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Pyrite is one of the most abundant metal sulfide tailings and is susceptible to oxidation, yielding acidic mine drainage (AMD) that poses significant environmental risks. Consequently, the exploration of pyrite surface oxidation and the kinetic influencing factors remains a pivotal research area. Despite the oxidation of pyrite producing a significant amount of sulfate (SO42−), a comprehensive investigation into its influence on the oxidation process is lacking. Leveraging pyrite's semiconducting nature and the electrochemical intricacies of its surface oxidation, this study employs electrochemical techniques—cyclic voltammetry (CV), Tafel polarization, and electrochemical impedance spectroscopy (EIS)—to assess the effect of SO42⁻ on pyrite surface oxidation. The CV curve shows that SO42− does not change the fundamental surface oxidation mechanism of pyrite, but its redox peak current density decreases with the increase in SO42−, and the surface oxidation rate of pyrite decreases. The possible reason is attributed to SO42− adsorption onto pyrite surfaces, blocking active sites and impeding the oxidation process. Furthermore, Tafel polarization curves indicate an augmentation in polarization resistance with elevated SO42− concentrations, signifying heightened difficulty in pyrite surface reactions. EIS analysis underscores an increase in Weber diffusion resistance with increasing SO42⁻, indicating that the diffusion of Fe3+ to the pyrite surface and the diffusion of oxidized products to the solution becomes more difficult. These findings will improve our understanding of the influence of SO42− on pyrite oxidation and have important implications for deepening the understanding of surface oxidation of pyrite in the natural environment. [ABSTRACT FROM AUTHOR]

BACKGROUND: Ammonia removal from wastewater by electrooxidation (EO) is an interesting approach because of its efficiency and easy maintenance and operation. In this process, ammonia is oxidized to nitrate or nitrogen gas. Ammonia conversion to the latter is desirable to remove nitrogen from the liquid; however, the influence of several operating parameters on nitrate generation has not been systematically evaluated. Therefore, this work aimed to investigate the effect of current density (200–800 A m−2), chloride concentration (0–10 000 mg L) and initial pH (5–9) on the electrooxidation of an ammonia‐containing solution and the associated generation of nitrate. For this purpose, a laboratory‐scale electrochemical reactor containing two Ti/RuO2 electrodes was used. RESULTS: The results indicated high ammonia removal efficiency – 98% within 150 min at 800 A m−2 and 97% within 240 min at 500 A m−2 – generating around 70 and 102 mg NO3−‐N L−1 under these conditions, respectively. Increasing the chloride concentration from 5000 to 7500 mg L−1 reduces the electrolysis time needed to remove all ammonia from 180 to 150 min. However, with increasing initial chloride concentration, the amount of nitrate generated rose from 69.5 to 135.9 mg N L−1. On the other hand, in the test without chloride, nitrate generation was considerably lower (0–0.61 mg L−1). CONCLUSION: The higher the current density applied, the greater the ammonia removal by EO. Although current density influenced the ammonia oxidation rates, it did not directly affect nitrate formation. The lower the concentration of ammonia in the solution, the more significant was the fraction of nitrate generated. Most of the inlet ammonia was oxidized to nitrogen gas, nitrite was rapidly oxidized to nitrate and higher chloride concentrations enhanced ammonia oxidation. © 2024 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

Alpha-lipoic acid (α-LA) is a naturally occurring compound that is both water and fat soluble, functioning as a powerful antioxidant in the body. In this study, multi-walled carbon nanotubes (MWCNTs) with SDS were electrodeposited onto a glassy carbon electrode (GCE) electrochemically. This modified electrode was characterized by electrochemical techniques (EIS, CV). The MWCNT/SDS-modified GCE was utilized for the analysis of α-LA. An electrochemical oxidation mechanism for α-LA was proposed using the developed electrochemical sensor. After optimizing the conditions, the MWCNT/SDS-GCE sensor exhibited a linear response in the concentration range of 0.6–9.0 µM, with a detection limit of 0.15 µM. Additionally, this chemical sensor was effectively utilized for the electrochemical analysis of α-LA in the food additive sample. [ABSTRACT FROM AUTHOR]

In this study, we report an environment‐friendly protocol by integrating the nonnatural catalytic activity of lipase with electrocatalysis for synthesizing C‐3 alkylated oxindoles, which are part of many natural and pharmaceuticals products. Gratifyingly, Candida antarctica lipase B (CALB) is found to be highly active and regioselective for catalyzing the nonnatural C‐3 alkylation reaction at indole when combined with an electrochemical C‐2 oxidation process in the same vessels. Further, the generality and feasibility of the developed protocol are shown by employing several functional groups on the indole moiety and obtaining the desired products in moderate to good yield. Besides, the control experiments are set up along with the molecular docking studies to substantiate the role of the active site of Candida antarctica lipase B (CALB) in carrying out the regioselective C‐3 alkylation reaction. In addition, control experiments and cyclic voltammetry are performed to get insight into the electrochemical C‐2 oxidation process and as a result, a plausible mechanism for the integrated process is presented. [ABSTRACT FROM AUTHOR]

Highlights This research involved the modification of carbon fiber (CF) through electrochemical anodizing under different conditions and focused on analyzing the impact of modifying CF surface and examining the interfacial characteristics of thermoset polyimide (PI) composites. The process of electrochemically oxidizing CF consists of two distinct stages. The oxidation stage mainly occurs under the conditions of low current intensity and low electrolyte concentration, at the graphite boundary defects on CF surface. The etching effect stage intensifies on CF surface under high current intensity and electrolyte concentration, resulting in the fracture and detachment of the carbon rings. Electrochemical oxidation improves CF roughness and the quantity of active functional groups, which enhances mechanical interlocking and chemical bonding between CF and PI. Furthermore, the introduction of reactive hydrogen groups can contribute to the PI curing process, significantly improving the weak interface bonding problem between CF and PI. The interfacial shear strength (IFSS) of the composites increased from 82.08 to 104.33 MPa and 114.08 MPa in acidic and alkaline electrolyte environments, respectively. Improved interfacial compatibility between CF and polyimide resin through electrochemical oxidation The relationship between the physical morphology and chemical composition of the surface of CF and their interfacial properties was investigated. The interfacial shear strength of CF/PI was increased by 38.99% without any loss in mechanical properties of the CF. The electrochemical oxidation mechanism of CF under different electrolytes was revealed. [ABSTRACT FROM AUTHOR]

The presence of benzene and toluene in groundwater poses a serious threat to both aquatic ecosystems and human health. The electrochemical removal of these contaminants is primarily hindered by the low generation yield of reactive oxygen species (ROS). Herein, polytetrafluoroethylene (PTFE) was electrodeposited onto the surface of Sb–SnO 2 -doped TiO 2 nanotubes (TNT/Sb–SnO 2 /5PTFE-300) to enhance electrochemical activity. The resulting nanoelectrode achieved removal efficiencies of 96.2 ​% for benzene and 97.6 ​% for toluene. The minimal variation in the degradation of benzene and toluene following 8 cycles of use verified its stability. Experiments confirmed that •OH was the primary ROS. Hydrophobic surface of the nanoelectrode promoted the one-electron reaction of H 2 O oxidation, leading to •OH concentrations that were 54.0 and 27.5 times higher, respectively, than those produced by Ti/Sb–SnO 2 , and 4.7 and 2.0 times higher, respectively, than those produced by TNT/Sb–SnO 2 -300. Moreover, intermediate products suggested the ring-opening of benzene and toluene, yielding easily degradable small organic molecules. The electrochemical oxidation (EO) process revealed a competitive relationship between benzene and toluene, with toluene exhibiting stronger competitive effects (kinetic constant was 2.1 times that of benzene). The efficient nanoelectrode provide a novel approach for the removal of benzene and toluene from aquatic environments through EO. [Display omitted] • The TNT/Sb–SnO 2 /5PTFE-300 nanoelectrode exhibited good cycling stability. • Hydrophobic surface promoted the one-electron H 2 O oxidation and enhanced the generation of •HO. • Interactions between benzene and toluene were elucidated. [ABSTRACT FROM AUTHOR]

During pyrite mining, tailings and waste residues are generated, and the oxidation of exposed metal sulfides leads to significant environmental issues such as acid mine drainage pollution. Studying the oxidation mechanism of pyrite is crucial for inhibiting or preventing the formation of acid mine drainage. Alkaline amino acids were used as electrolytes to explore the electrochemical oxidation mechanism of pyrite. Through electrochemical methods such as OCP, CV, Tafel polarization curve, LSV, and EIS, the electrochemical behavior of pyrite surfaces was measured, confirming the feasibility of pyrite oxidation in an alkaline amino acid system. The oxidation mechanisms of pyrite were consistent across the 3 alkaline amino acids, with the oxidation rate of pyrite following the order: lysine>arginine>histidine. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Harbin Institute of Technology. Social Sciences Edition / Haerbin Gongye Daxue Xuebao. Shehui Kexue Ban is the property of Harbin Institute of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Electrochromic (EC) films are widely used in smart windows, automobile mirrors, and low-power displays due to their capability of reversibly changing color under an external potential. Transition metal oxides, due to their ability to switch between multiple oxidation states, are primarily used as EC films. They require low operating power and provide high coloration efficiency in EC applications. However, their thin-film fabrication through a low-cost and scalable process is still challenging. Here, nickel oxide (NiO) EC films have been synthesized by room-temperature electrochemical oxidation of Ni thin films. The Ni films were grown by electroless deposition and annealed at three different temperatures of 100°C, 200°C, and 300°C. The morphological, optoelectronic, and electrochemical properties of the films have been comparatively analyzed to obtain an optimized EC film. The NiO film annealed at 100°C exhibited superior properties with coloration and bleaching times of 1.8 s and 2.9 s, respectively, and a coloration efficiency of 20 cm2/C. This annealed film is further used to fabricate a EC device with NiO and tungsten oxide (WO3) as the electrode layers and a phosphoric acid-based gel as the electrolyte. The low-temperature deposition process used here can also be extended to flexible substrates. [ABSTRACT FROM AUTHOR]

Perfluoroalkyl and polyfluoroalkyl substances (PFASs) have recently gained considerable attention due to their potential risks to human health and ecosystems. The response to these concerns has led to regulations and bans on legacy PFASs, such as perfluorooctanoic acid and perfluorooctane sulfonic acid. Thus, fluoride production has shifted toward short-chain PFASs and emerging fluorinated alternatives. Several technologies are available for PFAS degradation, among which electrochemical oxidation (EO) is a promising method to mineralize legacy PFASs and other emerging fluorinated alternatives in water treatment. This review provides an overview of the recent advancements in EO, comprehensively elucidating PFAS degradation mechanisms at the anode and exploring key factors that influence PFAS removal efficiency, such as anode materials as well as reactor designs and configurations. Moreover, the review elucidates the impact of operating conditions and parameters, including current density, electrolytes, pH, initial PFAS concentrations, and other coexisting pollutants, on the EO process. Finally, the constraints in the EO process are discussed when considering practical implementations, including undesired by-product generation, incomplete mineralization resulting in the accumulation of short-chain PFASs, and low PFAS concentrations in the natural environment leading to mass transfer limitations and low defluorination efficiency. Consequently, this review provides a perspective on potential solutions integrating the pre-concentration steps and EO process for effective PFAS remediation. [ABSTRACT FROM AUTHOR]

Copyright of Chemical Engineering (China) / Huaxue Gongcheng is the property of Hualu Engineering Science & Technology Co Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The accumulation of harmful residuals can lead to voluminous environmental problems and then negatively affect human health. For this purpose, it is necessary to focus on the development of a rapid and sensitive strategy for its monitoring. In this work, a green, fairly fast, inexpensive and sensitive electrochemical sensor was developed to determine and monitor Cipro residues in various samples such as environmental resources, wastewater, urine, and drug formulations (Flonox 500 Aflox 500 and Cifloxine 250). It consists of a carbon paste electrode (CPE) modified with clay‐supported reduced graphene oxide composite (GrGO/CL@CPE). The rGO was prepared using green and easily chemically converted GO (electrochemically prepared) to rGO nanosheets based on glucose (G) as a green reducing agent (GrGO). The proposed sensor demonstrates a high electro‐oxidation signal compared with other based sensors, and the oxidation potential was found to be reduced by around 35 mV. The GrGO/CL@CPE was used for monitoring Cipro in the range of 0.05–10 μM in phosphate buffer at a biological pH of 7 (PB_7) and it offered a low detection limit (DL) (S/N=3) of 0.048 μM. Furthermore, it was found to be capable of detecting Cipro in pronounced samples with excellent results, offering promising prospects for actual clinical assays. [ABSTRACT FROM AUTHOR]

Copyright of Industrial Water Treatment is the property of CNOOC Tianjin Chemical Research & Design Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Esomeprazole (ESO) is one of the proton pump inhibitors (PPIs) that is commonly used to treat extreme acidity and gastrointestinal irritation. Since it is used at a high rate, it is now classified as a pollutant of emerging concern (CEC). ESO gravely jeopardizes the health of living beings because it persists in water and wastewater sources even after standard treatment. Studies on the effective removal of PPIs, especially ESO, are scarce. In the current study, esomeprazole is disintegrated in water using electrochemical oxidation (EO). Titanium cathode with sodium sulfate electrolyte and carbon coated titanium (C/Ti) anode were used to apply EO. Through optimization studies utilizing COD measurement, it was discovered that 93% of the COD could be removed at pH 3, 60 mM sodium sulfate concentration, 300 min treatment period, and 115 mA cm−2 current density. Whereas TOC research revealed only 44% mineralization, HPLC‐PDA experiments revealed 100% ESO transformation. High resolution mass spectrometry (HRMS) studies were used to propose a degradation mechanism and pathway. The primary processes of degradation included desulfurization, thioperoxole group formation, sulfinyl benzimidazole group breakage, and demethylation. More than 20 reuses of the anode and cathode materials were possible without significantly lowering their oxidation efficiency. [ABSTRACT FROM AUTHOR]

A novel Ti/PANI/PbO2-Ce electrode was fabricated using the electrodeposition method for the degradation of 2,3-dimethylphenol, a typical phenolic pollutant in coking wastewater. Scanning electron microscopy (SEM), x-ray photoelectron spectroscopy (XPS), and x-ray diffraction (XRD) analyses confirmed the successful incorporation of Ce into the PbO2 matrix. The polyaniline (PANI) interlayer significantly enhanced the electrode's stability and service lifetime. The addition of the rare earth element Ce resulted in the formation of a three-dimensional spherical PbO2 structure, increasing the electrode's surface area and reducing the PbO2 grain size. Compared to the conventional Ti/PbO2 electrode, the Ti/PANI/PbO2-Ce electrode exhibited a higher oxygen evolution potential (OEP, 1.91 V), larger specific surface area, lower charge transfer resistance, and superior hydroxyl radical (•OH) generation capacity. The degradation conditions for 2,3-dimethylphenol were optimized through single-factor experiments, achieving a degradation efficiency of 99.86% at a voltage of 14 V, plate spacing of 1.5 cm, Na2SO4 electrolyte concentration of 0.25 mol/L, pH of 10, and reaction time of 120 min. The calculated activation energy (Ea) and thermodynamic parameters indicate that the electrocatalytic process is an endothermic process. The efficient anodic oxidation of 2,3-dimethylphenol was primarily driven by indirect •OH oxidation. Potential degradation pathways of 2,3-dimethylphenol were elucidated through UV–visible spectrophotometry and gas chromatography-mass spectrometry (GC–MS) analysis of the degradation intermediates. [ABSTRACT FROM AUTHOR]

The protonic ceramic fuel cells (PCFCs) can convert the chemical energy of fuel directly into electric power, with the advantages of high efficiency and alternative fuel range at intermediate temperatures. Ammonia has been regarded as a promising fuel for PCFCs due to its carbon‐free and hydrogen‐rich properties, high volumetric energy density and easy storage/transportation. However, the performance of ammonia PCFCs (NH3‐PCFCs) is far inferior to the hydrogen PCFCs (H2‐PCFCs) because of the sluggish and complex kinetics at anodes. In this study, we established an elementary reaction kinetic model for NH3‐PCFCs, investigated the effect of reaction parameters, anode components and reaction partition, and explored the coupling mechanism between the ammonia decomposition and electrochemical reaction. Importantly, the ammonia decomposition and electrochemical reaction can be flexibly regulated by adjusting anode parameters, then affecting the performance ratio of NH3‐PCFCs and H2‐PCFCs. The detailed rate‐determining steps were further identified by experimental and model analysis. Thus, the ammonia/hydrogen performance ratio of the cell can exceed 95% at 550°C after accelerating the ammonia decomposition reaction. Our work provides insights into the kinetics in NH3‐PCFCs for improving their performance with optimization. [ABSTRACT FROM AUTHOR]

Objectives: Single crystal silicon carbide (SiC) is known for its high hardness and high chemical inertness, making it chanllenging to process effectively using traditional chemical mechanical polishing (CMP) methods. CMP often struggles to balance processing efficiency and surface quality for SiC. Electrochemical mechanical polishing (ECMP) is an effective method to achieve high material removal rates (MRR) and excellent surface quality when processing SiC. This study explores the main components and optimal ratios of SiC ECMP slurry through process testing.Methods: Using MRR and surface roughness as evaluation indicators, the types of conductive medium and abrasive particles in the ECMP slurry are first determined through single-factor experiments. Then, the influences of the conductive medium types, abrasive particle concentration, and the pH value of the polishing slurry, on both MRR and surface roughness, are analyzed to identify the optimal slurry parameters. Results: The results of the experiments indicate that when NaCl is used as the conductive medium and SiO2 as the polishing abrasive, SiC achieves both good polishing efficiency and surface quality. The increase in NaCl concentration enhances the electrochemical oxidation of SiC, leading to an increase in MRR and surface roughness. As the concentration of abrasives increases, the surface conductivity of SiC improves, boosting both material removal efficiency and surface roughness. However, after reaching a certain abrasive concentration, the oxidation state of SiC stabilizes, and both MRR and surface roughness tend to reach a constant value. When the polishing slurry is acidic, electrochemical oxidation of SiC is inhibited, leading to a reduced MRR. Conversely, when the slurry is alkaline, abrasive particles undergo chemical reactions, resulting in poor polishing surface quality. A neutral slurry effectively balances both MRR and surface quality. The optimal slurry paramaters for achieving this balance are a NaCl concentration of 0.6 mol/L, a SiO2 mass fraction of 6%, and a pH value of 7. Under these conditions, the MRR and surface roughness of SiC polishing were found to be 2.388 μm/h and 0.514 nm, respectively. Conclusions: The low oxidation rate of SiC, due to its high chemical inertness, is a key factor limiting the polishing efficiency in traditional CMP methods. ECMP overcomes this limitation by replacing chemical oxidation with electrochemical oxidation, allowing for both high polishing efficiency and superior surface quality of SiC.

The effects of oxychlorides (ClOx-) produced by electrochemical oxidation of real wastewater on evaluation of COD removal performance and biotoxicity are rarely reported. In this study, an electrolytic reaction system with Ti/RuO2-IrO2-SnO2-Sb2O5 as anode was constructed to treat the air floatation produced water and effluent water. The experimental results showed that increasing the current density promoted the production of ClOx- and exacerbated the overestimation of the COD removal efficiency in electrochemical oxidation when treating the two types of water, mainly due to the produced ClO3- acted as a mask for the determination of COD by the dichromate method. When treating the air floatation produced water, ammonia nitrogen and organic matter in the water consumed HClO/ClO- and inhibited the production of ClOx- by blocking the conversion of HClO/ClO- to ClO3-. As a result, the degree of over-evaluation of COD removal was relatively low in this case. Further analysis by cyclic voltammetry revealed that the indirect oxidation of ammonia nitrogen could rapidly capture and react with active chlorine, thus inhibiting the formation of ClOx-. The Chlorella bioassay experiments showed that toxic by-products were formed during electrolysis of chlorinated wastewater, and ClOx- was the main substance for the increase of biotoxicity.

This contribution describes the indirect electrochemical oxidation of wastewater laden with bromothymol blue and methyl red dyes using a laboratory-scale electrochemical reactor with a Ti/Ru0.3Ti0.7O2 anode and stainless-steel cathode. The influence of current density, pH, and electrolyte concentrations on the oxidative degradation pattern of the dyes in the wastewater was also investigated by coupling the electrochemical reactor with an Ultraviolet–Visible spectrometer. By indirect oxidation, 97% of the bromothymol blue at 10 mA cm–2 current density and pH 3.0 and 98% of the methyl red at 2 mA cm–2 current density at pH 3.0 were indirectly oxidized in 10 min Initial concentrations of each were 200 ppm. During the degradation of the dyes, electrochemically generated chlorine and hypochlorite ions (OCl)– played pivotal roles. Under the aforementioned ideal circumstances, the minimum energy consumption values for bromothymol blue and methyl red were 0.2025 and 0.0636 kW h m–3, respectively. The anode exhibited an excellent service life for treating dye wastewater, and repeated tests and surface analysis revealed no evident passivation. In this way, a variety of dyes in effluents can be cheaply degraded by electrolyzing with a Ti/Ru0.3Ti0.7O2 anode, utilizing readily available electrolytes and with minimal electricity requirements. [ABSTRACT FROM AUTHOR]

Electrochemical synthesis of graphene oxide (GO) is known to occur with potential oscillations, but the structural changes underlying these oscillations have remained unclear. In situ time‐resolved synchrotron radiation X‐ray diffraction demonstrates that the electrochemical synthesis of GO in aqueous H2SO4 can be described as an oscillating reaction. The transformation from graphite to GO proceeds through periodic structural oscillations that correlate with potential cycles. Stage‐1 graphite intercalation compound (GIC) is found only at the peak of the potential cycle, but not at the bottom of the cycle. Stage‐1 GIC is formed in the first half‐cycle from stage‐2 GIC and then transforms into “pristine graphite oxide” (PGO) on the lower side of the potential cycle, after which the cycle restarts with the formation of a new portion of stage‐1 GIC. Water‐washing results in the transformation of PGO into water‐swollen GO with d(001) ~11 Å. These periodic structural changes can be considered a new type of oscillating reaction. The presented results provide broad insights into the oscillating structural changes occurring during the anodic graphite oxidation in aqueous H2SO4 and allow to update of the mechanism of GO electrochemical formation. [ABSTRACT FROM AUTHOR]

The electrooxidation of 3‐methyladenine (3‐mAde) in aqueous electrolytes on the glassy carbon electrode (GCE) was investigated by voltammetric techniques and electrochemical impedance spectroscopy (EIS). Different experimental factors were explored, such as the influence of concentration, composition and pH of the medium, mass transport, adsorption of products on GCE and the presence of possible interferers on the oxidation of 3‐mAde. The electrochemical data demonstrated that the methyl group is not electroactive, but strongly influences the oxidation mechanism of 3‐mAde. The anodic behaviour of 3‐mAde occurred from mass transport by diffusion, in a single irreversible pH‐dependent step, in an electrode reaction with the removal of one electron and one proton. By cyclic voltammetry the diffusion coefficient of 3‐mAde was assessed in physiological neutral pH (D3‐mAde=1.57×10−5 cm2 s−1). In comparison to adenine, the oxidation of 3‐mAde occurred at more positive potential values (~200 mV), thus allowing the simultaneous voltammetric determination of both bases. A new differential pulse voltammetric method for determination of 3‐mAde in acetate buffer (pH=4.5) and phosphate buffer (pH=7.0) was also proposed. Recovery experiments were performed and additions of 3‐mAde with known concentrations were made in samples prepared from mixtures of free DNA bases and the 7‐mGua adduct in acetate buffer (pH=4.5). The results were quite satisfactory (96.4 – 101.3% recovery), indicating excellent precision and accuracy, as well as advantages such as simplicity, speed and cost of the proposed method. [ABSTRACT FROM AUTHOR]

A highly effective oxidation cross-coupling method involving para -cresol derivatives and malononitrile derivatives has been developed utilizing undivided electrolytic conditions. This electrochemical approach offers a robust route for synthesizing diverse malononitrile derivatives featuring quaternary carbon centers and incorporating para -phenol groups. Notably, the direct electrooxidation of the C(sp3)–H bond in the para -cresol derivative plays a crucial role in this process under electrolytic conditions. Various para -cresol derivatives and malononitrile derivatives with different substituents are readily compatible with this electrochemical transformation, affording coupling compounds in up to 99% yield. [ABSTRACT FROM AUTHOR]

This work developed new electrocatalysts for direct alcohol oxidation fuel cells (DAFCs) by using graphene and reduced graphene oxides (GO and rGO) as supporting nanomaterials for copper–nickel (CuNi) nanocomposites. The manufacture of CuNi, CuNi-GO, and CuNi-rGO nanocomposites was realized through the adaptation of Hummer's method and hydrothermal techniques, with subsequent analysis using a range of analytical tools. The electrocatalytic behavior of these materials in DAFCs, with methanol and ethanol as the fuels, was scrutinized through various methods, including cyclic voltammetry, linear sweep, chronoamperometry, and electrochemical impedance spectroscopy. This investigation also assessed the stability and charge transfer dynamics. The rGO-based CuNi nanocomposite demonstrated a remarkable performance boost, showing increases of approximately 319.6% for methanol and 252.6% for ethanol oxidation compared to bare CuNi. The integration of silver nanoparticles into the Ag-CuNi-rGO electrode led to a current density surge to 679.3 mA/g, which signifies enhancements of 254.2% and 812.6% relative to the CuNi-rGO and CuNi electrodes, respectively. These enhancements are ascribed to the augmented densities of hot sites and the synergistic interactions within the nanocatalysts. The findings underscore the potential of Ag and rGO as effective supports for CuNi nanocomposites, amplifying their catalytic efficiency in DAFC applications. [ABSTRACT FROM AUTHOR]

Exploring and controlling surface tension‐driven phenomena in liquid metals may lead to unprecedented possibilities for next‐generation microfluidics, electronics, catalysis, and materials synthesis. In pursuit of these goals, the impact of minor constituents within liquid alloys is largely overlooked. Herein, it is showed that the presence of a fraction of solute metals such as tin, bismuth, and zinc in liquid gallium can significantly influence their electrocapillarity and electrochemistry. The instability‐driven fractal formation of liquid alloy droplets is investigated with different solutes and reveals the formation of distinctive non‐branched droplets, unstable fractals, and stable fractal modes under controlled voltage and alkaline solution conditions. In their individually unique fractal morphology diagrams, different liquid alloys demonstrate significantly shifted voltage thresholds in transition between the three fractal modes, depending on the choice of the solute metal. Surface tension measurements, cycle voltammetry and surface compositional characterizations provide strong evidence that the minor alloy components drastically alter the surface tension, surface electrochemical oxidation, and oxide dissolution processes that govern the droplet deformation and instability dynamics. The findings that minor components are able to regulate liquid alloys' surface tensions, surface element distributions and electrochemical activities offer great promises for harnessing the tunability and functionality of liquid metals. [ABSTRACT FROM AUTHOR]

Mn‐based oxides promise high energy density and low toxicity cathodes for aqueous zinc‐ion batteries (ZIBs) but suffer from complex irreversible phase transitions, accompanied by continuous disproportionation reactions and manganese dissolution. Tailor‐made reversible and robust crystal structure in Mn‐based material is crucial and challenging. Here a controllable electrochemical oxidation induced crystal transition strategy is developed for the transformation of cubic α‐Mn2O3 into amorphous Zn0.17MnO2−n·0.52H2O, which serves as the host of Zn2+, empowering more highly accessible built‐in zincophilic sites whilst alleviating the lattice repulsion of Zn2+ (de)intercalation. As confirmed by crystal structure evolution characterizations and theoretical simulations, the amorphous Zn0.17MnO2−n·0.52H2O with excellent electronic properties and low zinc‐ion migration barrier can be reversibly converted into ZnMn3O7·3H2O. This stabilized dynamic electrochemical crystal transition equilibrium contributes ultrahigh capacity (558 mAh g−1), high‐energy density (696 Wh kg−1@6 kW kg−1), and superior stability (5000 cycles). The approach can also extend to Mn3O4 and α‐MnO2, opening new insights into electrochemical oxidation induced crystal conversion to build highly reversible and durable ZIBs. [ABSTRACT FROM AUTHOR]

In this study, our primary objective was to synthesize and characterize a copper nanoparticle-modified oxidized graphite carbon nitride (ox-g-C3N4). This modified ox-g-C3N4 material was utilized as a reusable catalyst for the environmentally friendly production of benzofuran 4(a-j) derivatives through C–H activation using an electrochemical oxidation system. The desired derivatives were obtained by reacting 2-bromophenol 1(a-c) with ethynylbenzene 2(a-g) yielding high yields ranging from 89 to 94%. The modified Cu/ox-g-C3N4 nanocomposite was thoroughly examined. using different analytical techniques, including thermogravimetric analysis (TGA), energy-dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), IR Fourier-transform infrared spectroscopy (FT-IR), Brunauer–Emmett–Teller (BET) analysis, cyclic voltammetry (CV), and X-ray diffraction (XRD) spectroscopy, and ultraviolet (UV) spectroscopy. The comprehensive identification was conducted in a comparative manner, allowing for a thorough understanding of the nanocomposite's properties. By employing this nanocatalyst, we implement a greener synthesis approach that reduces the need for dangerous and toxic substances, while reducing waste generation by promoting reuse. The synthesized products in this research were subjected to characterization utilizing techniques such as melting point analysis, CHN analysis and 1HNMR spectroscopy. These analytical methods were utilized to confirm the identification and assess the purity of the benzofuran compounds synthesized 4(a-j). [ABSTRACT FROM AUTHOR]

A new thermally stable chromophore exhibiting the intense blue fluorescence with the high quantum yield of 91%, 4-(4-(9H-carbazol-9-yl)phenyl)-2,6-bis-(4-N,N-diphenyl-aminophenyl)pyridine, was synthesized in a high yield via the three-component reaction of 4-(N,N-dimethylamino)acetophenone, 4-(9H-carbazol-9-yl)benzaldehyde, and ammonium acetate. [ABSTRACT FROM AUTHOR]

Copyright of Technology of Water Treatment is the property of Technology of Water Treatment Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Technology of Water Treatment is the property of Technology of Water Treatment Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The prevalence of polyfluoroalkyls and perfluoroalkyls (PFAS) represents a significant challenge, and various treatment techniques have been employed with considerable success to eliminate PFAS from water, with the ultimate goal of ensuring safe disposal of wastewater. This paper first describes the most promising electrochemical oxidation (EO) technology and then analyses its basic principles. In addition, this paper reviews and discusses the current state of research and development in the field of electrode materials and electrochemical reactors. Furthermore, the influence of electrode materials and electrolyte types on the deterioration process is also investigated. The importance of electrode materials in ethylene oxide has been widely recognised, and therefore, the focus of current research is mainly on the development of innovative electrode materials, the design of superior electrode structures, and the improvement of efficient electrode preparation methods. In order to improve the degradation efficiency of PFOS in electrochemical systems, it is essential to study the oxidation mechanism of PFOS in the presence of ethylene oxide. Furthermore, the factors influencing the efficacy of PFAS treatment, including current density, energy consumption, initial concentration, and other parameters, are clearly delineated. In conclusion, this study offers a comprehensive overview of the potential for integrating EO technology with other water treatment technologies. The continuous development of electrode materials and the integration of other water treatment processes present a promising future for the widespread application of ethylene oxide technology. [ABSTRACT FROM AUTHOR]

With the growing significance of green chemistry in organic synthesis, electrochemical oxidation has seen rapid development. Compounds undergo oxidation–reduction reactions through electron transfer at the electrode surface. This article proposes the use of electrochemical methods to achieve cleavage of the benzyl C–N bond. This method selectively oxidatively cleaves the C–N bond without the need for metal catalysts or external oxidants. Additionally, primary, secondary, and tertiary amines exhibit good adaptability under these conditions, utilizing water as the sole source of oxygen. [ABSTRACT FROM AUTHOR]

The oxidation of alcohols to ketones constitutes a crucial aspect of undergraduate organic chemistry theory. Benzophenone, the resultant product of the reaction, finds extensive applications in fields such as photoinitiators and UV-curable coatings. Compounds featuring benzophenone as their backbone also hold significance in targeted drug release. Traditional methods for benzophenone synthesis suffer from long reaction time, the use of heavy metal oxidation reagents, and the complexity of dehydrogenation catalyst preparation, limiting their suitability for undergraduate laboratory teaching. This paper presents an environmentally friendly electrochemical synthesis approach for benzophenone. The method employs potassium iodide as the electrolyte and a mixed solvent of acetonitrile and water, facilitating the direct electrolytic oxidation of diphenylmethanol to benzophenone without the need for additional oxidation or dehydrogenation agents. This improved method boasts shorter reaction time, higher yield, simplified post-processing, and employs inexpensive, readily available reagents, making it ideal for introductory organic chemistry experiments. The experiment integrates thin-layer chromatography (TLC), melting point determination, ¹HNMR, and liquid chromatography-mass spectrometry to analyze and identify reaction systems or products, thereby enhancing students’ proficiency in experimental operations and product identification. [ABSTRACT FROM AUTHOR]

Electrochemical oxidation of o-tolidine has been assessed in a mixture (70/30) of buffer/acetonitrile and various pHs. The electrochemical results corroborate that the mechanism of electrooxidation of o-tolidine acidic, neutral, and alkaline solutions are different, and three pH zones with different oxidation mechanisms were obtained: in the first region, a reversible oxidation reaction under the E mechanism, in the second region, observing the two one-electron oxidation–reduction under the ECDispE mechanism, and observation of the evidence of the ECE mechanism in the third region. In the continuation, electrosynthesis of a new azo compound has been reported in the third region. This process involves the electrochemical oxidation of o-tolidine in an aqueous phosphate buffer (pH = 7.2) in a divided cell using a carbon anode. [ABSTRACT FROM AUTHOR]

Anodic oxidation is a promising method for removing organic pollutants from water due to its high nonselectivity and effectiveness. Nevertheless, its widespread application is limited due to its low current efficiency, high energy consumption and low treatment rates. These problems may be overcome by the optimization of the process parameters, reactor design and electrode geometry, by coupling the experimental investigations with mathematical modeling. Here we review the modeling of anodic oxidation with focus on basics of this process, the competition phenomenon in real wastewater, flow cells and batch cells, historical aspects, general modeling equations, modeling with plate electrodes, modeling with porous 3-dimension electrodes and the density functional theory. Mathematical modeling can provide current, voltage and concentration distributions in the system. Mathematical modeling can also determine the effects on the performance of parameters such as diffusion layer thickness, flow velocity, applied current density, solution treatment time, initial concentration and diffusion coefficients of organic pollutants, electrode surface area, and oxidation reaction rate constant. Mathematical models allow to determine whether the limiting factor of the process is kinetics or diffusion, and to study the impact of competition of phenomena. The density functional theory provides information on probable reaction pathways and by-products. [ABSTRACT FROM AUTHOR]

Artificial transplantation of the human body, which requires high technology, has been an attractive issue in the 4th industrial revolution era. The artificial equipment for human applications could contain a small-scale power supply. Enzyme fuel cells (EFCs) that generate green energy are being researched for use as the power supply for pacemakers, insulin pump, and retinal implant in human body. This study focused on an (EFC) using thin film electrodes-based on enzyme immobilization technology. The performance of this EFC was improved by enzyme immobilization and electron transfer. To improve the electron transfer, the GO/Co/chitosan composite was modified on the surface of thin film electrode. The properties of this modified surface of thin film electrode were confirmed by analysis of field emission gun scanning electron microscopy, Fourier transform infrared spectroscopy, and atomic force microscopy. The performance of the designed EFC was optimized with immobilized redox enzyme on the modified electrode. The highest power density and voltage are determined as 441.48 µW/cm2 and − 0.443 V by thin film electrode, respectively. The optimum conditions of the EFC were 0.1 M D-glucose, 0.1 g/L glucose oxidase, pH 7.0, and reaction time of 4 h for both two types of thin film-electrodes. [ABSTRACT FROM AUTHOR]

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Liquid digestate can be used to provide nutrients for microalgae cultivation but the medium needs to be clear and colorless. The aim of this work was to use liquid digestate from coffee waste biomass to produce a light-permeable medium for microalgae cultivation. A boron-doped diamond anode was applied for electrochemical decolorization of the digestate. The electrochemical oxidation process reduced the platinum-cobalt color value by up to 97% and the chemical oxygen demand by 84.1%. After electrochemical oxidation, 87.4% of the ammonium nitrogen (NH4-N) was retained. Decolorization of the spent coffee grounds liquid digestate was compared with that of dairy cow manure liquid digestate. It took 90 min longer to fully decolorize the spent coffee grounds liquid digestate compared with the dairy cow manure liquid digestate. The boron-doped diamond anode performed better in the decolorization than Ti/IrO2 and Ti/Pt anodes. The effects of the initial Fe2+ concentration and current on the electrochemical oxidation process were also evaluated. Increasing the initial Fe2+ concentration enhanced the Fenton reaction and chemical oxygen demand removal. A higher current enhanced the electrochemical decolorization process and side reactions. Electrochemical oxidation using a boron-doped diamond anode is a promising method for producing an appropriate medium for microalgae cultivation because it promotes decolorization of liquid digestate and retains most of the NH4-N. [ABSTRACT FROM AUTHOR]

Wastewater from livestock farms contains high concentrations of suspended solids, organic contaminants, and nitrogen compounds, such as ammoniacal nitrogen. Discharging livestock effluents into water bodies without appropriate treatment leads to severe environmental pollution. Compared to conventional treatment methods, electrochemical oxidation exhibits higher nitrogen removal efficiencies. In the present work, the electrochemical removal of ammoniacal nitrogen from real livestock wastewater was investigated through a lab-scale reactor. Preliminary experiments were carried out to investigate the effects of different anode materials, including boron-doped diamond and iridium/ruthenium-coated titanium, on the total nitrogen removal efficiency using synthetic wastewater. Boron-doped diamond, a well-known non-active electrode, allowed to obtain 63.7 ± 1.21 % of total nitrogen degradation efficiency. However, the iridium/ruthenium-coated titanium electrode, belonging to the class of active anodes, showed a higher performance, achieving 78.8 ± 0.76 % contaminant degradation. Coupling iridium/ruthenium-coated titanium anode with a stainless-steel cathode improved the performance of the system, achieving even 96.2 ± 2.73 % of total nitrogen removal. The optimized cell configuration was used to treat livestock wastewater, resulting in the degradation of 67.0 ± 2.25 % of total nitrogen and 37.3 ± 0.68 % of total organic carbon when sodium chloride was added. At the end of the process, the ammonium content was completely removed, and only 17.7 ± 0.51 % of the initial nitrogen turned into nitrate. The results show that the proposed system is a promising approach to treating livestock wastewater by coupling high contaminant removal efficiencies with low operational costs. Anyway, further studies on process optimization with an emphasis on power requirements and electrode costs need to be carried out.

[Display omitted] Substituted 2,5-dimethoxy-2,5-dihydrofurans (cis / trans isomer mixtures) were obtained via the electrochemical oxidation of the corresponding furans in an undivided cell in methanol in the presence of bromides as mediators. The method is suitable for furans containing electron-donating groups. [ABSTRACT FROM AUTHOR]

The effects of boron concentration and deposition pressure on the microstructure and electrochemical oxidation performance of Ti/BDD electrodes during HFCVD growth were systematically investigated. The electrode's surface morphology, composition, and electrochemical performance were characterized by scanning electron microscope (SEM), Raman spectroscopy, ultraviolet spectrophotometry, and an electrochemical workstation. Tetracycline served as a simulated pollutant to evaluate the electrochemical oxidation degradation performance of BDD electrodes fabricated with different boron concentrations and deposition pressures. As air pressure increases, the grain quality of the diamond gradually decreases, yet boron atom doping enhances the grain quality of the diamond. Under high boron concentration and low pressure conditions, the boron atom concentration on the diamond film's surface is elevated. BDD electrodes with larger grain sizes and higher boron atom concentrations, prepared under these conditions, exhibit superior electrochemical performance, increased degradation efficiency, and reduced degradation energy consumption.

The trade-off between efficiency and stability has limited the application of TiO2 as a catalyst due to its poor surface reactivity. Here, we present a modification of a TiO2 layer with highly stable Sub-5 nm Fe2O3 nanoparticles (NP) by modulating its structure-surface reactivity relationship to attain efficiency-stability balance via a voltage-assisted oxidation approach. In situ simultaneous oxidation of the Ti substrate and Fe precursor using high-energy plasma driven by high voltage resulted in uniform distribution of Fe2O3 NP embedded within porous TiO2 layer. Comprehensive surface characterizations with density functional theory demonstrated an improved electronic transition in TiO2 due to the presence of surface defects from reactive oxygen species and possible charge transfer from Ti to Fe; it also unexpectedly increased the active site in the TiO2 layer due to uncoordinated electrons in Sub-5 nm Fe2O3 NP/TiO2 catalyst, thereby enhancing the adsorption of chemical functional groups on the catalyst. This unique embedded structure exhibited remarkable improvement in reducing 4-nitrophenol to 4-aminophenol, achieving approximately 99% efficiency in 20 ​min without stability decay after 20 consecutive cycles, outperforming previously reported TiO2-based catalysts. This finding proposes a modified-electrochemical strategy enabling facile construction of TiO2 with nanoscale oxides extandable to other metal oxide systems.

TiO2 nanoparticles, as a typical inert metal oxide, were added into Pb2+ plating solutions to prepare Ti/PbO2+nano-TiO2 composite coatings. The effect of TiO2 nanoparticles on the electrodeposition process of PbO2 was investigated by voltammetric studies. The composition, structure and morphology of the obtained composite coatings were characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and scanning electron microscopy (SEM), respectively. Cyclic voltammetry was employed to study the effect of nano-TiO2 particles on the PbO2 electrodeposition process. It is found that high doping (2–8 g/L) of TiO2 nanoparticles significantly decreased the crystallite size which can be attributed to a crystallite-refining effect of nano-TiO2 during the electrodeposition of PbO2. [ABSTRACT FROM AUTHOR]