure characteristics. Wide ranges in osmotic efficiency and intrinsic permeability, 0.0035–0.14 and 1.19 × 10–19 to 4.75 × 10–18 m2, respectively, reflect the difference in the solution composition based on the salt type, difference in solute concentration, and variation in the pore size distributions of Wakkanai mudstones. The effective diffusion coefficients with filtration effects, at 2.98 × 10–11 to 5.92 × 10–11 m2 s–1, vary depending on salt type, but remain invariant among samples, indicating no difference in fluid flow path associated with small values of osmotic efficiency. In contrast, the osmotic efficiencies are related to differences in salt concentrations. Our findings indicate that salt concentration and pore structure characteristics determine not only the semipermeability of the Wakkanai mudstones but also the diffusivity and permeability.

Novel Sensor Based on Poly (1,2‐Diaminoanthraquinone) for Individual and Simultaneous Anodic Stripping Voltammetry of Cd2+, Pb2+, Cu2+ and Hg2+

AbstractA novel electrochemical sensor based on glassy carbon electrode (GCE) modified by poly (1,2‐diaminoanthraquinone) (P1,2‐DAAQ) has been developed for individual and simultaneous determination of Cd2+, Pb2+, Cu2+ and Hg2+ using square wave anodic stripping voltammetry (SWASV). P1,2‐DAAQ was characterized by cyclic voltammetry (CV) and scan electron microscope (SEM). Several analytical parameters such as the type of electrolyte solution, polymer film thickness, metal deposition time and deposition potential were investigated and optimized. Optimal conditions were obtained by using five scan cycles for polymer synthesis and 120 seconds at −1.6 V for metal electrodeposition in acetate buffer solution. Good linear responses to Cd2+, Pb2+, Cu2+ and Hg2+ in the concentration range from 0 to 120 μg/L were obtained. The limit of detections (LOD) for simultaneous determination of Cd2+, Pb2+, Cu2+ and Hg2+ were 0.3 μg/L, 0.58 μg/L, 1.94 μg/L and 0.26 μg/L, respectively. The developed method was also applied for their detection in real water samples for which favorable results obtained compared with those obtained using inductively coupled plasma – optical emission spectroscopy (ICP‐OES).

Effect of electrolyte type on the morphology and crystallinity of TiO2 nanotubes from Ti-6Al-4V anodization

A good biocompatibility material such as Ti-6Al-4V is neededfor a dental application.However,Ti-6Al-4V has no antibacterial properties. Therefore Ti-6Al-4V is modified using anodizing methods to improve its anti-bacterial properties. One of the most influential factors in the anodizing process is the type of electrolyte solution. The influence of electrolyte solution based on glycerol and ethylene glycol to morphology and crystallinity of TiO2 nanotubes is studied. Smoothing and chemical polishing was performed against the Ti-4Al-6V plate. Then, the anodizing process for each plate in glycerol and ethylene glycol solution was done for 2 hours and 50 volts. Calcination was carried out for 3 hours at a temperature 500°C. FESEM-EDX and XRD were employed to analyze the surface morphology and crystallinity of TiO2 nanotubes. Viscosity of the electrolyte solution influenced surfacemorphology. Calcination process influenced crystallinity of TiO2 nanotubes.The average tube diameter and thickness from glycerolelectrolyte solution was 135.45 nm and 26.27 nm, while ethylene glycol was 68.52 nm and 35.62 nm respectively. The size of anatase crystal was 34.95 nm for glycerol and 44.77 nm for ethylene glycol.

High-Voltage Supercapacitors with Solutions Based on Adiponitrile Solvent

This paper focuses on high voltage supercapacitors with non-aqueous solutions. We used two types of electrolyte solutions: tetraethyl ammonium tetra fluoroborate (Et4NBF4) in adiponitrile (ADN) and a mixture of Et4NBF4 with tetraethyl ammonium hexa-fluorophosphate (Et4NPF6) in ADN. We show that supercapacitors based on activated carbon electrodes with electrolyte solutions comprising a mixture 0.7 M Et4NBF4 and 1 M Et4NPF6 in ADN display 100% efficiency over 10,000 cycles at 3.5 V and a current density of 2.5 mA cm−2 at room temperature. These supercapacitors works well even at 60°C.

Sub-100 nm features seamless roller mold using anodization and atomic layer deposition, for roll-to-roll nanoimprint lithography

The authors demonstrate an approach using direct anodization and atomic layer deposition (ALD) to prepare a sub-100 nm seamless roller mold for roll-to-roll nanoimprinting. In this approach, the roller mold is prepared by direct anodization of a cylindrical Al roller and the mold's pore size is further reduced by ALD process. This direct anodization of the Al rod as a roller mold creates a hard and durable seamless roller mold for nanoimprinting process. The pores were found to be uniformly anodized on the cylindrical Al rod and ordered pores can be obtained after multisteps anodization. The sub-100 nm pores are hexagonally packed with a diameter of 43.8 ± 3 nm (before pore-widening process) and interpore spacing of 87.0 ± 8 nm, estimated using an image processing software (imagej). The size, interpore spacing, and depth of the pores depend on the anodization conditions such as type of electrolyte solution, anodization voltage, and duration. The pores' size can be further reduced by ALD of TiO2 film which can coat conformally and precisely onto the cylindrical Al roller mold. The Al roller mold was nanoimprinted onto polycarbonate (PC) and creates PC nanopillars of desired dimensions depending on the anodization condition and the number of ALD cycles. Thus, sub-100 nm pattern resolution can be produced directly on a cylindrical object, achieving a high resolution and seamless roller mold for continuous nanoimprint processing.