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This study presents a method for synthesizing superparamagnetic nanoparticles through the co-precipitation method, with a coating of tetrahydroxy-1,4-quinone (THQ). The diameter of the magnetite nanoparticles (MNPs) covered with THQ varied depending on the recovery method applied. When collected through magnetic decantation, they exhibited an average diameter of 15 ± 3 nm, while centrifugation of the supernatant further reduced the diameter to 12 ± 3 nm. In contrast, the uncoated MNPs had an average diameter of 17 ± 5 nm. The smaller MNPs coated with THQ displayed very low magnetic hysteresis and demonstrated superparamagnetic behavior, indicated by a blocking temperature of less than 300 K. Characterization of both the coated and uncoated MNPs encompassed structural, morphological, size, and magnetic property analyses using X-ray diffraction (XRD), transmission electron microscopy (TEM), and vibrating sample magnetometer (VSM), respectively. Fourier-transform infrared spectroscopy (FT-IR) and UV–Vis spectroscopy were employed to investigate the chemical interaction between THQ and the MNPs. In addition, cyclic voltammetry was used to compare the electrochemical changes of THQ, MNPs, and MNPs coated with THQ. [ABSTRACT FROM AUTHOR]

Fluorinated organic compounds (FOCs) represent a class of synthetic chemicals distinguished by their resilient carbon–fluorine bonds, which demonstrate an ability to withstand environmental degradation over an extended period. The integration of FOCs into cutting-edge applications, including lithium-ion batteries (LiBs), presents considerable potential for environmental harm that has not yet been sufficiently addressed. This study focuses on the environmental fate of two fluorinated aromatics, tris(pentafluorophenyl)borane (TPFPB) and tris(pentafluorophenyl)phosphine (TPFPP), given their important role in improving the performance of LiBs. To achieve this, laboratory simulation methods including total oxidizable precursor assay, electrochemistry (EC), Fenton reaction, UV-C irradiation, and hydrolysis were employed. Liquid chromatography and gas chromatography coupled with high-resolution mass spectrometry were used for identification of transformation products (TPs) and prediction of their molecular formulae. Despite the structural similarity between TPFPB and TPFPP, distinct differences in electrochemical behavior and degradation pathways were observed. TPFPB readily underwent hydroxylation and hydrolysis, resulting in a wide range of 49 TPs. A total of 28 TPs were newly identified, including oligomers and highly toxic dioxins. In contrast, TPFPP degraded exclusively under harsh conditions, requiring the development of innovative conditioning protocols for EC. In total, the simulation experiments yielded nine structurally different compounds, including seven previously undescribed, partially defluorinated TPs. This study highlights the potential risks associated with the use of FOCs in LiBs and provides insight into the complex environmental behavior of FOCs. [ABSTRACT FROM AUTHOR]

The development of cost-effective and highly efficient electrocatalysts is critical to help electrochemical non-enzymatic sensors achieve high performance. Here, a new class of catalyst, Ru single atoms confined on Cu nanotubes as a single-atom alloy (Ru1Cu NTs), with a unique electronic structure and property, was developed to construct a novel electrochemical non-enzymatic glucose sensor for the first time. The Ru1Cu NTs with a diameter of about 24.0 nm showed a much lower oxidation potential (0.38 V) and 9.0-fold higher response (66.5 μA) current than Cu nanowires (Cu NWs, oxidation potential 0.47 V and current 7.4 μA) for glucose electrocatalysis. Moreover, as an electrochemical non-enzymatic glucose sensor, Ru1Cu NTs not only exhibited twofold higher sensitivity (54.9 μA mM−1 cm−2) and wider linear range (0.5–8 mM) than Cu NWs, but also showed a low detection limit (5.0 μM), excellent selectivity, and great stability. According to theoretical calculation results, the outstanding catalytic and sensing performance of Ru1Cu NTs could be ascribed to the upshift of the d-band center that helped promote glucose adsorption. This work presents a new avenue for developing highly active catalysts for electrochemical non-enzymatic sensors. [ABSTRACT FROM AUTHOR]

Nanozymes are a class of nanomaterials with biocatalytic function and enzyme-like activity, whose advantages include high stability, low cost, and mass production. They can catalyze the substrates of natural enzymes based on specific nanostructures and serve as substitutes for natural enzymes. Their applied research involves a wide range of fields such as biomedicine, environmental governance, agriculture, and food. Molecular logic gates are a new cross-disciplinary discipline, which can simulate the function of silicon circuits on a molecular scale, perform single or multiple input logic operations, and generate logic outputs. A molecular logic gate is a binary operation that converts an input signal into an output signal according to the rules of Boolean logic, generating two signals, a high level, and a low level. The high and low levels represent the "true" and "false" values of the logic gates, and their outputs correspond to "l" and "0" of the molecular logic gates, respectively. The combination of nanozymes and logic gates is a novel and attractive research direction, and the cross-application of the two brings new opportunities and ideas for various fields, such as the construction of efficient biocomputers, intelligent drug delivery systems, and the precise diagnosis of diseases. This review describes the application of logic gates based on nanozymes, which is expected to provide a certain theoretical foundation for researchers' subsequent studies. [ABSTRACT FROM AUTHOR]

Voltage-responsive biosensors capable of monitoring real-time adsorption behavior of biological analytes onto electroactive surfaces offer attractive strategies for disease detection, separations, and other adsorption-dependent analytical techniques. Adsorption of biological analytes onto electrically switchable surfaces can be modelled using neutravidin and biotin. Here, we report self-assembled monolayers formed from voltage-switchable biotinylated molecules on gold surfaces with tunable sensitivity to neutravidin in response to applied voltages. By using electrochemical quartz crystal microbalance (EQCM), we demonstrated real-time switchable behavior of these bio-surfaces and investigate the range of sensitivity by varying the potential of the same surfaces from −400 mV to open circuit potential (+155 mV) to +300 mV. We compared the tunability of the mixed surfaces to bare Au surfaces, voltage inert surfaces, and switchable biotinylated surfaces. Our results indicate that quartz crystal microbalance allows real-time changes in analyte binding behavior, which enabled observing the evolution of neutravidin sensitivity as the applied voltage was shifted. EQCM could in principle be used in kinetic studies or to optimize voltage-switchable surfaces in adsorption-based diagnostics. [ABSTRACT FROM AUTHOR]

The current study is concerned with understanding the synthesis and application of the diversified BaS3:La2S3:Dy1.8 dithiocarbamate sulphide by the single source precursor (SSP) approach. Analytical approaches were used to evaluate the optical, crystalline, vibrational crosslinking, morphological, and thermal properties of BaS3:La2S3:Dy1.8 chalcogenide. The synthesized chalcogenide has an average crystallite size of 16.35 nm and mixed phases, with a direct band gap energy of 3.9 eV. The study of functional groups revealed the presence of metal sulphide bonds. In terms of morphology, BaS3:La2S3:Dy1.8 chalcogenide has an uneven shape with a small amount of aggregation. The electrochemical charge storage behavior of BaS3:La2S3:Dy1.8 was studied using a nickel foam electrode. The trichalcogenide-decorated electrode exhibited charge-storing behavior, with a specific capacitance of 723 F g− 1 determined by cyclic voltammetry. The electrode has a specific power density of 11,166 W kg− 1 and a low series resistance of 0.9 Ω, as shown by impedance measurements. [ABSTRACT FROM AUTHOR]

In this paper, we introduce a density-based topology optimization framework to design porous electrodes for maximum energy storage. We simulate the full cell with a model that incorporates electronic potential, ionic potential, and electrolyte concentration. The system consists of three materials, namely pure liquid electrolyte and the porous solids of the anode and cathode, for which we determine the optimal placement. We use separate electronic potentials to model each electrode, which allows interdigitated designs. As a result, a penalization is required to ensure that the anode and cathode do not touch, i.e., causing a short circuit. We compare multiple 2D designs generated for different fixed conditions, e.g. material properties. A 3D design with complex channel and interlocked structure is also created. All optimized designs are far superior to the traditional monolithic electrode design with respect to energy storage metrics. We observe up to a 750% increase in energy storage for cases with slow effective ionic diffusion within the porous electrode. [ABSTRACT FROM AUTHOR]

Water pollution by metals is increasing. An electrode material, copper hexacyanoferrate (CuHCF), for capacitive deionization (CDI) to remove Co2+ from wastewater was developed. The asymmetric electrode structure of the CDI overcomes the limitations of traditional activated carbon electrodes (low ion removal capacity, ion removal rate, and charge efficiency). The specific capacitance of the CuHCF electrode (216.7 F g−1) at 1 mV s−1 was higher than that of a traditional electrode (92.0 F g−1), and its deionization capacity was 156.85 mg g−1 in 50 mg L−1 aqueous Co2+ (charge efficiency = 68.4%). CuHCF is a high-performance electrode material for wastewater remediation. [ABSTRACT FROM AUTHOR]

In order to measure the migration parameters of nuclides in bentonite more conveniently, an improved through-discharge electromigration method was developed. In this method, the nuclides first were driven by the electric field to migrate through the bentonite column fast, then discharged with the carrier fluid, and finally collected automatically for measurement. Meanwhile, based on the analysis of the important process in the method, the solution equation for deriving the migration parameters of nuclides was established. Furthermore, two kinds of through-discharge electromigration devices were designed in term of the different nuclide sorption behaviors onto the bentonite, and the electromigration breakthrough curves of 88Sr and 239Pu in bentonite were obtained for the first time. The result indicated that the improved electromigration technology was quite efficient for acquiring the migration parameters of 88Sr with weak adsorption capacity. However, it was found that more experimental data were needed to support the analysis of 239Pu migration behavior because of its complex electrochemistry reaction with bentonite. [ABSTRACT FROM AUTHOR]

Poly (ethylene glycol dimethacrylate-1,2-ethanedithiol) (P(EDGMA-EDT)) and poly (ethylene glycol dimethacrylate-3,6-dioxy-1,8-octanedithiol) (P(EDGMA-DODT)) are excellent solid polymer electrolytes synthesized experimentally. The coordination structure, redox properties, and modification design of P(EDGMA-EDT)-LiTFSI and P(EDGMA-DODT)-LiTFSI are investigated by density functional theory. The theoretical simulation of infrared spectra and the coordination structure information show that the ester carbonyl group in P(EDGMA-EDT) and the ester carbonyl group and ether oxygen in P(EDGMA-DODT) interact with Li+ ions. Li+ ion coordination numbers in these two electrolytes are 4 and 5; thioether and ester groups in polymers are their redox active sites, respectively. Modified sulfone oxide P(EDGMA-EDT)2-SO2 and P(EDGMA-DODT)2-SO2 cannot only maintain the reduction stability but also greatly improve the oxidation potential. LiPF6, LiDFBOP, and LiBF3Cl are good candidates for sulfone-based polymers. The electron-withdrawing groups (− 4Br, − 4Cl, − 4F, − NO2, and − CN) substitution can improve the oxidation potential of P(EDGMA-EDT) but have little effect on the oxidation potential of P(EDGMA-DODT) and reduce the reduction stability of both polymers. These findings provide theoretical guidance for the coordination structure as well as the molecular design of solid electrolytes containing ester groups and thioether. [ABSTRACT FROM AUTHOR]

Iron-based Prussian blue analogs (PBAs) are synthesized using a modified coprecipitation approach at different temperatures to study the effect of coprecipitation reaction temperature on structural and electrochemical performance. The experimental results showed that the iron-based PBAs transferred from the cubic structure to the monoclinic phase as the temperature increased from 5 °C to 60 °C, with the former exhibiting rich-in-boundary morphology and the latter showing a well-defined cubic shape. The electrochemical performance of the samples is closely related to the structure: the PBAs with monoclinic structures exhibit a higher charge/discharge specific capacity than those of PBAs with cubic structures. In addition, the samples are further treated at 270 °C, new phases are probed, and the charge/discharge specific capacity for the HT-PB-60 sample is significantly improved by more than 36.15%. [ABSTRACT FROM AUTHOR]

In this paper, based on the principle of gradient aperture, a cathode gas diffusion layer with three microporous layers was prepared using conductive carbon black with three different particle sizes. The thickness of the microporous layers was studied, and a gradient hydrophobic structure was designed. The purpose was to maximize the output performance of the cell by adjusting the preparation parameters of the microporous layers. The physical and electrochemical properties of each sample showed that the change in micropore layer thickness redistributed the pore size distribution of the gas diffusion layer, especially increasing the number of pore sizes in the range of 20–40 µm. They improved the liquid water transport capacity of the gas diffusion layer at high current density. The gradient hydrophobic structure of the microporous layer promoted the cathode gas diffusion layer to expel liquid water in time and ensure the oxygen supply. The results showed that when the microporous layer thickness was 60 µm. The hydrophobic agent content in the three microporous layers was 10 wt%, 20 wt%, and 30 wt%, respectively, the limiting power densities of 0.883, 0.916, and 0.863 W/cm2 could be achieved under the three humidity conditions of 40%, 60%, and 100%, respectively. The limiting power density increased by 17.1%, 12.0%, and 18.1%, respectively, compared with the samples with the same optimal thickness but no gradient hydrophobic structure. [ABSTRACT FROM AUTHOR]

Sand aging, defined by time-dependent increases in stiffness and strength over periods ranging from days to months, poses significant challenges in geotechnical engineering and soil science. Despite its relevant implications, the mechanisms driving sand aging remain understood. This review systematically examines sand aging, emphasizing the classification of chemical and mechanical processes involved. Key advancements in chemical aging understanding, particularly the influence of surface chemistry and electrokinetic forces, are discussed. Additionally, the review underscores the critical role of micromechanical modeling, especially discrete element methods, in elucidating particle interactions and aging phenomena. The review also identifies essential directions for future research, notably incorporating particle shape and surface texture into aging models. Hence, this comprehensive resource aims to enhance the understanding of sand aging. [ABSTRACT FROM AUTHOR]

1070 aluminum has good plasticity, but its anisotropy and low dissolution rate limit its application as a soluble sealing ring. To solve the existing plastic anisotropy problem of 1070 aluminum-rolled plate, the effect of heat treatment and copper plating were studied. The results of static uniaxial tensile tests showed that the average elongation of the heat-treated samples increased by 50.54% and the standard deviation of the elongation in different directions decreased by 28.42%. The simulated setting and pressure-stabilizing test further showed that the sealing ring after heat treatment has better sealing performance. Copper plating containing massive uniformly distributed micropores was prepared by electroless plating. The morphology and elements distribution of the copper plating were observed by optical microscope and scanning electron microscope. The dissolution rate and corrosion behavior were characterized by immersion experiment and the electrochemical test. The results showed that the average dissolution rate of copper-plated samples increased by two orders of magnitude compared with 1070 aluminum and a large number of pitting pits with the maximum pitting depth of about 2400 μm generated on the surface of the copper-plated samples due to the synergistic effect of Cl− and "Al-Cu" galvanic corrosion. [ABSTRACT FROM AUTHOR]

Tetracycline antibiotics are a common type of antibiotics in life. In this research, Fe2+ and Cu2+ was used to modify granular activated carbon, and peroxydisulfate was activated under the synergistic action of electrochemistry (EC/Fe-Cu-GAC/PS). The effects of the initial concentration of tetracycline hydrochloride (TCH), initial pH, current density, and plate spacing on the degradation of TCH were investigated. Experimental results indicated that the removal efficiency of TCH was 87.27% by the EC/Fe-Cu-GAC/PS system. The removal rate of TCH decreased with the increase of initial concentration of TCH. The TCH removal rate is maintained at a high level when pH values range from 3 to 7. Increasing the amount of catalyst and persulfate in a certain range, as well as the magnitude of current density and plate spacing are helpful for TCH removal. When the initial TCH concentration is 20 mg/L, the initial pH value is 5.0, the amount of Fe-Cu-GAC is 2.0 g, the PS concentration is 2 mmol/L, the electrolyte concentration is 25 mmol/L, the current density is 15 mA/cm2, and the plate spacing is 9 cm, the TCH removal effect is the most effective. The free-radical experiment showed that sulfate radicals (SO4•−) played a dominant role under acidic conditions. According to the data analysis, the kinetic model of the EC/Fe-Cu-GAC/PS system was consistent with the first-order reaction kinetics. According to the reaction dynamics, we get the rating of influencing factors that influence the effect of TCH removal. The EC/Fe-Cu-GAC/PS system can effectively degrade tetracycline antibiotics in water. [ABSTRACT FROM AUTHOR]

Metal-organic frameworks (MOFs) are highly attractive porous materials with applications spanning the fields of chemistry, physics, biology, and engineering. Their exceptional porosity and structural flexibility have led to widespread use in catalysis, separation, biomedicine, and electrochemistry. Currently, most MOFs are synthesized under equilibrium liquid-phase reaction conditions. Here we show a general and versatile non-equilibrium flame aerosol synthesis of MOFs, in which rapid kinetics of MOF formation yields two distinct classes of MOFs, nano-crystalline MOFs and amorphous MOFs. A key advantage of this far-from-equilibrium synthesis is integration of different metal cations within a single MOF phase, even when this is thermodynamically unfavorable. This can, for example, produce single-atom catalysts and bimetallic MOFs of arbitrary metal pairs. Moreover, we demonstrate that dopant metals (e.g., Pt, Pd) can be exsolved from the MOF framework by reduction, forming nanoclusters anchored on the MOF. A prototypical example of such a material exhibited outstanding performance as a CO oxidation catalyst. This general synthesis route opens new opportunities in MOF design and applications across diverse fields and is inherently scalable for continuous production at industrial scales. Metal-organic frameworks (MOFs) are typically synthesized in equilibrium liquid-phase reactions. Here, the authors have developed and present a general non-equilibrium flame aerosol method to produce nanocrystal, amorphous, and bi-metallic MOFs. [ABSTRACT FROM AUTHOR]

In this research, we describe the first aptasensor for the detection of the Rift Valley Fever virus (RVFV). The process involved the selection of aptamers through the systematic evolution of ligands by the exponential enrichment (SELEX) technique. After 12 rounds of selection, 6 aptamers were selected and the corresponding binding affinities were assessed using fluorescence binding assays, revealing dissociation constants ranging from 15.45 to 40.98 nM. Notably, among the aptamers, RV2 and RV3 exhibited the highest binding affinities toward RVFV, with dissociation constants of 15.45 and 18.62 nM, respectively. Thiol-modified aptamers were subsequently immobilized onto screen-printed gold electrodes, facilitating the label-free detection of RVFV through square wave voltammetry. The voltammetric aptasensor demonstrated an excellent sensitivity, with a detection limit of 0.015 ng/mL. In addition, cross-reactivity assessments were conducted, where negligible response was obtained when the aptasensor was exposed to non-specific proteins. [ABSTRACT FROM AUTHOR]

Despite national curricula and instructional reforms calling for collaborative problem-solving skills (CPS), however, there is an absence of a theory-laden model showing how to effectively construct CPS for science learning. We therefore developed and validated a simulation-based CPS model that exploits its constructs, sequences, and causal relationships, and evaluating its effectiveness on students' problem-solving. Over the span of a two-week physics science course, 57 ninth-grade students were recruited from two intact middle school classes to engage in this online simulation-based collaborative problem-solving (CPS) program. This program consisted of nine electrochemistry problem-solving lessons spread across four class sessions, each lasting 45 min. Results indicated that the simulation-based CPS model was validated and proven to contribute to effective problem-solving by linking PS solution proposing, peer communication, implementing PS solutions with simulation, and providing evidence-based explanations. The simulation-based CPS model successfully improved the performance of both high- and low-achieving students. With the support and presence of high-achievers, low-achievers' collaboration attitude was boosted, which lead them to achieve similar learning success. [ABSTRACT FROM AUTHOR]

A cortisol biosensor was developed based on double-conducting polymer nanowires, which exhibits excellent conductivity, resistance to biological contamination, and outstanding sensing performance. The biosensor employs dual-mode electrochemical techniques, namely, differential pulse voltammetry (DPV) and chronoamperometry (CA), for the sensitive and low fouling detection of the glucocorticoid hormone cortisol. Experimental results demonstrated that the linear detection range of the biosensor in DPV mode was 1.0 × 10−14–1.0 × 10−8 M, with a detection limit of 0.131 × 10−14 M. In CA mode, the biosensor exhibited a detection range of 1.0 × 10−13–1.0 × 10−7 M and a detection limit of 0.313 × 10−13 M. The biosensor was successfully utilized for the rapid detection of cortisol in human saliva. The combination of a high-specificity cortisol aptamer and functionalized double-conducting polymer nanowires ensured the exceptional specificity and sensitivity of the biosensor in detecting real biological samples. [ABSTRACT FROM AUTHOR]

A theoretical investigation of the electrochemical reaction between β-nitrostyrene and benzaldehyde was conducted at the DFT M06-2X/def2-TZVP level of theory. The reaction mechanism was dissected into five proposed routes, via 3 pathways, concluding with 4 possible products (P1 to P4). To gain a comprehensive understanding, we explored these routes both in the gas phase and in solution using three solvents: dimethylformamide, methanol, and water. In the gas phase, the overall barriers of these five routes (the energy in parentheses refers to the relative G versus reactants in kcal/mol) are in this order: A2 (− 48.22) < A1 (21.29) < C1 (21.59) < B (29.81) < C2 (77.59). The ΔG for the formation of four products (the energy in parentheses refers to the relative G versus reactants in kcal/mol) are in this order: P2 (− 233.40) < P4 (− 82.13) < P3 (− 74.18) < P1 (− 46.97). Therefore, in the extra amount of both benzaldehyde and proton, P2 is the major product, in the extra amount of benzaldehyde and minimum amount of proton, P1 is preferred, and in the small amount of benzaldehyde and proton, P4 is preferred (only via C1 route). In the solvents, despite the gas phase data, path B and product P3 are a favorable path and products. Thermodynamically, the average relative G in three solvents for P3 is − 112.09 kcal/mol, for P2 is − 112.1, for P4 is − 118.46, and for P1 is − 60.25. Kinetically, the average relative G in three solvents for the transition states of P3 is − 8.25 kcal/mol, P2 is − 42.84, P4 is 34.16 via route C1 and 29.05 via route C2, and P1 is 95.81. Therefore, in the excess concentration of proton, P2 is the most favorable product by both kinetic and thermodynamic data and in low concentration of proton, P3 is the most favorable product. [ABSTRACT FROM AUTHOR]

Despite the recent advances in the selective functionalization of C–C bonds in specific substrates, cleavage and functionalization of C–C bonds in acyclic substrates, such as ethane derivatives, remains challenging. In contrast to the well-developed functionalization of one carbon fragment after C–C bond cleavage, herein, we report a novel electro-reductive carboxylation of C (sp3)–C(sp3) bond in multi-aryl ethanes with carbon dioxide (CO2) by utilizing both carbon fragments. Thus, this reaction exhibits an atom-, step-economic approach for the synthesis of carboxylic acids, fulfilling principal aspirations of organic synthesis. Moreover, this method features mild reaction conditions, broad substrate scope, and good functional group tolerance. Symmetric and asymmetric substrates bearing primary, secondary, or tertiary C(sp3)–C(sp3) bonds are all amenable to this strategy, enabling one or two structurally different carboxylic acids to be facilely constructed at the same time. Mechanistic investigations indicate that carbanions might be the key intermediates in this reaction, which could be captured by CO2 efficiently. [ABSTRACT FROM AUTHOR]

This study developed an innovative biosensor strategy for the sensitive and selective detection of canine mammary tumor biomarkers, cancer antigen 15–3 (CA 15–3) and mucin 1 (MUC-1), integrating green silver nanoparticles (GAgNPs) with machine learning (ML) algorithms to achieve high diagnostic accuracy and potential for noninvasive early detection. The GAgNPs-enhanced electrochemical biosensor demonstrated selective detection of CA 15–3 in serum and MUC-1 in tissue homogenates, with limits of detection (LODs) of 0.07 and 0.11 U mL−1, respectively. The nanoscale dimensions of the GAgNPs endowed them with electrochemically active surface areas, facilitating sensitive biomarker detection. Experimental studies targeted CA 15–3 and MUC-1 biomarkers in clinical samples, and the biosensor exhibited ease of use and good selectivity. Furthermore, ML algorithms were employed to analyze the electrochemical data and predict biomarker concentrations, enhancing the diagnostic accuracy. The Random Forest algorithm achieved 98% accuracy in tumor presence prediction, while an Artificial Neural Network attained 76% accuracy in CA 15–3-based tumor grade classification. The integration of ML techniques with the GAgNPs-based biosensor offers a promising approach for noninvasive, accurate, and early detection of canine mammary tumors, potentially revolutionizing veterinary diagnostics. This multilayered strategy, combining eco-friendly nanomaterials, electrochemical sensing, and ML algorithms, holds significant potential for advancing both biomedical research and clinical practice in the field of canine mammary tumor diagnostics. [ABSTRACT FROM AUTHOR]

The Ti–29Nb–13Ta–4.6Zr alloy (TNTZ) is a β-Ti alloy that has a potential for use in biomedical applications as an alternative to the less-compatible Ti64 alloys. Enhancing the strength and the surface finish of TNTZ is essential for biomedical applications. In this research, a combination of high-pressure torsion (HPT) and laser treatment was used to improve the TNTZ properties. The HPT-treated samples showed significantly enhanced mechanical properties when compared with the traditional solution-treated TNTZ. A laser surface treatment immediately forms a hydrophilic surface that transforms into a steady hydrophobic state after 14 days in air and the surface roughness increases with an increase in laser power and a slower scanning rate. The corrosion resistance of TNTZ improves significantly after laser treatment, with the corrosion current dropping from 1 × 10−8 to 1.2 × 10−9 A and the corrosion potential peak shifting to a more positive value from − 0.349 to − 0.158 V. The friction coefficient after laser treatment decreased from 0.134 to 0.093 and then further reduced to 0.082 after 14 days in air thereby suggesting an enhancement in the tribological properties. Overall, the results show that HPT processing combined with a post-HPT laser treatment is beneficial for enhancing the mechanical properties and the corrosion and wear performance of the TNTZ alloy. [ABSTRACT FROM AUTHOR]

The interface between electrocatalyst and electrolyte is highly dynamic. Even in absence of major structural changes, the intermediate coverage and interfacial solvent are bias and time dependent. This is not accounted for in current kinetic models. Here, we study the kinetics of the hydrogen evolution, ammonia oxidation and oxygen reduction reactions on polycrystalline Pt with distinct intrinsic rates and intermediates (e.g. *H, *OH, *NH2, *N). Despite these differences, we discover shared relationships between the pre-exponential factor and the activation energy that we link to solvation kinetics in the presence of electronic excess charge and charged intermediates. Further, we study dynamic changes of these kinetic parameters with a millisecond time resolution during electrosorption and double layer charging and dynamic *N and *NO poisoning. Finally, we discover a pH-dependent activation entropy that explains non-Nernstian overpotential shifts with pH. In sum, our results demonstrate the importance of accounting for a bias and time-dependent interfacial solvent and catalyst surface. Interfacial ion solvation is omnipresent in electrochemistry. Sarabia et al. now explore solvation kinetics with a millisecond time resolution and shine light on the critical role of the solvent during dynamic catalyst and electrosorption kinetics. [ABSTRACT FROM AUTHOR]

The pretreatment and saccharification of dewaxed bagasse (DWB) has been investigated under various reaction conditions ranging 2000 to 3200 psi, at 70 ± 1 °C in supercritical carbon dioxide (SCC). This has been in attempt to transform the DWB into fermentable sugar and bioethanol in high yields. The effect of SCC mediated pretreatment and enzymatic hydrolysis on structural and morphological alterations in DWB has been ascertained through diverse analytical methods. The sugar has been released through cellulase (40 FPU/mL) mediated enzymatic hydrolysis of pretreated DWB in sodium acetate buffer (pH 4.7) within 1 h at SCC 2800 psi, 70 ± 1 °C. The released sugar was subsequently fermented in the presence of yeast (Saccharomyces crevices, 135 CFU) at 28 ± 1 °C over 72 h to afford the bioethanol. The SCC mediated process conducted in acetic acid:water media (1:1) at 2800 psi, 70 ± 1 °C over 6 h has afforded the pretreated DWB with maximum yield towards the production of fermentable sugar and bioethanol. The production of fermentable sugar and bioethanol has been electrochemically estimated through cyclic voltammetry (CV) and square wave voltammetry (SWV) over glassy carbon electrode in KOH (0.1 M). The electrochemical methods were found selective and in close agreement for estimation of the yields (%) of fermentable sugars and bioethanol. The yield (%) of fermentable sugar estimated from CV and SWV were 80.10 ± 5.34 and 79.00 ± 5.09 respectively. Whereas the yield (%) of bioethanol estimated from CV and SWV were 81.30 ± 2.78% and 78.6 ± 1.25% respectively. Present investigation delivers a SCC mediated green and sustainable method of pretreatment of DWB to afford the enhanced saccharification, to produce bioethanol in high yields. [ABSTRACT FROM AUTHOR]

We present a new simple approach for electrochemical synthesis of semi-condensed ambipolar perinone polymers with phthaloperine (p1) or phenanthroline (p2) skeleton from available and cheap perimidine precursors. Polymerization of perimidine derivatives varies in efficiency depending on the monomer, but overall is highly efficient, especially when electropolymerization is used. Electrooxidation is well controllable and provides a certain characteristic share of new bonds in the structure of perimidine polymers: semi-ladder bis-perimidine unit, ladder bis-perimidine unit, and protonated bis-perimidine unit. Polymer p2 obtained with higher efficiency was put through broader analysis (UV–Vis, IR, ESR and quantum-chemical calculations). As indicated, donor–acceptor structure and specific intermolecular interactions of p2 assure its electrical conductivity and complex redox activity. Although protonated bonds break π-conjugation in the structure of the macromolecule, there is also a diradical state that favors intermolecular interactions and intermolecular π-conjugation channels within bis-perimidine segments. It has been proven that there is a diradical state which appears as an intermediate state between the oxidized and reduced states of the protonated polymer unit. This work positions perimidine polymers as a versatile ambipolar multiredox p- and n-type conductor, indicating a potential for expanding perinone-based perylene-diperimidine polymers for innovative electronics and (bio)sensors. [ABSTRACT FROM AUTHOR]

The preparation of highly active, rare earth, non-platinum-based catalysts for hydrogen evolution reactions (HER) in alkaline solutions would be useful in realizing green hydrogen production technology. Perovskite oxides are generally regarded as low-active HER catalysts, owing to their unsuitable hydrogen adsorption and water dissociation. In this article, we report on the synthesis of Li2ZrO3 perovskites substituted with samarium and terbium cations at A-sites for the HER. LSmZrO3 (LSmZO) and LTbZrO3 (LTbZO) perovskite oxides are more affordable materials, starting materials in abundance, environmentally friendly due to reduced usage of precious metal and moreover have potential for several sustainable synthesis methods compared to commercial Pt/C. The surface and elemental composition of the prepared materials have been confirmed by X-ray photoelectron spectroscopy (XPS). The morphology and composition analyses of the LSmZO and LTbZO catalysts showed spherical and regular particles, respectively. The electrochemical measurements were used to study the catalytic performance of the prepared catalyst for hydrogen evolution reactions in an alkaline solution. LTbZO generated 2.52 mmol/g/h hydrogen, whereas LSmZO produced 3.34 mmol/g/h hydrogen using chronoamperometry. This was supported by the fact that the HER electrocatalysts exhibited a Tafel slope of less than 120 mV/dec in a 1.0 M alkaline solution. A current density of 10 mA/cm2 is achieved at a potential of less than 505 mV. The hydrogen production rate of LTbZO was only 58.55%, whereas LSmZO had a higher Faradaic efficiency of 97.65%. The EIS results demonstrated that HER was highly beneficial to both electrocatalysts due to the relatively small charge transfer resistance and higher capacitance values. [ABSTRACT FROM AUTHOR]

NaAlCl4 solid electrolyte is a highly promising solid-state sodium-ion electrolyte with significant application potential. However, most studies on the modification of such material have focused on the impact of cation doping on performance, and the effects of anion doping remain unknown. In this work, fluoride (F−) and borohydride (BH4−) were successfully introduced into NaAlCl4 using a mechanical ball milling method, resulting in the synthesis of NaAlCl4−xFx (x = 0, 0.1, 0.3, 0.5, and 0.7) and NaAlCl4−x(BH4)x (x = 0.1 and 0.3). These derivatives maintain the same orthorhombic structure as NaAlCl4. Electrochemical measurements validate the feasibility of F− and BH4− doping for modifying the NaAlCl4 electrolyte. X-ray photoelectron spectroscopy (XPS) analyses demonstrate that the fluorinated Na/NaAlCl3.5F0.5 interphase formed during cyclic voltammetry (CV) measurements, this prevented further side reactions. This work reveals that F− and BH4− doping exhibit similar electrochemical effects, holds profound practical significance for future research in modifying halide-based sodium ion solid electrolytes. [ABSTRACT FROM AUTHOR]

The effect of the boron content doped in the diamond electrode on the oxidative degradation behaviour of the active pharmaceutical ingredient abacavir was investigated. The characteristics of five working boron-doped diamond electrodes, differing in a B/C doping ratio of 500 ppm, 1000 ppm, 2000 ppm, 4000 ppm, and 8000 ppm, were studied. The oxidative degradation of the substance abacavir was studied in a batch cell. The degradation took place under potentiostatic electrolysis at potentials from +0.6 V to +3.7 V. The boron level has a significant effect on the oxidative degradation of the substance at potentials greater than +2.0 V only. Liquid chromatography coupled with mass spectrometry was employed to verify the generation of two primary degradation by-products, namely OP1 (m/z = 319.20) and OP2 (m/z = 247.19). The relative amounts of these degradation products showed variability depending on the diamond electrode used, which was conditioned by different B/C ratios. [ABSTRACT FROM AUTHOR]

This review discusses the electrochemical behavior of chlorophylls and bacteriochlorophylls as individual molecules, as well as their complexes, like reaction centers and photosystems I and II. The first part is devoted to describing chlorophylls and bacteriochlorophylls structures, and oxidation and reduction processes on various electrode materials in various solvents. The dependence of number, positions, and reversibility of the observed redox peaks on the solvent composition and aggregation is also discussed. The following part is aimed at reaction centers and photosystems naturally occurring in living organisms. Attention is paid to proper electrode modification, orientation of the studied systems on the electrode surface and reproducibility of the observed phenomena. The differences in electrochemical behavior at metallic and graphitic electrodes are discussed. In the last part, possible future opportunities are pronounced, like modern electrode materials, in situ studies and extension of the redox studies to the reaction centers and photosystems from other organisms. [ABSTRACT FROM AUTHOR]

In this study, a nitrogen-doped multi-walled carbon nanotube (N-MWCNTs)/silver nanowire (AgNWs) nanocomposite electrode was prepared, using polydimethylsiloxane (PDMS) as a flexible substrate and N-MWCNTs and AgNWs as conductive materials. Trace Cu(II) in water was monitored by square wave stripping voltammetry (SWSV). Compared with commercial electrodes, the N-MWCNTs/AgNWs composite electrode generated much higher responsive peak current in detecting Cu(II), due to the enhanced conductivity of the composite electrode and the strong complexing ability of the N-MWCNTs for Cu(II). In the SWSV, this new electrode showed 0.06 μg/L (S/N = 3) limit of detection, a linear range from 0.500 to 100 μg/L, high resistance to interfering metals such as Ca(II), K(I), Zn(II), Na(I), Al(III), Fe(III), Hg(II), Cr(VI), Bi(III), Sb(III) and Sn(II), and stable response in natural water samples without sample pretreatment. This study established a new method for facile fabrication of high-performance flexible Cu(II) sensor with N-MWCNTs and AgNWs. [ABSTRACT FROM AUTHOR]

The global shift from non-renewable to renewable energy sources demands advancements in energy storage solutions to effectively mitigate carbon footprints. Towards this direction, this study envisages the utilisation of activated carbon (AC) derived from jering pods (JP) synthesised at three different temperatures as supercapacitor (SC) electrode material. The physicochemical properties of the material were studied using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR), and nitrogen (N₂) gas adsorption studies. In a half-cell study conducted in a 6 M aqueous KOH electrolyte, the best-performing AC delivered a specific capacitance (CS) of 301 F/g at 0.5 A/g. A full device assembly demonstrated a CS of 71 F/g at 0.5 A/g, energy density (ED), and power density (PD) of ~ 14 Wh/kg and ~ 9000 W/kg, respectively. The device showed excellent cyclic stability of ~ 96% of its initial capacitance after 3000 cycles. These findings present the viability of the valorisation of JP as a sustainable electrode material for SC application. [ABSTRACT FROM AUTHOR]

Here, the capacities of S-C48, S-C-nanotube, S-B24N24 and S-BN-nanotube in Mg-ion and Na-ion batteries are investigated. The Ecohesive of Si48, C48, S-C48, B24N24, S-B24N24, CNT(7, 0), S-CNT(7, 0), BNNT(7, 0) and S-BNNT(7, 0) are -5.86, -5.98, -6.24, -6.35, -6.47, -6.60, -6.88 and -7.01 eV in gas phase. The electrochemical parameters of Si48, C48, C-nanotube, B24N24, BN-nanotube, S-C48, S-C-nanotube, S-B24N24 and S-BN-nanotube in batteries are calculated. The Vcell and Ctheory of Si48, C48, CNT, B24N24, BNNT, S-C48, S-CNT, S-B24N24 and S-BNNT in Mg-ion batteries are higher than Na-ion batteries. Results demonstrated that the Vcell and Ctheory of C48, S-C48, B24N24, S-B24N24, CNT(7, 0), S-CNT(7, 0), BNNT(7, 0) and S-BNNT(7, 0) in batteries are higher than corresponding values of Si-nanotubes, C-nanocages and Si-nanocages, C-nanotubes, C-nanocages and BN-nanocages and BN-nanotubes. Results indicated that the S-C48, S-B24N24, S-CNT(7, 0) and S-BNNT(7, 0) have acceptable capacities in metal-ion batteries. Finally, the S-Si48, S-BNNT(7, 0) and S-CNT(7, 0) are proposed to utilize in batteries. [ABSTRACT FROM AUTHOR]

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The zinc boron complex formation was studied as a function of temperature (25, 50 and 70 °C) in boric acid solutions of various concentration (0.25, 0.50 and 0.68 mol·kg−1). pH was monitored during zinc ion addition by galvanostatic dissolution of a zinc metal electrode, in a solution of boric acid. The determination of the complex formation showed the importance of an accurate model of the polyborate speciation, recalculated for this work based on the previous literature data mainly potentiometric measurements completed by Raman spectroscopy and Ab Initio calculations. Modelling of our experimental results, considering various scenarios of boric acid speciation, was performed using R and PhreeqC, suggesting the formation of an aqueous triborate-zinc (II) complex, ZnB 3 O 3 (OH) 4 (aq) + , according to the reaction: Zn 2 + + 3 B (OH) 3 ⇌ ZnB 3 O 3 (OH) 4 (aq) + + 2 H 2 O + H + . The nature and structure of this aqueous complex disagrees with the results reported previously in the literature. Three formation constants of the triborate-zinc (II) complex were determined at 25, 50 and 70 °C as log 10 K ZnB = − 4.73 ± 0.10, − 4.21 ± 0.16 and − 4.94 ± 0.12, respectively. The evolution of zinc boron complex formation as a function of temperature (between 25 and 70 °C) provides information on the effect of the polyborate predominance in the solution on the complexation of zinc. [ABSTRACT FROM AUTHOR]

A century and a half ago, Helmholtz's model was at the forefront of development. There is no doubt that this model came into being because of the experimental data that was available at the time. Not only Helmholtz but also scientists like Nernst, Maxwell, and Pellat made their contribution to the double layer model. It is difficult to be precise about the date of origin of the Helmholtz model. Helmholtz formulated the definition of a double layer in 1853. It was in 1874 that Helmholtz pointed out the similarity between the double layer of platinum electrodes and a capacitor, but it was a capacitor with leakage (Ann. Phys. 226:483–495). Nevertheless, the 1879 article (Ann. Phys. 243:337–382) is traditionally considered the foundational work. Perhaps this opinion should be revised in favor of the 1874 work. In addition to the theoretical model, this article briefly reviews the development of experimental methods for measuring double layer capacitance: the instruments used, the equivalent circuit, and so on. The author hopes that this article will be useful in the teaching of electrochemistry. [ABSTRACT FROM AUTHOR]

Astract: One of the most common oral diseases affecting millions of people worldwide is periodontitis. Usually, proteins in body fluids are used as biomarkers of diseases. This study focused on hydrogen peroxide, lipopolysaccharide (LPS), and lactic acid as salivary non-protein biomarkers for oxidative stress conditions of periodontitis. Electrochemical analysis of artificial saliva was done using Gamry with increasing hydrogen peroxide, bLPS, and lactic acid concentrations. Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) were conducted. From EIS data, change in capacitance and CV plot area were calculated for each test condition. Hydrogen peroxide groups had a decrease in CV area and an increase in percentage change in capacitance, lipopolysaccharide groups had a decrease in CV area and a decrease in percentage change in capacitance, and lactic acid groups had an increase of CV area and an increase in percentage change in capacitance with increasing concentrations. These data showed a unique combination of electrochemical properties for the three biomarkers. Scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) employed to observe the change in the electrode surface and elemental composition data present on the sensor surface also showed a unique trend of elemental weight percentages. Machine learning models using hydrogen peroxide, LPS, and lactic acid electrochemical data were applied for the prediction of risk levels of periodontitis. The detection of hydrogen peroxide, LPS, and lactic acid by electrochemical biosensors indicates the potential to use these molecules as electrochemical biomarkers and use the data for ML-driven prediction tool for the periodontitis risk levels. [ABSTRACT FROM AUTHOR]

This paper introduces a novel mathematical model for chronoamperometric analysis of electrochemical reactions in the EC2 scheme. Utilizing the homotopy perturbation method, we address the highly nonlinear reaction–diffusion equations, even under non-steady state conditions. We offer an approximate analytical expression for species O and R concentrations, along with sensitivity analysis on diffusion and kinetic parameters. Results under steady state conditions validate our model against prior findings. Additionally, we provide a numerical solution using Matlab and Maple software, demonstrating satisfactory agreement with experimental data. [ABSTRACT FROM AUTHOR]

A family of inorganic-organic hybrid crystalline materials made up of organic ligands and metal cations or clusters is known as metal-organic frameworks (MOFs). Because of their unique stability, intriguing characteristics, and structural diversity, zirconium-based MOFs (Zr-MOFs) are regarded as one of the most interesting families of MOF materials for real-world applications. Zr-MOFs that have the ligands, metal nodes, and guest molecules enclosed show distinct electrochemical reactions. They can successfully and sensitively identify a wide range of substances, which is important for both environmental preservation and human health. The rational design and synthesis of Zr-MOF electrochemical sensors and biosensors, as well as their applications in the detection of drugs, biomarkers, pesticides, food additives, hydrogen peroxide, and other materials, are the main topics of this comprehensive review. We also touch on the current issues and potential future paths for Zr-MOF electrochemical sensor research. [ABSTRACT FROM AUTHOR]

An electrochemical biosensor has been developed for detection of Escherichia coli O157 by integrating lateral flow with screen-printed electrodes. The screen-printed electrodes were attached under the lateral flow detection line, and organic–inorganic nanoflowers prepared from E. coli O157-specific antibodies as an organic component were attached to the lateral flow detection line. In the presence of E. coli O157, an organic–inorganic nanoflower-E. coli O157-antimicrobial peptide-labelled ferrocene sandwich structure is formed on the lateral flow detection line. Differential pulse voltammetry is applied using a smartphone-based device to monitor ferrocene on the detection line. The resulting electrochemical biosensor could specifically detect E. coli O157 with a limit of detection of 25 colony-forming units mL−1. Through substitution of antibodies of organic components in organic–inorganic nanoflowers, biosensors have great potential for the detection of other pathogens in biomedical research and clinical diagnosis. [ABSTRACT FROM AUTHOR]

Si has been considered as an appealing anode material for high-performance lithium-ion batteries due to its high theoretical capacity. However, the large volume variation limits its practical application. Herein, a binder-, conductive additive- and current collector-free Si/reduced graphene oxide film has been constructed via a simple thermal-reduction method. In the film, Si nanoparticles are encapsulated by reduced graphene oxide, which can accommodate the volume change of Si during cycling efficiently. When utilized as a negative electrode, the Si/reduced graphene oxide film has displayed a high reversible capacity of 1733.4 mAh g−1 after 50 cycles at 200 mA g−1. Importantly, the electrochemical impedance spectroscopy results suggest that the composite film possesses more efficient electrochemical reaction kinetics. The strategy reported in this work may supply a facile preparation route for other metal or metal oxides/reduced graphene oxide films. [ABSTRACT FROM AUTHOR]

HRB500E rebar is a low-alloy high-strength steel with excellent mechanical properties and good plasticity but suffers from deficient corrosion resistance. This can be solved by adding trace elements, including rare earth elements. Herein, the corrosion-resistant behavior of rebar was evaluated by weightlessness testing and electrochemical measurements, and the effects of Ce on the structural evolution of the corrosion product layer were investigated by scanning electron microscopy (SEM), Electron Probe X-ray Micro-Analyzer (EPMA), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The results showed that adding Ce to the rebar improved the densification of the reinforcing surface corrosion products, as well as reduced the corrosion rate of the experimental rebar. Compared to C0 sample without Ce, the rebar sample containing 0.044 wt.% Ce displayed increased Ecorr by 0.051 V, decreased Icorr by 15.573 mA cm−2, enhanced Rc of the corrosion product layer by 112.71 Ω cm2, incremented α-FeOOH content in the corrosion product layer, and boosted ratio of α/γ* in the corrosion product layer by 10.11%. Furthermore, the oxide (CeO2) formed by Ce in the corrosion layer of the rebar bar surface existed in the rust layer, resulting in a stable corrosion product layer with improved blocking ability of the corrosive medium. Overall, the addition of Ce at certain ratios looks promising to produce HRB500E rebar with excellent corrosion resistance and extended service life under harsh conditions. [ABSTRACT FROM AUTHOR]

In this work, through a facile liquid–liquid (L–L) interfacial-assisted synthesis at room temperature, a new two-dimensional (2D) metal coordination nanosheet Co-TPY-LB has been synthesized by the coordination between Co2+ ion and 1,3,5-tris(4′-tripyridinylphenyl)benzene (Tris-tpy). The flat and smooth sheet structure with a thickness of 83.3 nm and a hexagonal structure with a lattice spacing of about 0.206 nm for the as-fabricated nanosheet Co-TPY-LB has been identified by AFM and HRTEM respectively, providing a large number of redox sites and ion diffusion channels. The fabricated Co-TPY-LB have been used as electrodes and exhibit the highest capacity of 2741.5 F g−1 at the current density of 1 A g−1, an excellent cycling stability with 97.6% capacity retention after 1000 cycles at the current density of 10 A g−1. Meanwhile, the assembled asymmetric supercapacitor with Co-TPY-LB as the positive electrode shows a high energy density 73.6 Wh kg−1 at a power density of 4800 W kg−1 as well as an excellent cycle stability of 92.9% capacity retention after 5000 cycles. Our work provides a controllable synthesis for the construction of 2D metal coordination nanosheet to overcome some defects of 2D nanosheet by traditional synthesis, leading such bottom-up nanosheet to a promising application in energy storage. [ABSTRACT FROM AUTHOR]

We report a novel functional bis(terpyridine)metal(II) complex coordination nanosheet (CONASH) comprising a three-armed terpyridine ligand and Ni2+ ion. The colourless Ni-terpyridine CONASH was synthesized by the method of interfacial coordination reaction at an interface of two immiscible liquids. The synthesized CONASH was characterized with various microscopic observations such as TEM, SEM, and AFM, and spectroscopic measurements such as XPS, IR, SEM/EDS, and UV–Vis spectroscopy. The bis(terpyridine)nickel(II) complex nanosheet demonstrated redox-activity stemming from terpyridine complexes without distinctive colour change. Thus, the bis(terpyridine)nickel(II) coordination nanosheet is a potential redox-active material with colourlessness and flexibility, necessary for future transparent electronics. [ABSTRACT FROM AUTHOR]

In this study, iron tin oxide nanocomposites with chemical structure of Fe1.42Sn0.435 O3 (Fe2O3:Sn) were synthesized by coprecipitation method. The effects of annealing temperatures at T = 250 °C, 450 °C, 550 °C, 650 °C and 750 °C on the formation of nanocomposite, crystallite size, morphology and optical, and electrochemical properties were investigated. The iron tin oxide nanoparticles were characterized by X-ray diffraction (XRD), field emission electron microscopy (FESEM), UV-Vis spectroscopy, Fourier-transform infrared spectroscopy (FTIR), cyclic voltammetry (CV), and specific capacitance (SC) analysis. The results obtained from structural analysis for the synthesized samples show that the sample annealed at T = 450 °C has the highest intensity with preferred peak (110) and more uniform grain size. The FESEM images from synthesized nanostructures show the polyhedral and cubic grain with a particle-cluster growth. The band gap (Eg) was determined between 1.96 eV and 2.58 eV, and SFO-2 sample annealed at T = 450 °C is the optimized sample with Eg = 2.20 eV. The FTIR results indicate the formation of tin ferrite oxide structure. The cyclic voltammetry (CV) results are consistent with the redox reactions carried out in hematite metal oxide, tin oxide, and KOH solution. The specific capacitance (SC) analysis for scan rates of 2–200 (mV s−1) shows values between 472–822 (F g−1). [ABSTRACT FROM AUTHOR]

Phytic acid (PA) benzotriazole composite conversion films with different concentrations of BTA were prepared by an impregnation method, and their wettability, microstructure, and corrosion resistance were studied. The results showed that when the BTA content was 1.6 wt %, the maximum water contact angle of the conversion film reached 137.5°, and the corrosion current density reached a minimum of 1.610 × 10–7 A/cm2. The salt spray and corrosive liquid environments experimental results also showed that the synergistic effect of PA and BTA was the best when the BTA concentration was 1.6 wt %. Hydrogen bonds are formed between PA chelates and BTA chelates enhancing the density of the conversion film leading to the improvement of corrosion resistance of conversion film on a copper surface with the introduction of BTA. [ABSTRACT FROM AUTHOR]

Nerve agents, including organophosphorus compounds such as paraoxon, are potent and highly toxic chemicals with grave implications for human health and the environment. In this paper, we present the development of a novel enzyme inhibition-based biosensor for the sensitive and selective detection of paraoxon, which is commonly used as a surrogate for nerve agents. The biosensor employs reduced graphene oxide as a screen-printed electrode surface modification nanomaterial, leading to increased surface electroactivity and, thus, more sensitive detection. The biosensor exhibits a low detection limit of 0.56 pg/ml (limit of detection, LOD) and 1.25 pg/ml (limit of quantification, LOQ), highlighting its high sensitivity for trace-level analysis of nerve agents in complex sample matrices. Our biosensor demonstrates remarkable selectivity for paraoxon, with minimal interference from other non-target chemicals. Stability and repeatability tests reveal that the system maintains its performance integrity over a 45-day period and consistently produces readings with a margin of error of only 5%. Real sample testing in river water, wastewater, and tap water further confirms the biosensor's practical utility, with recovery percentages ranging from 84 to 115%. This biosensor represents a significant advancement in biosensor technology, facilitating the rapid, cost-effective, and reliable detection of toxic substances in real-world scenarios. [ABSTRACT FROM AUTHOR]

A new representative of 1,2-diphosphaferrocenes containing p-fluorophenyl substituents on the 1,2-diphosphacyclopentadienyl ring was synthesized. Its structure was confirmed by multinuclear NMR, IR, and Mössbauer spectroscopy, and its electrochemical properties were studied. [ABSTRACT FROM AUTHOR]

This study aims to investigate the photoelectrochemical behavior of the n-type 4H-SiC, focusing on aqueous, hydroxide-based electrolytes. Despite its high stability, this wide-bandgap semiconductor material undergoes electrochemical reactions, such as anodic oxidation or etching, under specific conditions. Since electrons are the majority charge carriers in n-type semiconductors, oxidation processes require above-bandgap illumination. Then, the reaction rate is influenced by the number of electron holes available for an oxidation process and the velocity of the transport of hydroxide ions to/from the surface. The goal is to focus on the essential reaction parameters (i.e., potential and electrolyte concentration) to clarify the reaction mechanism in aqueous (alkaline) electrolytes. Methods with controllable hydrodynamic conditions are required to investigate the transport processes in the electrolyte. Even though the rotating disk electrode (RDE) is a commonly used and powerful method, it is not well suited for our purpose. Photoelectrochemical etching of SiC is extraordinary because it involves both mass transfer phenomena and gas evolution but also needs high-intensity illumination from an appropriate light source. Hence, a new concept for an inverted rotating cell was developed and implemented. This setup was used to study the effect of the mass transport of hydroxide ions on the photoelectrochemical behavior of SiC in each potential region at varying rotation speeds. In order to interpret the experimental findings, a distinct electrical network model was formulated for simulating the results, aiding in unraveling the underlying reaction mechanism. Electrochemical measurements were complemented by surface-sensitive analytical techniques. XPS was the method of choice to investigate the composition of the sample surface before and after etching. SEM and AFM allow the characterization of the surface morphology in the initial stages of etching. The totality of this information provides a complete picture of the complex processes in the vicinity of the semiconductor electrode. [ABSTRACT FROM AUTHOR]

Fossil fuels have a vital role in global energy resources. The burning of fossil fuels produces pollutants and harms the environment. These environmental problems can be solved by searching for a substitute for fossil fuels. Hydrogen production by water electrolysis has emerged as a promising substitute. It is a green, clean, and renewable energy source. Low-cost water is abundant on the Earth. The metal and its composite material have been used to develop water electrolysis. Among these composite catalytic materials, WS2/WO3 composite catalyst is well-known for its excellent physical and chemical behavior in water electrolysis to produce hydrogen. Engineered catalysts can further enhance the catalytic performance. Therefore, we investigate and analyze the catalytic performance of copper (Cu), palladium (Pd), and r-GO co-doped WS2/WO3 composite material for water electrolysis to produce green, clean, and renewable hydrogen energy by hydrogen evolution reaction (HER). The hydrothermal synthesis method is used to prepare the WS2/WO3 composite material co-doped with Cu, Pd, and r-GO. The co-doping is favorable for fast charge transfer by providing many active catalytic sites for HER and enhancing the HER catalytic performance. Therefore, the co-doped tungsten disulfide/oxide could be a potential composite material for efficient water electrolysis for clean and renewable hydrogen production by electrochemical water electrolysis. [ABSTRACT FROM AUTHOR]