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Electrochemically driven C−C coupling has the potential to reduce the cost and environmental impact of some organic syntheses currently accomplished through thermochemical methods. Here, we use electrochemical oxidation of carboxylic acids as a source of reactive carbon‐centered radicals that enable radical addition to alkenes in the anode boundary layer. We demonstrate an optimization of reaction conditions to suppress the thermodynamically favored, but synthetically undesirable radical self‐coupling in favor of radical addition to styrene. In methanol solvent, 88 % selectivity and 72 % Faradaic efficiency for targeted functionalized benzenes are achieved. For low current densities, iridium anodes outperform platinum, gold, palladium, and glassy carbon anodes. With constant potential or constant current electrolyses, the deposition of organic by‐products on the catalyst surface leads to anode passivation. We show that periodic cathodic current pulses effectively regenerate the catalyst. Lastly, we confirm the role of free radicals in the reaction mechanism with a radical trap. [ABSTRACT FROM AUTHOR]

For direct methanol fuel cells, developing low‐cost, highly efficient, and long‐term stable electrocatalysts is crucial. In this work, we report easy and single‐step electrodeposition of nickel sulfide thin film incorporating carbon nanofibers on indium tin oxide (denoted as Ni4S3‐CNF/ITO). The electrodeposited materials were characterized by X‐ray Diffraction, Scanning Electron Microscopy, and Energy Dispersive X‐ray spectroscopy. The electrocatalytic activity toward Methanol Oxidation Reaction (MOR) was investigated using Cyclic Voltammetry, Chrono‐Amperometry, and Electrochemical Impedance Spectroscopy. The electrocatalyst exhibited good electrocatalytic activity regarding methanol electrooxidation in an alkaline medium with retention of its activity over a significant period of time. These results indicate that the incorporation of carbon nanofibers into nickel sulfide allows the electrocatalyst to gain higher surface area and high tolerance to the catalyst‐poising species generated during MOR. The electrocatalytic activity of electrodeposited Ni4S3‐CNF/ITO makes it a promising electrocatalyst for low‐cost, high‐efficient fuel cells. [ABSTRACT FROM AUTHOR]

Featured Application: Understanding leachate treatment systems through organic matter monitoring. The presence of refractory compounds in stabilized leachates makes treatment complex. In leachate treatment systems, the lack of data on the characterization of leachates and effluents makes it difficult to track and explain the evolution of organic matter. In this study, the fractionation of chemical oxygen demand (COD) and humic substances, including humic acids (HA) and fulvic acids (FA), in addition to the application of spectroscopic techniques (Fourier transform infrared and ultraviolet–visible spectroscopy), were used to solve this data gap. A treatment system was proposed: electro-coagulation (EC) and electro-oxidation (EO). Optimal conditions (maximum COD removal) were EC, I: 4.3 A, stirring: 120 revolutions per minute, and pH: 7; EO, added NaCl: 1.0 g L−1, distance between electrodes: 0.75 cm, I: 2 A, and pH: 7. Under optimal conditions COD, HA, and FA % removals were achieved: EC: 64, 69, and 63; EO: 83, 40, and 55; respectively. In EC, the % of biodegradable COD increased from 26 to 39 and in EO it increased from 39 to 58. The biodegradability index increased from 0.094 to 0.26 with EC and reached 0.46 with EO. The generated data allowed us to establish the transformations of organic matter in the process, which was useful for understanding the processes and functioning as a tool for improving treatment systems. [ABSTRACT FROM AUTHOR]

A series of bimetallic Sn-Pd catalysts were prepared by a template-free two step electrodeposition method. According to this method, Sn was electrodeposited firstly in potentiostatic or galvanostatic regime on Cu electrodes in the form of dendrites, then Pd was galvanostatically electrodeposited in the second step on the electrode with the electrodeposited Sn dendrites. The produced Sn-Pd electrocatalysts were compared with an electrocatalyst obtained by Pd electrodeposition on a bare Cu electrode. The morphological and elemental analysis of Sn-Pd and Pd electrocatalysts was performed by means of scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) techniques. The dendrites of various shapes and degree of branching were obtained by Sn deposition depending on electrodeposition regime, while Pd was electrodeposited in a form of compact Pd islands on both Sn dendrites and the Cu electrode. Cyclic voltammetry (CV) was applied for the electrochemical examination of Sn-Pd and Pd catalysts towards the ethanol oxidation reaction (EOR) in the alkaline solution. The electrocatalyst Sn0.6-Pd0.4 with an atomic ratio of 60 at.% Sn-40 at.% Pd showed higher oxidation efficiency and better tolerance towards intermediate species in EOR than the other examined electrocatalysts . It was shown that the lower fraction of Pd, relative to Sn, was crucial to achieving optimal synergy of Sn with Pd thus contributing to enhanced electrochemical behavior regarding EOR.

Electrochemical pinacol coupling of carbonyl compounds in an undivided cell with a sacrificial anode would be a promising approach toward synthetically valuable vic-1,2-diol scaffolds without using low-valent metal reductants. However, sacrificial anodes produce an equimolar amount of metal waste, which may be a major issue in terms of sustainable chemistry. Herein, we report a sacrificial anode-free electrochemical protocol for the synthesis of pinacol-type vic-1,2-diols from sec-alcohols, namely benzyl alcohol derivatives and ethyl lactate. The corresponding vic-1,2-diols are obtained in moderate to good yields, and good to high levels of stereoselectivity are observed for sec-benzyl alcohol derivatives. The present transformations smoothly proceed in a simple undivided cell under constant current conditions without the use of external chemical oxidants/reductants, and transition-metal catalysts.

The hybrid water electrolysis affords a green route for the generation of fine chemicals accompanied with hydrogen production relying on the rapid development of anodic electrocatalysts. Herein, a nickel‐cobalt layered double hydroxide (NiCo LDH) modified nickel foam, prepared at room temperature via simple soaking processes, could effectively catalyze the dehydrogenation oxidation of primary amines to generate aromatic and aliphatic nitriles with good yields. Further expanding the application of the easily available electrode, the NiCo LDH electrode could function as the electron reservoir to realize the decoupled water electrolysis with 100% coulombic efficiency in the membrane-free electrolytic cell.

Abstract Electrochemically driven C−C coupling has the potential to reduce the cost and environmental impact of some organic syntheses currently accomplished through thermochemical methods. Here, we use electrochemical oxidation of carboxylic acids as a source of reactive carbon‐centered radicals that enable radical addition to alkenes in the anode boundary layer. We demonstrate an optimization of reaction conditions to suppress the thermodynamically favored, but synthetically undesirable radical self‐coupling in favor of radical addition to styrene. In methanol solvent, 88 % selectivity and 72 % Faradaic efficiency for targeted functionalized benzenes are achieved. For low current densities, iridium anodes outperform platinum, gold, palladium, and glassy carbon anodes. With constant potential or constant current electrolyses, the deposition of organic by‐products on the catalyst surface leads to anode passivation. We show that periodic cathodic current pulses effectively regenerate the catalyst. Lastly, we confirm the role of free radicals in the reaction mechanism with a radical trap.

Electrochemical systems are attracting increasing interest in environmental protection as relatively sustainable processes, particularly in wastewater treatment and reuse. However, cathode scaling in electrochemical processes for wastewater treatment is a major issue that is often overlooked. It is proposed for the first time to investigate the anodic contribution towards CaCO3 electroprecipitation phenomena under the advanced electrooxidation conditions applied to remove organic biorecalcitrant pollutants. The contribution of the reaction of the hydroxyl radical (•OH) with carbonates, which reduces cathodic scaling at a micrometric interelectrode distance (500 µm) and at a high current density (16 mA cm−2), is described in detail. In addition, the anti-scaling effect of local anodic acidification should be considered. A new kinetic model of electroprecipitation fits the experimental curves well (root mean square error (RMSE)

This report describes the unprecedented electrooxidation of a solvent (e.g. DMF)‐ligated B2cat2 complex, whereby a solvent‐stabilized boryl radical is formed via quasi‐homolytic cleavage of the B−B bond in a DMF‐ligated B2cat2 radical cation. Cyclic voltammetry and density functional theory provide evidence to support this novel B−B bond activation strategy. Furthermore, a strategy for the electrochemical gem‐diborylation of gem‐bromides via paired electrolysis is developed for the first time, affording a range of versatile gem‐diborylalkanes, which are widely used in synthetic society. Notably, this reaction approach is scalable, transition‐metal‐free, and requires no external activator. [ABSTRACT FROM AUTHOR]

The sequential sodium borohydride (SBH, NaBH4) reduction method was utilized to prepare the 0.1 % CdSe/CNT, 0.1 % CdS/CNT, 0.1 % (CdS−CNT)/CdTe, and 0.1 % (CdSe−CNT)/CdTe catalysts. The XRD, SEM‐EDS, TEM, and XPS analyses were used to characterize the catalysts. The electrochemical measurements were examined by cyclic voltammetry (CV), chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS) analyses for glucose electrooxidation. The characterization analyses revealed that the desired structure was formed on the support material. The electrochemical analysis results indicated that the 0.1 % (CdSe−CNT)/CdTe catalyst has higher catalytic activity, stability, and resistance compared to other catalysts with a specific activity of 2.4 mA cm−2. [ABSTRACT FROM AUTHOR]

In this work, a novel system composed of non-precious nickel-based metal oxide/reduced graphene oxide nanocomposite (Ni–PbO2–GN) is used for electrooxidation of ethylene glycol (EG) in 1.0 M NaOH solution and compares its activity with that of Ni, Ni–GN, and Ni–PbO2. The facile electrodeposition technique is used to prepare the catalysts on glassy carbon (GC) substrates. The outcomes of electrochemical measurements show a high performance towards EG oxidation is obtained for Ni-nanocomposite electrodes compared to that of Ni mainly due to their higher surface areas. The excellent electrocatalytic properties of the Ni-nanocomposite could be ascribed to the synergistic contributions of PbO2 and graphene (GN) nano-sheets that help the reduction of Ni grains. A smaller charge transfer resistance value of 34.5 Ω cm2 for EG oxidation reaction at + 360 mV is recorded for GC/Ni–PbO2–GN compared to the other prepared electrodes. Moreover, it exhibits higher kinetic parameters of EG such as diffusion coefficient (D = 3.9 × 10–10 cm2 s−1) and charge transfer rate constant (ks = 32.5 mol−1 cm3 s−1). The overall performance and stability of the prepared catalysts towards EG electrooxidation have been estimated to be in the order of GC/Ni–PbO2–GN > GC/Ni–GN > GC/Ni–PbO2 > GC/Ni. [ABSTRACT FROM AUTHOR]

For practical applications such as fuel cells, it is important to exploit electrocatalysis with high activity for methanol and glycerol oxidation. A platinum nanostructured electrode (PtNPs) is modified by gold adatoms and is created by application of a square wave potential regime to a tantalum surface electrode. In nanostructured platinum, the structure and the surface properties are characterized by scanning electron microscopy (SEM), X-ray powder diffraction (XRD) and cyclic voltammetry (CV). In acid and alkaline media, the CV and Chronoamperometric (CA) are studied to investigate the catalytic activity of the PtNPs nanoparticles for the electrooxidation of methanol and glycerol. The prepared nanostructured platinum on a tantalum electrode was allowed to balance an open circuit with a 1.0×10-3 M solution containing an Au ion. Consequently, the proximity of the irreversibly adsorbed Au-adatoms on the already described Pt-nanostructured electrode. In acidic and alkaline solutions, the electrocatalytically activities toward methanol and glycerol oxidation were evaluated and is found to strongly on the surface of the gold-modified PtNPs. The PtNPs modified by Au electrode system used direct methanol fuel cell (DMFC) and direct glycerol fuel cell (DGFC). The DMFC and DGFC are much higher than in acid output in alkaline. Comparison of the i-E curves of nanostructure platinum electrode with that of a platinum nanostructure electrode modified by Au under similar conditions for the letter, the charge under the peak (i-E curve) in the oxidation region was higher. Furthermore, rough chronoamperometric measurements confirmed the results. The results of showed that the electrocatalytic properties of the nanostructured prepared surface were enhanced by the inclusion of gold adatoms with a variable extent of advancement. The current peak (Ip) and the current chronoamperometric (ICA) of glycerol oxidation on the PtNPs electrode modified by Au in acid media (130 mA/cm², 47 µA/cm²) were higher than those of the bare PtNPs electrode and in alkaline media (171 mA/cm², 66 µA/cm²). The stronger catalytic behavior in alkaline media of the Au-PtNP electrode indicates its promising use in alkaline direct alcohol cells. [ABSTRACT FROM AUTHOR]

During the past few years, electrochemical oxidative reactions through radical intermediates have emerged as an environmentally-benign, powerful platform for the facile formation of C–E (E = C, N, S, Se, O and Hal) bonds through single-electron-transfer (SET) processes at the electrodes. Functionalized unsaturated molecules and unusual structural motifs can, for instance, be directly constructed under exceedingly mild reaction conditions through initial radical attack onto alkynes. This minireview highlights the recent advances in electrooxidation in radical reactions until June 2022, with a particular focus on radical additions onto alkynes. [ABSTRACT FROM AUTHOR]

An underground municipal solid waste (MSW) container should be washed periodically to prevent/reduce odor and leachate production. In this study, the treatment process of wastewater derived from the washing process of an MSW container was investigated using the electrochemical (EC) treatment process with different anode materials (Fe, TiO2, and graphite). Response surface methodology (RSM) was used to evaluate the effect of process parameters such as initial pH, applied current, and reaction time on chemical oxygen demand (COD), Tannin/Lignin, and color removals. According to the results obtained from the RSM models, all process parameters were significant. The optimum process parameters in terms of COD removal were derived from the models for each anode material. Under the optimized conditions, the COD removals were determined to be 93.25%, 75.95%, and 98.46% for Fe–Fe, TiO2-Fe, and graphite-Fe electrode pairs, respectively. The color and Tannin/Lignin removals were determined as 98.12% and 77.78% for the Fe–Fe, 92.76% and 98.45% for the TiO2-Fe and 94.50% and 79.56% for the graphite-Fe electrode pair, respectively. The specific energy consumption (SEC) values were found as 46.95, 300.02, and 32.95 kWh/m3 for each electrode combination given above, respectively. In terms of both removal efficiencies and SEC, the most effective anode material was determined as graphite, followed by iron. [ABSTRACT FROM AUTHOR]

Fuel cells are a very good candidate to provide energy conversion with green technology. Glucose is used as a fuel in fuel cells since it is easily available and has a high energy density. Herein, hydroxyapatite (HAp) was synthesized by precipitation method, and the sodium borohydride (NaBH 4) reduction method was used to fabricate HAp supported PdIn (PdIn/HAp) alloy anode catalysts at varying atomic molar ratios for glucose electrooxidation. Structural, crystallographic, and morphological properties of the PdIn/HAps were determined with X-ray diffraction analysis (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), Brunauer-Emmett-Teller (BET) analysis, transmission electron microscopy (TEM), and inductively coupled plasma mass spectrometry (ICP-MS). Electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and chronoamperometry (CA) were employed for the electrocatalytic activity and stability of PdIn/Haps toward glucose electrooxidation. The results show that HAp has a boosting effect for PdIn alloy towards glucose electrooxidation. Pd 80 In 20 /HAp showed 2.6 times higher electrocatalytic activity than Pd/HAp, and it is the most active and stable catalyst in this study with a specific activity of 5.64 mA/cm2. [Display omitted] • PdIn/HAp catalysts with varying atomic molar ratios were synthesized by the NaBH 4 reduction method. • Pd 80 In 20 /HAp exhibited excellent electrocatalytic activity for glucose electrooxidation. • Pd 80 In 20 /HAp showed long-term stability as a DGFC anode catalyst. [ABSTRACT FROM AUTHOR]

In situ and simultaneous remediation of a variety of pollutants in sediments remains a challenge. In this study, we report that the combination of electrocoagulation (EC) and electrooxidation (EO) is efficient in the immobilization of phosphorus and heavy metals and in the oxidation of ammonium and toxic organic matter. The integrated mixed metal oxide (MMO)/Fe anode system allowed the facile removal of ammonium and phosphorus in the overlying water (99% of 10 mg/L NH 4 +-N and 95% of 10 mg/L P disappeared in 15 and 30 min, respectively). Compared with the controls of the single Fe anode and single MMO anode systems, the dual MMO/Fe anode system significantly improved the removal of phenanthrene and promoted the transition of Pb and Cu from the mobile species to the immobile species. The concentrations of Pb and Cu in the toxicity characteristic leaching procedure extracts were reduced by 99% and 97% after an 8 hr operation. Further tests with four real polluted samples indicated that substantial proportions of acid-soluble fraction Pb and Cu were reduced (30%–31% for Pb and 16%–23% for Cu), and the amounts of total organic carbon and NH 4 +-N decreased by 56%–71% and 32%–63%, respectively. It was proposed that the in situ electrogenerated Fe(II) at the Fe anode and the active oxygen/chlorine species at the MMO anode are conducive to outstanding performance in the co-treatment of multiple pollutants. The results suggest that the EC/EO method is a powerful technology for the in situ remediation of sediments contaminated with different pollutants. • Electrocoagulation coupled with electrooxidation is effective in sediment remediation • The dual MMO/Fe anode system allows oxidation of ammonium and organic pollutants • Immobilization of phosphorus, Pb, and Cd is also achieved in the system • Electrogenerated Fe(II) and active oxygen/chlorine are the key species [Display omitted]. [ABSTRACT FROM AUTHOR]

In the present research, a method for depositing copper oxide onto surface-attached deoxyribonucleic acid (DNA) forming spherical nanoparticles for fabrication of a modified electrode (GCE/DNA/CuONPs) is presented. Scanning electron microscopy cyclic voltammetry and electrochemical impedance spectroscopy were used for characterization of the modification process. This electrode was used for the detection and determination of 2,4-dichlorophenoxyacetic acid (2,4-D) herbicide. For the first time, the electrooxidation of 2,4-D herbicide was investigated at two applied potentials by the proposed electrode. The electrochemical behaviors of this electrode were also studied by cyclic voltammetry and amperometry techniques. Based on the results, CuONPs and DNA exhibited a good electrocatalytic activity for the electrooxidation of 2,4-D herbicide. Many advantages were demonstrated by this research including application in sensitivities, linear ranges, and low detection of limits in two areas of potential for determination and detection of 2,4-D. [ABSTRACT FROM AUTHOR]

Direct methanol fuel cells (DMFCs), as an important alternative energy source for portable devices, have attracted considerable interest because of the high energy density of methanol, the simplicity of processing it as a fuel, and the suitability of storage as a liquid fuel. Nevertheless, fuel cell catalysts suffer from strong adsorption of CO on platinum, which leads to poison on the catalyst's surface and the prevention of further oxidation of methanol. Improvements are needed in terms of lowering the number of precious metals required for large-scale applications. Carbon powder, carbon nanotubes, and conducting polymer matrix are shown to have high electrocatalytic performance. Consequently, platinum loading has been diminished pointedly with improved Pt utilization. In this sense, particularly in the current study, the electrooxidation of methanol was investigated on Pt, Ru, and metal oxide nanoparticles such as V2O5 and WO3, modified by polyaniline (PANI)-functionalized multi-wall carbon nanotubes (fCNTs) composite electrodes in terms of DMFCs and related applications. Only electrochemical techniques were utilized throughout the synthesis of electrodes. The citrate method was utilized for preparing all of the metal and metal oxide nanoparticles. A comparative study was realized in each step of the experimental study. It was seen that ternary alloy nanosized electrodes showed much more activity than those of mono or bimetallic systems. The prepared electrodes were viewed and analyzed by SEM, EDX, Raman, and TEM techniques. Moreover, kinetic studies were carried out to determine important parameters. As a concluding remark, the current research presents a highly feasible procedure to produce PANI–fCNTs/Pt–Ru–metal oxide nanoparticle composite materials. [ABSTRACT FROM AUTHOR]

Efficient and low-cost materials to generate electrical energy from small organic materials are highly demanded for a large-scale commercialization of direct urea fuel cells. The purpose of this work is to improve the electrochemical performance of nickel phosphide (Ni) through palladium (Pd) doping via the facile solvothermal method and dispersing the obtained palladium nickel phosphide (PdNiP) on poly(3,4-ethylenedioxythiophene): poly(styrene sulfonate)/reduced graphene oxide (PEDOT:PSS/rGO) support material via a simple ultrasonic process. The electrochemical activities of Pd doped NiP and PdNiP@PEDOT:PSS/rGO electrodes toward urea electrooxidation were tested using cyclic voltammetry (CV). The CV test reveals the significant efficiency improvement in nickel phosphide (NiP) upon Pd doping, and further improvement was achieved when obtained PdNiP dispersed on PEDOT:PSS/rGO toward alkaline urea oxidation. Since PdNiP@PEDOT:PSS/rGO remarkably outperformed NiP and PdNiP, it is a promising novel material for alkaline urea oxidation in a direct urea fuel cell. [ABSTRACT FROM AUTHOR]

Re-evaluation of conventional wastewater treatment processes is of paramount importance to improve the overall quality of our aquatic environment. Electrochemical Advanced Oxidation Processes (EAOPs) are the most promising alternative methods with application in wastewater treatment facilities since in situ electrogenerated oxidant agents degrade and mineralize a wide range of water pollutants. Boron-doped diamond (BDD) technology has proven its excellency in the anodic oxidation (AO) of different pollutants. In this work, we describe the use of a systematic literature review (SLR) methodology and a bibliometric analysis tool for the assessment of a representative sample of work (hundreds of publications) concerning the synergism between AO using BDD technology and other oxidation methods. One section of the discussion relates to different techniques used to enhance the AO performance of BDD technology, namely persulfate radicals or ozone and photoelectrocatalysis, whereas the second one considers Fenton-based reactions. A standard synergism effect occurs between AO using BDD technology and the add-ons or the Fenton-based methods, resulting in the enhancement of the degradation and mineralization efficiencies. The future of EAOPs using BDD technology must include renewable energy sources to self-sustain the overall process, and further research on the subject is mandatory to enable the effective acceptance and application of such processes in wastewater remediation facilities. [ABSTRACT FROM AUTHOR]

A series of bimetallic Sn-Pd catalysts were prepared by a template-free two step electrodeposition method. According to this method, Sn was electrodeposited firstly in potentiostatic or galvanostatic regime on Cu electrodes in the form of dendrites, then Pd was galvanostatically electrodeposited in the second step on the electrode with the electrodeposited Sn dendrites. The produced Sn-Pd electrocatalysts were compared with an electrocatalyst obtained by Pd electrodeposition on a bare Cu electrode. The morphological and elemental analysis of Sn-Pd and Pd electrocatalysts was performed by means of scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) techniques. The dendrites of various shapes and degree of branching were obtained by Sn deposition depending on electrodeposition regime, while Pd was electrodeposited in a form of compact Pd islands on both Sn dendrites and the Cu electrode. Cyclic voltammetry (CV) was applied for the electrochemical examination of Sn-Pd and Pd catalysts towards the ethanol oxidation reaction (EOR) in the alkaline solution. The electrocatalyst Sn0.6-Pd0.4 with an atomic ratio of 60 at.% Sn-40 at.% Pd showed higher oxidation efficiency and better tolerance towards intermediate species in EOR than the other examined electrocatalysts. It was shown that the lower fraction of Pd, relative to Sn, was crucial to achieving optimal synergy of Sn with Pd thus contributing to enhanced electrochemical behavior regarding EOR. [ABSTRACT FROM AUTHOR]

The possibility of using a membrane electrolytic cell for the electrochemical oxidation of Fe(II) and purification from impurities of real industrial solutions obtained by atmospheric leaching of low-grade zinc concentrates is considered. The average indicators for carrying out the electrooxidation process are given. The principal possibility of conditioning a zinc sulfate solution by hydrolytic purification with preliminary oxidation of iron in a membrane electrolytic cell with an anion-exchange membrane MA-41 TU 2255-062-05761695-2009 is considered. Carrying out direct electrooxidation of iron (II) in sulfate zinc solutions in the anode chamber of a flow membrane electrolyzer ensures good filterability of precipitates after hydrolytic precipitation of iron, since this solution does not contain Fe(II) ions, the presence of which leads to significant difficulties in the operations of separating solid and liquid phases. This makes it possible to exclude the thickening operation from the technological scheme. The degree of oxidation of iron during the test period was 99.8–99.9%. The residual concentration of iron after precipitation from solutions obtained after electrochemical oxidation in the form of oxide and hydroxide compounds was less than 0.01 g/dm3. [ABSTRACT FROM AUTHOR]

In this work, we studied the application of photovoltaic solar energy for driving the electrochemical processes of electrocoagulation and electrooxidation to remediate drilling fluid wastewater, and simultaneously harvest energy in the form of electrolytic hydrogen gas produced at the cathode. The electrocoagulation was performed with sacrificial aluminium electrodes and electrooxidation with dimensionally stable boron-doped diamond electrodes in batch-wise and continuously operated mode, and their efficiency in both pollutants removal and hydrogen gas production was elucidated. The parameters affecting the efficiency of the applied electrochemical processes, such as applied current density, pH, electroprocessing time and flow rate, were investigated. The electrochemical processing was monitored by measuring the chemical oxygen demand (COD) of treated wastewater. The electrocoagulation treatment conducted with current densities of 30, 60 and 90 mA/cm2 reduced the wastewater COD by about 67%, whereas the electrooxidation treatment at the same conditions yielded a COD removal of over 95%. The amount of produced hydrogen was 171 L/g COD removed from treated wastewater. [ABSTRACT FROM AUTHOR]

Being one of the leading industries worldwide, the textile industry has been consuming large quantities of groundwater and discharging huge volumes of dye-contaminated effluents into our aquatic environment. Augmentation of water sources via reuse of treated effluents is therefore highly necessary. In the present study, the decolorization and degradation of synthetic toxic dye from an aqueous solution were investigated through an electro-biological route. Initially, decolorization of synthetic dye solutions (100, 500, and 1000 mg L−1) was carried out by electrooxidation process using mixed metal oxide and titanium as anode and cathode, respectively. The electrooxidation solutions were further treated using bacteria (Pseudomonas aeruginosa) that were isolated from petroleum-transporting pipelines. UV–Vis, TOC, chemical oxygen demand, and NMR analyses revealed that the biodegradation process with electrooxidation enhanced the mineralization of the synthetic dye solutions. An optimum NaCl electrolyte concentration of 3 g L−1 was sufficient to produce reactive species viz., free chlorine and hypochlorite, which are responsible for the Reactive Blue 19 (RB-19) decolorization. Among the three RB-19 concentrations, the highest removal percentage was noticed at 100 mg L−1 (100%) with energy consumption and energy costs equal to 5.44 kWh m−3 and 0.65 USD m−3, respectively. [ABSTRACT FROM AUTHOR]

The electrooxidation of glucose on gold (Au) and platinum (Pt) nanoparticles (NPs) is investigated in alkaline medium by cyclic voltammetry after chronoamperometry at different potentials (+0.100 V, +0.200 V, and +0.400 V vs the reversible hydrogen electrode, RHE), in situ Fourier transform infrared spectroscopy, and differential electrochemical mass spectrometry measurements. We show that glucose can adsorb on both metallic Au and Pt surfaces at low potentials, but that the adsorbed species are different: hydrogen atoms, carbon monoxide (CO), lactones and gluconate species on Pt-NPs, and only hydrogen atoms and gluconate species on Au-NPs. On Pt-NPs, the first oxidation peak between +0.050 V vs RHE and +0.250 V vs RHE is due to glucose adsorption and hydrogen atoms oxidation into protons (H+), whereas the second electrochemical feature between +0.250 V vs RHE and +0.800 V vs RHE is due to the oxidation of glucose into lactone and gluconate and of adsorbed CO into carbon dioxide (CO2). For Au-NPs, adsorbed hydrogen atoms are not oxidized into H+ but transformed into molecular hydrogen H2, and glucose is adsorbed as gluconate species that are desorbed into gluconates for potentials higher than +0.300 V vs RHE. [ABSTRACT FROM AUTHOR]

The significant increase in the turnip sector has brought a wastewater problem that needs to be managed. In this study, turnip juice wastewater treatment was studied using the electrocoagulation/electroflotation and electrooxidation processes. Independent process parameters such as electrode type (aluminum–aluminum, iron–iron, boron-doped diamond–platinum and graphite–platinum), current density (25–100 A/m2) and retention time (15–180 min) were investigated for the optimization of treatment conditions. Removal efficiencies of chemical oxygen demand and total phenol were studied. It was determined that the optimum removal efficiencies in both electrocoagulation/electroflotation and electrooxidation processes were the same under the conditions of 100 A/m2 current density, pH 5.4, and 45 min reaction time. Here, 100% removal efficiencies were achieved for both chemical oxygen demand and total phenol. The operating cost of the electrocoagulation/electroflotation process was calculated as 1.58 $/m3, while it was determined as 0.61 $/m3 for electrooxidation for the optimum removal parameters. It is seen in laboratory scale test results that electrocoagulation/electroflotation and electrooxidation processes are applicable/feasible for the treatment of turnip juice wastewater. [ABSTRACT FROM AUTHOR]

[Display omitted] • Suitable dopants were selected to boost oxygen vacancy of Ti 4 O 7. • Ti 4 O 7 anode was prepared by direct ink writing technology for the first time. • 3D printing technology could effectively avoid the clogging problem of anode. • Nd-Ti 4 O 7 anode evidently promote the removal of Escherichia coli and tetB. • Electrochemical disinfection mechanism is cell membrane perforation. Simultaneous removal of antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) is absolutely imperative to prevent the spread of antibiotic resistance in the environment. Herein, suitable dopants of Ti 4 O 7 anode from the lanthanide elements were firstly selected to boost Ti 4 O 7 electrooxidation ability according to density functional theory simulation. 3D printing technology was further adopted to prepare 3D printed lanthanide-doped reactive electrochemical membrane (REM) electrodes, which could efficiently avoid the problem of membrane clogging in the electrochemical filtration operation and increase the hydroxyl radical yield by 56–442 % compared to Ti 4 O 7 REM. We found that complete inactivation (>8.0-log inactivation) of antibiotic resistant Escherichia coli (AR E. coli) was achieved during Nd-Ti 4 O 7 REM (1 wt% Nd) treatment in a single pass at 4 mA cm−2, indicating significant improvement of disinfection efficiency than Ti 4 O 7 REM (3.3-log inactivation) operated in same conditions occurred. Morphology characterization results of treated AR E. coli revealed that cytoplasmic leakage in cell membrane perforation was the main inactivation mechanism. In addition, Nd-Ti 4 O 7 REM also exhibited better electrooxidation efficiency for ARGs removal, thereby eliminating the spread risk of antibiotic resistance. These findings greatly promoted the preparation and application of Ti 4 O 7 REM with highly efficient electrooxidation ability in the treatment of wastewater containing an abundance of antibiotic resistant bacteria. [ABSTRACT FROM AUTHOR]

[Display omitted] • Electrocatalysts showed a response to uric acid (UA) in the absence of enzyme (UOx); • A correct choice of UA-sensitive electrocatalyst should exclude the reaction with hydrogen peroxide; • The design of UA-sensing layer based on hydrogen peroxide- insensitive electrocatalyst was developed; • The original enzymatic quantification strategy of UA based on negative calibration was proposed. Uric acid (UA) is one of the most electroactive low molecular weight compounds that can be electrochemically oxidized on the surfaces of numerous noble and non-noble electrocatalysts under applied polarization. Consequently, enzymatic determination of UA in model and real samples is complicated by possible interference between electrochemical and biochemical routes. Herein, a novel strategy for amperometric enzymatic hydrogen peroxide independent UA sensing at low concentrations (e.g., below 50 µM) is proposed. The UA-sensitive strategy relies on the use of screen printed electrodes modified by an electrodeposited hybrid functional sensing film comprising a non-noble electrocatalyst, a bioorganic layer containing enzyme uricase (UOx), and data acquisition enabling the biochemical transformation of UA to be distinguished from the electrochemical oxidation route. Performed selectivity test utilizing adenine, xanthine, urea, ascorbic acid, ethanol and glycerol did not reveal interferences during detection of UA. This proposed approach was tested for UA detection in model and fermentation samples. The quantitative results obtained in fermentation samples were validated through optical oxygen mini sensor studies and fluorescence-based bioassays. [ABSTRACT FROM AUTHOR]

• The MOF-derived CeO 2 /C immobilized Pd nanoparticles have been synthesized. • The Ce3+-doped ZIF-67 has been used as the template to generate CeO 2 /C. • The metallic co have been used as the reductant to reduce the H 2 PdCl 4. • The as-prepared nanocomposite present superior electrocatalytic performance. The operation of direct ethylene glycol fuel cells (DEGFCs) to generate electric energy from ethylene glycol rely on the effective electrocatalysts for the ethylene glycol oxidation reaction (EGOR). The fabrication of EGOR electrocatalysts with high activity, high durability and high resistance for corrosion, is essential important for the DEGFCs. Herein, we report a fabrication of Pd nanoparticles immobilized by the Ce-doped ZIF-67-derived carbon (Pd-CeO 2 /ZDC). The Pd nanoparticles are generated by the in-situ reduction reaction between the H 2 PdCl 4 and the Co nanoparticles formed during the ZIF-67 pyrolysis. Owe to the porous structure and N-doping inherited from the ZIF-67, the Pd and CeO 2 nanoparticles show a uniform distribution. Due to the enhanced EGOR electrooxidation kinetic promoted by the ZIF-67-derived support, the multiple-components and structure synergies, the resultant Pd-CeO 2 /ZDC catalyst affords a EGOR current density of 32.4 mA cm-2, which is higher than the commercial Pd/C as well as the counterpart Pd/ZDC catalyst without CeO 2. Furthermore, the Pd-CeO 2 /ZDC catalyst also present a better EGOR durability. This work provides a strategy for the design of EGOR catalyst with multiple-components and desired structure, which may inspire the new tactics for controllable design and synthesis of other electrocatalysts for various electrocatalysis. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Explored the electrocatalytic activity of single Au@Ag core–shell nanoparticle for nitrite oxidation. • Employed single-entity electrochemistry approach using ultramicroelectrodes. • Analysis of catalytic activity differences according to the thickness of the Ag Shell. • Spike collision signals follow "Hit-and-Run" method. • Addressed the complex interactions between Au@Ag nanoparticle, ultramicroelectrodes and nitrite ions. Single-entity electrochemistry (SEE) has been extensively utilized for analyzing various substances, elucidating their mechanisms, and predicting particle behavior on electrode surfaces. In this paper, we propose a novel method for analyzing the electrochemical reactions between core–shell nanoparticles (NPs) and nitrite ions at the single-particle level. This method employs single Au@Ag core–shell NPs, nitrite ions (NO 2 -), and a carbon ultramicroelectrode (C-UME), utilizing the electrochemical oxidation of NO 2 - ions upon collision with individual core–shell nanoparticles on the C-UME surface. Au@Ag core–shell NPs with different ratios were synthesized to achieve the effective oxidation of NO 2 - ions, and their electrochemical properties were analyzed. Various parameters, such as applied potential and NO 2 - ion concentration, were adjusted in chronoamperometric experiments to analyze the resulting signals. This study is expected to significantly contribute to the analysis of oxidation/reduction, dispersion, and catalytic properties of various NPs, particularly core–shell NPs. [ABSTRACT FROM AUTHOR]

Florfenicol (FLO) is the most widely used veterinary antibiotic and has been detected frequently in various animal products and water bodies. Electrooxidation and electroreduction are effective strategies to eliminate halogenated environmental pollutants in water. In this work, SnO 2 -Sb 2 O 3 /Ti felt electrode and Pd/Ni foam electrode were used to treat FLO in water. The influence of water quality parameters on the removal efficiency of the two technologies was investigated, and the suitability of the two technologies was evaluated from the perspectives of energy consumption, stability, microbial inhibition and product toxicity. The experimental data show that both technologies can effectively remove FLO within 60 min, the energy consumption of oxidative degradation is 8.6 times that of reduction dehalogenation, and more toxic intermediate products are produced during the oxidation process. However, oxidative degradation process can realize the removal of microbial inhibition faster than the reduction dehalogenation process. Combined with UHPLC-Q EXACTIVE, the destruction of FLO main molecular structure and the substitution of F atoms are the key that weaken the antimicrobial properties of the degradation products. This work provides theoretical basis for the controllable treatment of halogenated antibiotics in water. [Display omitted] • FLO in water was treated by electrooxidation and electroreduction respectively. • The efficiency and interference factors of the two strategies were studied. • Both approaches can eliminate the antibacterial activity of FLO. • The potential antibacterial sites of FLO were identified via mass spectrometry. [ABSTRACT FROM AUTHOR]

• A novel device was designed for in-situ C and N resource utilization of wastewater. • A novel strategy for conversion of refractory organics and nitrate to urea and NH 3. • Efficient mass transfer promoted pollutant oxidation and C, N conversion efficiency. • Pollutant removal synergized CO 2 reduction enhances electron utilization efficiency. • The mechanism of "pollutants→CO 2 →value-added chemicals" was proposed. The advanced oxidation process is an efficient technology for the degradation and detoxification of refractory organics to ensure water safety. However, most researches focus on improving pollutant degradation but overlook carbon emission and resource utilization. In this study, a flow-through electrochemical integrated system was constructed to simultaneously realize bisphenol A (BPA) oxidation into small non-toxic organics and CO 2 , and generated CO 2 coupled with nitrate-containing wastewater conversion to urea and ammonia on a porous cathode (Zr-Fe/CN). The synergistic effect between anodic BPA oxidation with cathodic CO 2 and NO 3 −reduction improves the electron utilization efficiency and thus increasing the BPA degradation, urea yield rate (UYR) and NH 3 yield rate (NYR) by 13.4 % 18.4 % and 8.3 %, respectively. Furthermore, the flow-through operation mode significantly increased the mass transfer efficiency and quickly carried generated CO 2 from the anode into the cathode to improve CO 2 utilization efficiency. Compared to the parallel plate electrode reactor, the BPA degradation efficiency, UYR and NYR in the flow-through reactor increased from 59.46 % to 84.49 % (the initial concentration of BPA was 40 mg/L), 9.94 mmol h −1 g −1 to 19.55 mmol h −1 g −1, and 80.31 mmol h −1 g −1 to 106.06 mmol h −1 g −1 within 60 min, respectively. Moreover, the total carbon conversion efficiency (from BPA to urea) increased from 20.2 % to 42.4 % and the total Faraday efficiency (FE) increased from 78.6 % to 96.3 %. This work provides a multi-win strategy of harmless, resource-based and carbon emission reduction for wastewater treatment. [ABSTRACT FROM AUTHOR]

Electrooxidation of small organic compounds is crucial in achieving clean and efficient energy production. In this context, ethylene glycol (EG) has attracted considerable interest due to its notable energy density, which is suitable for applications in direct alcohol fuel cells. In light of this, we prepared Ag-Pt nanotubes (Ag-PtNTs) supported on silica (SiO 2) for the electrooxidation of this alcohol. However, our goal was not only to create an electrocatalyst that enhances electrooxidation efficiency but also to explore the interaction between the SiO 2 and the nanotubes. Such an exploration aims to contest the prevailing perception of SiO 2 as an inert and non-conductive material. Thus, comprehensive physicochemical characterization of the electrocatalyst was conducted, supported by density functional tight-binding (DFTB) calculations, to elucidate the correlation between composition, electronic effects, and catalytic performance, showing that Ag interacts more with the oxygen of SiO 2 that Pt. The interaction between SiO 2 and Ag-Pt NTs was explored through Mott-Schottky (M-S) analysis and electron paramagnetic resonance (EPR) spectroscopy, revealing the creation of oxygen vacancies (o-vacancies) and heterojunction formation, which enhance charge transfer and catalytic activity, both supported by theoretical calculations. In addition, mechanistic insights into the electrooxidation process were obtained through potential energy surface (PES) assessments, revealing a concerted pathway for glycolaldehyde formation with low barrier energy and favorable thermodynamics. Finally, the synthesized Ag-PtNTs/Si electrocatalyst exhibited an onset potential/current density of 0.45 V/0.09 mV mA cm−2 at 25 °C, demonstrating efficient electrooxidation capabilities. Therefore, this study provides valuable insights into designing efficient and stable electrocatalysts for alcohol electrooxidation, contributing to improving cleaner energy technologies. • Efficient ethylene glycol electrooxidation with Ag-Pt nanotubes onto SiO 2. • Effective creation of oxygen vacancies and heterojunction formation. • DFTB calculation revealed the process of enhanced catalytic performance. • Concerted mechanism pathway for glycolaldehyde formation. [ABSTRACT FROM AUTHOR]

[Display omitted] • The Cu 3 (BTC) 2 -2-MIM/CFCNPs nanocomposite was prepared for the first time. • Physicochemical characterizations of the Cu 3 (BTC) 2 -2-MIM/CFCNPs nanocomposite were studied. • The Cu 3 (BTC) 2 -2-MIM/CFCNPs/GCE displayed remarkably enhanced electrocatalytic activity toward ACR oxidation in NaOH solution. • The designed sensor shows wider linear range, lower LOD, good stability, high reproducibility and sensitivity. • The present sensor was applied for the electrodetermination of ACR in real samples. • This study provides a new strategy through a simple preparation method for the fabrication of high performance ACR sensor. With the aim of expansion of nanocomposite materials in electrochemical sensors, the use of nanostructures as the electrode modifier has been shown to improves the kinetics of the electron transfer reactions and consequently increases the sensitivity of the sensors. So, in this study, a new electrochemical sensor was fabricated by using the nanocomposite of copper (II) metal–organic framework with functionalized imidazolate linker [Cu 3 (BTC) 2 -2-MIM] and cationic functionalized carbon nanoparticles (CFCNPs) at the glassy carbon electrode (GCE); Cu 3 (BTC) 2 -2-MIM/CFCNPs/GCE. The as prepared nanocomposite; Cu 3 (BTC) 2 -2-MIM/CFCNPs was characterized using various instrumental techniques. To identify the capabilities and electrocatalytic activity of the synthesized nanocomposite in analytical chemistry, it was used as an electrochemical modifier along with suitable electrochemical techniques. In this regard, the prepared modified electrode; Cu 3 (BTC) 2 -2-MIM/CFCNPs/GCE was utilized to the electrooxidation and determination of the acyclovir (ACR) in NaOH solution. Under optimal experimental conditions, the Cu 3 (BTC) 2 -2-MIM/CFCNPs/GCE showed low detection limit (0.24 µM) over the concentration ranges of 2.49–84.28 μM of ACR. On the other hand, the present sensor has robust stability, good reproducibility, high selectivity and sensitivity (5.907 µAµM−1 cm−2) in electrodetermination of ACR. Also, the diffusion coefficient of ACR (D ACR = 9.25 × 10−6 cm2 s−1), the transfer coefficient (α = 0.34) and catalytic rate constant (k cat = 10.1 × 105 cm3 mol−1 s−1) of ACR electrooxidation reaction were estimated at the surface of modified electrode in NaOH solution. Finally, the Cu 3 (BTC) 2 -2-MIM/CFCNPs/GCE was applied as a promising and low-cost sensor for determination of the ACR in actual pharmaceutical formulations and biological samples. [ABSTRACT FROM AUTHOR]

Herein, 5.0 mg of chitosan hydrochloride was accurately weighed and dissolved in 5.0 mL of Milli-Q water. To this solution, 3.0 mg of MoS 2 and 2.0 mg of MWCNTs were added. The mixture underwent ultrasonic dispersion in a sonicator for 1 h. Then, 6 µL of the nanocomposite was dropwise added onto the GCE surface and dried in a drying oven at 35°C for 50 min. Finally, the dried electrodes were equilibrated at room temperature for 10 min. [Display omitted] • One-step construction of composite nanomaterial films based on MWCNTs, MoS 2 and Chitosan. • The sensors exhibited a wide linear range, with an LOD of 0.16 µmol/L. • The prepared sensors showed good recoveries in several water samples. • The prepared sensors can be used to explore the principles of CIP electrochemical reactions. • The sensor exhibited reliable reproducibility, selectivity and stability. Ciprofloxacin (CIP), extensively used in medical, agricultural, and forestry sectors as an antibiotic, poses risks of water contamination due to misuse or improper disposal, highlighting the pressing necessity for accelerated detection methods. Hydrophilic multi-walled carbon nanotubes (MWCNTs) and molybdenum disulfide (MoS 2) were co-dispersed in a chitosan (CS) solution, which facilitates film formation. The high specific surface area of MWCNTs, coupled with the excellent semiconducting properties of MoS 2 and the overall hydrophilicity of the composite nanomaterial film, markedly increases the active sites and reaction contact area. Subsequently, a drop-coating method was used to fabricate a MWCNTs@MoS 2 @Chitosan film onto the surface of a glassy carbon electrode (GCE) for CIP detection spanning from 0.50 to 1200.00 µmol/L using Differential Pulse Voltammetry (DPV), achieving a limit of detection (LOD) of 0.16 µmol/L. Simultaneously, the sensor demonstrates excellent reproducibility, stability, and selectivity. In several real water samples, the sensor performance was verified using a spiked recovery method. And in three water samples the recoveries ranged from 98.38 to 113.53 %, with a relative standard deviation (RSD) of less than 4.80 %. Meanwhile, the accuracy of these result was verified using UV–visible (UV–vis) spectroscopy. Furthermore, we proposed an electrooxidation mechanism for CIP that involves a reaction with two electrons and two protons. [ABSTRACT FROM AUTHOR]

A novel ultrasonic-assisted Fenton reaction inducing surface reconstruction strategy enables the low-spin states of Ni2+ (t 2 g 6 e g 2) and Fe2+ (t 2 g 4 e g 2) on the NiFe-LDH surface to partially transform into high-spin states of Ni3+ (t 2 g 6 e g 1) and Fe3+ (t 2 g 3 e g 2) and formation of the highly active species of NiFeOOH. The as-prepared electrode not only shows superior activity for water oxidation but also for various organics electrooxidation. [Display omitted] Nickel/iron-layered double hydroxide (NiFe-LDH) tends to undergo an electrochemically induced surface reconstruction during the water oxidation in alkaline, which will consume excess electric energy to overcome the reconstruction thermodynamic barrier. In the present work, a novel ultrasonic wave-assisted Fenton reaction strategy is employed to synthesize the surface reconstructed NiFe-LDH nanosheets cultivated directly on Ni foam (NiFe-LDH/NF-W). Morphological and structural characterizations reveal that the low-spin states of Ni2+ (t 2 g 6 e g 2) and Fe2+ (t 2 g 4 e g 2) on the NiFe-LDH surface partially transform into high-spin states of Ni3+ (t 2 g 6 e g 1) and Fe3+ (t 2 g 3 e g 2) and formation of the highly active species of NiFeOOH. A lower surface reconstruction thermodynamic barrier advantages the electrochemical process and enables the NiFe-LDH/NF-W electrode to exhibit superior electrocatalytic water oxidation activity, which delivers 10 mA cm−2 merely needing an overpotential of 235 mV. Besides, surface reconstruction endows NiFe-LDH/NF-W with outstanding electrooxidation activities for organic molecules of methanol, ethanol, glycerol, ethylene glycol, glucose, and urea. Ultrasonic-assisted Fenton reaction inducing surface reconstruction strategy will further advance the utilization of NiFe-LDH catalyst in water and organics electrooxidation. [ABSTRACT FROM AUTHOR]

Nowadays, the excessive utilization of fossil-based chemicals has caused serious environmental problems, especially due to the negative carbon footprints. Addressing this issue by substituting fossil resources with environmentally friendly biomass is imperative. This study focuses on the electrooxidation of 5-hydroxymethyl-2-furaldehyde (HMF), a biomass-derived chemical, into 2,5-furandicarboxylic acid (FDCA) in alkaline solutions, a crucial feedstock, for the chemical industry. Given the acknowledged instability of HMF in an alkaline environment, this research investigated the kinetic approximation of HMF degradation under varying concentrations of KOH solutions (0.1 M and 1 M KOH) over 12 hours. Then, the electrooxidation of HMF to FDCA over cobalt-iron-based catalysts was investigated. As a result, the FDCA was successfully produced in 0.1 M KOH solution with a remarkable yield of up to 94 %, while a higher concentration (1 M KOH solution) accelerated the electrooxidation process. However, the yield and Faradaic efficiency could be greatly dropped after 12 hours of storing time due to the effects of HMF degradation reactions (Cannizaro and polymerization reactions). Therefore, this degradation phenomenon should be considered on an industrial scale, particularly when HMF may be stored for an extended period before utilization. [Display omitted] • Humins and Cannizzaro products can be rapidly formed in strong alkali environments. • Direct electrooxidation of HMF in the fresh solution showed satisfying results. • The prepared optimum CoFe-based electrocatalyst exhibited exceptional stability. • Electrooxidation of degraded HMF resulted in lower FDCA yield as well as FE. [ABSTRACT FROM AUTHOR]

This work devised a simple glycerol-assisted synthesis of a low-Cu2+-doped CoFe2O4 and the electrochemical detection of acetaminophen (AC). During the synthesis, several polyalcohols were tested, indicating the efficiency of glycerin as a cosolvent, aiding in the creation of electrode-modifier nanomaterials. A duration of standing time (eight hours) before calcination produces a decrease in the secondary phase of hematite. The synthesized material was used as an electrode material in the detection of AC. In acidic conditions (pH 2.5), the limit of detection (LOD) was 99.4 nM, while the limit of quantification (LOQ) was found to be (331 nM). The relative standard deviation (RSD), 3.31%, was computed. The enhanced electrocatalytic activity of a low-Cu2+-doped CoFe2O4-modified electrode Cu0.13Co0.87Fe2O4/GCE corresponds extremely well with its resistance Rct, which was determined using the electrochemical impedance spectroscopy (EIS) technique and defined its electron transfer capacity. The possibility of a low-Cu2+-doped CoFe2O4 for the electrochemical sensing of AC in human urine samples was studied. The recovery rates ranging from 96.5 to 101.0% were obtained. These findings suggested that the Cu0.13Co0.87Fe2O4/GCE sensor has outstanding practicability and could be utilized to detect AC content in real complex biological samples.

In this study, seven compounds of environmental and health concern were treated by electrooxidation to determine their removal efficiencies from domestic wastewater. A batch type lab-scale reactor was used for the treatment process, and the analytes studied included two obsolete pesticides, two alkylphenols, two hormones, and bisphenol A. Titanium oxide and graphite electrodes were used as anode and cathode, respectively. Parameters of the electrooxidation process including pH of wastewater, ionic strength, applied current and treatment period were optimized by the univariate approach to maximize the removal efficiency of the analytes from wastewater. The optimum conditions were determined as nonadjusted pH of wastewater, 1.5 A current, 15 min treatment period and 5.0 g/L sodium chloride. Dispersive liquid-liquid microextraction was used to preconcentrate analytes before and after treatment in order to calculate the removal efficiency of analytes. The removal efficiency obtained under the optimum conditions was satisfactory for all seven analytes at different influent concentrations. HIGHLIGHTS Seven endocrine disrupting compounds were removed from wastewater using electrooxidation.; Electrooxidation parameters were optimized univariately.; An optimized DLLME-GC-MS method was used to analyze influent and effluent samples.; Over 95% removal efficiency was recorded for all analytes spiked to wastewater at three different concentrations.;

The application and design of treatment systems in wastewater are necessary due to antibiotics' potential toxicity and resistant genes on residual effluent. This work evaluated a coupled bio-electrochemical system to reduce chloramphenicol (CAP) and chemical oxygen demand (COD) on swine wastewater (SWW). SWW characterization found CAP of 99.99%, respectively. This coupled system can be applied to eliminate antibiotics and other organic pollutants in agricultural, industrial, municipal, and other wastewaters. HIGHLIGHTS Preliminary application of an anaerobic Reactor (UASB) allowed a reduction of 62.4% initial concentration of chloramphenicol.; The optimization of the electrooxidation process, for chloramphenicol (CAP) removal, reduces operation time and current intensity.; UASB + EO combined treatment allowed 82.35 and >99.9% of COD and CAP elimination.; The coupled system proved to be helpful for the CAP treatment in swine wastewater;

Boron-doped diamond (BDD) electrodes are eco-friendly and widely used in efficient water remediation through electrochemical advanced oxidation processes (EAOPs). These anodes can completely mineralize a wide range of pollutants, only requiring electrical energy. Over the last 2 decades, numerous commercially available BDD electrodes have emerged, but little is known about their electrooxidation performance, particularly if compared to laboratory-produced anodes by different research groups. In this critical review, a comparison between in-house-made and commercially available BDD electrodes based on a systematic literature review (SLR) is carried out. SLR was quite useful in locating and selecting the scientific publications relevant to the topic, enabling information gathering on dissemination, growth, and trends in the application of BDD electrodes in the degradation of water pollutants. More specifically, data concerning the origin of the employed BDD electrodes, and their physicochemical properties were extracted from a thorough selection of articles. Moreover, a detailed analysis of the main parameters affecting the BDD electrodes’ performance is provided and includes selection and pre-treatment of the substrate material, chemical vapor deposition (CVD) method, deposition parameters, characterization methods, and operational conditions. This discussion was carried out fully based on the numerous performance indicators found in the literature. Those clearly revealed that there are only a few analogous points across works, demonstrating the challenge of establishing an accurate comparison methodology. In this context, we propose a figure-of-merit equation which aims at normalizing BDD degradation results for a specific contaminant, even if working under different experimental conditions. Two case studies based on the degradation of solutions spiked with phenol and landfill leachate treatment with commercial or in-house-made BDD electrodes are also presented. Although it was not possible to conclude which electrode would be the best choice, we propose a set of guidelines detailing a consistent experimental procedure for comparison purposes in the future.

We have developed an electrochemical method for phosphorothiolation of 2H‐indazoles using S‐hydrogen phosphorothioates via cross dehydrogenative coupling reaction under metal‐free and electrolyte‐free conditions. This protocol is compatible with electron donating groups like −Me, −OMe, halogen and elctron withdrawing groups such as −COOEt, affording respective indazolyl phosphorothioates in 62%‐91% yields. Comprehensive mechanistic studies indicate that the reaction proceeds through a radical pathway. [ABSTRACT FROM AUTHOR]

This study was carried out to investigate the removal of Methyl Blue dye from synthetically prepared wastewater by a lab-scale electrooxidation process using Ti/IrO2/RuO2 as the anode material and stainless steel as the cathode material. The effect of operating variables, including wastewater initial pH (3.0, natural pH (≈ 5.0), 7.0, 9.0, and 11.0), current density (1.0 mA cm-2, 1.5 mA cm-2, 2.0 mA cm-2, and 2.5 mA cm-2), type of support electrolyte (NaCI, KCI, Na2SO4, and NaNOs), and concentration of support electrolyte (1.0 mM, 1.5 mM, 2.0 mM, and 2.5 mM) on Methyl Blue dye removal efficiency was investigated. In the 30-minute electrochemical treatment, the highest removal (78.31%) of the Methyl Blue dye was obtained at the natural pH (≈5). After determining NaCl as the best-supporting electrolyte with 78.31% removal efficiency as the supporting electrolyte type, the removal efficiency increased from 78.31% to 88.25% by increasing the concentration of NaCl from 1.0 mM to 2.5 mM. As the last parameter whose effect was examined, Methyl Blue dye removal efficiency increased from 78.31% to 88.98% by increasing from 1.0 mA cm-2 to 2.5 mA cm-2 the current density which is one of the operating parameters. Experimental results demonstrated the suitability of the electrooxidation process for the effective removal of Methyl Blue dye using Ti/IrO2/RuO2 anode. Especially in indirect oxidation, it was determined that Methyl Blue dye electrolyzes only in the presence of chloride ions, which act as a redox mediator. Also, it was confirmed that the reaction was affected by pH, chloride concentration and applied current density. [ABSTRACT FROM AUTHOR]

Herein, carbon nanotube supported bimetallic catalysts (PtBi/CNT) are synthesized at various metals weight loadings by NaBH4 reduction method. The surface morphology and crystal structure of the catalysts are investigated via X-ray diffraction (XRD) and electron microscopy with energy dispersive X-ray (SEM-EDX) advance surface methods. According to XRD results, the crystal size of PtBi(90:10)/CNT catalyst is determined as 4.66 nm. Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and chronoamperometry (CA) electrochemical techniques are used to determine 1-propanol electrooxidation activities of the catalysts. The highest specific activity and mass activity are obtained with PtBi(90:10)/CNT catalyst as 5.663 mA/cm² and 447.21 mA/mg Pt, respectively. However, it is concluded that PtBi(90:10)/CNT catalyst can be used as an anode catalyst in 1-propanol electrooxidation with long-term stability and low resistance. [ABSTRACT FROM AUTHOR]

A novel nanocomposite of nitrogen‐doped reduced graphene oxide‐ZnFe2O4/β‐cyclodextrin (NRGO‐ZnFe2O4/β‐CD) was synthesised for electrocatalytic applications on platinum electrode. The structural and morphological characterisation of the synthesised nanocomposite was carried out using FTIR, XRD, EDAX, FESEM, HRTEM etc. The electrochemical characterisation was performed using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). NRGO‐ZnFe2O4/β‐CD proved to be an excellent electrocatalyst for the electrochemical detection of epinephrine on platinum electrode and the optimum pH for the response was found to be 7. The electrochemical characteristics of the oxidation of epinephrine was found to be quasi reversible and diffusion controlled with charge transfer coefficient and diffusion coefficient of 0.55 and 1.03×10−5 cm2/s respectively. Detection limit in the micromolar range of epinephrine was achieved with specific recognition in presence of other structurally similar catecholamines like norepinephrine and dopamine even in their ten‐fold excess concentration at β‐CD/NRGO‐ZnFe2O4/Pt electrode and the electrode exhibited good repeatability, excellent reproducibility and stability for the oxidation of epinephrine. Recognition of epinephrine with high selectivity could be attained in presence of other common substances present in biological fluids. [ABSTRACT FROM AUTHOR]

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Studies of methanol electrooxidation reactions have achieved considerable advancements in the recent years for their encouraging contributions in the exciting fields of energy conversion and storage, organic syntheses, wastewater treatment, sensing, medicinal and environmental analyses, and many others thriving fields of modern technology. Accordingly, the fabrication of less expensive, efficient and decent quality electrocatalysts with high material stability, faster electro‐oxidation kinetics, as well as less carbonation and decent corrosion inhibition activities are highly urged. Consequently, scientists around the globe are in continuous search for alternative economical smart anode‐nanocatalysts for methanol oxidations with superior electrochemical performances. In the recent years, various inexpensive and readily‐available nanocatalysts of non‐noble metals like Ni, Co, Cu, etc., in reference to electrooxidation of organic molecules have been reported. The present work highlights the recent progress accomplished by rapidly flourishing nickel‐based electrocatalysts for electrooxidation of methanol. The discussion comprehensively includes the basic mechanistic understandings and fundamentals for achieving high efficacy of methanol electrooxidation with nickel‐based electrocatalysts. Also, the current challenges faced in this emerging area have been outlined to achieve superior, productive, and commercially viable catalysts for methanol electrooxidation in the near future. [ABSTRACT FROM AUTHOR]

Studies of the ammonia oxidation reaction (AOR) for the synthesis of nitrite and nitrate (NO2/3−) have been limited to a small number of catalytic materials, majorly Pt based. As the demand for nitrate‐based products such as fertilisers continues to grow, exploration of alternative catalysts is needed. Herein, 19 metals immobilised as particles on carbon fibre electrodes were tested for their catalytic activity for the ammonia electrooxidation to NO2/3− under alkaline conditions (0.1 m KOH). Nickel‐based electrodes showed the highest overall NO2/3− yield with a rate of 5.0±1.0 nmol s−1 cm−2, to which nitrate contributed 62±8 %. Cu was the only catalyst that enabled formation of nitrate, at a rate of 1.0±0.4 nmol s−1 cm−2, with undetectable amounts of nitrite produced. Previously unexplored in this context, Fe and Ag also showed promise and provided new insights into the mechanisms of the process. Ag‐based electrodes showed strong indications of activity towards NH3 oxidation in electrochemical measurements but produced relatively low NO2/3− yields, suggesting the formation of alternate oxidation products. NO2/3− production over Fe‐based electrodes required the presence of dissolved O2 and was more efficient than with Ni on longer timescales. These results highlight the complexity of the AOR mechanism and provide a broad set of catalytic activity and nitrate versus nitrite yield data, which might guide future development of a practical process for the distributed sustainable production of nitrates and nitrites at low and medium scales. [ABSTRACT FROM AUTHOR]