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Methanol oxidation stands out as a pivotal solution in addressing the global energy crisis and environmental pollution, owing to its practical applicability, high current density, and the ready availability of methanol as a fuel source. To effectively catalyze methanol oxidation, an electrocatalyst is imperious to overcome the activation energy barrier. Herein, a three‐dimensionally arranged NiSe2 nanosheet‐based electrocatalyst is synthesized through a facile solvothermal followed by an annealing method. The catalyst's porous structure enhances catalytic efficiency by providing a substantial electrochemical surface area (ECSA) equivalent to 0.121 mF cm−2. Notably, the electrocatalyst exhibits a remarkable response of 21.58 mA cm−2 at an overpotential of 1.70 V vs RHE, accompanied by the lowest Tafel slope recorded at 39.14 mV dec−1. The electronic circuit, represented by Rs(Qf(RfW(QdlRct)), aligns well with electrochemical impedance spectroscopy data, elucidating the reaction path and intrinsic properties. Furthermore, the catalytic performance is elucidated concerning ECSA and weight, revealing current densities of 5.60 mA cm−2 and 71.34 mA mg−1, respectively. Impressively, the catalyst demonstrates exceptional resistance to poisoning and sustained stability over a continuous 3600‐s operation. This comprehensive study underscores the promising potential of the NiSe2 nanosheet‐based electrocatalyst for efficient methanol oxidation, providing valuable insights for advancing clean energy technologies. [ABSTRACT FROM AUTHOR]

Transition metal oxides have garnered attention for the methanol electro‐oxidation reaction owing to their easy availability, high catalytic applicability, and multiple oxidation capabilities. Bimetal‐based catalysts further enhance the performance of the methanol oxidation reaction. In this context, a chrysanthemum‐flower‐like MoO2/WO3 is synthesized through a solvothermal and annealing strategy. The morphology attests to the rough surface and pores in the catalyst, augmenting its surface area for reactions and enhancing catalytic applicability. Electrochemical oxidation of methanol yields an optimal current density of 0.99 mA cm−2 and 2.07 mA mg−1 at a potential of 0.57 V versus Ag/AgCl. The catalyst exhibits a remarkably low Tafel slope of 37.45 mV dec−1, affirming its rapid reaction kinetics. Electrochemical impedance spectroscopy (EIS) reveals an equivalent electronic circuit of R(Q(R(QR)Q(RW))), confirming low charge transfer resistance (Rct) and diffusion‐controlled kinetics attributable to the pores in the sample. The sample also demonstrates an electrochemically active surface area (ECSA) value equal to 0.122 mF cm−2 and long‐term stability over continuous 5000 s, exhibiting no change and high resistance to CO poisoning. All these characterizations and obtained results collectively affirm that the chrysanthemum‐flower‐like MoO2/WO3 serves as a highly suitable electrocatalyst for the electrochemical oxidation of methanol. [ABSTRACT FROM AUTHOR]

The highly substituted mono‐aryl/alkylthio‐(hetero)acenes prepared in this study have been found to be thermally more stable (Tdecomp.=331–354 °C) than the known di‐aryl/alkylthio‐substituted acenes by an average of 25 °C. They are also much more photostable at 254 and 365 nm (in both argon and air) than the parent anthracene and other reported anthracenes. The most photostable aryl/alkylthio‐anthracenes at 254 nm were found to be 60–70 (in air) and 130 (in argon) times more stable in solution than the unsubstituted anthracene, and much more stable than known EDG/EWG‐substituted anthracenes (EDG=electron‐donating group, EWG=electron‐withdrawing group) with an extended aromatic core. Furthermore, the acenes showed significantly higher photostability at 365 nm in both air and argon. The anthracenes were obtained by the novel thio‐Friedel–Crafts/Bradsher cyclization reaction of hitherto unknown [o‐(1,3‐dithian‐2‐yl)aryl](aryl)methyl thioethers. The developed approach provides a general access to mono‐aryl/alkylthio‐substituted (hetero)acene frameworks containing at least three fused (hetero)aromatic rings. The characteristic feature of this approach, which leads to highly substituted acenes, is that the substituents, unlike in other methods, may be introduced at an early stage of the synthesis. DFT and TD‐DFT calculations confirmed the stabilizing role of the aryl/alkylthio substituent in the mono‐aryl/alkylthio‐substituted anthracenes, which are the most stable anthracenes prepared to date. Their high photostability is mainly due to the quenching of singlet oxygen by the acene and the quenching of the acene S1 state by molecular oxygen. [ABSTRACT FROM AUTHOR]

In this paper a theoretical study of stripping processes at planar electrodes under conditions of square‐wave voltammetry is presented. A mechanistic examination for cathodic stripping electrode mechanisms, a simple anodic striping mechanism, and anodic stripping mechanisms coupled with adsorption equilibrium of the analyte are discussed using varying square‐wave amplitudes. The methodologies described here use two typical features: the peak potential separation of square‐wave components and the amplitude‐based quasireversible maximum. Both methods can be applied at a constant frequency, i. e., constant scan rate. The received data are combined with the critical parameters of electrode reaction kinetics. Thus, the established methodologies allow for a simple kinetic characterization. The received diagnostic criteria are verified with experiments at a glassy carbon electrode for lead ions. [ABSTRACT FROM AUTHOR]

Abstract: The electrochemical reduction of lactofen (LCT) at the glassy carbon (GCE) and silver amalgam film electrode (AMFE) is investigatedin detail by the means of square wave voltammetry (SWV), square wave stripping voltammetry (SWSV) and cyclic voltammetry. The influence of various factors such as supporting electrolyte composition and SW parameters were studied. The AMFE electrode showed an excellent electrochemical activity toward the electro‐reduction of LCT, leading to a significant improvement in sensitivity as compared to the glassy carbon electrode.The SWSV detection limits for GCE and AMFE were 285.0 nM and 2.0 nM, respectively. The applicability of the developed voltammetric method for analysis of tap water and river water is illustrated with spiked samples analysis. Moreover, as lactofen is highly toxic to fish and other aquatic organisms, its interaction with dsDNA isolated from salmon sperm was tested. The intercalative mode of LCT binding to dsDNA was estimated. The heterogeneous rate constants were calculated for the free LCT and the LCT‐dsDNA complex. Moreover, LCT‐dsDNA complex binding ratio and equilibrium constant were determined. The decrease in the SWV peak current of LCT in the presence of dsDNA was used for the determination of dsDNA. [ABSTRACT FROM AUTHOR]

For the purpose of simplification of the electrochemical study under conditions of square-wave voltammetry (SWV), a simplified form of potential modulation is proposed by replacing the staircase potential ramp with a constant potential. The resulting potential modulation, which could be considered as a pulse form of a chronoamperometric experiment (i. e., square-wave chronoamperometry), is provisionally termed as electrochemical faradaic spectroscopy, considering the fact that the main tool in the kinetic analysis is the frequency of the potential pulses applied. The proposed technique is illustrated with theoretical analysis of a simple, kinetically controlled electrode reaction of a dissolved redox couple and experimentally verified with the Eu3+(aq)/Eu2+(aq) redox couple at a mercury electrode. The square-wave chronoamperometry exhibits unique features of the response absent in both conventional SWV and chronoamperometry, widening the range of accessible electrode kinetics. [ABSTRACT FROM AUTHOR]

Oxidation and reduction processes of the insecticide fenthion was comparatively investigated at a reduced graphene oxide modified glassy carbon electrode (RGO-GCE) and a cyclic renewable silver amalgam film electrode (Hg(Ag)FE) using square wave stripping voltammetry (SWSV). The influence of pH and SW parameters was investigated. The linear concentration ranges were found to be 1 × 10−6 - 2 × 10−5 and 1 × 10−7 - 2 × 10−5 mol L−1 for Hg(Ag)FE and RGO-GCE, respectively. The detection and quantification limits were calculated as 1.3 × 10−7 and 4.5 × 10−7 mol L−1 for Hg(Ag)FE and 7.6 × 10−9 and 2.5 × 10−8 mol L−1 for RGO-GCE. Both of the developed electroanalytical methods offer rapid and simple detection of fenthion and were used on spiked tap and river water and apple juice samples. Scanning electron microscopy was used for RGO-GCE surface characterization. [ABSTRACT FROM AUTHOR]

The electrochemical behaviour of profluralin (PFL) was investigated with square wave voltammetry (SWV) and cyclic voltammetry at bare and modified with graphene, graphene oxide, reduced graphene oxide, carbon nanotubes glassy carbon electrode. The influence of various factors such as pH, buffer composition, ionic surfactants and voltammetric parameters was studied. The best results in terms of signal shape and intensity were recorded in 0.04 M Britton-Robinson buffer at pH 2.0 at −0.43 V versus Ag/AgCl. In acidic medium profluralin produces single cathodic signal of an irreversible nature. Observed peak (two superimposed signals from two nitro groups) is a result of PFL reduction controlled by diffusion processes. Linearity of peak currents ( Ip) vs. concentrations of profluralin was found in the range of 1.0×10−7 to 1.0×10−6 M with a detection limit of 2.6×10−8 M using fast and sensitive SWV. The developed method has been applied for the quantitative analysis of profluralin in spiked environmental samples with very good average recoveries in the range from 98.6 to 99.9 % with a mean relative standard deviation of 4.0 %. [ABSTRACT FROM AUTHOR]

The aim of the research was the use of square wave adsorptive stripping voltammetry (SWAdSV) in conjunction with a hanging mercury drop electrode (HMDE) for the determination of nitrothal-isopropyl. It was found that optimal SW technique parameters were frequency, 200 Hz; amplitude, 50 mV; and step potential, 5 mV. Accumulation time and potential were studied to select the optimal conditions in adsorptive stripping voltammetry: 45 s at 0.0 V, respectively. The calibration curve (SWSV) was linear in the nitrothal-isopropyl concentration range from 2.0 × 10−7 to 2.0 × 10−6 mol L−1 with detection limit of 3.46 × 10−8 mol L−1. The repeatability of the method was determined at a nitrothal-isopropyl concentration level equal to 6.0 × 10−7 mol L−1 and expressed as RSD = 5.5% (n=6). The proposed method was successfully validated by studying the recovery of nitrothal-isopropyl in spiked environmental samples. [ABSTRACT FROM AUTHOR]

The electrode kinetics of vitamin B2 was measured at a constant scan rate of a square-wave (SW) voltammetric experiment by recently introduced method based on alteration of the height (amplitude) of the SW potential pulses. The electrode reaction mechanism was analyzed in the light of the simplified model considering two-electron one step surface electrode mechanism, as well as to more appropriate EE surface reaction pathway consisting of two successive one-electron quasireversible reactions. Theoretical analysis indicated that the evolution of the voltammetric response under variation of the SW amplitude enables estimation of the rate determining step of the EE mechanism. [ABSTRACT FROM AUTHOR]

The kinetics of surface confined electrode reactions of alizarin, vitamin B12, and vitamin K2 is measured with square-wave voltammetry over a wide pH interval, by applying the recent methodology for kinetic analysis at a constant scan rate [V. Mirceski, D. Guziejewski, K. Lisichkov, Electrochim. Acta­ 2013, 114, 667-673]. The reliability and the simplicity of the recent methodology is confirmed. The methodology requires analysis of the peak potential separation of the forward and backward component of the response as a function of the pulse height (SW amplitude), for a given frequency (i.e. constant scan rate) of the potential modulation. [ABSTRACT FROM AUTHOR]

Acibenzolar- S-methyl (ASM) is a novel fungicide applied for crop protection. A renewable silver amalgam film electrode was used for the determination of ASM in pH 3.4 BrittonRobinson buffer using square wave adsorptive stripping voltammetry (SW AdSV). The parameters of the method were optimized. The electroanalytical procedure made possible to determine ASM in the concentration range of 5×10−8-3×10−7 mol L−1 ( LOD=4.86×10−9, LOQ=1.62×10−8 mol L−1). The effect of common interfering pesticides and heavy metal ions was checked. The validated method was applied in ASM determination in spiked water samples. [ABSTRACT FROM AUTHOR]