The ionic pairing of 1-butyl-3-methylimidazolium tetrachloroferrate [Bmim] [FeCl4] magnetic ionic liquid in two plasticizers ethylene carbonate (EC), propylene carbonate (PC) separately and combination of (EC–PC) has been studied by ATR Infrared spectroscopy. Spectra were taken in the IR range 600 to 4000 cm–1. For experimental analysis plasticizer concentration range of 0.5 to 2.0 mol was used. The interaction of [Bmim] with these plasticizers (EC, PC and EC + PC) modifies the Hydrogen bonding. The complex and broad bands in FTIR after interactions is an indication of ionic pairing.
The transport properties of sodium nitrate (NaNO3) and ammonium nitrate (NH4NO3) in aqueous 2-butoxyethanol (mass fractions: 0.20, 0.40, and 0.60) mixtures were examined using electrical conductivity measurements at 298.15, 303.15, 308.15, and 313.15 K. The experimental conductance data were analyzed using the Fuoss conductance–concentration equation (1978) to evaluate ion association parameters and to gain insights into the ion–solvent and ion–ion interactions within the mixed solvent systems. The estimates of the individual ionic contributions to the limiting molar conductance were also made in this analysis. The calculated values of ion association parameters suggest a weak electrostatic ion solvent interaction for these two salts in aqueous 2-butoxyethanol mixture. Moreover, the electrolytes were found to exist predominantly as free ions across all solvent compositions and within the entire temperature range investigated in this study. The influence of temperature and solvent composition on the association constants and single-ion conductivities of the electrolytes was systematically examined and discussed. The Walden products of the ions exhibited significant deviations with changes in temperature and solvent composition.
An electrode based on Cu–Al layered double hydroxide-modified carbon paste was successfully developed for analyzing residual free chlorine levels in water. To evaluate the electrode, its structure, composition, and electrochemical performance were characterized by X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), Fourier-transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), and various electrochemical techniques. The electrochemical response to free chlorine was examined for various parameters, including accumulation time, pH, scan rate, and electrolyte effect. This study used differential pulse voltammetry (DPV) to measure free chlorine, as this technique is highly sensitive and efficient. A linear range of 0.0005 to 1000 µM, with a detection limit of 0.00015 µM (S/N = 3), was obtained under optimal conditions. The electrode exhibited satisfactory reproducibility and selectivity. The proposed sensor successfully quantified residual free chlorine in real water samples.
Herein, a CC@Fe3O4 nanowire-modified carbon cloth composite was constructed to investigate the interfacial chemistries and catalytic features pertaining to lithium polysulfides. The carbon cloth sheathed by one-dimensional Fe3O4 nanowires provides abundant polar active sites as well as highly conductive electron pathways. The CC@Fe3O4 composite exhibits a suppressed shuttle effect of lithium polysulfides. Visual adsorption experiments and UV-visible spectroscopy confirm the strong chemical bonding between CC@Fe3O4 and lithium polysulfides. X-ray photoelectron spectroscopy reveals the formation of Fe–S and Li–O interfacial bonds, which stabilizes a dual-site chemical anchoring mechanism. The polysulfide redox kinetics, evaluated in symmetrical cells, demonstrate that Fe3O4 nanowires serve as efficient catalysts to accelerate the electrochemical conversion of sulfur species. Benefiting from these features, the composite delivers higher Li+ diffusion coefficients and lower charge-transfer resistance. These results verify that CC@Fe3O4 establishes a chemically regulated and catalytically active interface, enabling simultaneous immobilization and rapid conversion of lithium polysulfides. This work provides a mechanistic insight into polar metal-oxide nanowire hosts and offers guidance for the rational design of advanced sulfur cathodes for lithium-sulfur batteries.
The binding interactions of (E)-2,4-di-tert-butyl-6-(((4-phenoxyphenyl)imino)methyl)phenol (TBIP) with bovine serum albumin (BSA), human serum albumin (HSA), and calf thymus DNA (CT-DNA) were investigated using square-wave voltammetry (SWV) at pH 7.40, as well as molecular docking (MD) application. In addition, the physicochemical properties, pharmacokinetic characteristics, toxicity potencies and biological targets of TBIP were predicted by using pkCSM and Swiss Target Prediction online tools. The ADMET properties of TBIP were compared to those of other analogue Schiff bases ((E)-1-((4-phenoxyphenylimino)methyl)naphthalen-2-ol, abbreviated as PMNO, and (E)-1-[(2-phenoxyphenylimino)methyl]naphthalen-2-ol, abbreviated as 2-PPMN). According to the SWV results, the decreased cathodic peak current of TBIP in the presence of aforementioned bio-molecules (BMs) indicated that it interacts with them. Moreover, the electrochemical results showed that BSA has a higher binding constant in the comparison to HSA and DNA, respectively, and also reveal that TBIP forms biomolecular complexes in the molar ratio of 1 : 1. On the other hand, the binding constants of TBIP to these biomolecules were also evaluated according to those of the bio-molecule (BM) complexes of PMNO, 2-PPMN, doxorubicin (Dox) and ethidium (Et+). The MD outcomes suggest that both hydrophobic and π-cation interactions were formed in the interaction between TBIP and HSA while only the hydrophobic interactions contributed to stabilizing the TBIP–BSA complex. In addition, the MD analysis of TBIP with A-DNA compound showed the binding affinity (BA) of −7.4 kcal mol−1 with two H-bonds and four π–π interactions when compared to B-DNA with BA of −7.9 kcal mol−1 and one H-bond. Finally, MD results exhibited that TBIP is a minor groove binder and H-bond interactions have paramount effect in the stabilities for its complexes with A- and B-DNA, respectively. The order in the estimated BA values of these BMs with TBIP was observed as follows: BSA>HSA>B-DNA>A-DNA. The BA values of TBIP to A- and B-DNA were compared with well-known DNA intercalators such as Dox and Et+. TBIP exhibited lower BA values than Dox, though higher than Et+. Finally, the differences observed in albumin-binding in comparison to PMNO analogue with 2-naphthol moiety appear to be mostly related to the steric effects of the tertiary butyl groups.
The content of Bromhexine HCl in pharmaceutical formulation was determined using adsorptive stripping voltammetry with a glassy carbon electrode (GCE) modified by electrochemical reduced graphene oxide (ErGO/GCE). The results revealed that the electrochemical oxidation of bromhexine HCl on the ErGO/GCE electrode is an irreversible process and adsorptive on the surface of the electrode. The optimal conditions included Britton–Robinson buffer at pH 5.5, an accumulation potential of 0 V, an accumulation time of 60 s, a scan rate of 0.025 V/s, and a linear concentration range from 1 × 10–8 to 5 × 10–6 mol L–1. The method demonstrated high sensitivity with a limit of detection (LOD) of 2.7 × 10–9 mol L–1 and a limit of quantification (LOQ) of 9 × 10–9 mol L–1. It exhibited good repeatability with a relative standard deviation (RSD) of less than 5
The gas diffusion layer (GDL) is a representative porous medium governing coupled heat and mass transfer in proton exchange membrane fuel cells (PEMFCs), where the through-plane porosity distribution critically affects reactant transport, water migration, and thermal behavior. To clarify the regulation mechanisms of porosity gradients on multi-physical transport, a three-dimensional PEMFC model is established. Uniform, exponential-gradient, and linear-gradient cathode GDL structures are systematically compared in terms of mass transport, heat transfer and electrochemical coupling characteristics. The results reveal that through-plane porosity gradients reconstruct the spatial distribution of effective diffusion resistance, eventually redistributing oxygen transport, water vapor removal, liquid water accumulation, and heat dissipation within the porous medium. Compared with the uniform GDL, the linear-gradient structure mitigates oxygen concentration decay near the CL, suppresses local water accumulation, and reduces the through-plane temperature gradient, resulting in more uniform heat–mass coupling. In contrast, exponential gradients induce locally intensified resistance due to abrupt porosity variations, leading to constrained transport regulation. Unlike previous studies focusing mainly on porosity size or averaged performance, this work demonstrates that the continuity and smoothness of through-plane porosity gradients govern the redistribution of transport resistance and reaction intensity. These findings provide mechanistic guidance for designing gradient structured porous media in coupled heat and mass transfer systems.
Results of determination of the diffusion coefficient of the [Bi-EDTA]– complex ion in aqueous electrolytes are shown. Two independent methods are compared, namely, the measurements of the limiting diffusion current on a rotating disk electrode and the analysis of transient processes within the framework of the chronoamperometric method. Considering an electrochemical system complicated by a high overpotential of metal nucleation on the glassy carbon electrode, the possibility of evaluating the diffusion coefficient from cyclic voltammetry data is assessed using the Cottrell equation for describing the descending branch of the voltammogram. The experimentally measured diffusion coefficient of the [Bi-EDTA]– complex ion is found to be (3.8 ± 0.2) × 10−6 cm2/s. The obtained results are of significant importance for optimizing the electrodeposition conditions for bismuth-containing alloys and compounds with controlled stoichiometry from EDTA-based electrolytes.
In this study, the aim is to investigate the effect of various factors on wide temperature anode oxidation, which can save energy in anode oxidation process of aluminum alloy and determined the optimum anode oxidation process index. When the aluminum alloy 6061 is anodized in an electrolyte solution with oxalic acid and nickel salt added to the sulfuric acid solution, the surface characteristics of the samples anodized at 35°C are similar to those of the samples anodized by the present method at 20°C, so that the allowable temperature range of anode oxidation can be increased to 10°C and the energy consumed for cooling of the electrolyte during the anode oxidation can be significantly reduced.
This study investigates the use of electrochemical impedance spectroscopy (EIS) and adaptive neuro-fuzzy inference system (ANFIS) modeling to predict the concentration of butyric and acetic acids in a fermentation broth. Initially, a simulation of the glycolysis process was conducted to produce butyric acid and acetic acid from glucose. Using insights from the simulation data, mixtures of acetic and butyric acids were prepared at known concentrations. EIS measurements were performed on these mixtures to extract impedance parameters, which were subsequently fitted to equivalent circuit models. The extracted parameters served as inputs for the ANFIS model, which was trained to establish a relationship between electrochemical parameters and acid concentrations. The developed ANFIS model acts as a soft sensor, enabling accurate prediction of acid concentrations in fermentation broth based on electrochemical data. This approach offers a novel method for real-time monitoring and control of fermentation processes, enhancing efficiency and product quality. The findings demonstrate the potential of combining EIS and ANFIS for advanced process analytics in biotechnological applications. Future work will focus on validating the model with diverse fermentation conditions and scaling up the methodology for industrial use.
Pd(WC1–x)/C-electrodes were obtained by redox reaction between Pd2+ ions and tungsten carbide WC1–x. The palladium mass released in 2 h from of 0.1 M PdCl2 + 0.5 M H2SO4 solution is 0.60 ± 0.03 mg/cm2 (the electrode geometric surface); the specific surface area is 8.5 m2/g. The palladium is found to be reduced to a zero oxidation degree during currentless deposition; the basic products of WC1–x oxidation are tungsten oxides. The catalytic effect of the Pd(WC1–x)/C-electrodes in the hydrogen evolution reaction and oxidation of formic acid reaction has been discovered.
To investigate the effect of selenization degree on the electrochemical performance of iron selenides, FexSey/carbon composites with different selenization degrees are successfully synthesized via a solid-state reaction using ferric citrate as the precursor, by regulating the reaction temperature and Fe/Se molar ratio. Structural characterization reveals that reaction temperature is the key factor determining the phase composition: with increasing temperature, the selenization degree decreases gradually, showing a phase evolution law of FeSe2 → Fe3Se4 → Fe7Se8. Electrochemical tests indicate that Fe3Se4 exhibited the optimal reversible capacity (754.5 mA h g–1) and cycling stability (86.7
Electrochemical hydrogen compression technology is a promising alternative for hydrogen compression due to its simultaneous compression and purification, high efficiency, and simple design. One of the main problems in electrochemical hydrogen compressors is to improve the properties of membranes such as proton conductivity, mechanical strength, low hydrogen crossover. Here we report the properties of sulfonated poly(ether ether ketone) composite membranes reinforced with cellulose nanocrystals (CNCs) for the electrochemical compression systems. The physicochemical properties, including the morphology of composite membranes, water uptake, mechanical strength, ion exchange capacity and proton conductivity were evaluated. The mechanical strength of composite membrane with 3 wt
Owing to the high specific surface area and adjustable pore size distribution, biomass-derived carbon nano-onions (CNOs) have lately aroused the interest of researchers in supercapacitor applications. Herein, we employ ajwain oil-derived, porous CNOs for supercapacitor applications. In this study, carbon nano-onions (CNOs) are synthesized through a simple, scalable, one-step “wick-and-oil” flame method followed by KOH activation. Microstructural analysis reveals monodisperse carbon nanoparticles with high porosity, attributed to the long-chain hydrocarbons and active components such as phenolic carvacrol and thymol present in ajwain oil, which contribute to high carbon yield and improved ion diffusion pathways. Electrochemical studies are performed using a three-electrode setup in 6 M KOH electrolyte. The CNO electrodes exhibits excellent charge transfer properties, achieving a specific capacitance of 276.2 F g–1 at 1 A g–1. The charge storage mechanism has analyzed through surface- and diffusion-controlled contribution analysis. At lower scan rates, diffusion charge contribution is more dominant, whereas at higher scan rates, a significant surface charge contribution of 88.4
Hydrogen evolution catalysts based on sodium-pectate nickel carbonized complexes are developed. These catalysts are promising for use in water electrolyzers. The leading catalyst with the sodium ions’ 25
Acidithiobacillus thiooxidans is an extremophilic bacterium adapted to highly acidic, metal-rich environments. While its role in extracellular electron transfer (EET) has gained interest, the contribution of type IV pilins (T4P) remains poorly understood. In this study, we electrochemically characterized two recombinant pilins from A. thiooxidans, PilA (major) and PilV (minor), to explore their potential involvement in redox activity. Using a three-electrode electrochemical setup, PilV displayed a distinct anodic response at 0.95 V with a peak current of 75 µA, indicating high redox responsiveness. In contrast, PilA showed a broader oxidation range (0.55–1.1 V) and a weaker signal ( 50 µA). These differences correlate with the surface accessibility of electroactive amino acids (EAAs), particularly tyrosine. Structural modeling revealed that while both pilins contain aromatic residues, in PilA they are partially buried within an α-helix, whereas in PilV they are more exposed in the globular domain. This spatial arrangement likely enhances PilV’s capacity for direct electron transfer. Altogether, our findings suggest that PilV’s structure is better suited for redox coupling with solid surfaces, supporting its potential role in EET and highlighting its relevance in future studies of microbial electron transport in extreme environments.
A poly L-arginine/β-cyclodextrin molecularly imprinted polymer-modified graphite electrode (PL-Arg/β-CD MIPs/GE) was developed for sensitive acetaminophen detection. The sensor achieved a wide linear range of 0.1–200 μmol L–1 and a low detection limit of 0.022 μmol L–1, attributed to synergistic enrichment and electron transfer. It demonstrated excellent selectivity, reproducibility, and high recovery (98.20–102.80
Electrocoagulation has turned out to be a versatile and sustainable remediation for wastewater alterations, with many advantages over established treatment techniques. This is an electrochemical process that complexes the principles of coagulation, flotation and precipitation to completely remove a variety of pollutants from various types of wastewaters. An electric current is applied to sacrificial iron or aluminum electrodes, whereby electrocoagulation causes the production of coagulants in situ, causing destabilization and aggregation of the inorganic and organic materials from the water. This method has been found to be promising in treating industrial effluent, municipal wastewater, and even emergent contaminants such as pharmaceuticals and personal care products. It is energy-efficient and requires only limited and less toxic chemicals and leads to deficient sludge generation, thereby making it an eco-friendly substitute to the conventional chemical coagulation methods. Besides, electro-coagulated systems are compact, easily automated and easily fit different scales of operation-right from small decentralized units to large treatment plants. Given the ever-escalating concern worldwide over water scarcity and pollution, electrocoagulation is one of the promising technologies for strengthened water management and environmental conservation.
To address the challenge regarding nitrate pollution from agriculture and industry, we developed a novel integrated system featuring a bimetallic membrane electrode assembly (Pt|Nafion|Pt–Cu) coupled with a suspended Pd–Cu/activated carbon (AC) catalyst for the nitrate reduction reaction (NRR) in low-conductivity media. This design leverages a synergistic mechanism, combining electrochemical reduction and catalytic hydrogenation for enhanced efficiency. The system demonstrated exceptional performance, achieving a high observed rate constant (kobs = 43.2 × 10−3 min−1) alongside superior product selectivity; notably low nitrite accumulation (15.8
A corrosion behavior of an intermetallic compound and solid solutions based on the Co75Me25 two-component systems, where Me = Si, Fe, Cr, is considered. The surface morphology of the samples is analyzed using electron and optical microscopy. Corrosion is studied using the polarization-curve method and electrochemical impedance spectroscopy. The greatest corrosion resistance is shown to be achieved in the Co–Cr sample due to the presence of chromium alloying additive, an inhibitory component. Results of corrosion tests for the catalytic capabilities of two-component alloys is discussed briefly. This study also made it possible to explain the role of the intermetallic compound Co2Si in terms of corrosion behavior of an active electrode-catalyst in the nitrate electrochemical reduction reaction.
