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A gold surface is functionalized by chemisorption of the enantiopure N,N′-bis-[2,2′;5′,2″]tert-thiophene-5-yl methylcyclohexane-1,2-diamine (2T3N), a chiral oligothiophene derivative, via overnight incubation in a 2T3N ethanol solution. The Au|2T3N interface is characterized by x-ray photoelectron circular dichroism and comparing x-ray photoemission spectroscopy and electro-desorption results. Charge transmission at the Au|2T3N| solution interface is characterized by recording the cyclic voltammetry of the Fe(III)/Fe(II) reversible redox couple, finding a charge transfer rate constant, k°, variation from 1 × 10−1 to 3.3 × 10−2 cm s−1, when comparing the bare Au and the Au|2T3N interfaces, respectively. The "anomalous" high value of k° found for the chiral Au|2T3N interface can be rationalized on the basis of the chiral-induced spin selectivity effect, as further proved by magnetic–conductive atomic force microscopy measurements at room temperature. A spin polarization of about 30% is found. [ABSTRACT FROM AUTHOR]

Electrochemical water splitting offers a promising route to sustainable hydrogen production. Metal-Organic Frameworks (MOFs) have emerged as potential electrocatalysts due to their tunable structure and composition. We investigated the electrocatalytic activity of ZIF-67 for the hydrogen evolution reaction (HER) in alkaline media. Synthesis parameters, including temperature, reaction time, acidity, molar ratio of 2-methylimidazole (2-MIM) to cobalt source, cobalt source type, addition method of 2-MIM, and solvent type, were systematically varied to optimize the electrocatalytic properties of ZIF-67. The synthesized ZIF-67 electrocatalysts were characterized using BET, FESEM, EDS, TEM, XRD, FTIR, and UV–vis spectroscopy. The electrocatalytic properties were evaluated by cyclic voltammetry (CV), linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS), and chronoamperometry methods. The optimized ZIF-67 electrocatalyst exhibited remarkable performance, with a low overpotential of 171 mV, a small Tafel slope of 82 mV.dec−1, a low charge transfer resistance of 97 Ω, a high double-layer capacitance of 13.5 mF cm−2, and high stability for 15 h at the current density of 10 mA cm−2. The enhanced electrocatalytic activity of the optimized ZIF-67 was attributed to its high surface area, tunable pore structure, and the presence of active cobalt sites. [Display omitted] • ZIF-67 electrocatalyst with superior performance (S16) is synthesized under optimized conditions (80–120 °C, 1 h, CoSO 4 ·7H 2 O precursor, dropwise 2-MIM addition, 2-MIM/Co ratio 16:1, pH 11). • The optimized ZIF-67 electrocatalyst exhibits a well-defined rhombic dodecahedral morphology with high surface area (1370 m2gr−1.), pore volume (1.02 cm³.gr−1), and narrow band gap (1.97 eV). • The cobalt-based electrocatalyst achieves exceptional HER activity in 1 M KOH: low overpotential (ƞ 10 = 171 mV), fast kinetics (β = 82 mV.dec−1), high C dl (13.5 mF cm−2), and remarkable stability (15 h). [ABSTRACT FROM AUTHOR]

The sensitivity of zinc (Zn(II)) detection using fast-scan cyclic voltammetry (FSCV) with carbon fiber microelectrodes (CFMEs) is low compared to other neurochemicals. We have shown previously that Zn(II) plates to the surface of CFME's and we speculate that it is because of the abundance of oxide functionality on the surface. Plating reduces sensitivity over time and causes significant disruption to detection stability. This limited sensitivity and stability hinders Zn(II) detection, especially in complex matrices like the brain. To address this, we developed plasma-treated gold fiber microelectrodes (AuMEs) which enable sensitive and stable Zn(II) detection with FSCV. Typically, gold fibers are treated using corrosive acids to clean the surface and this step is important for preparing the surface for electrochemistry. Likewise, because FSCV is an adsorption-based technique, it is also important for Zn(II) to adsorb and desorb to prevent irreversible plating. Because of these requirements, careful optimization of the electrode surface was necessary to render the surface for Zn(II) adsorption yet strike a balance between attraction to the surface vs. irreversible interactions. In this study, we employed oxygen plasma treatment to activate the gold fiber surface without inducing significant morphological changes. This treatment effectively removes the organic layer while functionalizing the surface with oxygen, enabling Zn(II) detection that is not possible on untreated gold surfaces. Our results demonstrate significantly improved Zn(II) detection sensitivity and stability on AuME compared to CFME's. Overall, this work provides an advance in our understanding of Zn(II) electrochemistry and a new tool for improved metallotransmitter detection in the brain. [ABSTRACT FROM AUTHOR]

The hormone Neuropeptide Y (NPY) plays critical roles in feeding, satiety, obesity, and weight control. However, its complex peptide structure has hindered the development of fast and biocompatible detection methods. Previous studies utilizing electrochemical techniques with carbon fiber microelectrodes (CFMEs) have targeted the oxidation of amino acid residues like tyrosine to measure peptides. Here, we employ the modified sawhorse waveform (MSW) to enable voltammetric identification of NPY through tyrosine oxidation. Use of MSW improves NPY detection sensitivity and selectivity by reducing interference from catecholamines like dopamine, serotonin, and others compared to the traditional triangle waveform. The technique utilizes a holding potential of −0.2 V and a switching potential of 1.2 V that effectively etches and renews the CFME surface to simultaneously detect NPY and other monoamines with a sensitivity of 5.8 ± 0.94 nA/µM (n = 5). Furthermore, we observed adsorption-controlled, subsecond NPY measurements with CFMEs and MSW. The effective identification of exogenously applied NPY in biological fluids demonstrates the feasibility of this methodology for in vivo and ex vivo studies. These results highlight the potential of MSW voltammetry to enable fast, biocompatible NPY quantification to further elucidate its physiological roles. [ABSTRACT FROM AUTHOR]

Comprehensive Summary The reaction between tripodal trisamidophosphine ligand H3PN3Ar and V(Mes)3(THF) (Mes = mesityl) yields the vanadium(III) complex (PN3Ar)V (1) with an open site in the axial position, which could coordinate with THF, pyridine, and NH3 to form the corresponding adducts (2—4). The vanadium(III) center is redox‐active, as demonstrated by cyclic voltammetry methods and chemical oxidation or reduction. Notably, a novel dinitrogen divanadium complex with a bridging N2 ligand, {K(THF)}2{[PN3Ar]V}2(μ‐N2) (6), was synthesized via treatment of 1 with 1 equivalent of potassium naphthalenide in THF under a N2 atmosphere. The electronic structures and binding properties of 6 are evaluated and discussed based on its DFT calculations. Additionally, these vanadium complexes (1, 5, 6) can serve as catalysts for the conversion of N2 into N(SiMe3)3 in the presence of reductants and Me3SiCl. [ABSTRACT FROM AUTHOR]

For the next generation of lithium batteries, polymer‐based electrolytes are promising candidates for resolving issues from liquid electrolytes such as leakage, flammability, and explosion. Various attempts have been carried out to develop polymer electrolytes based on poly(ethylene oxide) (PEO), polyacrylonitrile, polyvinylidene fluoride, etc., resulting in suppression for dendrite growth on Li metal and mechanical support against internal or external shock as well. Among these polymer electrolytes, PEO has been widely used due to their relatively high ionic conduction through the hopping of Li ions. Herein, poly(GAP‐co‐THF) diol (PGT) having a similar main chain to PEO while containing azide groups in a side chain is synthesized. To enhance the processability of polymer electrolytes, the thermal crosslinking process is performed via azide‐alkene cycloaddition between PGT and poly(ethylene glycol) diacrylate with lithium bis(trifluoromethanesulfonyl)imide without any initiators and organic solvents. Thickness controllable thin film of polymer electrolyte is obtained after the crosslinking process, resulting in outstanding advantages with respect to stacking of batteries. To check the electrochemical stabilities and cell performances of these polymer electrolytes, cyclic voltammetry, linear symmetric voltammetry, LiFePO4∥Li cell, and Li symmetric cell tests are accomplished. [ABSTRACT FROM AUTHOR]

AbstractThis study reports the design and development of a disposable amperometric biosensor for the determination of L-glutamate. Glutamate oxidase (GlOx) was immobilized onto a screen-printed carbon electrode (SPE) modified with poly-L-Aspartic acid (PAsp), carbon quantum dots (CQD), and platinum nanoparticles (PtNP) for the construction of the biosensor. The surface composition of the modified SPE was optimized using the one variable at a time method. The morphological properties of the biosensor were characterized by scanning electron microscopy and energy-dispersive X-ray spectroscopy. The electrochemical behavior of the modified electrodes was studied by cyclic voltammetry. Under the optimized experimental conditions the linear working range, detection limit and sensitivity of the GlOx/PtNP/CQD/PAsp/SPE were found to be 1.0 − 140 µM, 0.3 µM and 0.002 µA µM−1, respectively. The GlOx/PtNP/CQD/PAsp/SPE biosensor also exhibited good measurement repeatability. The as-developed biosensor was applied for the determination of L-glutamate in spiked serum samples and the average analytical recovery of added glutamate was 98.9 ± 3.9%. [ABSTRACT FROM AUTHOR]

In the current study, multi-layer graphene (MLG) and reduced graphene oxide (rGO) were effectively synthesized and characterized by several techniques, including FT-IR, XRD, TGA, CHNS/O Analyzer, Raman spectroscopy, UV–Vis spectroscopy, TEM, and SEM. The electrochemical hydrogen storage (EHS) capacity was measured through cyclic voltammetry (CV), galvanostatic charge/discharge (GCD), and electrochemical impedance spectroscopy (EIS). High-quality graphene (I D /I G < 0.16), obtained from the simple liquid phase exfoliation method, exhibited a remarkable hydrogen storage capacity, reaching up to 200 F g−1 which equals 0.1 wt%. Furthermore, MLG outperforms rGO in terms of coulombic efficiency, achieving 100% in 10 cycles as opposed to rGO's 50% under identical conditions. This study presents the first-ever EHS using a new method that shows promising results. [Display omitted] • The prominent parameters in electrochemical hydrogen storage were examined. • MLG (200 F g−1) outperformed rGO (25 F g−1) electrochemically. • MLG exhibited a discharge capacity 53 times higher than commercial one. • MLG reached 200 F g−1 without metal loading. • The LPE method was determined to have considerable potential in EHS. [ABSTRACT FROM AUTHOR]

Electric trains equipped with efficient electric motors and powered by high-capacity hydrogen fuel cells are a choice of the global transportation industry to accelerate the global transition to a low-carbon transportation system. The operation of distinct vehicle types in varying geographical regions is characterized by unique features. Concurrently, the continually fluctuating demand for electricity necessitates the utilization of fuel cells in conjunction with energy storage devices. Thus, this study centers on examining the role of the PEMFC-supercapacitor direct hybridization system within the authentic driving profile of the subway in the Bangkok metropolitan region. The supercapacitor within the hybridization system serves as an energy management device, enhancing the durability of fuel cells when subjected to diverse load demands associated with train propulsion. In order to validate this hypothesis, an MRT (Mass Rapid Transit) protocol was formulated to emulate and serve as the load demand for the investigation, and then the PEMFC-supercapacitor direct hybridization system was operated using the created profile. Subsequently, the hybridization system undergoes electrochemical characterizations and fuel cell performance tests for diagnostic purposes. Empirical findings validated that the supercapacitor operates as a filter, generating a stable voltage response to varying load requirements, and possesses the capability to assimilate energy originating from regenerative braking. The integration of supercapacitors in stabilizing the operational parameters of proton exchange membrane fuel cells (PEMFCs) has markedly prolonged their operational lifespan. This assertion is substantiated by voltage signal analysis, which demonstrated a negligible increase in surface resistance of merely 0.23%, as depicted by Nyquist plots. Furthermore, cyclic voltammetry revealed that the system attained a peak electrochemical surface area (ECSA) of 0.0089 (106 cm2/mg of Pt). The information presented in this article constitutes data that has been minimally explored in existing research. Specifically, the study concentrates on the practical driving pattern of electric trains. Consequently, experimental results were deemed advantageous for the advancement of heavy-duty electric vehicles. [Display omitted] • Exploring the relationship between the utilization of an energy storage device as a SC and energy generation as a PEMFC. • Establishing a connection between the authentic current profile of an MRT metro system and an accelerated stress test. • Examining the electrochemical reactions within fuel cells, drawing upon operational data from the transportation sector. [ABSTRACT FROM AUTHOR]

A nanocomposite of CaO:MgAl2O4 was synthesized through a straightforward and cost-effective sol–gel method. The investigation of the novel CaO:MgAl2O4 nanocomposite encompassed an examination of its morphological and structural alterations, as well as an exploration of its photocatalytic activities and electrochemical characteristics. XRD analysis revealed a nanocomposite size of 24.15 nm. The band gap, determined through UV studies, was found to be 3.83 eV, and scanning electron microscopy (SEM) illustrated flake-like morphological changes in the CaO:MgAl2O4 samples. TEM, HRTEM, and SAED studies of a CaO:MgAl2O4 nanocomposite would reveal important details about its morphology, crystallography, and nanostructure. Photocatalytic activity was quantified by studying the degradation of Acid Red-88 (AR-88) dye in a deionized solution, achieving a 70% dye degradation under UV irradiation in 120 min. Plant growth examinations were carried out using dye degraded water to test its suitability for agriculture. The electrochemical energy storage and sensing applications of the prepared nanocomposite were examined using CaO:MgAl2O4 modified carbon paste electrode through cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). In conclusion, the synthesized CaO:MgAl2O4 nanocomposite demonstrated promising morphological and structural characteristics, efficient photocatalytic activity, and potential applications in electrochemical energy storage, highlighting its versatility for various technological and environmental applications. [ABSTRACT FROM AUTHOR]

Square planar complexes of Ni(II) and Pd(II) of a new redox-active pentadentate azo-appended 2-aminophenol ligand (H4L = N,N′-bis(2-hydroxy-3,5-di-tert-butylphenyl)-2,2′-diamino-ortho-azobenzene) in three accessible redox levels [amidophenolate(2−), semiquinonate(1−) π radical, and quinone(0)] were synthesized. The coordinated HL(3−) ligand provides four donor sites [two N(iminophenolates), an N′(azo), and an O(phenolate)], while the phenolic OH group remains free in the three complexes. Cyclic voltammetry on complex [Ni(L)] 1 and its corresponding Pd(II) analogue [Pd(L)] 2 in CH2Cl2 displayed three redox responses (two oxidative at E1/2 = 0.06 V and Epa (anodic peak potential) = 0.80 V and one reductive at −0.77 V for 1 and at E1/2 = 0.08 V and Epa = 0.85 V and at −0.74 V for 2vs. Fc+/Fc). The chemical oxidation of 1 with AgSbF6 afforded [Ni(L)]SbF6·2CH2Cl2 (3·2CH2Cl2). Complex [Pd(L*)] 4, which is coordinated by a phenoxazinyl derivative of L(4−), was obtained via intraligand cyclization in the parent complex 2 under basic oxidizing conditions. The molecular structures of 1, 2, 3·2CH2Cl2 and 4 were elucidated through X-ray crystallography at 100 K. Characterization using 1H NMR, X-band EPR, and UV–VIS–NIR spectroscopy established that the complexes have [NiII{(LISQ)˙2−}] 1, [PdII{(LISQ)˙2−}] 2, [NiII{(LIBQ)−}]SbF6/1+SbF6−(3), and [PdII{(L*AP)˙2−}] 4 electronic states. Complexes 1, 2, and 4 possess paramagnetic St (total spin) = 1/2 ground-state, whereas 3 is diamagnetic (St = 0). Density functional theory (DFT) electronic structural calculations at the B3LYP level rationalized the observed experimental results. Time-dependent (TD)-DFT calculations allowed us to identify the nature of the observed absorption spectra. [ABSTRACT FROM AUTHOR]

Direct hydrazine fuel cells (DHFC) insist on the evolved and persistent electrocatalysts for anodic hydrazine oxidation reaction (HzOR). Herein, PdO promoted CuO heterostructures supported on γ‐Al2O3 are depicted as efficient electrocatalysts for HzOR. γ‐Al2O3 is prepared by precipitation method while metal precursors are incorporated by co‐impregnation technique. Physiochemically characterized PdO‐CuO/Al2O3 mesoporous composites displayed large electrochemical active surface area (ECSA) i. e., 0.18 cm2, high current density (j) i. e., 35.7 mA cm−2, larger diffusion coefficient (D°) i. e., 29.3×10−4 (cm2s−1), large apparent rate constant (kapp) i. e., 13.2 cm−1 with low charge transfer resistance (Rct) i. e., 3.6 kΩ shown by the best catalyst i. e., 1 % PdO‐CuO/Al2O3. Cyclic voltammetry indicated that the fabricated working electrodes offer high efficiency towards HzOR in alkaline medium in such a way that 1 % PdO‐CuO/Al2O3 produced 600 times higher oxidation current than CuO/Al2O3 composite. Owing to stability and reproducibility, PdO modified CuO/Al2O3 would achieve a huge catalytic significance in multiple electrochemical oxidation reactions with economic and ecological benefits. [ABSTRACT FROM AUTHOR]

To meet the increasing demands for food production, the utilization of cost‐effective pesticides like carbofuran (CB) becomes essential. CB poses a significant risk to human health due to its high toxicity. Therefore, accurate quantification of CB residue is essential for environmental safety and human health. Electrochemical sensors have proven to be an outstanding choice for the accurate detection and quantification of carbofuran residues. CB is electrochemically inactive and was first hydrolyzed in an alkaline medium to yield an anodically active phenolic derivative carbofuran phenol (CP). This report details the development of a voltammetric sensor for the accurate detection of CB residues utilizing the cyclic voltammetry technique and the electrochemical reactions of CP at WS2 nanosheet‐modified electrodes in phosphate buffer solution (PBS). The constructed sensor has displayed a linear range of carbofuran detection from 10–90 μM, with a limit of detection (LOD) of 0.38 μM and sensitivity of 0.303 μA μM−1 cm−2. Additionally, the developed sensor has been employed to monitor CB residues in real soil and water samples and it shows a recovery greater than 95 %. The developed sensor enables the cost‐effective monitoring of carbofuran in real samples. [ABSTRACT FROM AUTHOR]

In this paper, the novel ECL sensor of the 6‐methoxychromone (6‐MC)/S2O82− system was designed by using 2‐naphthalene sulfonic acid (2‐NSA) as a co‐reaction accelerator. Fluorescence, ECL spectrum, and cyclic voltammetry (CV) were used to explore extensively the ECL mechanism of the system. It is worth pointing out that 2‐naphthalene sulfonic acid (2‐NSA) was first proposed as a co‐reaction accelerator, reacting with the coreactant K2S2O8 rather than the luminophore, promoting the generation of additional oxidant SO4− from S2O82−, thus amplifying the ECL signal. Furthermore, under the optimal experimental conditions, the high sensitivity of the 2‐naphthalene sulfonic acid (2‐NSA)+6‐methoxychromone (6‐MC)/S2O82− system was realized for the detection of methyl violet (MV) in the linear range of 10−8~10−2 M, with a detection limit of 5.14×10−10 M. In addition, this find offers some guidance for further developing co‐reaction accelerators with excellent performance in the future. [ABSTRACT FROM AUTHOR]

Metal ion-DNA interactions play a crucial role in modulating the structure and function of genetic material in the natural environment. In this study, we report on the favorable electrochemical activity of holmium(III) (Ho3+) on a glassy carbon electrode (GCE) and its interaction with double-stranded DNA. The interaction between DNA and Ho3+ was investigated for the first time using cyclic voltammetry and differential pulse voltammetry. The electrochemical behavior of Ho3+ ions on a GCE exhibited a reversible electron transfer process, indicative of its redox activity. A linear correlation between the peak current and the square root of the scan rate was observed, suggesting a diffusion-controlled kinetic regime for the electrochemical process. Additionally, fluorescence and absorption spectroscopy were employed to confirm the binding of Ho3+ to DNA. Our findings demonstrate that, at pH 7.2, specific DNA bases and phosphate groups can interact with Ho3+ ions. Moreover, electrochemical measurements suggest that Ho3+ ions bind to DNA via a groove binding mode, with a calculated binding ratio of 1:1 between Ho3+ and DNA. Notably, under optimal conditions, an increase in the amount of DNA leads to a significant reduction in the current intensity of Ho3+ ions. [ABSTRACT FROM AUTHOR]

Azobenzenes (ABs) are versatile compounds featured in numerous applications for energy storage systems, such as solar thermal storages or phase change materials. Additionally, the reversible one‐electron reduction of these diazenes to the nitrogen‐based radical anion has been used in battery applications. Although the oxidation of ABs is normally irreversible, 4,4'‐diamino substitution allows a reversible 2e− oxidation, which is attributed to the formation of a stable bis‐quinoidal structure. Herein, we present a system that shows a bipolar redox behaviour. In this way, ABs can serve not only as anolytes, but also as catholytes. The resulting redox potentials can be tailored by suitable amine‐ and ring‐substitution. For the first time, the solid‐state structure of the oxidized form could be characterized by X‐ray diffraction. [ABSTRACT FROM AUTHOR]

The ongoing pursuit of cost-effective approaches for synthesizing transition metal sulfide heterostructure oxygen evolution electrocatalysts, with the objective of optimizing active site exposure and stabilizing spatial framework, remains a significant challenge. In this study, self-supported bimetallic iron-nickel sulfide (Fe 1-x S-NiS/NF) nanosheet heterostructures were successfully fabricated in situ on nickel foam through the direct sulfurization of bimetallic carbonate precursors. The effects of sulfurization temperature and Fe content on the oxygen evolution reaction (OER) performance of the catalyst are investigated, and the best conditions are found to be 350 °C and 2 mmol, respectively. As expected, the optimized catalyst demonstrates remarkable OER performance in an alkaline solution with low overpotentials of 235 mV and 333 mV at high current densities of 50 mA cm−2 and 100 mA cm−2, respectively. Furthermore, the catalyst shows long-term stability lasting for 35 h at 60 mA cm−2 with a negligible shift in the polarization curve observed even after 2000 cyclic voltammetry cycles, while also exhibiting good structural preservation. The current study has the potential to offer valuable insights into the fabrication of electrocatalysts based on metal sulfide heterostructures. A simple hydrothermal-sulfurization strategy was adopted to fabricate series of self-supported iron-nickel sulfide nanosheet heterostructures catalysts with excellent OER performance. [Display omitted] • Self-supported Fe 1-x S-NiS/NF nanosheets were synthesized by sulfurization of carbonates. • Effects of sulfurization temperature and Fe content on the OER performance are investigated. • The Fe 1-x S-NiS/NF-2 catalyst exhibits excellent OER performance. [ABSTRACT FROM AUTHOR]

High-oxygen-permeability ionomers (HOPIs) are being actively developed to enhance the performance and durability of high-power polymer electrolyte membrane fuel cells (PEMFCs). While methods for evaluating binder performance are well-established, techniques for assessing binder durability and measuring its degradation in situ during the AST process remain limited. This study examines the distribution of relaxation times (DRT) and Warburg-like response (WLR) methods as in situ analysis techniques during the catalyst-accelerated stress test (AST) process. We conducted catalyst-ASTs (0.6–0.95 V cycling) for 20,000 cycles, monitoring changes using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and linear sweep voltammetry (LSV). Contrary to expectations, during the catalyst-AST, the ion transport resistance of the binder decreased, indicating no binder degradation. Scanning electron microscopy/energy dispersive spectrometer (SEM/EDS) analysis revealed that the degradation rate of the catalyst and the support was relatively higher than that of the binder, leading to a reduction in catalyst layer thickness and improved binder network formation. By applying the DRT method during the catalyst-AST process, we were able to measure the increase in oxygen reduction reaction (ORR) resistance and the decrease in proton transport resistance in situ. This allowed for the real-time detection of the reduction in catalyst layer thickness and improvements in ionomer networks due to catalyst and support degradation. These findings provide new insights into the complex interplay between catalyst degradation and binder performance, contributing to the development of more durable PEMFC components. [ABSTRACT FROM AUTHOR]

In this study, a new and simple glassy carbon electrode modified with carbon nanohorns (SWCNH/GCE) was used for the determination of Cr(VI) in aqueous matrices via adsorptive cathodic stripping voltammetry (AdCSV). The modified electrode was characterized via field emission scanning electron microscopy and cyclic voltammetry, which revealed a homogeneous distribution of spherical agglomerates of SWCNH on the electrode surface. The modification increased the electrochemically active area from 0.10 cm2 ± 0.01 (GCE) to 0.16 cm2 ± 0.01 (SWCNH/GCE). The optimized analytical conditions were as follows: a supporting electrolyte (0.15 mol L−1 HCl), an accumulation potential of 0.8 V versus Ag/AgCl, and an accumulation time of 240 s. Validation of the analytical methodology was performed, obtaining a linear range between 20 and 100 µg L−1, a limit of detection of 3.5 µg L−1, and a limit of quantification of 11.6 µg L−1 with good accuracy and precision. The method was applied to the analysis of spiked tap water samples, and the results were compared using a flame atomic absorption spectrophotometer (FAAS) with no significant statistical differences. [ABSTRACT FROM AUTHOR]

This study aimed to develop an electrochemical method for the electrochemical determination of bufexamac (BUF), an important anti-inflammatory drug. For this purpose, the electrochemical properties of BUF were elucidated using a glassy carbon electrode (GCE) and cyclic voltammetry. The electrochemical performance of BUF was examined by the differential pulse voltammetry (DPV) method. It was observed that the response of GCE to DBT was linear in the concentration range of 6.0 × 10-6 M and 1.0 × 10-4 M. The limit of detection (LOD) was found to be 2.64 × 10-8 M; The limit of quantification (LOQ) was calculated as 8.79 × 10-8 M. The dexketoprofen tromethamine (DEX), diclofenac (DIC), and ibuprofen (IBU) were used as model active compounds to illustrate the oxidation mechanism of BUF. A simple, rapid, and sensitive electrochemical method for quantitatively determining BUF in a commercial sample of human serum was developed and validated. The calibration curve was linear in the 8.0 × 10-6 - 1.0 × 10-4 M in the biological media. The LOD for the commercial sample of human serum was set at 1.59 × 10-7 M. The electrochemical response of BUF in the presence of interferent was evaluated. The data obtained from the study showed that the developed method can be used in sensitive and selective BUF determination. [ABSTRACT FROM AUTHOR]

Carbon steel piping and tubing can be degraded by hydrogen uptake. The hydrogen permeation method is commonly applied to testing and qualification steel in response to hydrogen atom diffusion. Cyclic voltammetry (CV) has recently been proposed because it is a more straightforward method than permeation. A comprehensive study was conducted to investigate whether these two methods are comparable. A model alloy of SA 210 grade was studied. The study involved preparing specimens with varying microstructures through different heat treatments. Subsequently, metallographic analysis was conducted on each microstructural variation, followed by mechanical testing to evaluate the changes obtained before and after the hydrogen absorption test. The CV method consisted of three steps: CV before H absorption to search for a reference voltammogram, H charging, and CV after H absorption to determine the after-charge voltammogram. Electrochemical hydrogen permeation tests were performed in a Devanathan–Stachursky double cell. A comparison of the CV and permeation methods revealed that they show pretty similar results in evaluating the interaction between steel and hydrogen. Permeation methods provide quantitative results, while CV offers more qualitative insights. Both methods show that the quenched steel has the slowest hydrogen diffusion rate compared with those in normalized and base material conditions. [ABSTRACT FROM AUTHOR]

Owing to their characteristics like fast charge–discharge rate, very long life, simple geometry and eco-friendly nature, supercapacitor is an emerging technology to fulfil the present and future requirements of the energy. The performance of a supercapacitor is derived from the composition and morphology of the electrode. 2D materials possess various excellent structural properties like surface area, flexibility in the atomic scale dimension and mechanical strength with high electrical conductivity. This makes them an entrusted material to be used as an electrode material. The teaming of 2D materials and layered transition metal dichalcogenides have been of great interest for electrode materials. In this study, the reduction of graphene oxide is done by an environment-friendly synthesis method using cow urine, and then, synthesizing the reduced graphene oxide (rGO) and transition metal dichalcogenides (TMD) composite using the refluxing method. The modified pencil graphite electrode (PGE) was functionalized using the above composite and the performance is comparable to that of glassy carbon electrode. Our main motive was to develop a low-cost, sustainable and highly effective MoS2–rGO/PGE, which is completely based on an environment and eco-friendly method using natural precursors. The prepared MoS2–rGO nanocomposite was characterized by XRD, SEM and EDX, which revealed the formation as well as its morphological scenario. MoS2–rGO/PGE is explored as electrode material by electrochemical characterization with the 3-electrode system through cyclic voltammetry and electrochemical impedance spectroscopy, which exhibit maximum specific capacitance with good cycle stability. [ABSTRACT FROM AUTHOR]

In this study, Cu- and Zn-doped SnO2 nanoparticles (NPs) were synthesized by using the solvothermal method. The synthesized NPs were explored to check their supercapacitor, photovoltaic and magnetic properties. The Cu-doped SnO2 NPs showed a high specific capacitance of 386 F g−1 at 20 mV s−1 in 1 M KOH electrolyte and remarkable catalytic performance as a counter electrode (CE) for dye-sensitized solar cells (DSSCs), achieving a power conversion efficiency (PCE) of 10.70%, comparable to that of Pt CE. Moreover, Cu-doped SnO2 NPs displayed the highest room-temperature ferromagnetism, indicating their potential for magnetic device applications. Our results suggest that doped SnO2 NPs are promising candidates for multifunctional nanomaterials in energy and information technologies. [ABSTRACT FROM AUTHOR]

A series of europium doped lanthanum oxychloride samples were prepared through solid state method which were utilized as an electrode material and also as photocatalyst. The compounds form tetragonal phase having P4/nmm space group (No. 129). The sample's energy band-gap vary in between 4.14 and 4.35 eV. With a carbon paste electrode in a 0.1 M KOH electrolyte, Cyclic Voltammetry (CV) and Electrochemical (AC) Impedance Spectroscopy are performed. Results reveal that the sample synthesized can be an electrode material for sensing tin in alkaline medium in the concentration range of 1 to 5 mM. Also, the samples are considered to be photocatalyst for the decolourization of Rhodamine.B (Rh.B) dye in aqueous medium concentration of 10 ppm using UV light irradiation. LaOCl:Eu3+ sample as catalyst be able to degrade the Rh.B dye to an extent of 90% in 60 mins. These results demonstrated the relevance of synthesized compound for sensor and photocatalytic applications. Novelty: In this article, the La1-xEuxOCl (0.00 ≤ x ≤ 0.09) synthesised compounds were characterized for morphological nature, structural feature, and functional group analysis with band gap energies. Very particularly for the first time the synthesized samples have undergone preliminary research into their possible usage as electrodes for sensor applicability involving the detection of Tin in alkaline media. Moreover, the samples offered improved photocatalytic effectiveness for the decolourization of Rhodamine.B dye under the UV light irradiation. [ABSTRACT FROM AUTHOR]

Additives are very important to enhance the performance of lead-acid batteries. In this paper, formic acid is used as an electrolyte additive to study its effect on battery performance. The results show formic acid has an opposite effect on the electrochemical properties of pure lead at positive and negative potentials. Besides, formic acid can make more active materials participate in the reaction, increase the rate of conversion of lead to lead sulfate, and reduce the internal resistance of the battery. Moreover, formic acid batteries exhibit better rate performance and higher specific discharge capacity than the blank. Especially, when the 0.5 wt% formic acid is used, the discharge capacity can reach 87.0 mAh g−1 when it is discharged at 400 mA g−1. After 1200 cycles of charge and discharge at a current density of 100 mA g−1, the specific discharge capacity is still 68.1 mAh g−1, which is 1.42 times higher than that of blank cells. [ABSTRACT FROM AUTHOR]

To prepare Mg–Al-Nd alloys electrochemically, the electrochemical co-reduction mechanism of Mg(II), Al(III), and Nd(III) was probed in the LiCl-NaCl-MgCl2-AlF3 melts on a molybdenum electrode by means of various electrochemical measurement techniques, i.e., cyclic voltammetry, square wave voltammetry, chronopotentiometry, and open circuit chronopotentiometry. It was found that Nd could deposit on pre-deposited Al metal and form Nd-Al intermetallics in the LiCl-NaCl-NdCl3-MgCl2-AlF3 system, and the electrochemical signal related to the formation of ternary intermetallics was not detected. The co-reduction of Mg(II), Al(III), and Nd(III) was carried out on molybdenum electrode by galvanostatic electrolysis to prepare Mg–Al-Nd alloy, and samples were characterized by X-ray diffraction, scanning electron microscopy (SEM) with energy-dispersive spectrometry (EDS), and inductively coupled plasma-atomic emission spectrometry (ICP-AES). The results indicate that the alloy products were comprised of Al2Nd intermetallic, Mg and Al phases, and the Mg–Al compound was not observed in the alloys. [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]

In this work, efficient and environmentally friendly electrocatalysts based on 2D nanocrystals of graphitic carbon nitride (g-C3N4) decorated with praseodymium orthoferrite (PrFeO3) nanoparticles were designed and synthesized for the efficient electrocatalytic treatment of pharmaceutical wastewater. Nanocrystalline g-C3N4 was obtained through the thermal polymerization of urea in air. Self-propagating high-temperature synthesis (SHS) was employed for producing PrFeO3. Subsequently, the nanopowders underwent ethanol-assisted mechanochemical treatment using a planetary ball mill. As a result, a series of samples was obtained with the PrFeO3 content ranging from 0 to 100 wt%. The resulting nanocomposites were dispersed in a solution of isopropyl alcohol with the addition of 0.5% Nafion; thereafter, the suspensions were applied to an ITO glass substrate to form electroactive thin films. The series underwent analysis using an X-ray diffraction, scanning electron microscopy, surface area and porosity analysis, cyclic voltammetry, and electrochemical impedance spectroscopy. The influence of the g-C3N4 to PrFeO3 ratio on the electrochemical activity during the decomposition of tetracycline hydrochloride was analyzed. Consequently, an optimal ratio was determined, leading to the rapid and complete decomposition of the antibiotic in a neutral aqueous environment. In conclusion, it should be noted that the process of electrocatalytic decomposition of tetracycline hydrochloride has been comprehensively studied. [ABSTRACT FROM AUTHOR]

A series of high-capacity chromium oxides (CrOx, x ≥ 2.5) were synthesized as cathode for lithium-ion batteries (LIBs) by a step calcination method at about 300 °C. The results of cyclic voltammetry (CV) test and impedance analysis indicated that there is a certain relationship between the structure compositions and electrochemical performance. The initial phase transitioned into two subsequent phases during the circulation process and the higher the ratio of tetrahedrons [CrO4] to octahedrons [CrO6], the smaller the potential difference between the two phases. The high ratio of Cr8O21 was examined as a case study, the structural evolution during the charge/discharge process was investigated utilizing ex-situ X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and transmission electron microscope (TEM), showing a sequential phase transition to nanoparticles of LiCrO2, which exhibit a close-to-amorphous structure, and an irreversible crystalline phase of LiCrO2 that does not contribute to any capacity. The capacity fading is believed due to the unique phase transition behaviors during Li+ insertion/extraction. It is worth noting that Cr8O21 exhibited a high discharge capacity of 320 mAh g−1 (10 mA g−1) with an impressive capacity retention of 88% after 40 cycles. The present study offers valuable insights into comprehending the capacity fading mechanism of a range of chromium oxides, potentially serving as a means to investigate the structural evolution in metal oxides comprising diverse valence states. A series of high-capacity chromium oxides (CrOx, x ≥ 2.5) were synthesized as cathode for lithium-ion batteries (LIBs) by a step calcination method at about 300 °C. This series of compounds was found to switch into [CrO4] and [CrO6] during the cell cycle. As a case study of Cr8O21 with high ratio, ex-situ X-ray diffraction, X-ray photoelectron spectroscopy, and transmission electron microscope show that the phases after transition are the nanoparticles LiCrO2 close to amorphous and the irreversible phase crystal LiCrO2 without providing any capacity, which is the main cause of the drastic capacity fading in the previous circulation. [ABSTRACT FROM AUTHOR]

Water-soluble binders—locust bean gum (LBG) and carboxymethyl cellulose (CMC) were tested with the SnS anode modified by new conducting material polypyrrole—carbon black composite (PPyCB) and compared with the environmentally unfriendly widely used polyvinylidene fluoride (PVdF) as an organic binder. The electrochemical properties of tested electrodes were investigated by galvanostatic charging/discharging tests, cyclic voltammetry, and electrochemical impedance spectroscopy. Kinetic parameters of electrode processes were calculated from resistances. The first discharge capacities were 2150 mAh g−1, 1250 mAh g−1, and 960 mAh g−1 for SnS-PPyCB-LBG, SNS-PPyCB-CMC, and SnS-PPyCCB-PVdF, respectively. The exchange current density for the SnS-PPyCB electrode is in the range of 4.6 × 10−6 mA cm−2 for the system with carboxymethyl cellulose to 1.97 × 10−6 mA cm−2 in the cell with LBG. Compared to PVdF, locust bean gum is an equally effective binder and may even enhance electrode kinetics. [ABSTRACT FROM AUTHOR]

In an effort to better probe the structure–function relationship on the biological [Fe4S4] cluster of [FeFe]‐hydrogenases, a new library of tertiary phosphine‐supported diiron dithiolate complexes [Fe2(μ‐adtNR)(CO)5{P(C6H4X)3}] (1–3) with various substituents (X = F vs. H vs. Me), wherein adtNR is denoted as abbreviation for the (SCH2)2N(C6H4C2H4OC(O)CH2C6H4Me) unit, is prepared as the active site mimics of [FeFe]‐hydrogenases. Notably, the substituent influences of tertiary phosphines on the structures and electrochemical behaviors of 1–3 are studied by spectroscopic and crystallographic techniques as well as cyclic voltammetry. For example, the electronic effect of tertiary phosphines [P(C6H4X)3] is responsible for the electron density around diiron center and the key Fe–Fe as well as Fe–P lengths in 1–3 as revealed by IR spectroscopy and crystallographic analysis. Further, complexes 1–3 show the electrochemical activity for proton reduction into molecular hydrogen (H2) using acetic acid (AcOH) as a proton source. Noticeably, F‐substituent‐containing diiron model complex 1 exhibits greater turnover frequency (i.e., turnover frequency value) and similar overpotential for electrocatalytic H2 evolution relative to H‐ or Me‐substituent‐bearing diiron homologs 2 or 3. [ABSTRACT FROM AUTHOR]

In a unified regenerative fuel cell (URFC) or reversible fuel cell, the oxygen bifunctional catalyst must switch reversibly between the oxygen reduction reaction (ORR), fuel cell mode, and the oxygen evolution reaction (OER), electrolyzer mode. However, it is often unclear what effect alternating between ORR and OER has on the electrochemical behavior and physiochemical properties of the catalyst. Herein, operando X‐ray absorption spectroscopy (XAS) is utilized to monitor the continuous and dynamic evolution of the Co, Mn, and Fe oxidation states of perovskite catalysts Ba0.5Sr0.5Co0.8Fe0.2O3‐δ (BSCF) and La0.4Sr0.6MnO3‐δ (LSM), while the potential is oscillated between reducing and oxidizing potentials with cyclic voltammetry. The results reveal the importance of investigating bifunctional catalysts by alternating between fuel cell and electrolyzer operation and highlight the limitations and challenges of bifunctional catalysts. It is shown that the requirements for ORR and OER performance are divergent and that the oxidative potentials of OER are detrimental to ORR activity. These findings are used to give guidelines for future bifunctional catalyst design. Additionally, it is demonstrated how sunlight can be used to reactivate the ORR activity of LSM after rigorous cycling. [ABSTRACT FROM AUTHOR]

This work is focused on the visualization of latent fingerprints left on unfired brass cartridges. Polymer films were prepared from 2 mM neutral red or 5 mM toluidine blue using two different electrochemical methods (cyclic voltammetry or chronoamperometry) with relatively short polymerization times. The conditions for the deposition of conductive polymers, poly(neutral red) and poly(toluidine blue), from a neutral medium (phosphate buffer with 0.1 M KNO3 or 0.1 M KNO3, respectively) were optimized to produce high-quality visualization of the remaining fingerprints on the brass substrates. The surface morphology and quality of the polymer films after the electrochemical deposition of both polyphenazine dyes were characterized by stereomicroscope. Phenazine dyes, which were used for the visualization of fingerprints, have been shown to provide different degrees of homogeneity in the deposited film. Furthermore, the dependence of the stability of the monomer solutions on their age, use, and storage conditions are discussed. Finally, a methodology is proposed for how to apply this technique of visualizing latent fingerprints with observed details of papillary lines in forensic practice. [ABSTRACT FROM AUTHOR]

In the present work, rare earth metal oxides composed of cerium tungstate/polyaniline (Ce2(WO4)3/PANI) composites were prepared by an in situ chemical oxidative polymerization process and their supercapacitive behavior was evaluated. The structural and morphological properties of the Ce2(WO4)3/PANI composites were characterized via spectral and analytical techniques. X-ray diffraction revealed that the two prominent peaks for Ce2(WO4)3 and PANI located at 2θ = 28.3° and 25.4° were in good accordance with the observed 2θ values in Ce2(WO4)3/PANI composite. Field-emission scanning electron microscopy (FESEM) studies of Ce2(WO4)3/PANI had a nano-spherical interconnected with a layer-like morphology, which results in a rapid electron exchange. Electrochemical analysis revealed that Ce2(WO4)3/PANI exhibited an increased supercapacitor electrode response with a significant specific capacity (Cs) of 399 C g−1 at 1 Ag−1 and exhibited a remarkable capacity retention of 90.5% even after 3000 galvanostatic charge-discharge (GCD) cycles with 84% columbic efficiency, suggesting its promising electrode material for SCs. [ABSTRACT FROM AUTHOR]

Green synthesis represents a superior strategy for mitigating the adverse effects of chemical synthesis on the environment. In particular, the utilization of bio-sourced materials for nanomaterial synthesis constitutes a more sustainable and environmentally sound alternative. In this study, silver–carbon particle (Ag-CP) nanocomposites were prepared by a green hydrothermal method using lily bulbs as raw materials and were employed for glucose detection. Through the use of various physical characterization techniques, it was demonstrated that the natural lily hydrothermal method yielded carbon particles that were modified with Ag nanoparticles. The electrochemical characteristics of the Ag-CP nanocomposites for glucose sensing were investigated using cyclic voltammetry and chronoamperometry. The results showed that the constructed glucose sensor was capable of detecting concentrations within the range of 1–11 mM (R2 = 0.998), with sensitivity of 203.56 μA mM−1 cm−2 and a detection limit of 76.6 μM (S/N = 3). The Ag-CP nanocomposite sensor also exhibited notable electrocatalytic activity and remarkable anti-interference capability. In light of the exceptional sensing performance, coupled with the straightforward and cost-effective preparation process, the development of nanocomposite materials employing naturally sourced biological materials represents an attractive avenue for the production of eco-friendly nanocomposites. [ABSTRACT FROM AUTHOR]

Biopolymer composite electrolytes consisting of cellulose acetate and magnesium perchlorate with different weight percent (wt.%) of Zinc Oxide fillers were prepared using the standard solution cast technique. The effect of incorporating various amounts of ZnO fillers in our composite electrolytes was investigated for their electrical and structural properties, and ion transference numbers. The ionic conductivity of 40 wt.% ZnO filler was found to be 8.75× 10−4 S/cm at 30 °C along with a 4.2 V electrochemical stability window. The ion transference number has been found to be 0.97 for CA + 40 wt.% of Mg(ClO4)2 + 40 wt.% with ZnO fillers. Furthermore, the electrochemical performances of the prepared electrolytes have also been investigated. The fabricated cell with this electrolyte shows an enhanced energy and high-power density of 2.78 Wh/Kg and 1000 W/Kg, respectively. An increase in the above-mentioned densities may be attributed to the high ionic conductivity ZnO fillers in the biopolymer matrix. Additionally, it shows 100% capacitance retention along with high coulombic efficiency after the 129th cycle. [ABSTRACT FROM AUTHOR]

Titanium niobium oxide (TNO) exhibits great potential as a lithium‐ion battery anode due to its high capacity, minimal volume change during cycling, and safe good operation characteristic enabled from its voltage profile. However, its intrinsically low electronic and ionic conductivity hinders its potential for practical applications. This work proposes a facile coprecipitation method to address these limitations by incorporating a nano‐macro structure and in situ Sn ion doping into bulk TNO. This approach ensures homogeneous integration of TNO precursors and the Sn dopant at a molecular level within the co‐precipitation nanoparticles. Additionally, the use of low toxicity solvents facilitate scalability of the synthesis process. Excellent rate capability, high reversible capacities, and good capacity retention are achieved simultaneously due to synergistic effects of the bulk doping, which expands the crystal volume and enhances Li+ diffusion, combined with abundant surface area of the nano‐macro structures. The specific capacity of Sn‐doped TNO nanospheres remains at 180 mAh/g at a high current density of 40 C (1 C=400 mA g−1), which is nearly four times higher than that of undoped samples. Furthermore, the cyclic voltammetry analysis at various scanning rates reveals an increased Li+ diffusion rate in Sn doped titanium niobium dioxide. [ABSTRACT FROM AUTHOR]

Organic dyes hold promise as inexpensive electrochemically‐active building blocks for new renewable energy technologies such as redox‐flow batteries and dye‐sensitised solar cells, especially if they display high oxidation and/or low reduction potentials in cheap, non‐flammable solvents such as water or protic ionic liquids. Systematic computational and experimental characterisation of a representative selection of acidic and basic dyes in buffered aqueous solutions and propylammonium formate confirm that quinoid‐type mechanisms impart electrochemical reversibility for the majority of systems investigated, including quinones, fused tricyclic heteroaromatics, indigo carmine and some aromatic nitrogenous species. Conversely, systems that generate longlived radical intermediates – arylmethanes, hydroquinones at high pH, azocyclic systems – tend to display irreversible electrochemistry, likely undergoing ring‐opening, dimerisation and/or disproportionation reactions. [ABSTRACT FROM AUTHOR]

A novel approach for investigating the formation of solid electrolyte interphase (SEI) in Na‐ion batteries (NIB) through the coupling of in situ liquid electrochemical transmission electron microscopy (ec‐TEM) and gas‐chromatography mass‐spectrometry (GC/MS) is proposed. To optimize this coupling, experiments are conducted on the sodiation of hard carbon materials (HC) using two setups: in situ ec‐TEM holder and ex situ setup. Electrolyte (NP30) is intentionally degraded using cyclic voltammetry (CV), and the recovered liquid product is analyzed using GC/MS. Solid product (µ‐chip) is analyzed using TEM techniques in a post‐mortem analysis. The ex situ experiments served as a reference to for insertion of Na+ ions in the HC, SEI size (389 nm), SEI composition (P, Na, F, and O), and Na plating. The in situ TEM analysis reveals a cyclability limitation, this issue appears to be caused by the plating of Na in the form of a “foam” structure, resulting from the gas release during the reaction of Na with DMC/EC electrolyte. The foam structure, subsequently transformes into a second SEI, is electrochemically inactive and reduces the cyclability of the battery. Overall, the results demonstrate the powerful synergy achieved by coupling in situ ec‐TEM and GC/MS techniques. [ABSTRACT FROM AUTHOR]

In the tumor treatment by Fenton reaction‒based nanocatalytic medicines, the gradual consumption of Fe(II) ions greatly reduces the production of hydroxyl radicals, one of the most active reactive oxygen species (ROS), leading to much deteriorated therapeutic efficacy. Meanwhile, the ROS consumption caused by the highly expressed reduced glutathione (GSH) in the tumor microenvironment further prevents tumor apoptosis. Therefore, using the highly expressed GSH in tumor tissue to promote the Fe(III) reduction to Fe(II) can not only weaken the resistance of tumor to ROS attack, but also generate enough Fe(II) to accelerate the Fenton reaction. In view of this, an allicin‒modified FeO1‐xOH nanocatalyst possessing varied valence states (II, III) has been designed and synthesized. The coexistence of Fe(II)/Fe(III) enables the simultaneous occurrence of Fenton reaction and GSH oxidation, and the Fe(III) reduction by GSH oxidation results in the promoted cyclic conversion of Fe ions in tumor and positive catalytic therapeutic effects. Moreover, allicin capable of regulating cell cycle and suppressing tumor growth is loaded on FeO1‐xOH nanosheets to activate immune response against tumors and inhibit tumor recurrence, finally achieving the tumor regression efficiently and sustainably. This therapeutic strategy provides an innovative approach to formulate efficient antitumor nanomedicine for enhanced tumor treatment. [ABSTRACT FROM AUTHOR]

ABSTRACT Oxidovanadium meso‐tetrakis(3,4,5‐trimethoxyphenyl) porphyrin [VO(T(OMe)3PP)] (Complex 1) was prepared. The oxidation product of Complex 1 has been characterized by cyclic voltammetry (CV), UV–visible spectrophotometer, electron paramagnetic resonance (EPR) and nuclear magnetic resonance (NMR) by the addition of SbCl5 to Complex 1. There is a one‐electron oxidation product in Complex 1 that creates π–cation radicals in CV data. This is supported by an IR spectrophotometer. Subsequent EPR spectra verified the initiation of the π–cation monoradical, which subsequently transforms into a triplet state where S = 1. DNA binding and antibacterial analysis with Complex 1 have also been analysed. In the DNA‐binding analysis, the CV data confirm the interaction between Complex 1 and DNA. Furthermore, the fact that Complex 1 is more effective at killing bacteria shows that the metal ion's chelation with the porphyrin ligand makes it more lipophilic. [ABSTRACT FROM AUTHOR]

ABSTRACT Methotrexate (MTX) is a chemotherapy agent and immune system suppressant that is widely used to treat a variety of malignant and nonmalignant diseases. Due to some drawbacks of the existing methods for the determination of MTX in aquatic and real samples, we prepared a new, simple, and selective dual‐mode fluorometric and electrochemical approach based on peroxidase‐mimic [Mo36] polyoxomolybdate nanoclusters (POMo) for sensing MTX. A turn‐on–off fluorometric approach for the detection of MTX was developed, which was based on the inhibition of the emission intensity of the terephthalic acid (TA)‐H2O2 system upon the addition of MTX to the reaction solution. The electrocatalytic performance of the obtained POMo was studied after making a carbon paste electrode (CPE) utilizing cyclic voltammetry and amperometry analysis. Under the optimum condition, good linearity was observed between the quenched emission intensity of the system and MTX dosage in the range of 0.5–250 μM with a limit of detection (LOD) of 0.91 μM. The electrochemical method illustrated a much better response with an extensive linear range of 0.01–475 μM and a lower LOD (1.61 nM). Analytical recoveries and RSD% values were, respectively, in the range of 87.72%–110% and 0.33%–1.32% for the fluorometric system and 96%–106% and 0.77%–1.02% for the electrochemical platform. Finally, the selectivity of the sensor was evaluated against various common interfering species, and the results indicated satisfactory selectivity of the POMo dual‐mode system towards MTX. [ABSTRACT FROM AUTHOR]

In this manuscript, we present a facile approach to synthesize a highly active catalyst for the electro-oxidation of ethanol using Pd nanoparticles supported on a Ag–Zn alloy on reduced graphene oxide. This nanocomposite material was fabricated via a two-step process of incineration followed by sol-gel synthesis. The physical properties of the catalyst were evaluated using X-ray diffraction, X-ray photoelectron spectroscopy, and scanning and transmission electron microscopies. To understand the catalyst's activity for ethanol oxidation, we performed a series of cyclic voltammetry and electrochemical impedance spectroscopy experiments in alkaline medium. The catalyst exhibited good catalytic activity with a current density of 13.01 mA cm−2, a value seven times higher than the commercial standard Pd/C catalyst and higher than any other previously reported Pd-based catalyst. The results were attributed synergistic effects between the Pd and alloy support along with the large electrochemically active surface area of the material. Taken together, these results suggest that ethanol electrocatalysts based on nanocomposites of Pd, Ag, and Zn is promising candidates for future ethanol fuel cells. • Facile strategy was used to prepare a support material and catalyst (Pd@Ag–Zn-rGO). • Synthesized Pd@Ag–Zn-rGO composite exhibited good catalytic activity towards ethanol electro-oxidation. • Pd@Ag–Zn-rGO catalyst exhibits lower charge transfer resistance (Rct) at the catalyst surface. [ABSTRACT FROM AUTHOR]

This study investigates the energy efficient and novel BaS 3 :La 2 S 3 :PrS 1.7 nanocomposite chalcogenide system synthesized using a single source precursor technique. The prepared metallic sulphide was marked by narrow band gap of 3.6 eV and 17.39 nm average crystallite size. Functional group analysis indicated the presence of various bonds inclusive of the metal sulphide bond. Morphologically, these nano-composite chalcogenide was expressive of the irregular shaped particles arranged in the form of agglomerates. The decomposition pattern of this chalcogenide took place in two steps shown by the thermal gravimetric analysis recorded in the range of 0–800 °C. The electrochemical charge-storing behavior was evaluated. According to cyclic voltammetric results in 1 M KOH, the fabricated electrode demonstrated favorable charge storage capabilities with a specific capacitance of 776.36 F g−1. This implies that the electrode has a large amount of potential for storing energy. Additionally, the impedance studies showed that this electrode had a specific power density of 7417.69 W kg−1 and a R s = 1.03 Ω. The OER overpotential and Tafel slope values are 457 mV and 78 mV/dec, respectively, while electrode produced a Tafel slope of 200 mV/dec and a HER overpotential value of 233 mV. • Novel BaS 3 :La 2 S 3 :PrS 1.7 with tuned narrow band gap. • Excellent specifications for energy applications. • Profound energy storage with of 776.36 F g−1 specific capacitance. • Specific power density of 7417.69 W kg−1 • Efficient HER electro-catalyst with 200 mV/dec Tafel slope. [ABSTRACT FROM AUTHOR]

The electrocatalytic performance of double perovskite-based composites can be significantly influenced by electronic interactions. In this study, the effect of electronic interaction on the electrocatalytic performance of a PrBa 0.5 Sr 0.5 Co 1.5 Fe 0.5 O 5+δ (PBSCF) double perovskite-based composite was investigated. A PBSCF-NiP composite coating was engineered to optimize the electrocatalytic hydrogen evolution performance. The tetragonal PBSCF double perovskite was synthesized using the sol-gel method, and the composite coating was prepared. The successful development of the composite coating was confirmed using advanced instruments, and the interaction between NiP and PBSCF double perovite unit cell was evaluated using double-phase crystal structural modelling. The optimized NiP-PBSCF 2 GL composite coating exhibited the lowest overpotential of 107.6 mV at a current density of 10 mA/cm2 with a Tafel slope of 83 mVdec−1. The increased electrochemically active surface area of NiP-PBSCF 2 GL was confirmed through cyclic voltammetry study, indicating excellent activity towards hydrogen evolution reaction. An electron trapping mechanism through oxygen defects centres may explain the improved composite coating's electrocatalytic efficiency. This comprehensive study provides valuable insights into the design of new materials for related applications. • A supercell of PBSCF was modeled with a unit cell of NiP situated in a vacancy site. • Two step synthetic strategy was adopted for double perovskite-based HER catalyst. • The coating exhibits a η 10 of 107.6 mV ensures superior HER activity. • The interaction between NiP and PBSCF double perovskite unit cell was evaluated. • The electrocatalytic HER efficiency was explained by electron trapping mechanism. [ABSTRACT FROM AUTHOR]

Stimulated by the increasing interest in ion adsorption effects on electrocatalytic reactions and by recent more detailed reports on the potential dependent adlayer structures formed on Ru(0001) in pure HClO4 and H2SO4 electrolytes, we revisited the oxygen reduction reaction (ORR) on structurally well‐defined Ru(0001) single crystal surfaces prepared under ultrahigh vacuum conditions. We demonstrate that the complex, potential‐dependent activity both for the ORR and for H2O2 formation is closely related to potential‐dependent changes in the composition and structure of the adlayer. Our results demonstrate the enormous effects adsorbed species can have on the ORR reaction characteristics, either by surface blocking, e. g., by (co‐)adsorbed bisulfate species, or by participation in the reaction, e. g., by *H transfer from adsorbed H or OH to O2. The comparison with results obtained on polycrystalline Ru, which differ significantly from Ru(0001) data, furthermore underlines the importance of using structurally well‐defined surfaces as a reference system for future theoretical studies. [ABSTRACT FROM AUTHOR]

The development of electricity‐driven oxygen evolution reaction (OER) is a potent solution for energy storage applications. In recent years, there is a surge in interest in designing transition metal‐based catalysts with stable linkages, presenting an efficient alternative to noble metal‐based electrocatalysts. Transition metal complexes linked by salen ligands garner considerable attention due to their capacity to chelate and stabilize metal ions. This work presents a novel approach by strategically incorporating the metal–salen core into a porous organic polymer (POP) backbone, thereby fabricating a highly effective electrocatalyst for oxygen evolution. The judicious selection of metal–salen active sites, coupled with the intramolecular free volume (IMFV) of the triptycene core and the high specific surface area of the salen–POPs, result in superior OER activity. By precisely tuning the structure through variation of the transition metal in the salen unit, deep insights are gained into their electrocatalytic behavior. Notably, the most efficient catalyst, Ni‐DHDA‐TAT, exhibits an impressively low overpotential (η10) of ≈ 270 mV at a current density of 10 mA cm−2 for OER (in 1 m KOH). Further, Ni‐DHDA‐TAT retains its activity even after 50 h of chronoamperometry and 1000 cyclic voltammetry cycles with negligible degradation in its initial performance. [ABSTRACT FROM AUTHOR]