Effect Of Electrochemical Parameters Research Articles

A New Electrochemical Sensor for the Detection of Azithromycin using Screen‐Printed Carbon Electrode Modified with Boron‐Doped Diamond Nanoparticles and Reduced‐Graphene Oxide

AbstractExcessive use of azithromycin (AZM) is associated with resistance and negative impacts on the environment. Therefore, this study aimed to develop an electrochemical sensor for AZM. The screen‐printed carbon electrode (SPCE) modified with boron‐doped diamond nanoparticle (BDDNP) and reduced‐graphene oxide (rGO) was successfully applied to measure the AZM concentration. The morphology of the modified electrode was characterized by scanning electron microscopy‐energy dispersive X‐ray (SEM‐EDX). Furthermore, the effect of electrochemical parameters, such as signal per background, scan rate, and selectivity was determined. The results showed that under optimum conditions, the plot of AZM demonstrated linearity in the range of 30–100 μM with a limit of detection (LOD) at 1.6 μM. The repeatability and recovery were also investigated, and the sensor was applied to real samples obtained from hospital wastewater. A remarkable 93.27 % recovery rate and excellent precision were recorded with an %RSD of 2.41 %. This study underscores the potential of SPCE modified with rGO/BDDNP for accurate and reliable measurement of AZM levels, showcasing great applicability in addressing the challenges associated with monitoring AZM in various environmental settings.

Insight into ettringite induced concrete crack healing by electrodeposition: Effects of electrochemical parameters and numerical simulations

The rapid healing of concrete through electrochemical deposition induced by ettringite has been recently proposed. In this paper, the rapid healing mechanism of this new approach is further disclosed via experimental investigations and numerical simulations. Nineteen groups of electrochemical deposition experiments are conducted with different electrochemical parameters. When the concentration ratio of calcium-aluminum is 2.5 and the current density is 2.0 A/m2, cracks can be healed within a day, with a permeability coefficient of 7.02 × 10⁻⁷ cm/s achieved at 7 days. Upon increasing the current density, the ettringite crystal gradually changes from fine needle-like to slender fibrous, and the deposited materials demonstrate refined pore sizes, with the highest proportion found in the 2–50 nm range. Meanwhile, the repair process is quantitatively demonstrated by incorporating the numerical model of the ion transport and the nucleation theory together. When the calcium-aluminum ratio is 2.5, the average nucleation frequency of ettringite is maximized, indicating the most favorable repair effect. Compared to the deposition products Zn(OH)2 and Mg(OH)2, ettringite exhibits higher values of nucleation frequency, enabling a more rapid repair effect.

Effect of electrochemical parameters on wear and tribocorrosion capabilities of the PEO coatings generated through pulsed waveforms on AZ91 magnesium alloy

In this study, PEO coatings were produced on AZ91 Mg alloy using pulsed waveforms at different electrical parameters such as type (unipolar and bipolar), cathodic duty cycle (20 and 40 %), and voltage amplitude (350 and 400 V) to assess wear and tribocorrosion resistance. The coating bath contained NaAl2O4 and NaF. The coating phase composition, microstructure, and chemical composition of the coatings were evaluated using GXRD, SEM, and EDS. Dry wear behavior was studied using the reciprocating ball-on-flat device, while tribocorrosion behavior was evaluated by immersing the coated specimens in 3.5 wt% NaCl solution and reading the OCP before, during, and after sliding. The worn area in both cases was also examined. The results showed that the bipolar waveform with the higher cathodic duty cycle (40 %) provided the best tribocorrosion and wear performance by forming MgF2 (as a corrosion-resistant phase) and MgAl2O4 (as a hard phase). At all three waveforms, the higher coating voltage (i.e. 400 V) enhanced the wear and tribocorrosion resistance by forming thicker coatings with higher amounts of MgF2 and MgAl2O4 phases.

Effects of Electrochemical Parameters on the Electropolymerisation of 2-nitro-p-phenylenediamine in Caustic and Neutral Solutions

Effects of Electrochemical Parameters on the Electropolymerisation of 2-nitro-p-phenylenediamine in Caustic and Neutral Solutions

Effect of electrochemical polishing on surface quality of nickel-titanium shape memory alloy after milling

Nickel-titanium shape memory alloys have been widely used in medical fields due to their unique shape memory effect, superelasticity, corrosion resistance and biocompatibility. However, there are still many processing difficulties to achieve required machined surface quality due to their high toughness and low elasticity. This paper proposes a sequential processing operations including milling, burnishing and electrochemical polishing. The effects of electrochemical parameters on surface quality, such as surface roughness, work hardening and surface grain size, are investigated in detail using orthogonal experiment. It is found that the electrochemical polishing parameters have the most significant effect on improving the surface roughness. With adjusting electrochemical polishing parameters, the surface roughness can be reduced to one tenth of the original value obtained by milling operations. Moreover, the current density in electrochemical polishing has more important influence on the surface quality than the distance and polishing time does, respectively. The conditions of 1.5A/cm2 current density, 7cm electrode distance and 20s polishing time can obtain the lower surface roughness, hardening degree and the larger grain size. The effects of electrochemical parameters on surface roughness, work hardening and grain size are related to each other. The degree of work hardening can be qualitatively estimated by surface roughness and grain size to avoid damage to the machined surface.

Effect of electrochemical parameters and working electrode material on the characteristics of bismuth (III) oxide obtained by electrodeposition and thermal oxidation

Bismuth (III) oxide was obtained by electrodeposition, followed by thermal treatment in air environment. The applied electrodeposition current density and electrode potential affect the surface morphology and chemical composition of the obtained deposit before and after the thermal treatment at 350?C, as well as its crystal structure after the thermal treatment at 350?C. The listed parameters affect the deposit?s morphology after the thermal treatment at 600?C, but do not affect its chemical composition and crystal structure. The conclusion is that investigated working electrode material does not affect the characteristics of synthesized material.

Controllable electrodeposition of ZnO nanorod arrays on flexible stainless steel mesh substrate for photocatalytic degradation of Rhodamine B

Well-aligned single-crystalline ZnO nanorod arrays (ZNRAs) were prepared on flexible stainless steel mesh (SSM) substrate in large-scale by using a direct electrodeposition method. The effects of electrochemical parameters, such as applied potential, applied nucleation potential time, substrate pretreatment, electrodeposition duration and times, on the orientation, morphology and density of ZNRAs were systematically studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM) and the selected area electron diffraction (SAED). The results showed that ZNRAs on SSM substrate with [001] preferred orientation and well crystallization were obtained by controlling the applied potential in the range of −0.9 to −1.1V. The density of ZNRAs could be increased obviously by applying a nucleation potential (−1.3V for more than 10s before deposition) or by means of substrate pretreatment (the SSM immersed in zinc acetate colloid for more than 10min before deposition), meanwhile, the deposited ZNRAs also had small average diameter (<46±4nm), narrow size distribution and good orientation. In addition, it was also found that the average diameter of ZNRAs could be increased from 89 to 201±5nm by extending the electrodeposition duration from 1800 to 7200s, and the length of rods was from 0.8 to 2.2±0.1μm when the times of the electrodeposition from one to six times. Furthermore, the band gap energy (Eg) of as-prepared ZNTAs was not closely related to the electrodeposition times (only changed from 3.30 to 3.32eV). The ZNRAs prepared with more electrodeposition times showed enhanced photocatalytic performance under the UV-lamp for degradation of Rhodamine B. The degradation efficiency of ZNRAs improved from 89.4% to 98.3% with the deposition times from one to six times.

Effect of electrochemical parameters on the formation of anodic films on commercially pure titanium by plasma electrolytic oxidation

In this paper the effect of current density and anodizing potential on both surface morphology and internal structure of Ti anodic coatings were studied. Anodic films were obtained in galvanostatic and potentiostatic modes. Anodic films obtained at galvanostatic mode do not show significant changes in surface morphology, exhibiting a porous structure of circular pores. Nevertheless, the anodic films obtained at potentiostatic mode show two different morphologies depending of the potential applied. The chemical composition of the coatings assessed by micro-Raman spectroscopy shows that the coatings are composed mainly of titanium dioxide in anatase phase with presence of some constituents of the anodizing solution as evidenced by EDS. Furthermore, EIS analysis allowed to correlate internal structure changes in the coatings with changes in the electrical parameters of the layers forming the coating.

Development and characterization of electro deposited Nickel–Titanium Carbo Nitride (TiCN) metal matrix nanocomposite deposits

The effects of electrochemical parameters on the development of Nickel–Titanium Carbo Nitride (TiCN) metal matrix nanocomposite deposits were studied in Watts type nickel bath. The extent of TiCN incorporation into nickel matrix was studied with respect to TiCN particle concentration ranged between 2 and 15 g l − 1 , current density ranging from 2 to 10 Ad m − 2 , bath pH from 2 to 5 and a bath temperature range of 30–70 °C. Effects of TiCN particle incorporation on surface morphology, crystal structure, micro hardness, wear resistance and corrosion resistance of the composite deposits were studied. It was found that the incorporation of TiCN particles in the composite deposit increased with increasing TiCN content in the bath. Operating the bath with 6 g l − 1 TiCN particle concentrations at 4 Ad m − 2 , at 50 °C, and at pH 4 gave about 23.9 vol.% TiCN incorporation in the composite deposit. The results showed that the codeposition of TiCN particles with nickel modified the surface morphology of nickel and its preferred orientation. The Ni–TiCN composite deposits showed better corrosion resistance in 3.5 wt.% NaCl solution and high hardness and wear resistance than nickel electrodeposited under the same conditions.

Effect of Electrochemical Parameters on the Morphology and Ca/P Ratios of Deposited Apatite Coatings on Metal and Alloy Substrates

Calcium phosphates were electrochemically deposited on stainless steel, titanium, and copper metal substrates with modified simulated body fluid of pH adjusted from 4 to 10 at 25 - 65 °C while maintaining cathodic potentials at -1.2 to -1.8 V (vs. SCE). The coatings were characterized by powder x-ray diffraction, scanning electron microscopy, and linear polarization corrosion method. X-ray diffraction show depositions in electrolytic solutions of pH below 8 contain hydroxyapatite along with a significant amount of impurities; however at pH 10 the deposit primarily consists of hydroxyapatite with little impurity, ideal for orthopedic implants. As the pH increases the morphology changes as shown with scanning electron microscopy, from an amorphous to a dense crystalline phase. Linear polarization and Tafel plot show surgical stainless steel has the most improvement in anticorrosion when coated with hydroxyapatite.

Electrochemical degradation of crystal violet with BDD electrodes: Effect of electrochemical parameters and identification of organic by-products

This paper explores the applicability of electrochemical oxidation on a triphenylmethane dye compound model, hexamethylpararosaniline chloride (or crystal violet, CV), using BDD anodes. The effect of the important electrochemical parameters: current density (2.5–15 mA cm −2), dye concentration (33–600 mg L −1), sodium sulphate concentration (7.1–50.0 g L −1) and initial pH (3–11) on the efficiency of the electrochemical process was evaluated. The results indicated that while the current density was lower than the limiting current density, no side products (hydrogen peroxide, peroxodisulphate, ozone and chlorinated oxidizing compounds) were generated and the degradation, through •OH radical attack, occurred with high efficiency. Analysis of intermediates using GC–MS investigation identified several products: N-methylaniline, N, N-dimethylaniline, 4-methyl- N, N-dimethylaniline, 4-methyl- N-methylaniline, 4-dimethylaminophenol, 4-dimethylaminobenzoic acid, 4-( N, N-dimethylamino)-4′-( N′, N′-dimethylamino) diphenylmethane, 4-(4-dimethylaminophenyl)- N, N-dimethylaniline, 4-( N, N-dimethylamino)-4′-( N′, N′-dimethylamino) benzophenone. The presence of these aromatic structures showed that the main CV degradation pathway is related to the reaction of CV with the •OH radical. Under optimal conditions, practically 100% of the initial substrate and COD were eliminated in approximately 35 min of electrolysis; indicating that the early CV by-products were completely degraded by the electrochemical system.

Effect of Electrochemical Parameters on the Morphology and Ca/P Ratios of Deposited Apatite Coatings on Metal and Alloy Substrates

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Parametric Approach Model for Determining Electrical Discharge Machining (EDM) Conditions: Effect of Cutting Parameters on the Surface Integrity

Electrical discharge machining (EDM) is one of the earliest non-traditional machining processes. EDM process is based on thermoelectric energy between the work piece and an electrode. There are various types of products which can be produced by using the EDM such as dies and moulds. Today many parts used in aerospace and automotive industry and also final processes of surgical components can be finished by EDM process. A simple and easily understandable model was proposed for predicting the relative importance of different factors (composition of the steels and Electro Discharge Machining processing conditions) in order to obtain an efficient pieces. A detail application on the tool steels machined by EDM was given in this study. This model is based on thermal, metallurgical and mechanical and also in situ test conditions. It gives detail information on the effect of electrochemical parameters on the surface integrity and sub-surface damage of the material (Heat Affected Zone, HAZ), the level of residual stresses, and the surface texture. This approach is an efficient way to separate the responsibilities of the steel maker and machining process designer for increasing the reliability of the machined structures.

Seed layer-free electrodeposition of well-aligned ZnO submicron rod arrays via a simple aqueous electrolyte

A potentiostatic electrodeposition technique was used to directly fabricate large-scale, well-aligned, and single-crystalline submicron ZnO rod arrays on tin doped indium oxide glass substrate without a pre-prepared seed layer of ZnO from an aqueous solution only containing zinc nitrate. The effects of electrochemical parameters, such as electrodeposition potential, electrodeposition duration, solution temperature, and precursor concentration, on the orientation, morphology, aspect ratio, and growth rate of ZnO rod arrays were systematically investigated. Results show that submicron ZnO rod arrays with (0 0 0 2) preferred orientation and perfect crystallization were obtained when electrodeposition potential was in the range from −0.6 to −1.1 V and solution temperature was controlled above 60 °C. Both high solution temperature and low precursor concentration resulted in the decrease in rod diameters. Photoluminescence measures showed that small diameter and nanotips of ZnO rod arrays should be responsible for strong and sharp ultraviolet emission in the room temperature photoluminescence spectra.

Electrogenerated chemiluminescence for determination of indole and tryptophan

Indole and tryptophan produce electrogenerated chemiluminescence (ECL) at a Pt electrode under triangular pulse voltage when using KCl as the supporting electrolyte; the intensity was enhanced in the presence of ca. 10 −2 mol 1 −1 H 2 O 2. The effects of electrochemical parameters, solution and interference conditions are investigated in detail. Under the optimum conditions, the detection limit (signal: noise = 3) for indole and tryptophan was 1 × 10 −7 mol 1 −1, with the linear calibration range extending up to 8 × 10 −5 mol l −1.