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ABSTRACT Tequila production occurs in Mexico's designated area of origin, principally in the Jalisco State. Its residues are a challenge in treatment and tracking due to a lack of technology, non-economic treatments available, low environmental consciousness and incipient control from authorities. In 2021, average production was close to 1.5 million tequila litres per day with an estimated residue yield of 10-12 litres of stillage (tequila vinasses) per tequila litre produced, including volatile fractions. This research aims to reduce organic matter by electrooxidation (EO) from 5 distillation volatile residual effluents (two-stage still distillation) from three tequila distilleries, first and second-stage heads and heads and tails and second-stage non-evaporated fraction. Round 3 mm titanium (grade-1) electrodes (one anode and one cathode) were used, with fixed voltage to a value of 30 VDC at 0, 3, 6, 9 and 12 h with 75 experiments. Gas chromatography was used to analyse methanol, ethanol, acetaldehyde, ethyl acetate, n-propanol, sec-butanol, iso-butanol, n-butanol, iso-amyl, n-amyl, and ethyl lactate content. Treatment shows positive results, reducing organic matter content in all effluents in a Chemical Oxygen Demand COD range of 580-1880 mg/L.h, particularly useful in the second-stage non-evaporated fraction for water recovery.HIGHLIGHTSResidual effluent treatment is beneficial to environmental and resource sustainability.Process without adding materials achieving cleaner treated effluents.Process aimed as the final step to recover water.This process could help the Tequila industry to reach a higher sustainability level by reducing water usage and untreated residues.

Background: Many type 1 diabetes patients using continuous subcutaneous insulin infusion (CSII) suffer from the phenomenon of unexplained hypoglycemia or "site loss." Site loss is hypothesized to be caused by toxic excipients, for example, phenolic compounds within insulin formulations that are used as preservatives and stabilizers. Here, we develop a bioinspired polyelectrolyte-modified carbon electrode for effective electrooxidative removal of phenol from insulin and eventual incorporations into an infusion set of a CSII device., Methods: We modified a carbon screen printed electrode (SPE) with poly-L-lysine (PLL) to avoid passivation due to polyphenol deposition while still removing phenolic compounds from insulin injections. We characterized these electrodes using scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS) and compared their data with data from bare SPEs. Furthermore, we performed electrochemical measurements to determine the extent of passivation, and high-performance liquid chromatography (HPLC) measurements to confirm both the removal of phenol and the integrity of insulin after phenol removal., Results: Voltammetry measurements show that electrode passivation due to polyphenol deposition is reduced by a factor of 2X. HPLC measurements confirm a 10x greater removal of phenol by our modified electrodes relative to bare electrodes., Conclusion: Using bioinspired polyelectrolytes to modify a carbon electrode surface aids in the electrooxidation of phenolic compounds from insulin and is a step toward integration within an infusion set for mitigating site loss., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

This study investigates electrooxidation of short (C3-C6) and long (C7-C-18) chain perfluorocarboxylic acids (PFCAs) including perfluorooctane sulfonate (PFOA) using Si/BDD electrode. The effect of operational parameters (supporting electrolyte type, applied current density, and initial pH) were explored for PFOA removal. At the optimized conditions, 74% TOC removal and 37% defluorination ratio were gained for 10 mg L -1 of PFOA solution which evidences that the shorter chain PFCAs were formed. The PFOA degradation pathway followed one direct electron transfer from PFOA molecule to anode surface. Then two different degradation pathways were proposed. The first proposed degradation mechanism involved the reaction of perfluoroheptyl radical and hydroxyl radical, the release of HF and hydrolysis. The second mechanism involved the reaction between perfluoroheptyl radical and O 2 , formation of C 7 F 15 O and perfluorohexyl radical with releasing COF 2 . The removal of short- (C3-C6) and long-chain PFCAs (C7-C18) was also characterized. More than 95% of removal efficiency was gained for all long-chain PFCAs, excluding C7. The removal ratios of short-chain PFCAs (C3-C6) were 39%, 41%, 66% and 70% for C3, C4, C5 and C6, respectively. Contrary to long-chain PFCAs, chain-length dependence for short-chain PFCAs were observed. Defluorination ratio of short-chain PFCAs was only 45% signifying that defluorination partially occurred. Water matrix did not significantly affect the degradation of short-chain PFCAs in deionized water (DI), river water and secondary effluent of a wastewater treatment plant (WWTP). In contrast, defluorination ratio of long-chain PFCAs was noticeably affected by water matrix with the order of DI water > WWTP effluent > river water., (Published by Elsevier Ltd.)

Commercial activated carbon fiber (ACF) has been employed as particle electrodes to degrade aqueous m-cresol in 3-D electrode systems. To enhance the electrooxidation performance, three types of new ACF modification modes (anodic oxidation, cathodic reduction, and aqueous oxidation with concentrated HNO 3 ) were introduced in this paper. These pretreated samples were characterized by N 2 adsorption, scanning electron microscopy (SEM), cyclic voltammetry (CV), temperature-programmed desorption mass (TPD-MS), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (FT-IR). It was revealed that the two new modification methods could efficiently modify the surface morphology as well as the chemical property. Eight types of surface oxygen groups (SOGs) were identified on the surface of ACF, and the types and amount of SOGs might be related to the oxidation effect of ACF on the 3-D electrodes. The effect and mechanism of these SOGs on electrooxidation performance were discussed with the aid of the frontier molecular orbital theory. It was demonstrated that the H 2 O 2 -·OH reaction mechanism was improved in the 3-D electrode system and the mechanism was elucidated.

The degradation of the herbicide fenuron was investigated using a new porous bifunctional electrode where the electrooxidation takes place on one side and the photocatalysis on the other side. The characterization of the synthetized bifunctional electrode (PbO 2 /SnO 2 -Sb 2 O 3 /Ti//Ti/TiO 2 ) was performed by scanning electron microscopy, energy dispersive X-ray spectrometry and X-ray diffraction analysis and showed that the anodic side (Ti/SnO 2 -Sb 2 O 3 /PbO 2 ) is covered with a tetragonal β-PbO 2 film and that the photocatalytic side (Ti/TiO 2 ) consists of an anatase phase of TiO 2 . The single application of electrooxidation achieved 87.8% fenuron degradation and 84.1% chemical oxygen demand (COD) removal while heterogeneous photocatalysis resulted in only 59.2% and 39.7% fenuron concentration decay and COD removal, respectively. On the other hand, the photocatalytically-assisted electrooxidation (photo-electrooxidation) performed on the bifunctional electrode provided higher performances of fenuron degradation (97.5%) and mineralization (97.4%). Investigation of operating parameters highlighted the positive effect of increase in current density. Conversely, an increase in fenuron concentration led to a decrease in degradation rate and COD removal. It was also found that the COD removal and mineralization efficiency are higher in a neutral medium., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

This study focuses on the effect of electrode materials on abatement of lindane (an organochlorine pesticide) by electrooxidation process. Comparative performances of different anodic (platinum (Pt), dimensionally stable anode (DSA) and boron-doped diamond (BDD)) and cathodic (carbon sponge (CS), carbon felt (CF) and stainless steel (SS)) materials on lindane electrooxidation and mineralization were investigated. Special attention was paid to determine the role of chlorine active species during the electrooxidation process. The results showed that better performances were obtained when using a BDD anode and CF cathode cell. The influence of the current density was assessed to optimize the oxidation of lindane and the mineralization of its aqueous solution. A quick (10 min) and complete oxidation of 10 mg L -1 lindane solution and relatively high mineralization degree (80% TOC removal) at 4 h electrolysis were achieved at 8.33 mA cm -2 current density. Lindane was quickly oxidized by in-situ generated hydroxyl radicals, (M( • OH)), formed from oxidation of water on the anode (M) surface following pseudo first-order reaction kinetics. Formation of chlorinated and hydroxylated intermediates and carboxylic acids during the treatment were identified and a plausible mineralization pathway of lindane by hydroxyl radicals was proposed., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Electrochemical oxidative degradation of diazo dye Amido black 10B (AB10B) as model pollutant in water has been studied using nanostructured ZnO-TiO 2 thin films deposited on graphite felt (GrF) substrate as anode. The influence of various operating parameters, namely the current intensity, the nature and concentration of catalyst, the nature of electrode materials (anode/cathode), and the adsorption of dye and ambient light were investigated. It was found that the oxidative degradation of AB10B followed pseudo first-order kinetics. The optimal operating conditions for the degradation of 0.12 mM (74 mg L -1 ) dye concentration and mineralization of its aqueous solution were determined as GrF-ZnO-TiO 2 thin film anode, 100 mA current intensity, and 0.1 mM Fe 2+ (catalyst) concentration. Under these operating conditions, discoloration of AB10B solution was reached at 60 min while 6 h treatment needed for a mineralization degree of 91 %. Therefore, this study confirmed that the electrochemical process is effective for the degradation of AB10B in water using nanostructured ZnO-TiO 2 thin film anodes.

Herein, we report a highly selective dopamine electrochemical sensor based on electrochemically pretreated graphite/nafion composite modified screen printed carbon (SPC) electrode. Electrochemically activated graphite/nafion composite was prepared by using a simple electrochemical method. Scanning electron microscope (SEM) used to characterize the surface morphology of the fabricated composite electrode. The SEM result clearly indicates that the graphitic basal planes were totally disturbed and leads to the formation of graphite nanosheets. The composite modified electrode showed an enhanced electrocatalytic activity toward the oxidation of DA when compared with either electrochemical pretreated graphite or nafion SPC electrodes. The fabricated composite electrode exhibits a good electrocatalytic oxidation toward DA in the linear response range from 0.5 to 70 μM with the detection limit of 0.023 μM. The proposed sensor also exhibits very good selectivity and stability, with the appreciable sensitivity. In addition, the proposed sensor showed satisfactory recovery results toward the commercial pharmaceutical DA samples., (Copyright © 2013 Elsevier Inc. All rights reserved.)

In this study, the characterization, optimization and effect of model compound Reactive Black 5 (RB5) dye on the process performance of lanthanum (La) and cerium (Ce) doped iridium‐ruthenium (Ir‐Ru) mixed metal oxide (MMO) electrodes were investigated. The electrodes had varying La and Ce doping levels at 5%, 10% and 20% concentrations and were coated by thermal decomposition technique. In addition, a mixed La/Ce electrode was prepared with 10% Ce and 10% La. This study focused on understanding the effects of La and Ce doping, pH, conductivity and concentration on the electrochemical degradation process. The experiments were conducted over various pH values ​​(3, 5, 7 and 9), dye concentrations (50, 100, 300 and 500 ppm), current densities (100, 200, 350 and 600 A.m‐2) and conductivities (1500, 3500, 5500 and 10000 µS.cm−1). It was found that the newly developed electrode doped with 10% Ce and 10% La showed the most efficient results. This study provides insights into optimizing the operational parameters for effective electrochemical process with the novel La/Ce doped MMO electrodes. [ABSTRACT FROM AUTHOR]

The use of electrocatalytic technology to replace traditional harsh thermocatalysis in the process of biomass utilization has undoubtedly been an effective means to achieve green and sustainable development. The use of the environmentally friendly method of synthesizing furoic acid (FA) from the biomass platform compound furfural (FF) by electrooxidation was investigated. The surface of the Ni–Co oxide electrode with a Ni content of 0.48 (Ni0.48Co0.36O0.16) obtained by a simple electrodeposition method was covered by a layer of flower-like porous structure, while NiO, Co2+, and Co3+ coexisted. Moreover, the Ni0.48Co0.36O0.16 electrode exhibited 95.4% FA faraday efficiency and 99.6% selectivity with a substrate concentration of 20 mM at 1.0 V vs. Hg/HgO and 50 °C. In addition, a mechanism for electrooxidation of FF into FA over a Ni–Co oxide electrode was proposed. [ABSTRACT FROM AUTHOR]

Modified electrodes based on gold particles, mixed-valence ruthenium oxides, and a binary system combining these components were developed for the voltammetric determination of ceftriaxone, cefotaxime, and cefoperazone. The electrode with the binary system of gold particles and mixed-valence ruthenium oxides, which exhibited the best performance, was used for the detection of cephalosporins in flow-injection analysis. Optimal conditions for the detection of cephalosporins in a flow-injection system were selected. The dependence of the analytical signal on the concentration of the compounds under consideration is linear on logarithmic coordinates over the range from 5 × 10–7 to 5 × 10–3 M. The proposed procedure was tested in the determination of cephalosporins in pharmaceuticals. [ABSTRACT FROM AUTHOR]

Direct ethanol fuel cells (DEFCs) are better than others in commercially used FCs due to easy availability, less toxicity, and C‐2‐type alcohol. Ethanol has a high theoretical efficiency of 97% and is a safe, plentiful, and renewable resource that can be stored and controlled using the infrastructure that is in place now. Nevertheless, low functional efficiencies and the release of carbon dioxide (CO2), acetaldehyde, and byproducts of acetic acid must be addressed if DEFCs are to grow and become more commercially viable. To overcome these problems, new anode and cathode catalysts are needed, so this review article discusses the introduction of FCs with their structure, working and mechanism. Further, the report covers various types of FC catalysts, and their application in FC technology is explained. The role of the catalyst (such as anode and cathode), similarities and differences between Pt/Pd‐based catalysts, and the importance of supporting materials (such as carbon, transition metal dichalcogenides, MXene, and black phosphorus‐based materials) in DEFCs are described. In addition, the applications, advantages, and disadvantages of the DEFCs are discussed. Finally, the proposed theme is concluded with the existing challenges in this field and the future prospect of DEFCs. [ABSTRACT FROM AUTHOR]

PdM/RGN (M = Co, Cu) self-supporting composite electrodes were synthesized via a simple two-step spontaneous reduction process using Ni foam as the substrate and reduced graphene oxide as support layer. The composites were characterized using X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy. Cyclic voltammetry, chronoamperometry, and electrochemical impedance spectroscopy were performed to study the electrocatalytic activities of the prepared electrodes for methanol and ethanol oxidation. The performances of PdM/RGN for methanol and ethanol oxidation increased and then decreased as the atomic ratio of Pd to M (Co, Cu) increased. The Pd 6 Co 1 /RGN and Pd 6 Cu 1 /RGN electrodes exhibited markedly superior catalytic activity and long-term stability. The peak current densities of Pd 6 Cu 1 /RGN and Pd 6 Co 1 /RGN electrodes reached 0.36 and 0.29 A/cm2 for methanol electrooxidation and which reached 0.8 and 0.5 A/cm2 for the ethanol electrooxidation, respectively. This excellent performance is owing to the three-dimensional structure of nickel foam, the improving specific surface area and the synergistic effect between Pd and M. [Display omitted] • The electrode manufacture process is facile, green, low energy consumption and binder-free. • Three-dimensional graphene substrate support resulted in excellent stability of PdM/RGN (Co,Cu). • Good synergy in PdM nanoparticles promotes electron transport and increases surface area. • The PdM/RGN (Co,Cu)electrode exhibitshigh catalytic performance for MOR and EOR. [ABSTRACT FROM AUTHOR]

The study was aimed at using Ti/IrO 2 -RuO 2 electrocatalytic electrodes for the purpose of removing 1,4-acetaminophen from a solution. The electrooxidation process's efficiency was studied by controlling various parameters such as pH (3−11), current density (100–1000 A.m-2), electrolyte type (NaCl, Na 2 SO 4 , KCl), and conductivity (1.5–10 mS.cm-1). Additionally, H 2 O 2 addition (100–1000 µL), and acetaminophen concentration (25–100 ppm) were also studied. In addition, it was found that when the initial concentrations were increased from 25 ppm to 100 ppm, there was a corresponding increase in the removal efficiencies, which ranged from 27% to 36% at a current density of 350 A.m-2 and a conductivity of 3.5 mS.cm-1 for a period of 90 min. The removal efficiency increased from 30% to 42% when 0.5 mL of 30% H 2 O 2 was added to the initial concentration of 50 ppm. The presence of chlorine ions in a solution has been demonstrated to result in the formation of oxidation products. This result has enabled researchers to investigate the toxic and disinfecting properties of the solution. The LC-MS spectra analysis revealed the formation of intermediate degradation products. The identification of these metabolites enabled the suggestion of their structure and degradation mechanism. [Display omitted] • The development of Ti/IrO 2 RuO 2 electrodes by thermal oxidation method was studied and the ratio of Ir56:Ru44 was tested. • Paracetamol degradation mechanism and by-products of the process were investigated. • Operational parameters were optimized and effect of H 2 O 2 addition was tested. • 0.5 mL H 2 O 2 increase the TOC removal efficiency from 30% to %40. [ABSTRACT FROM AUTHOR]

The electrocatalytic selective oxidation of 5‐hydroxymethylfurfural (HMF) presents a highly efficient and eco‐friendly method for biomass utilization. Herein, we synthesized pure β‐Ni(OH)2 and amorphous Ni(OH)2 on nickel foam (NF) using a facile stepwise electrodeposition technique and evaluated their catalytic performances for the oxidation of HMF to 2,5‐furan dicarboxylic acid (FDCA). The β‐Ni(OH)2 nanosheets‐decorated electrode (β‐NiNS/NF) exhibited excellent interfacial lattice matching with the substrate nickel, resulting in enhanced electron transfer at the catalyst‐substrate interface, as confirmed by electrochemical analysis. Consequently, the β‐NiNS/NF electrode displayed improved intrinsic electrocatalytic activity and interfacial stability. Additionally, it demonstrated effective HMF adsorption capability. These advantageous properties led to enhanced HMF conversion, selectivity, and structural stability. Notably, the β‐NiNS/NF electrode achieved an unprecedented FDCA yield of 80.6 % under relatively large current density galvanostatic electrolysis commonly used in industry. Moreover, our investigation identified a novel possible oxidation pathway during HMF electrocatalysis. This study not only showcases an efficient and scalable synthetic approach but also highlights the potential of the β‐NiNS/NF electrode for industrial HMF electrocatalytic oxidation under conditions involving relatively large applied currents. [ABSTRACT FROM AUTHOR]

In this study, poly(N-Isopropylacrylamide) (PNIPAM), poly(acrylamide) (PAAM), poly(acrylic acid) (PAAc), and poly(methacrylic acid) (PMAc) polymers are synthesized by radical polymerization method. The chemical composition and surface morphology of the PMAc polymer are examined by micro-Raman spectroscopy and scanning electron microscopy (SEM). The electrochemical measurements are examined by cyclic voltammetry (CV), chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS) analyses for glucose (Glu) electrooxidation. The characterization analyses reveal that the polymer structure was formed. The electrochemical analysis results indicate that the PMAc/G electrode has higher catalytic activity, stability, and resistance compared to other electrodes with a specific activity of 1.7 mA/cm2. [ABSTRACT FROM AUTHOR]

Electrochemical oxidation (EO) technology, which may directly reduce refractory contaminants into simple inorganic molecules like H 2 O and CO 2 , is an efficient approach for treating high-concentration wastewater. Boron doped diamond (BDD) electrodes has been extensively researched and used to degrade organic contaminants from real textile wastewater. In this study, two-dimensionally stable anodes, Ti/RuO 2 -IrO 2 , were produced and compared with BDD electrodes for the treatment of textile wastewater. This study focuses on the optimization of the produced electrode under different pH and current densities. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis revealed that the oxide coating on the Ti plate's surface was effectively produced. The EO process parameters were optimized using central composite design (CCD) under response surface methodology (RSM), with total organic carbon (TOC), chemical oxygen demand (COD), and color removals as responses and pH, current density, and reaction time as control variables. The analysis of variance (ANOVA) revealed good coefficients of determination (R2) values of.0.90, indicating that the second-order regression model matched the experimental data satisfactorily. In optimized conditions, pH 4 was shown to have the maximum effectiveness for both electrodes. The best treatment efficiency was obtained by applying an 800 A/m2 current for 5 h, taking into account the time component in the different current values employed. BDD had a color, TOC, and COD removal of 93%, 75%, and 48%, respectively, whereas Ti/RuO 2 -IrO 2 had a color, TOC, and COD removal of 88%, 62%, and 41%, respectively. In addition, the toxicity of water treated with the BDD electrode was found to be lower, whereas the toxicity of water treated with the Ti/RuO 2 -IrO 2 electrode was found to be higher. [Display omitted] • Ti/RuO 2 -IrO 2 electrode was prepared by thermal decomposition method. • Effective color removal (88%) in real textile wastewater. • Promising performance according to BDD vs Ti/RuO 2 -IrO 2 studies. • Optimization studies done clearly with central composite design (CCD) under response surface methodology (RSM). [ABSTRACT FROM AUTHOR]

The present paper focuses on a hybrid system combining electrochemical oxidation (EO) and activated carbon (AC) adsorption in a concept known as three-dimensional (3D) electrocatalytic technology for the treatment of oxytetracycline from aqueous solution; the conventional one-factor-at-a-time variation approach (AC dosage, OTC concentration, and current density) was used for determining the effects of operating parameters on the 3D electrochemical process and optimized via fuzzy logic modeling. The process's superior performance was assessed based on comparative studies of the degradation efficiency of the 3D electrochemical process with AC adsorption and conventional 2D electrochemical process. The study showed that the AC particle electrode enhanced the performance of the 3D system by up to 21% in terms of OTC degradation efficiency compared to both adsorption and the conventional two-dimensional (2D) electrochemical system. When 2D and 3D processes were compared in required energy and electricity budgets, 3D electrode process with 0.75 g/L activated carbon requires 27.60 kWh/m3 and it perceived 2 times lower than 2D process; accordingly, the electricity budget is €5.38 and €2.81 for electrooxidation and 3D electrode process, respectively. The obtained results suggest that under the electric field, polarized AC worked as both adsorbent and a catalyst in the 3D electrochemical system, enhancing subsequently the decomposition of electro-generated H2O2 to more hydroxyl radicals (·OH) and promote the capacity of OTC mineralization. [ABSTRACT FROM AUTHOR]

Electrochemically deposited MnO2 on graphene coated Pencil Graphite Electrode (PGE) has been used to develop a facile electrochemical sensor for the determination of Cholesterol. Cyclic voltammetric (CV) studies and electrochemical impedance spectroscopic (EIS) technique were used to investigate the electrochemical properties of the modified sensing platform. The physicochemical properties of the modified electrodes were characterized by X‐ray photoelectron spectroscopy (XPS), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), X‐ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The experimental conditions such as effect of scan rate, concentration and pH were optimized. The linear dynamic range for the determination of Cholesterol was found to be 12×10−10 M–240×10−10 M under optimum conditions. The ultralow level of detection limit (0.42 nM) demonstrates the high sensitivity of the proposed method. The developed method was successfully applied for the non‐enzymatic determination of Cholesterol in human blood samples at ultralow levels. [ABSTRACT FROM AUTHOR]

Regularities of the electrooxidation of sulfite ions in an alkaline medium (рН ≥ 8; LiClO4, KNO3, Na2SO4, NaOH) on a composite carbon-containing electrode modified by submicron (300 nm or smaller) gold particles are studied using cyclic voltammetry. The electrocatalytic nature of the analytical signal is substantiated; a scheme of the oxidation process is proposed. A procedure for the preliminary electrochemical treatment of the modified electrode, ensuring an increase in the substrate oxidation current and consisting in the anodic polarization of the electrode in the potential range 0.9–1.4 V (Ag/AgCl reference electrode) in a supporting electrolyte is optimized. The essence of activation is an increase in the surface area of gold particles participating in the catalytic generation/reduction cycle of gold (hydr)oxides and providing an increase in the value of the analytical signal. The proposed approach ensures a significant increase of the sensitivity of the voltammetric method for determining sulfite ions. The concentration dependence of the analytical signal is linear in the concentration range of -ions 1 × 10–7–2 × 10–4 М (limit of detection 5.5 × 10–8 M). The results of the determination of sulfite ions in wines, beer, and juices indicate a higher accuracy of the voltammetric method compared to the standard iodometric procedure. [ABSTRACT FROM AUTHOR]

In this work, it has been evaluated how the performance of an electrolyzer, used to treat a clopyralid waste and directly powered without regulation by a battery, is influenced by the electrodes resistance. Electrolyzers were equipped with electrodes consisting of the same boron‐doped diamond (BDD) coating deposited on different substrate (Si, Ta and Nb). The results expose great differences despite using the same coating. Faster removal rates were attained with Ta‐ and Nb‐BDD electrodes. The amount of energy required to attain the same removal efficiency showed great differences. Up to 1.95 mg/Wh of pesticide were removed when using Si, compared to 2.14 mg/Wh removed with Ta. Furthermore, the quantity and strength of the generated oxidants were also quite different. 86.78 mmol of oxidants were needed to remove a gram of pesticide with Ta‐BDD and 30.57 mmol with Si‐BDD. Therefore, the electrode resistance is an important aspect that must be considered in order to get a suitable design of energy storage systems that allow the green photovoltaic powering of electrochemical technologies using conventional batteries as a booster to ensure a continuous operation. [ABSTRACT FROM AUTHOR]

Micropollutants cover a variety of compounds that mainly originate from the pharmaceutical and agricultural sectors. Even at trace concentrations, the discharge of micropollutants into water bodies pose a serious threat to the environment and human health. Their removal from wastewaters at treatment plants before their discharge into the environment has become one of the leading topics of research. Physical, chemical, and biological treatment methods have been listed in the literature for efficient removal of a variety of pollutants. In this study, seven micropollutants, namely 4‐tert‐octylphenol, atrazine, 2,4,6‐trichlorophenol, fluoxetine, estrone, penconazole, and di‐n‐octyl phthalate, are spiked into municipal simulated synthetic wastewater and treated by a laboratory‐scale electrooxidation (EO) system using oxidized titanium and graphite electrode as anode and cathode, respectively. Sensitive determination of the selected micropollutants by gas chromatography–mass spectrometry (GC‐MS) before and after treatment is performed after their pre‐concentration using an eco‐friendly switchable solvent liquid‐phase microextraction method (SSLPME). The pH value, applied current, and reaction period are optimized to enhance the removal efficiency of micropollutants. Results show that the highest removal efficiency of all micropollutants is obtained at pH 3, 20 min reaction period, and 3 A applied current. The operational costs are also investigated in this study. [ABSTRACT FROM AUTHOR]

Tannery wastewater is known to contain high concentrations of organic compounds, pathogens, and other toxic inorganic elements such as heavy metals, nitrogen, sulfur, etc. Biological methods such as aerobic and anaerobic processes are unsuitable for tannery wastewater treatment due to its high salinity, and electrochemical oxidation offers a promising method to solve this problem. In this study, raw tannery wastewater treatment using DSA® Ti/RuO2, Ti/IrO2 and Ti/BDD electrodes with continuous flow systems was examined. Effects of current densities and electrolysis times were investigated, to evaluate the process performance and energy consumption. The results showed that a Ti/BDD electrode is able to reach higher treatment efficiency than Ti/IrO2, and Ti/RuO2 electrodes across all parameters, excluding Total Nitrogen. The main mechanism of tannery wastewater oxidation at a Ti/BDD electrode is based on direct oxidation on the electrode surface combined with the generation of oxidants such as oOH and Cl2, while at DSA® Ti/RuO2 and Ti/IrO2 electrodes, the oxidation mechanisms are based on the generation of chlorine. After treatment, the effluents can be discharged to the environment after 6-12 h of electrolysis. Electrooxidation thus offers a promising method for removing the nutrients and non-biodegradable organic compounds in tannery wastewater. [ABSTRACT FROM AUTHOR]

A novel and rapid voltammetric assay for the simultaneous determination of monolinuron (MLN) and linuron (LIN) using an electrochemically pretreated pencil graphite electrode (PGE*) is reported for the first time. Enhanced oxidation peak currents of MLN and LIN were observed at PGE* when compared with electrochemically non-pretreated PGE. Differential pulse voltammetric (DPV) results showed distinct anodic peaks at 1.064 V and 1.170 V for MLN and LIN, respectively. Under optimum conditions, the detection limits were 3.7 × 10−7 mol L−1 and 5.8 × 10−7 mol L−1 for MLN and LIN respectively. The DPV method was applied for the quantitative determination of the mentioned compounds in spiked tap water samples enriched by solid phase extraction. The voltammetric results were in good agreement with high-performance liquid chromatography data. • Electrochemically activated pencil graphite electrode (PGE*) • Simultaneous electroanalytical determination of LIN and MLN at PGE* without previous separation • The detection limits were 5.8·10−7 M for LIN and 3.7·10−7 M for MLN. • Voltammetric determination of LIN and MLN in spiked tap water matrices enriched by solid phase extraction using PGE* [ABSTRACT FROM AUTHOR]

Electrooxidation of hazardous organic pollutants contaminating wastewater using thin‐film boron‐doped diamond (BDD) electrodes is an efficient and well‐studied treatment technique. In this review, the three main reactive species, namely: reactive oxygen, chlorine and sulfate species, which can be electrogenerated and then participate in the oxidation processes during electrooxidative wastewater treatment using BDD electrodes, are discussed. The main factors affecting the nature and quantity of the electrogenerated reactive species, specifically the composition of the BDD electrode (doping level and sp3/sp2 ratio) and the operating parameters (working current density and composition of water matrix been electrolyzed) were explained with relative examples. Extensive discussion on mode and reactivity of the three reactive species with organic pollutants during electrooxidation was provided and the future perspectives and direction of research on reactive species generated on BDD electrodes were also discussed. [ABSTRACT FROM AUTHOR]

Over the past few decades, environmental applications of the boron‐doped diamond (BDD) electrode are reported to be vast and versatile. Applications of BDD electrodes in the field of electrochemical advanced oxidation processes (EAOPs) for the abatement of toxic persistent organic pollutants are significant, owing to the easy and effective way of treatment. This article focuses on highlighting and summarizing the applications of the BDD electrode for the treatment of different synthetic and real wastewaters, such as those involved in pharmaceuticals and personal care products, pesticides/herbicides, dyes, etc. We also review the processes and methodologies involving the synthesis of BDD electrodes and summarize the desirable characteristic features required for the application of EAOPs. Applications of BDD electrodes for the treatment of wastewater through different EAOPs, including anodic oxidation, electro‐Fenton, coupling processes such as electro‐Fenton pyrite, bioelectro‐Fenton, and their recent advancements are also discussed in detail. It envisages the greater potential for complete treatment of different toxic wastewater effluents. This Review shows that the application of BDD electrodes in the field of wastewater treatment is tremendous and proves to be a promising material for future perspectives. [ABSTRACT FROM AUTHOR]

The electroactivity of cytochrome c on screen-printed graphite electrodes modified with stable dispersions of multi-walled carbon nanotubes in aqueous solution of amphiphilic poly(n-butyl acrylate) 100 - block -poly(acrylic acid) 140 diblock copolymers was estimated. Using a broad potential window, the reduction and oxidation of heme iron at a near-zero potential, the electrooxidation of Tyr and Trp at +0.6 V and the electrooxidation of heme at +0.8 V were detected in a wide concentration range of 1–100 μm with a limit of detection of 1–2 μm. Such a multipoint detection can be used as an electrochemical fingerprint of cytochrome c for its electrochemical recognition and quantification in complex (bio)chemical analytes. [ABSTRACT FROM AUTHOR]

Abstract The performance and cost of electrodes are two most important aspects in the design of polymeric fuel cells. In this work, doped Pt nanoparticles in NiO-MgO solid solution (PNMSS) particles were synthesized through co-precipitation method. The prepared PNMSS particles were characterized and incorporated as promoter to electrocatalyst containing palladium. The electrochemical studies were employed to compare the electrochemical behaviour of Pd and Pd-PNMSS. The electrochemical surface area was increased about 10 times with addition of PNMSS to Pd. The incorporation effect of PNMSS to Pd on catalytic activity toward the electrooxidation of methanol and ethanol was assessed in alkaline media. According to our results, the alcohols electrooxidation on Pd/PNMSS had the more negative potential and higher current density than PNMSS and Pd catalysts. It was proved that PNMSS incorporation improves the kinetics of alcohol electrooxidation on Pd particles. The various data such as: turnover number, turnover frequency, reaction order, activation energy, electron transfer and diffusion coefficients were calculated for electrooxidation both alcohols. As well as, the methanol and ethanol adsorption on the Pd-PNMSS surface was analyzed and the experimental data were fitted to Temkin isotherm via novel method to evaluate the analyte adsorption on the surface of electrocatalyst. Graphical abstract Unlabelled Image [ABSTRACT FROM AUTHOR]

Abstract In this work, a new approach for the determination of the veterinary drug nitroxinil is presented, and its electrochemical behavior is investigated as well as voltammetric determination based on its oxidation signal is proposed. A glassy carbon electrode (GCE) was used as an electrochemical sensor for the determination of this compound, and a square–wave voltammetric (SWV) technique with the optimized parameters was applied for the quantification of nitroxinil. The effect of the supporting electrolytes, such as Britton–Robinson buffer solution (BRBS), citrate buffer solutions (CBS), and hydrochloric acid–potassium chloride buffer solutions (HCl–KClBS), on the SWV determinations of nitroxinil was investigated, and the experiments showed that the supporting electrolyte has a significant effect on the nitroxinil determination. The highest analytical SWV response of nitroxinil was obtained in acidic medium of the investigated supporting electrolytes, i.e. in the BRBS at pH 2.0, the CBS at pH 2.0, and the HCl–KClBS at pH 1.8. The corresponding current at ca. +1.3 V vs. Ag/AgCl/3 mol L−1 KCl reference electrode increased linearly with the concentration of nitroxinil within two linear dynamic ranges (LDR) in each supporting electrolyte solution. The lowest limit of detection (LOD) and quantification (LOQ) for nitroxinil were achieved in the BRBS at pH 2.0 (LOD = 0.28 μmol L−1 and LOQ = 0.93 μmol L−1). In addition, the analytical parameters obtained from calibration curves indicated the best sensitivity in the BRBS at pH 2.0 (0.124 μA L μmol−1). Cyclic voltammetric (CV) experiments showed that the electrode reaction of nitroxinil is irreversible (oxidation peak at ca. +1.3 V) and diffusion–controlled in each supporting electrolyte solution. Highlights • A new approach for the voltammetric determination of nitroxinil is presented. • SWV determination of nitroxinil based on its oxidation signal is proposed. • Significant effect of supporting electrolyte on SWV determination was observed. • Two linear dynamic ranges were achieved in each supporting electrolyte. • The lowest LOD and the best sensitivity were obtained in BRBS, pH 2.0. [ABSTRACT FROM AUTHOR]

The anodic oxidation of serine anion on smooth (Pt) and platinized (Pt(Pt)) platinum electrodes is studied by the methods of cyclic and linear voltammetry, rotating disk electrode, coulometry, and reflectance IR spectroscopy. On both electrodes, the potential regions of electrochemical transformation of this amino acid are determined. It is shown that electrooxidation of serine proceeds with abstraction of 4 and 2 electrons on Pt and Pt(Pt) electrodes, respectively. It is found that the anodic oxidation of serine anions proceeds from the adsorbed state; a possible kinetic scheme of this process is proposed. [ABSTRACT FROM AUTHOR]

• A cocatalyst loading strategy is proposed for wastewater electrochemical treatment. • The cocatalyst NiOOH accelerates the charge transfer, thus promoting water oxidation. • The increased reactive oxygen species promote the electrooxidation of organics. • The electrode shows great promise for pharmaceutical wastewater treatment. Acetaminophen (APAP), a common pharmaceutical and personal care product, is highly toxic and resistant to conventional wastewater treatment. Electrochemical oxidation is a promising technique for removing pharmaceuticals and personal care products (PPCPs), and the Ti-doped α -Fe 2 O 3 electrode is a low-cost alternative to noble-metal electrocatalysts. Herein, we present a novel cocatalyst loading strategy to enhance the electrocatalytic ability of the electrodes by loading a cocatalyst, NiOOH, by electrodeposition. The cocatalyst leads to a higher potential drop (97.7%) on the Helmholtz layer than the bare one (80.5%) and accelerates the charge transfer by ten. The increased production of reactive oxygen species during water activation further facilitates the electrooxidation of APAP, resulting in a threefold increase in removal rate and a twofold increase in Faraday efficiency. Additionally, the obtained NiOOH/Ti-Fe 2 O 3 electrode shows excellent ability (100% APAP removal in 2 h) and stability (removal efficiency greater than 94% after ten cycles) for pharmaceutical wastewater treatment containing APAP. These findings provide a novel and generalized strategy for enhancing the electrocatalytic ability of Ti-doped α -Fe 2 O 3 electrodes and offer valuable guidelines for exploring efficient and economic electrocatalysts for refractory wastewater treatment. [ABSTRACT FROM AUTHOR]

A novel modified electrode was fabricated by a mixed-valent nickel hexacyanoferrate (NiHCF) and poly 1,5-diaminonaphthalene (PDAN) hybrid at glassy carbon (GC) electrode. The obtained NiHCF/PDAN/GC modified electrode was characterized using cyclic voltammetry (CV) technique and scanning electron microscope (SEM). This electrode showed excellent catalytic properties toward the electrooxidation of ascorbic acid (A.A), dopamine (D.A) and uric acid (U.A) in 0.1 M NaCl solution using CV and square wave voltammetry (SWV) techniques. The NiHCF/PDAN/GC modified electrode exhibits high sensitivity, selectivity and stability making it a suitable sensor for the simultaneous detection of A.A, U.A and D.A in single and ternary mixture solutions. Different analytical parameters such as low detection limit (LOD), low quantification limit, correlation coefficient ( R) and linear dynamic range were reported and discussed. The NiHCF/PDAN/GC modified electrode exhibits linear responses to A.A, D.A and U.A in the range 600-1000, 600-1000 and 600-1000 µM, respectively. The LOD for A.A, D.A and U.A were 0.036, 0.034 and 0.037 µM, respectively. The analytical behavior of this sensor had been evaluated for the detection of A.A and U.A in human serum and urine samples with satisfactory results. [ABSTRACT FROM AUTHOR]

Zinc nitroprusside (ZnNP) nanoparticles were fabricated at the surface of zinc powder-doped carbon ceramic electrode (CCE) by a chemical derivatization process. This modified electrode was characterized by scanning electron microscopy, atomic force microscopy and cyclic voltammetry techniques. The charge transfer rate constant ( k ) and charge transfer coefficient ( α) were calculated for the electron exchange reaction of the ZnNP thin film. The ZnNP nanoparticle-modified CCE (ZnNP|CCE) showed good electrocatalytic activity toward hydrazine oxidation. The limit of detection (S/N = 3) and sensitivity were found to be 0.16 µM and 0.21 µA/µM, respectively. The mechanism of hydrazine electrooxidation at the electrode surface was studied. Finally, the ZnNP|CCE was successfully used for the determination of trace amount of hydrazine in different spiked and real samples. [ABSTRACT FROM AUTHOR]

A novel voltammetric assay for the simultaneous determination of hydroquinone (HQ), catechol (CC) and resorcinol (RS) by using an electrochemically treated pencil graphite electrode modified with cobalt-phthalocyanine is described. Differential pulse voltammetric results showed three well-distinct oxidation peaks for HQ, CC and RS at 102 mV, 203 mV and 591 mV (vs. Ag/AgCl), respectively. Thus, the method can be applied to direct simultaneous determination without previous separation. The detection limits are 3.38 × 10 mol L for HQ, 3.40 × 10 mol L for CC and 7.23 × 10 mol L for RS. The method was successfully applied to the direct determination of dihydroxybenzene isomers in tea samples, and the results were compared with chromatographic data. [ABSTRACT FROM AUTHOR]

[Display omitted] • BDD, Ti/PbO 2 , and Ti/Pt electrodes were compared for EOx system. • The PCT degradation efficiency for US, EOx and EOx-US were obtained as < 1%, 70.5 % and 92.4 %. • Effect of US frequency (100–600 kHz) and power (25–100 W) were investigated. • Best conditions were obtained with 200 kHz, 75 W with BDD electrode. In this work, paracetamol (PCT) containing synthetic wastewater was investigated by electrooxidation (EOx) and ultrasound (US) hybrid process. Firstly, anode type (BDD, Ti/PbO 2 , and Ti/Pt) and process types including ultrasound (US), electro-oxidation (EOx) and hybrid process (EOx-US) were investigated for the degradation of paracetamol (PCT). The PCT degradation efficiency for US, EOx and EOx-US using BDD anode were obtained as < 1%, 70.5 % and 92.4 %, respectively. US-EOx process was found the most effective process in PCT and TOC degradation by using BDD electrodes because of the synergistic effect between sonolysis and electrocatalysis. Then, the effects of operation parameters such as US frequency (100–600 kHz) and US power (25–100 W), conductivity (3500–5500 μS cm−1), current density (50–500 A m−2), initial PCT concentration (20–500 ppm) and pH (2–8) on the PCT degradation with time dependency by EOx-US hybrid process were investigated. The optimum conditions were found as 200 kHz, 75 W, pH 2, 4500 μS cm−1, 100 A m−2, and 100 ppm when the PCT and TOC degradation efficiencies and the operating circumstances were considered. Additionally, the toxicity of the treated wastewater was examined, and it was discovered that the byproducts' formation caused the inhibition ratio to rise, making the solution more toxic than the initial solution. Frequency effect has not been studied much in hybrid processes in the literature, and it makes this study in this sense valuable. [ABSTRACT FROM AUTHOR]

The palladium species were deposited on the multi-walled carbon nanotubes dispersed in nafion membrane by pulsed electrodeposition technique. The resulting modified electrode was defined CNT-Pd. The Pd electrodeposition was carried out in 50 mM H 2 SO 4 solution containing 4.0 mM Pd(NO 3 ) 2 using a double pulse sequence of potentials: E 1 = −0.4 V vs SCE (t 1 = 0.03 s) and E 2 = 0.4 V vs SCE (t 2 = 3 s). SEM analysis showed a well-efficient distribution of Pd nanoparticles dispersed along the nanotubes randomly oriented in the nafion matrix. A surface loading of electrodeposited Pd species comprised between 2.0 nmol and 2.5 nmol was generally observed. The prepared electrode is useful to catalyze the electrooxidation of hydrazine and propranolol. The electroanalytical properties of the electrode were evaluated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Under optimized DPV conditions, the CNT-Pd electrode exhibits interesting analytical performance in terms of linear range of concentrations, low detection limits (i.e., 8 μM and 2 μM for hydrazine and propranolol, respectively) and good temporal stability of the responses (i.e., 4%–5%). [ABSTRACT FROM AUTHOR]

This work presents a detailed study of silver electrode activity toward glycerol electrooxidation reaction (GEOR) in alkaline media. The effect of pH and glycerol concentration on GEOR kinetics was investigated by cyclic voltammetry technique. It has been found that hydroxyl ions concentration leads to an oxidation current increase, which indicates that glyceroxide could be the active species for GEOR. The presence of silver oxide layer inhibits the glycerol oxidation process, reaching maximum current densities of 2.3 mA cm − 2 (1 M glycerol in 1 M NaOH). HPLC studies indicate that formic, glycolic and glyceric acids are the main products. [ABSTRACT FROM AUTHOR]

The production, characterization, and application of boron doped diamond grown on titanium substrates (BDD/Ti) are proposed in a systematic study taking into account the optimized parameters to produce high quality electrodes in a suitable doping level applied in the electrooxidation of the Brilliant Green dye. The process efficiency was analyzed as a function of the BDD doping levels as well as their sp 2 hybridization content in the film structures. A large set of sixteen BDD/Ti samples were applied in the electrooxidation experiments at constant current density of 100 mA cm − 2 , using 100 mg L − 1 of the Brilliant Green dye in K 2 SO 4 0.1 mol L − 1 solution for 300 min. The electrooxidation efficiency in the whole sample set was analyzed by UV/VIS Spectrophotometry and by Total Organic Carbon techniques considering the influence of the electrode characteristics in the degradation process. The results showed that all the electrodes were efficient in the solution discolorization and in the organic compound mineralization. However, BDD/Ti electrode with the lowest sp 2 content associated to the intermediate doping level presented the best results. A mechanist route for the dye degradation was proposed, using the normalized parameters for the best BDD electrode, from high performance liquid chromatography — mass spectroscopy analyses. [ABSTRACT FROM AUTHOR]

Cysteine is an important organic molecule in electrochemistry. It can be used as an electrode modifier and is responsible for the adsorption of many proteins. Although it is a well-studied molecule, cysteine's behavior and mechanism of oxidation remain unclear in the literature. The current study is focused on investigating the electrochemical behavior of this molecule in acidic media on a Pt electrode using electrochemical techniques and Raman spectroscopy. The adsorption process appears to be similar to the one proposed in the literature (i.e. a monoelectronic oxidation). The adsorbed species appear to strongly interact with one another, and therefore, this adsorption is more suitably described by a Temkin model. The Raman spectra indicate that the adsorption is most likely due to the thiol group on the side chain of the amino acid. In addition, the carboxyl group interacts more with the electrode than the amino group. The oxidation of these adsorbed species is achieved by 5 electrons, and supports the formation of the previously proposed species. Other experiments suggest that the adsorption does not occur in a single step. Using voltammetry and pseudocapacitance adsorption model interpretations, a monoelectronic rate-limiting step was detected, which indicates the existence of a more complex mechanism for the oxidation of cysteine on platinum. [ABSTRACT FROM AUTHOR]

The activation of peroxymonosulfate (PMS) by redox-active quinones-like compounds has been proposed as a viable approach for water decontamination, which is, however, limited by the secondary pollution associated with ex situ addition of organic activators. Herein, we demonstrated a novel in situ produced quinone intermediates-mediated PMS activation technique for organic decontamination. The parent pollutant (e.g., aniline) was first transformed to quinones-like intermediates by electrooxidation, followed by nucleophilic addition with PMS to initiate the production of singlet oxygen (1O 2), which significantly improved the pollutant degradation and mineralization kinetics when compared to conventional electrooxidation technologies. Advanced characterizations and experimental evidence showed that the proposed method could significantly reduce electrode fouling, which is a common limitation of electrooxidation processes. The system could function efficiently across a pH range of 3–11. Experiments with genuine aniline-contaminated dyeing effluent confirmed the excellent system efficacy. [Display omitted] • An electrogenerated quinone intermediate-mediated PMS activation system was proposed. • The system enabled simultaneous water purification and electrode antifouling. • Theoretical calculations and experimental evidence collectively verified the key role of 1O 2. • Excellent system efficacy could be obtained across a wide pH range. [ABSTRACT FROM AUTHOR]

The purpose of this paper is the investigation of the capability of electrochemical methods, such as electrocoagulation, electrooxidation and electro-Fenton for decolorization and degradation of synthetic aqueous solutions and actual dye house effluents containing nylanthrene red reactive dye. All electrochemical experiments with the synthetic dye solutions were conducted in electrochemical cell of volume 500 ml containing 200 mL of dye solution at concentration 50 mg/L and interelectrode distance of 1 cm. The three different electrochemical processes were analyzed, and their removal efficiencies were measured and evaluated. In addition, a flow diagram is designed for a continuously operated electrochemical process for remediation of synthetic and actual dye house effluents laden with nylanthrene dye. In the electrocoagulation process with aluminum electrodes, the colored aqueous dye solution was treated at the applied current densities of 5, 10 and 15 mA/cm2 and was quantitatively decolorized in 11, 9 and less than 6 minutes of electroprocessing time respectively. The electrooxidation process conducted with Ti/Pt and boron doped diamond (BDD) electrodes, at the applied current density of 10 mA/cm2 led to the quantitative decolorization and destruction of the dye in 25 and 15 min respectively. In the electro-Fenton process with iron electrodes, supply of added hydrogen peroxide and applied current density of 10 mA/cm2 complete decolorization and degradation of the nylanthrene red dye occurred in 6 min. The actual polyamide textile dyeing effluent of same volume 200 mL with initial turbidity of 114 NTU and COD of 1755 mg/L was treated by electrocoagulation at the same applied current density of 10 mA/cm2. The turbidity was quantitatively eliminated in only 10 min, while COD was reduced by 74.5 % in 40 minutes of electrolysis time. [ABSTRACT FROM AUTHOR]

Palladium nanoparticles/nanostructured carbon black composite (PdNPs/NCB), supported on the carbon–ceramic electrode (CCE), has been prepared by a chemical reduction method using sodium borohydride as a reducing agent. The synthesized composite was characterized by scanning electron microscopy, high resolution transmission electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction and electrochemical methods to delineate its surface morphology, nanostructure properties, composition, crystal phases and electrochemical properties. The obtained modified electrode, PdNPs/NCB/CCE, was used as an efficient electrocatalyst for the oxidation of formic acid. Electrochemical techniques including cyclic voltammetry and chronoamperometry were applied for electrocatalytic investigations and it was found that the PdNPs/NCB/CCE was catalytically more active than the Pd nanoparticles supported on the CCE without NCB (PdNPs/CCE). The effect of some experimental factors was studied and optimum conditions were suggested. The obtained results show that the PdNPs/NCB/CCE has satisfactory stability and reproducibility for electrooxidation of formic acid when stored in ambient conditions and improved electrocatalytic activity in continued cycling which make it more attractive for formic acid fuel cell applications. [ABSTRACT FROM AUTHOR]

The pathway of phenol degradation by electrochemical oxidation was studied in an aqueous solution using AISI 304 stainless steel electrodes. The increase in pH due to the generation of NaOH in the aqueous solution was found to be critical for the proposed degradation mechanism since the deprotonation of phenol occurs at pH 10. The phenoxy anion produced as a result of deprotonation is resonance stabilized. The Fe ions (Lewis catalyst) released from the stainless steel anode and the chlorine gas formed by the electrolysis of sodium chloride are found to be responsible for the chlorination of phenoxy anion ensuing the formation of 2-, 4-, 6-substituted chlorophenols. The mechanism was proposed for elucidating the possible degradation pathway of phenol under the above specified conditions. [ABSTRACT FROM AUTHOR]

A series of diphosphonate-bridged dipalladacycles [(phpy)Pd(EtO)P(O)], [(bhq)Pd(EtO)P(O)], [(phpz)Pd(EtO)P(O)] (phpy=2-phenylpyridine, bhq=benzo[h]quinoline, phpz=1-phenylpyrazole), which are known to be involved in catalytic C-H phosphonation reactions, was prepared and characterized by NMR spectroscopy and cyclic voltammetry in acetonitrile solutions and in carbon paste electrode. Diphosphonate dipalladacycles are oxidized irreversibly at more positive potentials as distinguished from related acetate palladacycles. Electrochemical preparative oxidations carried out under mild conditions without any specially added oxidants quantitatively afforded corresponding arylphosphonates. For complete conversion of dipalladacycles into arylphosphonates, four electrons per each palladium atom are required, that probably indicates a mechanism involving Pd(IV)/Pd(II) redox couple. [ABSTRACT FROM AUTHOR]

BACKGROUND The decomposition of carbamazepine ( CBZ) in synthetic solution and in municipal effluent was investigated using a sono-electrochemical reactor. Sono-electrolysis was conducted using two concentrical electrodes installed in a cylindrical reactor containing a ceramic transducer. RESULTS CBZ concentration ( C0=10 mg L−1) optimally diminished up to 90% by applying a current intensity of 4.86 A for 177 min and by imposing an ultrasound power of 38.29 W. The optimal conditions were subsequently applied for tertiary treatment of municipal wastewater effluent contaminated with 10 µg CBZ L−1. The reported removal efficiencies of CBZ, TOC, COD and colour were 93%, 60%, 93% and 86%, respectively. Likewise, the toxicity was completely removed (bacterium Vibrio fisheri) from the municipal wastewater effluent (>96%). CONCLUSIONS The advantages of coupling ultrasonication and electrooxidation ( US-EO) treatment for CBZ removal were demonstrated. An experimental design methodology based on response surface methodology was applied to determine the optimal experimental conditions in terms of cost/effectiveness of removal. © 2014 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

[Display omitted] • 2D Materials increased the electrocatalytic activity of graphene sponge electrodes. • hBN-doped electrode enhanced the π-π interactions of less polar contaminants. • Borophene-doped electrode enhanced the removal of polar organic contaminants. • Electrogenerated 1O 2 enhanced the oxidation of pollutants with electron-rich moieties. • Role of surface-bound and dissolved HO · was elucidated in scavenging experiments. Low-cost graphene sponge electrodes were functionalized with two-dimensional (2D) materials, i.e., borophene and hexagonal boron nitride (hBN), using a one-step, hydrothermal self-assembly method. Borophene and hBN-modified graphene sponge anode and N-doped graphene sponge cathode were employed for electrochemical degradation of model persistent contaminants of emerging concern in one-pass, flow through mode, and using low-conductivity supporting electrolyte. Functionalization of the reduced graphene oxide (RGO) coating with 2D materials led to specific modifications in the electrodés electrocatalytic performance and interactions with the target contaminants. For instance, addition of hBN promoted the adsorption of more hydrophobic organic contaminants via van der Waals and π-π interactions. Functionalization of the graphene sponge anode with borophene enhanced the generation of oxidant species such as H 2 O 2 and O 3 and yielded an order of magnitude higher concentration of hydroxyl radicals (HO ·) compared with the non-functionalized graphene sponge anode, thus enhancing the removal of target contaminants. Experiments conducted with the selective radical scavengers indicated the key role of surface-bound hydroxyl radicals (HO · ads) and singlet oxygen (1O 2) in electrochemical degradation. The study demonstrates that functionalization of graphene sponge electrodes with 2D materials can enhance their electrocatalytic activity and modulate the interaction with specific organic contaminants, thus opening new possibilities for designing electrodes tailored to remove specific groups of pollutants. [ABSTRACT FROM AUTHOR]

Electrooxidation of 2,4,6-tribromophenol on platinum gauze electrode in 90 % (v/v) alcohol (methanol, ethanol, propan-1-ol, butan-1-ol) was studied. Products were investigated by gas chromatography/mass spectrometry. Structures of several different types of monomeric as well as dimeric alkoxy derivatives have been suggested according to mass spectra of the detected products. Series of 2,6-dibromo-4-alkoxyphenols, 2,4,6-tribromo-6-alkoxycyclohexa-2,4-dien-1-ones and 2,6-dibromo-6-alkoxycyclohex-2-ene-1,4-diones were found. By analogy to identified monomeric alkoxy derivatives, a serie of dimeric 2,6-dibromo-4-(2,6-dibromo-4-alkoxyphenoxy)phenols was suggested and identified in respective chromatograms as well. [ABSTRACT FROM AUTHOR]

A small quantity of palladium metal (Pd, 5 wt%) nanoparticles supported by a polypyrrole/manganese oxyhydroxide (PPy/MOH) nanocomposite was developed and investigated as an electrocatalyst for the alcohol electrooxidation reaction in alkaline media. In voltammetric studies, the PPy/MOH/Pd catalyst, compared to C/Pd, exhibited improved electrocatalytic activity for methanol electrooxidation. The peak current density ratios ( j/ j) for the C/Pd and PPy/MOH/Pd nanocomposite electrodes were 0.67 and 2.43, respectively, indicating that the PPy/MOH/Pd nanocomposite electrode was much more resistant to catalytic poisoning. The electrooxidation of ethylene glycol (EG), glycerol, and xylitol was also tested using the PPy/MOH/Pd nanocomposite electrode. Among these alcohol electrooxidations, that of EG exhibited the maximum power density of 430 mA cm. The intermediates formed during the electrooxidation reactions were removed by increasing the upper sweep potential from +0.2 to +1.0 V. The catalytic performance of the PPy/MOH nanocomposite is discussed in detail. The study results demonstrate that PPy/MOH acts as a superior catalytic supporting material for alcohol electrooxidation reactions in alkaline media. [ABSTRACT FROM AUTHOR]