Active Surface Area Of Electrode Research Articles

Evaluating Bacterial Nanocellulose Interfaces for Recording Surface Biopotentials from Plants.

The study of plant electrophysiology offers promising techniques to track plant health and stress in vivo for both agricultural and environmental monitoring applications. Use of superficial electrodes on the plant body to record surface potentials may provide new phenotyping insights. Bacterial nanocellulose (BNC) is a flexible, optically translucent, and water-vapor-permeable material with low manufacturing costs, making it an ideal substrate for non-invasive and non-destructive plant electrodes. This work presents BNC electrodes with screen-printed carbon (graphite) ink-based conductive traces and pads. It investigates the potential of these electrodes for plant surface electrophysiology measurements in comparison to commercially available standard wet gel and needle electrodes. The electrochemically active surface area and impedance of the BNC electrodes varied based on the annealing temperature and time over the ranges of 50 °C to 90 °C and 5 to 60 min, respectively. The water vapor transfer rate and optical transmittance of the BNC substrate were measured to estimate the level of occlusion caused by these surface electrodes on the plant tissue. The total reduction in chlorophyll content under the electrodes was measured after the electrodes were placed on maize leaves for up to 300 h, showing that the BNC caused only a 16% reduction. Maize leaf transpiration was reduced by only 20% under the BNC electrodes after 72 h compared to a 60% reduction under wet gel electrodes in 48 h. On three different model plants, BNC-carbon ink surface electrodes and standard invasive needle electrodes were shown to have a comparable signal quality, with a correlation coefficient of >0.9, when measuring surface biopotentials induced by acute environmental stressors. These are strong indications of the superior performance of the BNC substrate with screen-printed graphite ink as an electrode material for plant surface biopotential recordings.

Degradation of Styrene-Poly(ethylene oxide)-Based Block Copolymer Electrolytes at the Na and K Negative Electrode Studied by Microcalorimetry and Impedance Spectroscopy

The electrode-electrolyte interface of alkali metal electrodes and solid polymer electrolytes (SPE) is challenging to access because solid electrolytes are difficult to remove without damaging the interphase region. Herein, the two non-invasive techniques isothermal microcalorimetry (IMC) and electrochemical impedance spectroscopy (EIS) are combined to explored degradation processes of reactive sodium and potassium metal electrodes in contact with SPEs. Comparison of the parasitic heat flows and interfacial resistances at different current densities with a liquid electrolyte (LE) system showed marked differences in aging behaviour. The data also suggest that the electrochemically active surface area of alkali metal electrodes increase with cycling, leading to larger parasitic heat flows and indicating morphological changes. SPE-based cells exhibit similar levels of parasitic heat flow at different current densities, which is in stark contrast to the LE cell where a strong correlation between the two is evident. The ambiguity of EIS spectra is challenging due to the overlapping time constants of the underlying electrode processes. However, equivalent circuit modelling can be used to follow trends in resistance evolution, for example to track the rapidly increasing cell impedance in K/K symmetric cells during a 48 h equilibration interval prior to cycling, which abruptly disappeared once cycling begins.

Challenging electroanalytical method for the determination of mirabegron in biological samples and pharmaceutical formulations

A simple, economic, sensitive, and time-saving differential pulse voltammetric (DPV) procedure using nanostructured zinc oxide modified carbon paste electrode (nano ZnO-CPE) in conjunction with an anionic surfactant sodium dodecyl sulfate (SDS) was developed for ultra- sensitive detection of mirabegron (MIR), the most prescribed pharmaceutical drug in treatment of overactive bladder (OAB). The use of nanostructured zinc oxide CPE modifier increased the electrode active surface area as well as improved the process of electron transfer, also it was found that at optimal conditions MIR electrochemical process was both irreversible and diffusion-regulated. The morphological characterization of the fabricated electrode was performed using field emission scanning electron microscopy (FESEM) and energy-dispersive X-ray spectroscopy (EDX). MIR voltammetric behavior was investigated using Nano ZnO-CPE in different content and electrode compositions. Therefore, ultra-sensitive results were attained with a linearity range of (0.55 to 100.20 ng ml−1) and a low limit of detection (LOD) of 0.51 ng ml−1 and limit of quantification (LOQ) of 1.54 ng ml−1 in a 0.04 M Britton-Robinson (BR) buffer at an adjusted pH of 6.0 with scan rate 100 mV s−1. Furthermore, the proposed approach was successful in measuring MIR with acceptable percentage recoveries (99.81–100.11 %) in pharmaceutical dosage form and varying concentration ranges in biological samples (99.74–100.35 %). The proposed method has been validated using ICH criteria and proven to be accurate and repeatable.

First Acyclovir Determination Procedure via Electrochemically Activated Screen-Printed Carbon Electrode Coupled with Well-Conductive Base Electrolyte.

In this work, a new voltammetric procedure for acyclovir (ACY) trace-level determination has been described. For this purpose, an electrochemically activated screen-printed carbon electrode (aSPCE) coupled with well-conductive electrolyte (CH3COONH4, CH3COOH and NH4Cl) was used for the first time. A commercially available SPCE sensor was electrochemically activated by conducting cyclic voltammetry (CV) scans in 0.1 mol L-1 NaOH solution and rinsed with deionized water before a series of measurements were taken. This treatment reduced the charge transfer resistance, increased the electrode active surface area and improved the kinetics of the electron transfer. The activation step and high conductivity of supporting electrolyte significantly improved the sensitivity of the procedure. The newly developed differential-pulse adsorptive stripping voltammetry (DPAdSV) procedure is characterized by having the lowest limit of detection among all voltammetric procedures currently described in the literature (0.12 nmol L-1), a wide linear range of the calibration curve (0.5-50.0 and 50.0-1000.0 nmol L-1) as well as extremely high sensitivity (90.24 nA nmol L-1) and was successfully applied in the determination of acyclovir in commercially available pharmaceuticals.

Electrochemical Sensing with Spatially Patterned Pt Octahedra Electrodes

AbstractLocally controlling the position of electrodes in 3D can open new avenues to collect electrochemical signals in complex sensing environments. Implementing such electrodes via an electrical network requires advanced fabrication approaches. This work uses corner lithography and Pt ALD to produce electrochemical 3D electrodes. The approach allows the fabrication of (sub)micrometer size Pt octahedra electrodes spatially supported over 3D fractal‐like structures. As a proof of concept, electrochemical sensing of ferrocyanide in biofouling environments, e.g., bovine serum albumin (BSA) and Pseudomonas aeruginosa (P. aeruginosa), is assessed. Differences between before and after BSA addition show a reduction in the active electrode surface area (ΔAeff) ≈49% ± 7% for the flat electrode. In comparison, a ΔAeff reduction of 25% ± 2% for the 3D electrode has been found. The results are accompanied by a 24% ± 16% decrease in peak current for the flat Pt substrate and a 14% ± 5% decrease in peak current for the 3D electrode 24 h after adding BSA. In the case of P. aeruginosa, the 3D electrode retains electrochemical signals, while the flat electrode does not. The results demonstrate that the 3D Pt electrodes are more stable than their flat counterparts under biofouling conditions.

Designing advanced 0D/2D heterojunctions of N, S-co-doped carbon dots/Ti3C2Tx MXene nanosheets in electrochemical sensor applications

Ti3C2Tx MXene has demonstrated well-established sensitivity in electrochemical sensing but is susceptible to oxidation. Nitrogen-sulfur doped carbon dots (N, S-CDs) were functionalized on Ti3C2Tx MXene nanosheets via a surface modification strategy, leading to significant enhancement in the performance of Ti3C2Tx MXene. The incorporation of N, S-CDs into Ti3C2Tx MXene nanosheets effectively prevents the aggregation of Ti3C2Tx MXene flakes, resulting in improvement of the interlayer spacing to 1.578 nm and a threefold expansion of the specific surface area. Furthermore, the N, S-CDs contribute to increase the effective active surface area of the Ti3C2Tx MXene electrode, facilitating accelerated the electron transfer rates and providing additional active sites. On this basis, a galvanic sensor for dopamine (DA) detection was attained through loading N, S-CDs/Ti3C2Tx on glassy carbon electrodes. The optimized sensor achieved a linear detection range of 1 μM–1000 μM for DA, with a detection limit of 0.91 μM (S/N = 3). This work presents a promising approach for the utilization of chemically stable Ti3C2Tx MXene and MXene-based sensors, offering a new avenue for quantitative detection of DA that holds potential for application in real sample analysis.

Design of hierarchical integration superbranched Ni–S clusters for efficient, stable hydrogen production

Transition metal sulfides (TMSs), especially iron-based metals (Fe, Co, Ni), were considered the most potential catalysts to replace noble metal-based materials for hydrogen evolution reaction (HER). This work selected metal ions as a variable to modulate the catalytic activity. Designing an electrode consisting of iron-based metal atoms sulfides sweeper-like hyperbranched clusters grown on nickel foam (NF) for HER. This particular structure consisted of 1D nanorods and adequate exposure of the lattice dislocation to exhibit enhanced electrocatalytic activity with low overpotential (135.9 mV) in alkaline conditions at 10 mA cm−2. In addition, stability test results showed that the electrode exhibited good durability. The enhanced electrocatalytic activity of Ni–S could be owing to high electrical conductivity characteristic, the hierarchical structure constituted with NF and the large active surface area of the self-grown electrode further facilitating the production of H2. The Ni sites on the Ni3S2 (110) crystal faces facilitated H adsorption, and all radical reactions under applied voltage proceed spontaneously. This work guides the selection and development of substrates for the design of synthetic transition metal catalysts, leading to cost-effective and efficient electrocatalytic hydrogen production.

Electrochemical Determination of Ascorbic Acid by Mechanically Alloyed Super Duplex Stainless Steel Powders

SAF-2507 super duplex stainless steel powders (SDSS) were prepared using a high-energy planetary ball milling process. The X-ray diffraction (XRD) shows peak broadening after 20 h of ball milling and revealed a phase transformation resulting in a two-phase alloy mixture containing nearly equal amounts of ferrite (α) and austenite (γ). After 20 h of ball milling the particle size was reduced to ~201 nm. Scanning electron microscope (SEM) micrographs showed small-size irregular grains with an average particle size ranging from 5–7 µm. The high-resolution transmission microscope (HRTEM) analysis confirmed the presence of nanocrystalline particles with sizes ranging from 10 to 50 nm. The presence of ferrite phase is visible in the corresponding diffraction pattern as well. In this paper, we have discussed the electrochemical sensor application of mechanically alloyed nano-structured duplex stainless steel powders. The fabricated 4 mg duplex stainless steel modified carbon paste electrode (SDSS-MCPE) has shown excellent current sensitivity in comparison with 2, 6, 8, and 10 mg SDSS-MCPEs during the detection of ascorbic acid (AA) in a phosphate buffer solution with a pH of 6.8. The calculated electrode active surface area of SDSS-MCPE was found to be almost two times larger than the surface area of the bare carbon paste electrode (BCPE). The limit of detection (LD) and limit of quantification (LQ) were found to be 0.206 × 10−8 M and 0.688 × 10−8 M, respectively, for the fabricated 4 mg SDSS-MCPE.

Enhanced Methanol Oxidation in Alkaline Media on Electrodeposited Ni Electrodes by Morphological and Crystallographic Evolution

This research aims at exploiting the electrocatalytic behaviour of nano-crystalline nickel electrodes electrodeposited by different techniques including direct current (DC), pulse current (PC), or pulse reversal current (PRC) for methanol electrooxidation in alkaline solutions. We understand that PC electrodeposition forms pyramidal shaped grains with a preferential Bragg diffraction peak of (111), whereas PRC produced refined spherical grain morphology with a strong (200) diffraction peak. However, DC electrodeposition exhibits an intermediate morphology and crystalline structure. Cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) show that PRC electrodeposition develops Ni electrodes with better electrocatalytic activity for methanol electrooxidation than other two nickel electrodes. Based on the CV curve, the current density for Ni prepared by PRC electrodeposition methods is about 75.26 mA.cm−2, which is higher than those of DC and PC methods. This higher activity of PRC electrodeposited nickel is attributed to the low charge transfer resistance confirmed by Nyquist plots. We attributed this behavior to the (200)-oriented crystallographic texture, spherical grain morphology, and consequently the high electrochemical active surface area of this nickel electrode. This work reveals the importance of surface morphology and crystallography on the electrocatalytic behaviour of nickel electrodes for electrochemical energy devices.

Fabrication of a simple and sensitive mitoxantrone electrochemical sensor based on topdown recycling of iron wool and tissue paper

The development of rapid, sensitive detection and quantification techniques for mitoxantrone is crucial for monitoring treatment, cancer research and pharmaceutical analysis. In this context, The aim was to research an electrochemical sensor with a cheaper source of electrode material through recycling. The current study successfully recycled domestically used iron wool and tissue paper wastes into functional electrode materials: iron oxide nanoparticles (Fe3O4 NP) and black carbon (BC). The synthesis of BC was achieved by completely charring used tissue paper in sulphuric acid followed by ultrasonic disintegration. Also, Fe3O4 NP was synthesised through a simple, rapid rusting of iron chippings with hydrogen peroxide. The current research is the first to report this synthetic approach to obtain iron oxide and black carbon composite. The materials were then mixed to produce nanocomposite Fe3O4 NP:BC. Cyclic voltammetry and differential pulse voltammetry were used to study the behaviour of the modified electrodes towards the drug. The result showed the combination of the two materials in a Fe3O4 NP:BC = 1:2 ratio improved the active surface area of the glassy carbon electrode and conferred superior electrocatalytic properties compared to the individual materials. The Fe3O4 NP:BC modified electrode was highly sensitive towards mitoxantrone with a linear range of 5 × 10−6 to 1.0 × 10−4 M and a detection limit of 2.55 × 10−10 M. The current electrode's detection limit is lower than all but one of the electrodes reported for the drug whiles being the simplest and cheapest.

Synthesis of N-acylated pyrazolines: Spectroscopic, crystallographic, Hirshfeld Surface, lead sensing and theoretical studies

N-Acylated-2-pyrazolines (NA2Pyr) were synthesized from chalcone and hydrazine hydrate under one pot cyclocondensation in the presence of propionic acid and trifluoroacetic acid respectively. The structures were determined using FT-IR, 1H NMR, 13C NMR spectral analyses, as well as single crystal diffraction study (Sc-XRD). An effective metal ion sensor (Lead ion) with a flat glassy carbon electrode (GCE) was produced for prospective use by coupling a conducting coating binder (PEDOT:PSS) with a thin-layer NA2Pyr modified electrode (NA2Pyr/GCE). Linear sweep voltammetry was used to detect lead (Pb2+) ions in phosphate aqueous phase. The sensitivity (11,867 uAnM−1cm−2) of the chemical sensor probe was measured utilizing the calibration curve slope and the adjusted electrode active surface area. The linear dynamic range (LDR: 0.01 nM to 10.0 mM) was computed using the calibration plot's maximal linearity line. The detection limit (0.008 nM) was calculated by including 3σ/m (where σ is the standard deviation of the blank response and m is the slope of the calibration curve). The novel electrochemical method is dependable and effective technique for detecting heavy metal ions as a selective lead-sensor for the protection of large-scale medical, biochemical, and environmental fields. Density functional theory (TD-DFT/B3LYP/6-311++G(d,p) was used to computed FMO computations and further study using the optimized geometric parameters of the ground state molecules. According to the predicted energies for HOMO and LUMO, in which the charge of molecule is conveyed, and MEP map, the chemically reactive zone suitable for drug action was identified. The Electron Localization Function (ELF), Non-Bonding Orbitals, Excitation Energies, AIM Charges, and Fukui Functions are also calculated. The docking study contributed to the analysis of EGFR protein binding.

In Situ Characterization of Kinetics, Mass Transfer, and Active Electrode Surface Area for Vanadium Redox Flow Batteries

Engineering the electrochemical reactor of a vanadium redox flow battery (VRFB) is critical to deliver sufficiently high power densities to achieve cost-effective, grid-scale energy storage. Understanding and ultimately alleviating the cell-level resistive losses in VRFBs fundamentally depend on the ability to accurately measure the electron and mass transfer rates as a function of applied potential and interpret the results in the context of VRFB operation. In this study, an in situ electroanalytical technique of electrochemical reaction in porous electrodes is proposed by a symmetrical cell design for VRFB. For both V2+/V3+ and VO2+/VO2 + redox couples, the polarization curves at different flow rates are acquired on the symmetrical flow cell. The high-frequency resistance is also obtained by electrochemical impedance spectroscopy at open circuit. The ohmic, kinetic, and mass transfer resistance are obtained by deconvoluting the total polarization curve. Corresponding key parameters (i.e., membrane conductivity, reaction rates, and mass transfer coefficients) are obtained along with the specific surface area of porous electrode. The full-cell simulations using extracted key parameters are in excellent agreement with experimental full-cell tests at different applied currents. This novel in situ electroanalytical technique provides an invaluable approach to characterize the performance of electrolyte and electrode in redox flow batteries.

Reduced graphene oxide supported monoclinic bismuth vanadate nanoparticles as an electrocatalyst for selective determination of dopamine in human urine samples

WHO report says that 6.8 million people succumb to neurological disorders every year. For early detection of disease and disease diagnostic purposes, dopamine detection in bio fluid is inevitable in the medical field. In this work, BiVO4 and different amounts of rGO-loaded BiVO4 were synthesized by hydrothermal technique followed by reflux method. The different analysis confirms the formation of BiVO4 and rGO/BiVO4 nanocomposite. The electrochemical active surface area of glassy carbon electrode (GCE), BiVO4/GCE, 5rGO/BiVO4/GCE, 15rGO/BiVO4/GCE and 30rGO/BiVO4/GCE nanocomposite are 0.0747, 0.0585, 0.06696, 0.0714, and 0.0774 cm2 respectively. The 30rGO/BiVO4 nanocomposite showed a high electrocatalytic current towards the oxidation of dopamine. In pH 3 phosphate buffer solution (PBS), 30rGO/BiVO4 nanocomposite exhibited a higher catalytic current than pH (4–7) and pH 3 choose as an optimal pH for whole dopamine sensing. The oxidation of dopamine on the surface of 30rGO/BiVO4 is a diffusion-controlled process. The Rct value of 30rGO/BiVO4/GCE is low compared to other samples which enhances the electron transfer between the analyte and modified electrode. The 30rGO/BiVO4/GCE electrode exhibited, two dynamic linear ranges is 0.25–5 μM and 10–100 μM with a limit of detection of 0.098 μM and 0.713 μM. From the practical application point of view, the main co-existing interference signal is from ascorbic acid and uric acid. The 30rGO/BiVO4 showed a distinctive SWV peak for ascorbic acid and uric acid. In the urine samples, 30rGO/BiVO4/GCE nanocomposite showed more than 89% recovery for spiked dopamine.

Modified graphite paper treated by anionic intercalation for manganese removal via electrochemical deposition in water treatment

Effective removal of excess manganese ions (Mn2+) from water is urgently needed to maintain human health and ecological balance. To date, electrochemical deposition (ED) techniques have been widely used for their simplicity and flexibility, while the active surface area and reliability of electrodes are still major issues. Herein, modified graphite papers (MGP) fabricated by the anionic intercalation method were used as the working electrode to remove Mn2+ from wastewater via the electrochemical deposition method. The results showed that the highest removal of Mn2+ by MGP-E was achieved when the voltage was 1.0 V, the deposition time was 6 h, and the pH value of the wastewater was 3.0. Under the above parameters, the removal rate of Mn2+ in simulated wastewater can reach over 99.73 %, while the removal rates in industrial wastewater and groundwater can reach 96.20 % and 99.27 %, respectively, which can meet the standard of water treatment. The related tests confirmed that the deposition process had excellent cycling stability and low energy consumption. This study may provide an economical, sustainable and efficient electrode material for Mn2+ removal from industrial wastewater and groundwater via electrochemical deposition technology.

Enhanced Surface Area Carbon Cathodes for the Hydrogen–Bromine Redox Flow Battery

The hydrogen–bromine redox flow battery is a promising energy storage technology with the potential for capital costs as low as 220 $ kWh−1 and high operational power densities in excess of 1.4 W cm−2. In this work, enhanced surface area bromine electrodes incorporating carbon black (CB) and graphene nanoplatelets (GnPs) on carbon paper and carbon cloth substrates were investigated, and the effect of electrolyte concentration on performance of the electrodes was studied. Carbon-black-modified electrodes are found to possess the largest electrochemically active surface areas, i.e., up to 11 times that of unmodified materials, while GnP electrodes are shown to have superior kinetic activity towards the bromine electrode reaction. In terms of performance, lower electrolyte concentrations are found to favour the improved kinetic parameters associated with graphene nanoplatelet electrodes, while highly concentrated electrolytes favour the larger electrochemically active surface area of carbon black electrodes. The optimal performance was achieved on a carbon-black-modified carbon cloth electrode in a 6 M HBr/2 M Br2 electrolyte concentration, with polarisation current densities approaching 1.6 A cm−2 at overpotentials of ±400 mV, and mean overpotentials of 364 mV during oxidation and 343 mV during reduction, resulting from bromine oxidation/reduction cycling tests at ±1.5 A cm−2.

Fabrication of a ZnO Hexagonal Plates/rGO Composite for Application in Nitrite Sensing and Photocatalytic Hydrogen Production

AbstractRecently, design and fabrication of electrochemical sensors have received huge attention because of their high sensitivity, cost‐effectiveness, good selectivity, simple processing, and low detection limit. Herein, we have fabricated zinc oxide (ZnO) hexagonal plates/reduced graphene oxide (rGO) composite under benign approach. Different characterization techniques and approaches such as XRD, SEM, EDX, UV‐vis, and XPS were utilized to authenticate the formation and phase purity of ZnO/rGO composite. Further, we have modified active surface area (3 mm) of bare glassy carbon electrode using ZnO/rGO as electro‐catalyst (electrode material) for the construction of nitrite sensor. This modified electrode (ZnO/rGO/GCE) demonstrated low‐limit of detection (DL) of 0.1 μM with good sensitivity of 2.47 μA/μMcm2. Moreover, fabricated ZnO/rGO/GCE exhibited excellent selectivity, stability and repeatability towards the detection of nitrite. Additionally, ZnO/rGO was also applied as photo‐catalyst towards photo‐catalytic hydrogen (H2) generation. The ZnO/rGO showed good H2 generation rate of 650.3 μmolg−1h−1 compared to the pristine rGO or ZnO.

Effect of phosphoric acid purity on the electrochemically active surface area of Pt-based electrodes

• H 3 PO 4 should be purified before ORR measurements to remove impurities which can be oxidized. • H 3 PO 3 was suggested as one of the impurities in the unpurified H 3 PO 4 solution. • ESCA HUPD analysis is more accurate than ESCA CO in the presence of H 3 PO 3. • H 3 PO 3 and CO compete for Pt surface active sites. • Commercial “crystalline H 3 PO 4 ” contains low amount of reduced phosphorus impurities. In this work, the effect of H 3 PO 4 purity on the activity of Pt/C thin film catalysts towards the oxygen reduction reaction (ORR) was investigated. H 3 PO 4 is routinely introduced in the electrolyte during rotating disk electrode (RDE) measurements to simulate the existing environment within high-temperature proton exchange membrane fuel cells (HT-PEMFC). Three different purity grades were tested: crystalline (99.99% purity), commercial H 3 PO 4 solution (85 wt%), hereafter, designated as non-purified H 3 PO 4 , and commercial H 3 PO 4 solution (85 wt%) purified with H 2 O 2 . H 3 PO 4 and/or its anions are known to strongly adsorb and interact with Pt surfaces. The presence of H 3 PO 4 negatively affected the electrochemically active surface area (ECSA) measured by H upd (ECSA H ), and by CO stripping (ECSA CO ), kinetic parameters in the high current density region and the limiting current density ( j lim ) of ORR. One major finding was that the crystalline and purified H 3 PO 4 solutions have similar effects on the Pt/C catalyst activity while the non–purified H 3 PO 4 showed a significantly more negative effect on the ECSA as well as on the ORR measurements. This was found to be due to the presence of H 3 PO 3 in the non-purified H 3 PO 4 solution. Adsorption isotherms of H 3 PO 3 were also measured using H upd and CO stripping in order to evaluate its adsorption on the catalyst surface. From these investigations, the purity level of H 3 PO 4 was shown to be an important factor in reliable ORR testing.

Numerical Parametric Investigation of Nonaqueous Vanadium Redox Flow Batteries

Nonaqueous redox flow batteries are promising candidates for large-scale energy storage technologies. However, the effect of structural design and key factors limiting the performance are still not thoroughly understood. In this work, we constructed a physical model to study the effect of various design parameters on the performance of such a battery. It was found that the kinetics of redox reaction was improved with active material concentration and electrode surface area. The modeling results also showed that the local current density was much higher in the vicinity of membrane than near the current collector due to relatively low ionic conductivity of electrolytes. Furthermore, decreasing the electrode thickness and increasing the membrane conductivity both reduced the voltage loss associated with ohmic resistance, thereby resulting in improved battery performance. The obtained numerical simulation results would be helpful not only for understanding the physicochemical process in nonaqueous vanadium flow batteries but also for future structural optimization of these batteries.

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

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

NiO/ZnO binary metal oxide based electrochemical sensor for the evaluation of hazardous flavonoid in biological and vegetable samples

Fabrication of binary transition metal oxide-based composite over the active surface area of glassy carbon electrode (GCE) stimulates the electrochemical activity due to their morphology, and higher active surface area, etc. The successful formation of (NiO/ZnO) composite has been scrutinized through various microscopic and spectroscopic techniques. Further, NiO/ZnO/GCE tends to exemplify exquisite kinetic performance with a higher electron transfer rate and charge transfer resistance (Rct) of 404 Ω. The electrochemical detection of Rutin (RT) on NiO/ZnO/GCE exemplifies a spacious linear range of 0.049 – 742.5 µM in linear sweep voltammetry (LSV) and differential pulse voltammetry (DPV). Moreover, the proposed NiO/ZnO/GCE sensor symbolizes Nanomolar level detection of RT (11.0 & 13.6 nM) in DPV and LSV with an appraisable sensitivity of 2.52 µA µM−1 cm−2 and 0.62 µA µM−1 cm−2, respectively. The practical feasibility analysis of the proposed NiO/ZnO/GCE sensor features exemplary selectivity, repeatability, reproducibility, and storage stability. On top of that, the real-time monitoring analysis demonstrates exquisite recovery results in blood and orange samples.