Electrochemical Impedance Spectroscopy Research Articles

Utilizing rare earth titanates to improve performance of solid-state electrochromic device

Abstract Exploring new materials and synthesis recipes are required to enhance the electrochromic performance especially when used in solid-state devices. Here polycrystalline gadolinium titanate (Gd2TiO5 or GTO), synthesized using a simple solid-state reaction method, has been used for this purpose by combining it with polythiophene (P3HT). The electrochemical investigation of Gd2TiO5 doped P3HT electrode has been carried out using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) which reveals the dominance of diffusion-controlled mechanism over charge storage on the electrode surface as compared to the P3HT electrode. The Gd2TiO5 doped P3HT solid-state electrochromic device shows color modulation at 515 nm and 670 nm wavelengths with color contrast of as high as 79% and 42%, respectively, under the external bias of as low as ± 1.4 V. The prepared device switches between maroon to transparent state in less than a second under the external bias (± 1.4 V) with a high coloration efficiency of 346 cm2/C. The device shows improved cycle life over 100 switching cycles at both the wavelengths, which makes it more suitable for real-life applications.

Ionic Conductivity Analysis of NASICON Solid Electrolyte Coated with Polyvinyl-Based Polymers

The global environmental crisis necessitates reliable, sustainable, and safe energy storage solutions. The current systems are nearing their capacity limits due to the reliance on conventional liquid electrolytes, which are fraught with stability and safety concerns, prompting the exploration of solid-state electrolytes, which enable the integration of metal electrodes. Solid-state sodium-ion batteries emerge as an appealing option by leveraging the abundance, low cost, and sustainability of sodium. However, low ionic conductivity and high interfacial resistance currently prevent their widespread adoption. This study explores polyvinyl-based polymers as wetting agents for the NASICON-type NZSP (Na3Zr2Si2PO12) solid electrolyte, resulting in a combined system with enhanced ionic conductivity suitable for Na-ion solid-state full cells. Electrochemical impedance spectroscopy (EIS) performed on symmetric cells employing NZSP paired with different wetting agent compositions demonstrates a significant reduction in interfacial resistance with the use of poly(vinyl acetate)—(PVAc-) based polymers, achieving an impressive ionic conductivity of 1.31 mS cm−1 at room temperature, 63.8% higher than the pristine material, notably reaching 7.36 mS cm−1 at 90 °C. These results offer valuable insights into the potential of PVAc-based polymers for advancing high-performance solid-state sodium-ion batteries by reducing their total internal resistance.

Is 3% Eu3+ Doping in ZnO Unique? An investigative case study of Photocatalytic Descriptors Using Multiparameter Approach. .

Abstract The hydrothermal approach was used to prepare different proportions of Europium (Eu3+) doped ZnO hybrid material which were characterized by powder X-ray diffraction (PXRD), Scanning electron microscopy (SEM) analysis with end results being Eu3+: ZnO nanocomposites. The XRD pattern obtained verifies the successful incorporation of Europium (Eu3+) into Zinc-Oxide (ZnO) host matrix. SEM analysis predicted that the ZnO was uniformly distributed and agglomeration was observed to be increased with increasing wt.% of Eu3+. The photocatalytic activity was carried out using the antibiotic Rifampicin under visible light and the observed results predicted the highest photocatalytic activity against the antibiotic for Eu3+: ZnO-3 wt.%. Rifampicin had a 90-minute degradation rate of around 90% for Eu3+: ZnO -3 wt.% which demonstrated that doping ZnO with Eu3+ allows a favorable adsorption with enhanced photocatalytic properties. When considering the collective findings of Electrochemical Impedance Spectroscopy (EIS), Photocurrent Measurements and UV-visible spectroscopy data, a unanimous inference can be drawn: the peak photocatalytic efficiency of Eu3+ doped ZnO aligns with a 3% wt. concentration of Europium (Eu3+).

Detectable quorum signaling molecule via PANI-metal oxides nanocomposites sensors.

The detection of N-hexanoyl-l-homoserine lactone (C6-HSL), a crucial signal in Gram-negative bacterial communication, is essential for addressing microbiologically influenced corrosion (MIC) induced by sulfate-reducing bacteria (SRB) in oil and gas industries. Metal oxides (MOx) intercalated into conducting polymers (CPs) offer a promising sensing approach due to their effective detection of biological molecules such as C6-HSL. In this study, we synthesized and characterized two MOx/polyaniline-dodecyl benzene sulfonic acid (PANI-DBSA) nanocomposites, namely ZnO/PANI-DBSA and Fe2O3/PANI-DBSA. These nanocomposites were applied with 1% by-weight carbon paste over a carbon working electrode (WE) for qualitative and quantitative detection of C6-HSL through electrochemical analysis. The electrochemical impedance spectroscopy (EIS) confirmed the composites' capability to monitor C6-HSL produced by SRB-biofilm, with detection limits of 624 ppm for ZnO/PANI-DBSA and 441 ppm for Fe2O3/PANI-DBSA. Furthermore, calorimetric measurements validated the presence of SRB-biofilm, supporting the EIS analysis. The utilization of these MOx/CP nanocomposites offers a practical approach for detecting C6-HSL and monitoring SRB-biofilm formation, aiding in MIC management in oil and gas wells. The ZnO/PANI-DBSA-based sensor exhibited higher sensitivity towards C6-HSL compared to Fe2O3/PANI-DBSA, indicating its potential for enhanced detection capabilities in this context. Stability tests revealed ZnO/PANI-DBSA's superior stability over Fe2O3/PANI-DBSA, with both sensors retaining approximately 85-90% of their initial current after 1month, demonstrating remarkable reproducibility and durability.

Synthesis and characterization of a new eco-friendly dopamine derivative schiff base as an effective corrosion inhibitor for mild steel in acidic environment

The natural corrosion inhibitor behaviour of a newly synthesized dopamine derivative Schiff base (4-DBAB) has been inspected on mild steel in aggressive 1 M HCl using linear polarization, electrochemical impedance spectroscopy and potentiodynamic polarization techniques. The Schiff base was synthesized by eco-friendly pathway. Characterization of the synthesized new non-toxic inhibitor was performed using FT-IR and 1H-NMR spectroscopy techniques. The anti-corrosive efficiencies at optimum concentration of 4-DBAB inhibitor was 87.4% after 1 h and 98.4% after 120 h by impedance technique in acidic solution. The potential of zero charge of mild steel was also determined to elucidate the inhibition mechanism in the presence of the highest 4-DBAB solution. The atomic force microscopy and field emission scanning electron microscopy researches performed on surface morphology to provide additional support on the interaction between the mild steel surface and 4-DBAB molecules. Adsorption behaviour of the inhibitor was also studied at different durations by experimental inhibition results and showed the Langmuir isotherm involving chemisorption. Highlights A new dopamine-derived Schiff base (4-DBAB) with natural and environmentally friendly corrosion inhibition properties was synthesized. (Synthesis of eco-friendly compound). 4-DBAB demonstrated a high anti-corrosive efficiency after 120 hours in aggressive 1M HCl, as determined by impedance technique. (Exceptional corrosion inhibition). The determination of the potential of zero charge of mild steel provided insights into the inhibition mechanism in the presence of the highest 4-DBAB solution. (Mechanism elucidation). AFM and FE-SEM studies on surface morphology supported the interaction between the mild steel and 4-DBAB molecules, affirming its corrosion inhibition properties. (Surface interaction analysis).

Synthesis of Zinc Oxide Nanoparticles Based on Coffee Husks Embedded on Mesoporous Silica for the Sensing of Acetaminophen

AbstractIn the present work, a green method improved by surface response methodology (SRM) has been used for the synthesis of zinc oxide nanoparticles (ZnONPs) from coffee husks extract, in which Santa Barbara‐15 (SBA‐15) mesoporous silica has been embedded. The composite formed has been drop coated on bare glassy carbon electrode and the resulting sensor (ZnONPs/SBA‐15/GCE) was used for the sensing of acetaminophen (ACT). Reaction factors such as pH, incubation time and precursor concentration were optimized during nanoparticles synthesis using SRM. The synthesized nanoparticles and the composite were characterized by ultraviolet‐visible spectrophotometry (UV‐Vis), Fourier transform infrared (FTIR) spectroscopy, powder X‐ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X‐ray (EDX/EDX‐mapping) analysis, thermogravimetry analysis/differential thermogravimetry (TGA/DTG), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS), showing the good elaboration of ZnONPs/SBA‐15/GCE. After optimization of parameters susceptible to affect the detection limit of ACT, the calibration curve was plotted from 4 μM to 32 μM, showing good linear response with a detection limit of 0.11 μM. The developed sensor shows good sensitivity, reproducibility, repeatability and storage stability at room temperature and was successfully applied for the determination of ACT in pharmaceutical sample.

Biolayer-Interferometry-Guided Functionalization of Screen-Printed Graphene for Label-Free Electrochemical Virus Detection.

Additive manufacturing holds promise for rapid prototyping and low-cost production of biosensors for diverse pathogens. Among additive manufacturing methods, screen printing is particularly desirable for high-throughput production of sensing platforms. However, this technique needs to be combined with carefully formulated inks, rapid postprocessing, and selective functionalization to meet all requirements for high-performance biosensing applications. Here, we present screen-printed graphene electrodes that are processed with thermal annealing to achieve high surface area and electrical conductivity for sensitive biodetection via electrochemical impedance spectroscopy. As a proof-of-concept, this biosensing platform is utilized for electrochemical detection of SARS-CoV-2. To ensure reliable specificity in the presence of multiple variants, biolayer interferometry (BLI) is used as a label-free and dynamic screening method to identify optimal antibodies for concurrent affinity to the Spike S1 proteins of Delta, Omicron, and Wild Type SARS-CoV-2 variants while maintaining low affinity to competing pathogens such as Influenza H1N1. The BLI-identified antibodies are robustly bound to the graphene electrode surface via oxygen moieties that are introduced during the thermal annealing process. The resulting electrochemical immunosensors achieve superior metrics including rapid detection (55 s readout following 15 min of incubation), low limits of detection (approaching 500 ag/mL for the Omicron variant), and high selectivity toward multiple variants. Importantly, the sensors perform well on clinical saliva samples detecting as few as 103 copies/mL of SARS-CoV-2 Omicron, following CDC protocols. The combination of the screen-printed graphene sensing platform and effective antibody selection using BLI can be generalized to a wide range of point-of-care immunosensors.

Wideband Measurement Approach for EIS of Lithium-Ion Batteries Using Low-Frequency Concentrated Disturbance

Precise and rapid measurement for electrochemical impedance spectroscopy (EIS) is conducive to the working state monitoring and fault diagnosis of lithium-ion batteries (LIBs). Although using a wideband signal can effectively reduce measurement time, it will deteriorate the measurement precision due to the insufficient Signal-to-Noise Ratio. Considering this issue, this paper proposes a wideband measurement approach using low-frequency concentrated disturbance for the EIS of LIBs. This approach can obtain high measurement accuracy and a wide measurement bandwidth under a small current disturbance. Besides, it effectively reduces the measurement time. First, LIBs are stimulated by a low-frequency concentrated binary sequence signal to enhance measurement precision in a low-frequency region. Then, in the entire frequency region, an accurate EIS can be obtained by a fast Morlet wavelet transform and covariance-based impedance calculation. Finally, the effectiveness of the proposed approach is verified on a buck-boost converter-based EIS measurement platform, and comparative analyses with literature methods are conducted. The experimental results illustrate that the maximum Normalized Root Square Error of the two types of LIBs at different state-of-charge is 0.37% under the response voltage amplitude of less than 10mV. Moreover, this approach is approximately 20 times faster than commercial electrochemical workstations in measurement time.

Synthesis and Characterization of Bis-Isoxazoline-Thiosemicarbazone as a Corrosion Inhibitor for Carbon Steel: Experimental Study, and Molecular Simulation

In this study, a novel compound, bis-isoxazoline-thiosemicarbazone (BIT), was synthesized and tested for its ability to protect carbon steel from corrosion in a 1M HCl solution. The compound's structure was confirmed using spectroscopic techniques such as 1H NMR, 13C NMR, and HRMS. Various methods, including mass loss analysis, potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), SEM, and EDX, were employed to assess BIT's effectiveness in inhibiting corrosion and its adsorption behavior on carbon steel in acidic conditions. The findings demonstrated the high effectiveness of BIT as a corrosion inhibitor, with a 95% inhibition rate observed at a concentration of 0.77 mM and a temperature of 298 °K. Analysis through PDP revealed that BIT operates as a mixed-type inhibitor, conforming to the Langmuir adsorption isotherm during its attachment to the carbon steel surface, indicating a mixed (chemical-physical) adsorption process.SEM-EDX analysis demonstrated even distribution of the inhibitor on the steel surface. Notably, BIT contains several functional groups (methoxy, carbonyl, isoxazolyl,..) and heteroatoms (N, O, and S) that play a crucial role, as supported by Density Functional Theory (DFT) studies. Experimental findings were validated by DFT and molecular dynamics (MD) simulation data.

Highly electroactive Co-ZnO/GO nanocomposite: electrochemical sensing platform for oxytetracycline determination

Antimicrobial residues in animal-derived foods have become a major source of concern around the world. Oxytetracycline (OTC), one of these antibiotics that belongs to the tetracycline family should be detected in these matrices. Nanostructured metal oxides have attracted a lot of scientific attention due to their special characteristics that can be exploited for creating innovative nanodevices. Therefore, in the present study, we report the fabrication of cobalt-doped ZnO/GO nanocomposites for OTC sensors using a simple and environmentally friendly method that does not require toxic solvents. Contact angle measurements, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and UV-Vis were used to confirm the successful fabrication of the Co-ZnO/GO nanocomposite and to determine the surface area, Structural, morphological features, chemical composition and purity of the nanocomposite. The electrochemical and electrocatalytic properties were recorded using cyclic voltammetry (CV), electrochemical impedance spectroscopy, and differential pulse voltammetry (DPV). Optimizing parameters such as scan rate, pH value, deposition time, and deposition potential, we achieve a wide linear concentration range from 10-12 M to 10-7 M, with an impressive detection limit of 1.6 10-13M.Notably, our sensor exhibits remarkable selectivity, demonstrating its usefulness for the detection of oxytetracycline traces in real milk samples. These results emphasize the novelty and practical significance of our work and provide a promising avenue for the development of sensitive and selective electrochemical sensing platforms in various fields.

A Study on the Corrosion Behavior of RGO/Cu/Fe-Based Amorphous Composite Coatings in High-Temperature Seawater

In this paper, based on an Fe-based amorphous alloy, four kinds of RGO/Cu/Fe-based amorphous composite coatings with mass ratios of 5%, 10%, 15%, and 20% of RGO/Cu were prepared on the surface of 45# steel by using high-velocity oxy-fuel (HVOF) spraying. The coatings were immersed in simulated seawater at room temperature and at 90 °C for different lengths of time, and their corrosion resistance was tested using electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), and X-ray diffraction (XRD), and the surface morphology and phase distribution of the samples were observed. The results showed that with the increase in the introduction ratio of RGO/Cu, when the addition ratio reached 15%, the composite coating had the best corrosion resistance. After soaking in simulated seawater at 90 °C for 18 days, the surface of the coating showed slight peeling and crack propagation, but no obvious pitting phenomenon occurred. The corrosion mechanism of the RGO/Cu/Fe coating in high-temperature seawater is mainly that high temperature causes the cracking of the coating, which opens up a transport channel for corrosion media. However, due to the addition of RGO, the corrosion has a certain self-limitation effect, which is mainly due to the toughening effect of RGO on the coating and its effect on extending the corrosion channel.

Electrocatalytic and photoelectrocatalytic investigation of Orange G degradation utilizing a novel BHP@Bi2O3 photoanode employing the CCD-RSM experimental design

In this study, we synthesized a bilayer film consisting of BaHPO4 (BHP) and Bi2O3 through the electrodeposition technique. The produced anode was subjected to characterization using cyclic voltammetry to clarify the deposition reactions. Subsequent to this, structural and morphological analyses were conducted utilizing X-ray diffraction alongside scanning electron microscopy, coupled with energy-dispersive X-ray spectroscopy. Additionally, UV–vis diffuse reflectance spectroscopy was employed to determine the bandgap energies of both semiconductors. Following an electrochemical characterization using linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS), and Mott-Schottky (MS) measurements, the photoanode was employed for the electro-degradation of the anionic dye Orange G (OG), varying key degradation parameters such as current density, pollutant concentration, supporting electrolyte concentration, and pH using the CCD-RSM experimental design method. A degradation efficiency of 98% was achieved within a 20-minute timeframe. Photoelectrocatalytic tests under UV irradiation reduced the degradation time from 20 to 6 min, with a degradation rate of 99%. Additionally, under the same conditions, the BHP@Bi2O3 photoanode exhibited good stability, enduring up to 11 cycles of use.

Exploring the Synthesis and Application of a Pyrazole Derivative in Corrosion Protection: Theoretical Modeling and Experimental Investigations

This research investigates the inhibitory performance of BM-02, a synthesized pyrazole derivative (R)-5-(4-methoxyphenyl)-1,3-diphenyl-4,5-dihydro-1H-pyrazole, against the corrosion of mild steel in a 1 M hydrochloric acid solution. A comprehensive array of experimental techniques, including weight loss analysis, potentiodynamic polarization, electrochemical impedance spectroscopy, and scanning electron microscopy, were employed to assess the inhibitory effectiveness. BM-02 is identified as a mixed inhibitor, showcasing a remarkable efficiency of 91.5% at a concentration of 10−3 mol/l. The adsorption behavior of the BM-02 molecule was investigated, revealing a physical adsorption model in accordance with the Langmuir isotherm. Furthermore, ATR-IR, 1H NMR, and 13C NMR spectra were acquired, complemented by density functional theory (DFT) calculations and molecular dynamics (MD) simulations to gain deeper insights into the molecular interactions and corrosion inhibition mechanism.

Effect of deposition time on properties of the ZnO by USD Method

This investigation aims to improve the properties of 304 L stainless steel (SS) substrates for use in corrosion, mechanical, and biomedical applications by depositing ZnO thin films. The ultrasonic spraying technique was used to prepare ZnO thin films with depositional times of 1, 4, and 9 minutes. XRD and Raman studied the surface characteristics of ZnO samples. XRD analysis revealed a hexagonal structure with an average crystallite size of 22 nm for ZnO. Indentation nano measurements indicated an increase in the hardness of the films examined. To determine the type of conductivity and estimate the charge carrier density, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and Mott-Schottky analysis were performed. The thin film deposited for 9 minutes was found to be the most effective in improving corrosion resistance.

Unveiling Enhanced PEC Water Oxidation: Morphology Tuning and Interfacial Phase Change in α-Fe2O3@K-OMS-2 Branched Core-Shell Nanoarrays.

A simple fabrication method that involves two steps of hydrothermal reaction has been demonstrated for the growth of α-Fe2O3@K-OMS-2 branched core-shell nanoarrays. Different reactant concentrations in the shell-forming step led to different morphologies in the resultant composites, denoted as 0.25 OC, 0.5 OC, and 1.0 OC. Both 0.25 OC and 0.5 OC formed perfect branched core-shell structures, with 0.5 OC possessing longer branches, which were observed by SEM and TEM. The core K-OMS-2 and shell α-Fe2O3 were confirmed by grazing incidence X-ray diffraction (GIXRD), EDS mapping, and atomic alignment from high-resolution STEM images. Further investigation with high-resolution HAADF-STEM, EELS, and XPS indicated the existence of an ultrathin layer of Mn3O4 sandwiched at the interface. All composite materials offered greatly enhanced photocurrent density at 1.23 VRHE, compared to the pristine Fe2O3 photoanode (0.33 mA/cm2), and sample 0.5 OC showed the highest photocurrent density of 2.81 mA/cm2. Photoelectrochemical (PEC) performance was evaluated for the samples by conducting linear sweep voltammetry (LSV), applied bias photo-to-current efficiency (ABPE), electrochemical impedance spectroscopy (EIS), incident-photo-to-current efficiency (IPCE), transient photocurrent responses, and stability tests. The charge separation and transfer efficiencies, together with the electrochemically active surface area, were also investigated. The significant enhancement in sample 0.5 OC is ascribed to the synergetic effect brought by the longer branches in the core-shell structure, the conductive K-OMS-2 core, and the formation of the Mn3O4 thin layer formed between the core and shell.

Floret Assembly of NiCo2O4@Tailored Nanostructured Carbon Support for Oxygen Evolution Reaction in Alkaline Medium

The oxygen evolution reaction (OER) is a bottleneck in overall water splitting due to the involvement of the four-electron process and requires a high overpotential. This hinders the stability and durability of electrocatalysts over a longer period. Herein, we report flower-like NiCo2O4 decorated on carbon nanostructures synthesized using a one-pot wet chemical method as an OER electrocatalyst in an alkaline medium. The catalytic activities were characterized by various electrochemical measurements including linear sweep voltammetry (LSV), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and turnover frequency (TOF). 90% NiCo2O4@rGO/f-MWCNT demonstrated a higher OER activity compared to stand-alone NiCo2O4, 90% NiCo2O4@rGO, 90% NiCo2O4@f-MWCNT and 80% NiCo2O4@rGO/f-MWCNT.

Revealing the degradation patterns of lithium-ion batteries from impedance spectroscopy using variational auto-encoders

The aging life estimation of lithium-ion batteries (LIBs) is of great significance to the use, maintenance and economic analysis of energy storage systems. The estimation method of aging life based on electrochemical impedance spectroscopy (EIS) has received more attention due to its high accuracy. Due to the high dimensionality of impedance data, it cannot directly reflect the decline trend, this paper proposes a method of combining variational auto-encoders (VAE) and bidirectional gated recurrent unit (BiGRU) for automatic feature extraction from EIS data and battery aging life estimation. Reducing the dimensionality of impedance data through VAE can greatly reduce computational complexity, and the high-quality features extracted are mapped to battery capacity using BiGRU, which can improve estimation accuracy. The validation results show that the method can adapt to various working conditions, and has good estimation accuracy and robustness. MAE and RMSE are less than 1.27 mAh and 1.43 mAh, respectively. We demonstrate that the latent variables extracted from EIS data using unsupervised learning method reliably represent the degradation patterns of LIBs.

Reagent-Free Lactate Detection Using Prussian Blue and Electropolymerized-Molecularly Imprinted Polymers-Based Electrochemical Biosensors.

Sweat lactate, a promising biomarker for assessing physical performance and health conditions, calls for noninvasive, convenient, and affordable detection methods. This study leverages molecularly imprinted polymers (MIPs) as a synthetic biorecognition element for lactate detection due to their affordability and high stability. Traditional MIPs-based electrochemical sensors often require external redox probes such as ferricyanide/ferrocyanide in the solution to signal the binding between analytes and MIPs, which restricts their applicability. To address this, our study introduces an innovative approach utilizing a layer of Prussian blue (PB) nanoparticles as the internal redox probe on screen-printed carbon electrodes (SPCE), followed by a layer of electropolymerized MIP (eMIP) for molecular recognition, enabling reagent-free lactate detection. The real-time growth of eMIP and the processes of template elution and lactate rebinding were examined and validated using electrochemical surface plasmon resonance (EC-SPR) spectroscopy. The sensor's performance was thoroughly investigated using Differential Pulsed Voltammetry (DPV) and Electrochemical Impedance Spectroscopy (EIS) with samples spiked in 0.1 M KCl solution and artificial sweat. The developed sensors demonstrated a fast and selective response to lactate, detecting concentrations from 1 to 35 mM with a Limit of Detection (LOD) of 0.20 mM, defined by a signal-to-noise ratio of 3 in the DPV measurements. They also exhibited excellent reproducibility, reusability, and a shelf life of up to 10 months under ambient conditions. These eMIP/PB/SPCE-based lactate sensors show considerable potential as point-of-care (POC) devices for sweat lactate detection, and the technology could be adapted for reagent-free detection of a broad spectrum of molecules.

Simultaneous and sensitive detection of ascorbic acid and uric acid using a novel MnTMPyP/LaTa2O7 nanocomposite modified glassy carbon electrode

A novel nanocomposite MnTMPyP/LaTa2O7 was synthesized via intercalation of [5, 10, 15, 20-tetrakis (N-methylpyridinium-4-yl) porphyrinato manganese (III) (MnTMPyP) into the laminar structure of RbLaTa2O7 using an ion exchange method. An electrochemical sensor utilizing a MnTMPyP/LaTa2O7 modified glassy carbon electrode (GCE) was employed for the simultaneous detection of ascorbic acid (AA) and uric acid (UA). X-ray diffractometry, Fourier infrared spectroscopy, and transmission electron microscopy were utilized to characterize the structure in this experiment. Differential pulse voltammetry (DPV), electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV) were employed to analyze the electrochemical properties. The MnTMPyP/LaTa2O7/GCE demonstrated a larger electrochemically active area (0.106 cm2), lower charge transfer resistance (43.1 Ω), and enhanced catalytic activity compared to single-component modified electrodes (RbLaTa2O7/GCE, bare/GCE). The detection limits, within the concentration ranges of 1.25–40.41 μM for AA and 0.62–11.81 μM for UA (S/N = 3), were estimated to be 0.37 μM and 0.44 μM, respectively. MnTMPyP/LaTa2O7/GCE also exhibits excellent stability, reproducibility, and anti-interference compared to previous literatures. Furthermore, the performance of MnTMPyP/LaTa2O7/GCE was demonstrated in real urine samples, achieving recoveries between 98.7 % and 103.5 %. The ion exchange provides a simpler method for the preparation of multifunctional electrochemical sensing.

Effect of Li2O composition and temperature on the ionic conductivity of lithium-borate-silicate glasses containing gold nanoparticles using electrochemical impedance spectroscopy

Effect of Li2O composition and temperature on the ionic conductivity of lithium-borate-silicate glasses containing gold nanoparticles using electrochemical impedance spectroscopy