Effect Of Electrolyte Type Research Articles

Electrochemical polishing properties of AlMgScZr alloy produced by laser powder bed fusion in NaNO3 and NaCl solutions

Electrochemical polishing (ECP) is a potential process to improve the surface quality of AlMgScZr alloy components produced by laser powder bed fusion (LPBF). Replacing traditional acid electrolytes with environment-friendly electrolytes is of great significance to the environment and safety. This work aims to study the ECP properties of LPBF AlMgScZr alloy in environment-friendly electrolytes (NaNO3 and NaCl solutions). In ECP, the electrochemical dissolution behavior of anode materials determines the polished surface quality. To this end, the effect of electrolyte type, uneven microstructure and applied current density on the anodic dissolution behavior of LPBF AlMgScZr alloy was examined experimentally. The results provide information about the suitability of the electrolytes selected for the ECP of LPBF AlMgScZr alloy, the dissolved surface quality in NaNO3 solution is significantly better because of the existence of a dense passive film. In addition, a microstructure analysis reveals that the bimodal distribution of grain size is the main factor leading to an uneven dissolved surface. Finally, the inner surface of LPBF AlMgScZr alloy channel was successfully polished in NaNO3 solution, the semi-welding particles were completely removed, and the surface roughness Sa was reduced from 20.73 μm to 2.48 μm.

Effect of Electrolyte Type on Supercapbatteries Based on Silicon as Anode and Cassava Tuber Activated Carbon as Cathode

Supercapbatteries are energy storage devices to solve low power and energy density problems. In this study, using cassava tubers activated carbon on the cathode side and silicon on the anode side. The electrodes are arranged in a coin cell device using various electrolytes 6M KOH and 1M Et4NBF4. The substrate used as the electrode is nickel foam with a drop-by-drop deposition technique. Microstructural properties of cassava tuber activated carbon and silicon were characterized using XRD, SEM, and FTIR. XRD showed cassava tuber-activated carbon was in an amorphous phase and the diffraction peak was similar to that of commercial activated carbon. On the other hand, silicon exhibits a crystalline phase. Based on SEM, the particle size distribution of cassava tuber activated carbon is 8.87μm, the average pore size is 0.988μm, and the percentage of porosity is 69.49%, while the particle size distribution of silicon is 0.065μm. The FTIR results show the formation of a C=C functional group which characterizes the nature of activated carbon at a wavelength of 1592.04 cm-1. GCD tests show that the electrochemical performance of super batteries is better when using 6M KOH electrolyte, specific capacitance, power density, and energy density 27.6F/g, 282.7W/kg, and 7.4Wh/kg.

Effects of electrolyte type and concentration on the anodic oxidation of 4H-SiC (0001) in slurryless electrochemical mechanical polishing

Slurryless electrochemical mechanical polishing (ECMP) is a promising polishing method for SiC wafers. To achieve a high polishing efficiency, low surface roughness, low cost, and low environmental load, the effects of the electrolyte type and concentration on the anodic oxidation and ECMP of the 4H-SiC (0001) surface were investigated. It is confirmed that the anodic oxidation rate is mainly affected by the conductivity but not the type of electrolyte, and the electric conductivity affects the oxidation current that determines the anodic oxidation rate and performance. The anodic oxidation rate of the SiC surface was restricted by the conductivity at low electrolyte concentrations, and the anodic oxidation rate increased with increasing electrolyte concentration in this stage. The anodic oxidation rate decreased with increasing electrolyte concentration after the conductivity exceeded ∼0.1 S/m, owing to the increasing resistance of the generated oxide layer. Overall, the anodic oxidation uniformity of the SiC surface increased with increasing electrolyte concentration owing to the increasing anodic oxidation current density. The changes in material removal rate of ECMP with increasing electrolyte concentration were consistent with those of the anodic oxidation rate, while the surface roughness obtained by ECMP always decreased with increasing electrolyte concentration. This study provides a new way to improve the performance of slurryless ECMP.

Review of microarc oxidation of titanium implant

Titanium and titanium alloys are the most commonly used implant materials, but they are biologically inert. These materials lack rapid osseointegration and resistance to bacterial infections, problems that remain unsolved. The preparation of titanium dioxide coatings by microarc oxidation improves both the biocompatibility of titanium-based materials and their resistance to corrosion during long-term presence in the body. This paper discusses and summarizes the mechanisms of microarc oxidation and some classical models that need to be developed to provide a better understanding and guidance for future research. Subsequently, the effects of electrolyte type, additives, and surface modification of the microarc oxidized coating on the coating morphology were analyzed in detail. In addition, biological applications of microarc oxidation coatings are analyzed, including antimicrobial properties, osseointegration, hydrophilicity, corrosion resistance, and wear resistance.

Correlating electrochemical biochar oxidation with electrolytes during biochar-assisted water electrolysis for hydrogen production

Biochar-assisted water electrolysis (BAWE) for hydrogen production is employed to reduce energy consumption by replacing the oxygen evolution reaction (OER) with thermodynamically more favorable biochar oxidation reaction (BOR). Electrolyte, as a carrier to dissolve the biochar particles and form conductive solution, is essential for the transfer and transformation of biochar particles and free radical precursors. Herein, the effects of electrolyte type, concentration, and pH on the BOR performance of BAWE system were investigated. Results show that 1 M KOH solution as an electrolyte was more suitable for the BAWE system, and the BOR of the alkaline BAWE system had the higher electrochemical activity (E10 = 1.649 V vs RHE, 56 mV∙dec−1) compared with the OER in conventional water electrolysis system (E10 = 1.982 V vs RHE, 189 mV∙dec−1). The anion adsorption phenomenon appeared in acidic media restricted the BOR kinetics. In addition, the diffusion coefficient of anodic reaction components showed a first decrease and then increase trend when the pH increased. And the diffusion coefficient reached the maximum value of 3.11 × 10−3 cm2∙s−1 at pH of 13.98, which was favorable for accelerating the diffusion of reaction components from the bulk solution to the electrode surface. This work can provide guidance for further improving the diffusion of reaction components, the biochar oxidation rate and hydrogen production in BAWE process.

Determination of naproxen by using differential pulse voltammetry with poly (aniline-2-sulfonic acid) modified boron doped diamond electrode

In this study, an electrochemical sensor based on a boron doped diamond electrode (BDDE) was developed for the determination of naproxen (NAP) using a poly(aniline-2-sulfonic acid)/boron doped diamond electrode, p(A2SA/BDDE). Polymerization of A2SA was conducted in a water/acetonitrile (1:1) mixture containing 0.1 M sodium perchlorate (NaClO4) on bare BDDE and the electrochemical properties studied by cyclic voltammetry in ferricyanide/KNO3 solution. The prepared p(A2SA/BDDE) was used for detection of NAP. Effects of parameters such as monomer type and concentration, the number of cycles, and scan rate were investigated using differential pulse voltammetry (DPV) in phosphate buffer containing 0.75 mM NAP. The effect of electrolyte type and pH on DPV responses to NAP were also studied. The oxidative current peak stem from NAP concentration observed at 1.1 V potential. A linear calibration curve was obtained in the range of 0.05–1.00 mM NAP concentration. Correlation coefficient (R2), detection limit, and quantification limit were calculated as 0.9944, 0.0328 mM, and 0.1093 mM, respectively. In conclusion, it may be claimed that the modified electrode constructed in this work can be used successfully as a naproxen-selective membrane due to its ease of preparation, high R2 value, and good reproducibility.

The Design of a Remediation Device for Heavy Metal Contaminated Soil Under Digital Economy

Since entering the new era, the economy has grown rapidly and the economic strength has improved significantly, but it is accompanied by resource and environmental problems caused by the high pollution and high energy consumption growth model. Realizing the transformation of economic development from “incremental” to “increasing quality” and promoting economic green transformation has become one of the main development goals of China in the next stage. With the rapid development of China’s social economy, the changes of industrialization, urbanization and agricultural intensification are getting faster and faster. The discharge of industrial “three wastes” and urban domestic wastewater has gradually increased, and a large amount of chemical fertilizers and pesticides have been applied to rural arable land. It accelerates soil heavy metal pollution. Electrodynamic remediation technology, as an emerging soil in situ remediation technology, has attracted wide attention due to its advantages of wide range of pollutant removal, low cost and good effect. In this paper, a remediation device for heavy metal-contaminated soil is designed based on electrodynamic remediation technology. That is, on the basis of the digital economy, an electrolyte circulation mechanism with high adsorption of heavy metal ions is introduced. In this paper, the feasibility of electrokinetic remediation of the contaminated soil was investigated, and the effects of electrolyte type, voltage, and remediation time on the removal of heavy metals were studied. The following results were obtained through a series of experimental studies: the pH values of region A in E1, E2, and E3 were 3.24, 3.18, and 3.09, respectively. The current peak values of E1, E2 and E4 are 0.44, 0.68 and 0.75 mA respectively. E4 had the best adsorption effect on heavy metal cadmium ions, with an average adsorption rate of 7.3%. The results show that the electrodynamic remediation device can effectively remove heavy metals in soil. It can also recycle the electrolyte solution, which is an environmentally friendly repair device.

Perspective on the passivity of Ti6Al4V alloy in H2SO4 and NaOH solutions

In this study, the effects of electrolyte type and its respective concentration on the corrosion behavior and passive film properties of the Ti6Al4V alloy were investigated. To do so, potentiodynamic polarization test, chronoamperometry method, X-ray diffraction (XRD), Mott-Schottky analysis and point defect model (PDM) were employed. The results indicated that the alloy exhibits superior corrosion resistance in alkaline electrolytes compared to acidic solutions. Moreover, increasing the electrolyte concentration results in inferior corrosion properties in both acidic and basic solutions, which is in agreement with XRD results. According to the PDM, the formation of more intact passive layers can be attributed to lower diffusivity of point defects in the resulting anodic films.

Experimental study on thermally enhanced permeability of rock with chemical agents

Previous researches focused on dry sample thermal treatment to enhance rock permeability indicate that thermal treatment can be a novel stimulation technique for geothermal and hydrocarbon reservoirs development. The mechanicm of thermal permeability enhancement depends on the generation of microcracks by thermal cracking. In this study, chemical solutions were introduced on sandstone rock samples and observed that they can be used to control thermal permeability enhancement. Sandstone specimens with the same order of permeability were saturated with different salt solutions and heated to different temperatures. The results quantify permeabilities and porosities of specimens saturated with electrolyts over them without chemical treatment but heated to the same temperature. The KCl solution had the largest effect on permeability enhancement for the tested rock and showed a tenfold increase in permeability, and followed by NaCl and K2CO3 solutions. However, CaCl2 solution and distilled water had negative effects. Laboratory results also revealed a positive correlation between some chemical concentration with the permeability increment of rock. The effects of electrolyte type and concentration on thermally permeability enhancement of the tested rocks were determined and a statistical model was fitted. The results show that the permeability increment follows an exponential growth with temperature when the rock was heated over the threshold temperature of thermal cracking. Introducing specific chemical species into a low-permeability formation and heating the formation beyond the threshold temperature of rock thermal cracking will be a promising way to further enhance formation permeability.

Surface modified carbon nanomats provide cationic and anionic rectifier membranes in aqueous electrolyte media

Carbon nanofibers (CNFs) are converted into anionic current rectifiers by surface modification with amine functional groups using hydrothermal means (forming modified CNFs, with generation-3 poly (propylene imine) dendrimer, urea and boric acid). To confirm surface charge, morphological changes and carbon nanomat thickness, zeta potential analysis, transmission electron microscopy (TEM) and scanning electron microscopy (SEM), were used. When a dispersion of surface modified carbon nanofibers in DMF is drop-cast asymmetrically to form nanomats onto laser drilled microholes (5, 10, or 20 µm diameter) of poly (ethylene terephthalate) substrates and immersed into aqueous electrolyte solutions, anionic diode behaviour is observed (in contrast to pristine carbon nanofibers, which exhibit cationic diode behaviour). The effects of electrolyte type, ionic strength, and microhole diameter on ionic diode performance were investigated using cyclic voltammetry, chronoamperometry, and impedance spectroscopy. Future applications in desalination are proposed.

The Use of Succinonitrile as an Electrolyte Additive for Composite-Fiber Membranes in Lithium-Ion Batteries

In the present work, the effect of temperature and additives on the ionic conductivity of mixed organic/ionic liquid electrolytes (MOILEs) was investigated by conducting galvanostatic charge/discharge and ionic conductivity experiments. The mixed electrolyte is based on the ionic liquid (IL) (EMI/TFSI/LiTFSI) and organic solvents EC/DMC (1:1 v/v). The effect of electrolyte type on the electrochemical performance of a LiCoO2 cathode and a SnO2/C composite anode in lithium anode (or cathode) half-cells was also investigated. The results demonstrated that the addition of 5 wt.% succinonitrile (SN) resulted in enhanced ionic conductivity of a 60% EMI-TFSI 40% EC/DMC MOILE from ~14 mS·cm−1 to ~26 mS·cm−1 at room temperature. Additionally, at a temperature of 100 °C, an increase in ionic conductivity from ~38 to ~69 mS·cm−1 was observed for the MOILE with 5 wt% SN. The improvement in the ionic conductivity is attributed to the high polarity of SN and its ability to dissolve various types of salts such as LiTFSI. The galvanostatic charge/discharge results showed that the LiCoO2 cathode with the MOILE (without SN) exhibited a 39% specific capacity loss at the 50th cycle while the LiCoO2 cathode in the MOILE with 5 wt.% SN showed a decrease in specific capacity of only 14%. The addition of 5 wt.% SN to the MOILE with a SnO2/C composite-fiber anode resulted in improved cycling performance and rate capability of the SnO2/C composite-membrane anode in lithium anode half-cells. Based on the results reported in this work, a new avenue and promising outcome for the future use of MOILEs with SN in lithium-ion batteries (LIBs) can be opened.

Influence of Electrolyte Type, pH, Temperature and Aging on the Viscosity Property of Okra Gum as a Suspending Agent in Paracetamol Suspension

The purpose of this study was to investigate the influence of electrolyte type, pH, temperature and aging on the viscosity property of okra gum using paracetamol as model drug. Paracetamol (125 mg/ 5 mL) suspension containing okra gum particles of undersize 180 µm as suspending agent was formulated. Similar suspension of paracetamol was formulated using tragacanth gum as a suspending agent for comparison. Effect of electrolyte type, pH, temperature and aging on the viscosity property of okra gum in paracetamol suspension was evaluated using standard methods. Addition of electrolytes, changes in pH, increase in temperature and increase in storage time were shown to decrease the viscosity of the paracetamol suspension. The effect of temperature and aging on the viscosity of the suspension formulation containing okra gum was more pronounced than on the formulation containing tragacanth gum. Conversely, the effect of alkaline pH and type of electrolyte on the viscosity of the suspension formulation containing tragacanth gum was more pronounced than on the formulation containing okra gum. On the basis of these, formulators and caregivers may consider these factors when designing or using pharmaceutical suspensions containing natural gums such as okra and tragacanth as viscosity enhancing agents.

Applications of Factorial Design in Dye-Sensitized Solar Cells with Titanium-Silicon Dioxide as Photoanode

Titanium-silicon dioxide (TiO2-SiO2) nanocomposite thin films have been synthesized by sol-gel process as a photoanode in dye-sensitized solar cells (DSSC). The photovoltaic performances, i.e. JSC, VOC, FF, and η were explored using I–V measurement. The effects of electrolyte type (iodolyte, PAN-based gel polymer: E1 and E2) and the preparation of photoanode (annealed temperature) on the performance of DSSC was significantly studied using factorial design methodology. It reveals that in factorial design, both main factors (electrolyte type and annealed temperature) and the interaction between these two factors were found statistically significant. It means that the effects of electrolyte type and annealed temperature, are the significant variables influencing the energy efficiency, as well as the two-factor interactions of electrolyte type and annealed temperature. The determination coefficient (R2) also in good alliance, which confirms that there exist a high association between these factors with the energy efficiency of DSSC. The optimum conditions of the energy efficiency occurs for a PAN-based gel polymer E2 when the photoanode was annealed at 350C, exhibits a highest energy efficiency of 1.5%.

Switching Anionic and Cationic Semipermeability in Partially Hydrolyzed Polyacrylonitrile: A pH-Tunable Ionic Rectifier.

Membrane materials with semipermeability for anions or for cations are of interest in electrochemical and nanofluidic separation and purification technologies. In this study, partially hydrolyzed polyacrylonitrile (phPAN) is investigated as a pH-switchable anion/cation conductor. When switching from anionic to cationic semipermeability, also the ionic current rectification effect switches for phPAN materials deposited asymmetrically onto a 5, 10, 20, or 40 μm diameter microhole in a 6 μm thick polyethylene-terephthalate (PET) film substrate. Therefore, ionic rectifier behavior can be tuned and used to monitor and characterize semipermeability. Effects of electrolyte type and concentration and pH (relative to the zeta potential at approximately 3.1) are investigated by voltammetry, chronoamperometry, and impedance spectroscopy. A computational model provides good qualitative agreement with the observed electrolyte concentration data. High rectification effects are observed for both cations (pH > 3.1) and anions (pH < 3.1) but only at relatively low ionic strengths.

Effect of Electrolyte Type on Properties of Diamond - like Carbon Films Electrodeposited onto N-Type Si Substrate, Application as Electrode for Supercapacitors

In this work, diamond-like carbon (DLC) thin films were successfully electrodeposited onto n-type Si(100) substrate using three types of organic electrolyte (as carbon precursor) namely dimethylsulfoxide (C2H6OS), acetonitrile (CH3CN) and ethanol (CH2CH2OH). The effect of electrolyte type on morphological, structural and chemical properties was investigated using Raman spectroscopy, scanning electron microscopy (SEM), energy dispersive X-ray and X-ray diffraction (XRD). The DLC films Raman spectra show the films are amorphous and the more disorder film is obtained by dimethylsulfoxide (DMSO). These results were confirmed by energy dispersive X-ray and XRD techniques. The SEM observations show that the DLC films were uniformly deposited on the whole Si substrate surface and that it contains of compact and small spherical grains with uniform distribution. Moreover, it was found that the DLC film obtained from a DMSO electrolyte is more conductive, which enables it to be more favorable for the fabrication of a good supercapacitor electrode. The study of electrochemical properties of Si and DLC/Si electrode has shown that the deposition of DLC films from DMSO electrolyte remarkably improves the electrochemical activity of Si electrode and the specific capacitance. Indeed, it allows to get a specific capacitance of 17 mF/cm2 in KOH aqueous solution at scan rate of 5 mV/s with capacitance retention of 95% after 4000 cycles. Thus, the deposition of DLC film from DMSO electrolyte onto silicon substrate can be considered as a simple and economical method to fabricate of a performant electrode of supercapacitors.

Scanning electrochemical microscopy imaging of poly (3,4-ethylendioxythiophene)/thionine electrodes for lactate detection via NADH electrocatalysis

Herein we report the use of scanning electrochemical microscopy (SECM) together with electrochemical and spectroscopic techniques to develop and characterise a stable and uniformly reactive chemically modified platinum electrode for NADH electrocatalysis. In order to achieve this, a range of different approaches for thionine entrapment within an electropolymerised poly (3,4-ethylendioxythiophene) (PEDOT) film were evaluated using SECM imaging in the presence of NADH, demonstrating the uniformity of the reactive layer towards NADH oxidation. The effect of electrolyte type and time scale employed during PEDOT electropolymerisation was examined with respect to thionine loading and the resulting charge transport diffusion coefficient (DCT) estimated via chronoamperometry. These studies indicated a decrease in DCT as thionine loading increased within the PEDOT film, suggesting that charge transport was diffusion limited within the film. Additionally, thionine functionalised nanotubes were formed, providing a stable support for lactate dehydrogenase entrapment while lowering the rate of thionine leaching, determined via SECM imaging. This enabled lactate determination at Eapp = 0.0 V vs Ag/AgCl over the range 0.25–5 mM in the presence of 1 mM NAD+.

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.

The Effect of Electrolyte Type and Concentration on the Release of Cd, Cu, Ni, and Zn in Some Contaminated Calcareous Soils

ABSTRACTThis paper reports the results of desorption experiments of cadmium (Cd), copper (Cu), nickel (Ni), and zinc (Zn) from some contaminated calcareous soils under four electrolyte types (CaCl2, MgCl2, NaCl and Na2SO4) with different electrolyte concentrations (0.5, 4 and 10 mM). Among electrolytes, CaCl2 significantly released more metals from soils. There was a negative relationship between total Cu and Zn content and percentage of Cu and Zn released (average of electrolyte concentrations) using CaCl2 solution, indicating a higher Cu and Zn released when their total content was low. Generally, Cd, Cu, and Zn speciation was affected by both type of electrolytes and their concentrations, whereas Ni speciation stayed mostly stable and was almost unaffected by applied solutions. It can be suggested that beside competition with cations, chloro-complexation is important parameter in Cd release, while CuOH+, and to some extent ZnOH+ are important species affecting release of Cu and Zn. The distribution coefficient (Kd) values for each metals greatly varied with the types of electrolytes and electrolyte concentration. On the basis of average percentage of metal released under different electrolytes and concentrations the following sequences was found: Cd > Cu > Ni > Zn. The results are important in understanding the mobility of metals under different solutions and indicating that, Cd and Zn soils may pose a higher and lower mobility and ecological risk in contaminated calcareous soils, respectively.

도금전해액의 종류에 따른 수지상 구리 분말의 형상 및 표면적 특성

도금전해액의 종류에 따른 수지상 구리 분말의 형상 및 표면적 특성

Preparation And Electrochemical Characterization Of PANI/PVA And PANI/Zr/PVA Composites For Supercapacitor Application

In the present work, the PANI and PANI/Zr composite powders were synthesized by the method of chemical polymerization in the inorganic acid medium. The morphology of prepared composites demonstrates fiber-like structure revealed by scanning electron microscopy. The value of the specific surface area estimated by the BET technique depends on the type of the composite powder and was found to be 66.8 and 142.05 m 2 /g for PANI and PANI/Zr respectively. UV–Vis spectroscopy was employed to characterize the optical properties of the synthesized powder composites. The incorporation of zirconium gives rise to the red shift of π– π* transition of pristine PANI. The synthesized composite powders were used for preparation of PANI/PVA and PANI/Zr/PVA composites which electrochemical properties were compared in different electrolytes: 0.5 M KOH, 0.5 M NaCl and 0.5 M H2SO4. Excellent electrochemical reversibility was found out for both PANI/PVA and PANI/Zr/PVA composites. Effect of electrolyte type and current value on the specific capacitance of the prepared composites was observed.