Electrochemical Reduction Process Research Articles

Application of nickel foam as an effective electrode for the electrochemical treatment of liquid hazardous wastes of COD analysis containing mercury, silver, and chromium (VI)

One of the heavy metal-rich liquid wastes produced in the environmental laboratories is related to COD tests. This waste contains Hg 2 + , Ag + , and Cr 6＋ , and it is; therefore, hazardous to the environment, and it should be treated before being discharged. For this purpose, an electro-amalgamation process was used to remove Hg 2 + , Ag + , and Cr 6＋ from this waste simultaneously. A graphite sheet was used as the anode and the nickel foam as the cathode. Three different electrode arrangements were investigated to choose the best electrode arrangement for designing the batch-scale experiments. The monopolar-paralleled arrangement was selected due to low remaining concentrations and energy consumption. The effects of the initial total heavy metals concentration, current intensity, and operating time on the removal efficiency were studied. For optimizing the process, the response surface methodology with the Box–Behnken method was utilized. The results indicated that the maximum reduction efficiency was achieved under the optimum operating conditions at a current intensity of 0.94 A, the total heavy metals concentration of 1000 mg L-1, and an operating time of 29 min. Also, some experiments were carried out on two different forms of nickel electrode, foam, and plate. Moreover, the results showed that the removal rates were decreased by using the plate electrode and also the reduced metals released in solution as ultrafine particles (57.8 nm). Consequently, the results indicated that the application of nickel foam in an electrochemical reduction process for treating the COD laboratory waste water was successful. • Electro-amalgamation process was used for Ag + , Hg 2+ , and Cr 6+ reduction. • Nickel foam electrode was proposed as the cathode in an electrochemical cell. • Ni foam showed better metal removal performance compared to Ni plate. • Removal efficiencies were above 99.8% under the optimum condition. • Amalgam particles adhere to Ni foam, but Ni plate releases them in the solution.

SYNTHESIS OF 3,3´-(1,4-PHENYLENE)BIS(1-(4-R-PHENYL)-5-PHENYL-5,6-DIHYDRO-1,2,4,5-TETRAZINIUM) PERCHLORATES

A series of 3,3'-(1,4-phenylene)bis(1-4-R-phenyl)-5-phenyl-5,6-dihydro-1,2,4,5-tetrazinium) perchlorates containing hydrogen, methyl, bromio, methoxy, acetyl and nitro groups (R = H, Me, Br, OMe, COMe, NO2) as substituents were obtained as a result of a three-stage synthesis from terephthalic aldehyde. The synthesis of tetrazinium salts was carried out by reaction of the corresponding formazans with formalin in the presence of perchloric acid in dioxane. Formazans were obtained by reaction of terephthalic aldehyde phenylhydrazone with arenediazonium tosylates in a mixture of DMF and pyridine. The usage of arenediazonium tosylates made it possible to extremely simplify the segregation and purification of formazans. The phenylhydrazone was synthesized according to the standard procedure from terephthalic aldehyde and phenylhydrazine/hydrochloric acid in aqueous dioxane. The formazans and tetrazinium perchlorates were isolated in individual state and characterized by elemental analysis, IR, UV, 1H and 13C NMR spectroscopy data. The process of electrochemical reduction of tetrazinium perchlorates was studied using the method of cyclic voltammetry (CV). Thus, the CV curves of all salts in the cathode region contain two one-electron reduction peaks, which are related to the sequential formation of a radical cation and a biradical. It was found that electron-donating substituents (R = Me, OMe) in the aromatic ring at position 1 facilitate the reduction of tetrazinium cation, while electron-withdrawing substituents (R = COMe, NO2) hinder this process. On this basis, it was suggested that the corresponding bis-verdazyl radicals should be easily formed in the presence of electron-donating substituents in the aromatic ring at position 1. Thus, 3,3´-(1,4-phenylene)bis(1-(4-R-phenyl)-5-phenyl-5,6-dihydro-1,2,4,5-tetrazinium-1) perchlorates are perspective precursors of symmetric biradical systems based on verdazyl radicals.

Investigation on the electrochemical degradation and mechanism of p-nitrochlorobenzene in aprotic media containing CO2

The electrochemical behavior of p-nitrochlorobenzene (PNCB) in the aprotic solvent was investigated by cyclic voltammetry, bulk electrolysis, and in situ FT-IR spectroelectrochemistry. In the absence of CO2, the electrochemical behavior of PNCB is reversibly one-step single-electron transfer during the scan between -0.4 and -1.4 V, but with adding CO2, it is transformed into completely irreversible 4-electrons transfer process. The only electrolysis product indicating high selectivity in the presence of CO2 is confirmed as 4,4′-dichloroazobenzene (DAB) by X-ray single crystal diffraction, 13C-NMR, 1H-NMR and FTIR. In the absence of proton donor, the electrochemical degradation of PNCB at low potential is achieved, and CO2 is electrochemically converted to CO32− simultaneously. Based on cyclic voltabsorptometry (CVA) and derivative cyclic voltabsorptometry (DCVA) techniques, double potential step time-resolved IR scanning electrochemical technique (DPS TR IRSEC) was developed to illustrate the adsorption behavior of CO2 in the electrochemical reduction process. Therefore, a new electrochemical mechanism of PNCB in the presence of CO2 has been proposed based on the above results, which will be beneficial for theoretical research. The electrochemical degradation method is a promising and green chemical process for the degradation of chloronitrobenzene compounds (CNBs).

Voltammetric Determination of Amoxicillin Using a Reduced Graphite Oxide Nanosheet Electrode.

A reduced graphite oxide nanosheet electrode (RGOnS) was prepared as a sensor for amoxicillin (AMX) detection, an antibiotic commonly used in the livestock farm, by the square-wave adsorptive stripping voltammetry technique. Graphite oxide with nanosheet shape was produced from a graphite electrode by a chronoamperometry process at 5 V and then an electrochemical reduction process was carried out to form RGOnS with restored long-range conjugated networks and better conductivity. The electrodes were characterized by SEM, EDX, and FTIR spectroscopy. The RGOnS electrode prepared at an optimal reduction potential of −1 V for 120 s exhibits a larger electrochemical active surface area, and the obtained oxidation signal of AMX is approximately ten times higher than that of the pristine graphite electrode. The analytical conditions such as the pH of electrolyte and accumulation time were optimized. The calibration curve built under the optimal conditions provided a good linear relationship in the range of AMX concentration from 0.5–80 µM with the correlation coefficient of 0.9992. The limit of detection was calculated as 0.193 µM. Satisfactory results are obtained from the detection of the AMX in different samples using the prepared electrode.

Isothermal and cyclic corrosion behaviour of Ni-based alloys in an electrochemical reduction process

ABSTRACT In this study, the isothermal and cyclic corrosion behaviours of Haynes 282 and Haynes 214 in a lithium molten salt were investigated at 650°C for 168 h and 7 thermal cycles, respectively; this was achieved by measuring the mass changes, surface and cross-sectional morphologies with their elemental distributions, and compositional changes in the subscale, substrate and spalled oxide scale. The weight loss of Haynes 282 comprising an external corrosion layer was approximately four times lower than that of Haynes 214 with a spalled external corrosion layer, depending on the effects of their alloying elements and the preservation, spallation and dissolution of the corrosion layer. After 168 h and 7 thermal cycles, corrosion products of Haynes 282 were Cr2O3 and CoCr2O4 and those of Haynes 214 were Cr2O3, LiFeO2 and FeCr2O4. In addition, the internal corrosion layers of Haynes 282 and Haynes 214 exhibited localised and uniform corrosion behaviours, respectively.

Cu-doped zeolite imidazole framework (ZIF-8) for effective electrocatalytic CO2 reduction

Electrochemical CO2 reduction is a beneficial process for converting CO2 into useful hydrocarbons, chemicals, and fuels. Many catalysts have been tested before for CO2 electroreduction however achieving good stability, activity, and selectivity of the required product remains a challenge. In this work, we demonstrate the solvothermal synthesis and characterization of Cu-doped ZIF-8 catalysts with varying Cu+2 doping and applying them in the electrochemical CO2 reduction process. Cu30%ZIF-8 showed the highest current density of -40 mA cm−2 at -2.1 V vs. Ag/AgCl and better selectivity for CH4 and CO compared to previous works on Cu electrodes. This high activity of the Cu-doped ZIF-8 catalyst is because of the crystalline nanostructure of our catalyst with sufficient copper active metal sites and N-content, micro-meso dual-porosity nature of the structure, and broad surface area of zeolite imidazole framework to work on.

Charge induced crystal distortion and morphology remodeling: Formation of Mn-CoP nanowire @ Mn-CoOOH nanosheet electrocatalyst with rich edge dislocation defects

Cobalt phosphide (CoP), as a potential electrocatalyst candidate for hydrogen evolution reaction (HER) as well as oxygen evolution reaction (OER), attracts rising interest. However, its intrinsic catalytic activity is still not comparable with those noble-metal-based ones while its surface species is easily oxidized to amorphous phosphate in air. Herein, abundant edge dislocations were successfully generated on the Mn doped CoP material with an electrochemical reduction process, leading to the formation of P vacancies, and lattice distortion, resulting in the modification of the electronic structure and the improvement of the whole catalysis performance. Based on the density functional theory (DFT) calculations, it is found that the P vacancies on the edge dislocation could change the Gibbs free energy, enhancing the intrinsic catalytic activity of Mn-CoP. Furthermore, the surface of Mn-CoP was in-situ converted to Mn-CoOOH with a nanosheet structure by an electrochemical oxidization, resulting in a Mn-CoP nanowire @ Mn-CoOOH nanosheet core@shell structure. The formed Mn-CoOOH nanosheet shell not only effectively prevented the continuous oxidation of Mn-CoP but also provided additional catalytic active sites for OER. Besides, the Mn-CoOOH was reduced to Mn-Co(OH)2 as the real active species during HER, which effectively promoted the decompsition of water to proton. As a result, such a defect-activated Mn-CoP nanowire @ Mn-CoOOH nanosheet electrocatalyst needed low overpotentials of 110 and 251 mV to support a current density of 10 mA cm−2 for HER and OER with high stability, respectively.

Direct Electrochemical Reduction of Natural Ilmenite into Ferrotitanium Alloys in a Molten Salt of LiCl-Li2O

This paper reports a promising method to decrease the operating temperature during electrolysis of natural ilmenite to produce a porous and laminar flake-type intermetallic ferrotitanium (FexTi, x = 1, 2) with a thickness of less than 1 μm by choosing a LiCl-Li2O electrolyte with a lower operating temperature (625 °C) under an inert atmosphere. Results indicate that the Li2O content in the electrolyte has a key effect on the phase transformation of natural ilmenite occurring in the electrochemical reduction process. Full conversion of natural ilmenite into ferrotitanium products can be achieved when the Li2O amount in the electrolyte and the cell voltage are approximately 1 wt.% and −2.5 V, respectively. In addition, the electrochemical reduction mechanism of natural ilmenite is proposed and discussed based on our experimental results and thermodynamic analysis.

A 4E analysis of renewable formic acid synthesis from the electrochemical reduction of carbon dioxide and water: studying impacts of the anolyte material on the performance of the process

Carbon dioxide utilization (CDU) is one of the most critical approaches in climate change control. CDU’s future depends on the future demand for carbon-derived products; among them, formic acid is an excellent candidate due to its distinctive characteristics as a hydrogen carrier in liquid form. It is non-toxic that can be used in hydrogen fuel cells, and its significant potential in the heavy oil and biofuel refining process as a hydrogen-carrier substance. This research aims to use Energy, Exergy, Exergoeconomic, and exergoenvironmental (4E) analysis to evaluate the impact of anolyte material on the efficiency of the electrochemical reduction process to synthesis formic acid (in the term of six new anolyte materials). Results show that the second scenario (IrO2 single circulation mode) is the best option for the power plant. Implementing this CDU system reduces the carbon capture of about 75.20 kg/s or about 89% of the power plant’s overall carbon emission. This process’s energy penalty can be adequately provided by the PV, which causes greater exergy efficiency and decreases the power plant’s energy performance rate. Moreover, the use of IrO2 anolyte is decreased the exergy rate cost and the flow rate cost to the 0.21 $/kWh and 2.280×10-2 $/s. The CDU’s investment cost using the DSA/O2 anolyte is 28% decreased compared to the KOH anolyte and reached 7.2 million USD for the CO2 utilization plant.

Investigation of electrochemical reduction effects on graphene oxide powders for high-performance supercapacitors

This study aims to investigate the electrochemical reduction effects on graphene oxide (GO) powders with various bias voltages and treatment times. Phosphate-buffered saline solution was used as the electrolyte in the electrochemical reduction process. The experimental results showed that the GO powders were reduced to produce the best reduced GO (rGO) powders as using a bias of −17.5 V for 2 h. After the analysis of Raman spectra for GO and rGO powders, the intensity ratios of the D and G bands increased from 0.85 to 1.08, respectively. The carbon to oxygen ratios increased from 0.4 to 1.79 measured by an X-ray photoelectron spectroscopy. Moreover, the electrical conductivity obviously increased from 7.92 × 10−4 to 4.16 × 10−1 S/cm. Fourier transform infrared spectra revealed the disappearance of oxygen-containing functional groups in rGO powders. According to the cyclic voltammetry analysis, the specific capacitance of the rGO powders could reach 183 F/g at the scan rate of 100 mV/S in 1 M KCl electrolyte solution. This specific capacitance value was 16 times higher than that obtained with the GO powders. The results indicated that the produced high-quality rGO powders could be used for high-performance supercapacitors.

Efficient Electrocatalytic CO2 Reduction to C2+ Alcohols at Defect-Site-Rich Cu Surface

Summary Electrochemical CO2 reduction is a promising approach for upgrading excessive CO2 into value-added chemicals, while the exquisite control of the catalyst atomic structures to obtain high C2+ alcohol selectivity has remained challenging due to the intrinsically favored ethylene pathways at Cu surface. Herein, we demonstrate a rational strategy to achieve ∼70% faradaic efficiency toward C2+ alcohols. We utilized a CO-rich environment to construct Cu catalysts with stepped sites that enabled high surface coverages of ∗CO intermediates and the bridge-bound ∗CO adsorption, which allowed to trigger CO2 reduction pathways toward the formation alcohols. Using this defect-site-rich Cu catalyst, we achieved C2+ alcohols with partial current densities of > 100 mA·cm−2 in both a flow-cell electrolyzer and a membrane electrode assembly (MEA) electrolyzer. A stable alcohol faradaic efficiency of ∼60% was also obtained, with ∼500 mg C2+ alcohol production per cm2 catalyst during a continuous 30-h operation.

Reduction of carbon dioxide (CO2) using ‘p’ & ‘d’ block electro-catalysts: A review

Carbon Dioxide pollution is the prime origin of climatic change, the rising of Earth’s surface temperature. A temperature analysis performed at NASA reported that Earth’s average temperature has increased by around 0.8 °C since 1880. From 1950–2004, CO2 emission from the burning of fossil fuels has increased by 79.39 %. India, the U.S., China, being the highest CO2 emitters of the world, are bearing an economic loss of $206 billion, $254 billion, and $243.6 billion, respectively. This depletion of fossil fuel reserves and the impacts of anthropogenic CO2 can be mitigated by electrochemically reducing CO2 to generate chemical feedstock and fuels. In this context, the present article discusses recent research progress in developing various catalysts among p and d-block elements to act as a cathodic working electrode with appropriate catholyte for electrochemical reduction of CO2. Further, it describes a promising mechanism to convert CO2 into other products via the electrochemical reduction process and reduction apparatus. The foremost aspect for considering p and d-block catalysts are screened alongside their methods/processes to prepare them as electrodes. Then the formation of various chemical compounds and their allied characteristics using novel catalysts are discussed.

In-Situ Soft X-Ray Spectromicroscopy Characterization of Electrochemical Processes

Soft X-ray Scanning Transmission X-ray microscopy (STXM) is a synchrotron-based technique which can provide both spectroscopic characterization (near edge X-ray absorption fine structure, NEXAFS) and chemically selective imaging with high spatial resolution (~30 nm). Recently, we have developed in situ flow electrochemical devices [1,2] which allow control of the electrochemical environment while conducting STXM measurements, thus providing a platform for in-situ studies of electrochemical oxidation and reduction processes. This presentation reports results of in situ flow electrochemical STXM studies on three different systems to demonstrate the present capabilities. First, the ability to rapidly exchange the electrolyte is demonstrated by a STXM Fe 2p and in situ electrochemical study of the ferro/ferricyanide solution redox system. Second Cu and Ag-doped Cu catalysts for CO2 electrochemical reduction (CO2R) were successfully prepared using in situ electrodeposition. Third, the electrolyte was changed from CuSO4 to NaHCO3 (as substrate for CO2R) and the cell was operated under electrochemical CO2 reduction conditions, while monitoring the changes to the Cu deposited layer at various potentials, including –0.5 V where CO2 reduction is expected [3]. The figure shows a cyclic voltammogram (CV) and color-coded Cu oxidation state maps which were derived from Cu 2p stacks measured under chronoamperometric conditions at the indicated potentials. These results demonstrate that in situ flow electrochemical STXM measurements can be performed in our device under varying electrochemical reaction conditions, enabling visualization of the morphology changes from selective energy imaging, and quantitative tracking of electrochemical transformations from spectromicroscopy. This system will be used for in situ studies of CO2 electrochemical reduction catalysis with the goal of obtaining mechanistic insights to guide the development of catalysts with improved efficiency and selectivity. In addition, the system will be used to study a variety of material science, chemistry and environmental science related questions associated with oxidation or reduction processes, such as mechanisms of extra-cellular electron transport in marine sediment microbial biofilms [4].This research is supported by NSERC (Canada). STXM measurements were performed at the ambient STXM facility at the Canadian Light Source, which is funded by the Canadian Foundation for Innovation.[1] V. Prabu et al., Rev. Sci. Inst. 89 (2018) 063702.[2] P. Ingino, et al., in preparation[3] L. Wang, D.C. Higgins, et al., Proc. Nat. Acad. Sci. (2020) 01821683. DOI: 10.1073/pnas.1821683117[4] M. Obst, et al., Microsc. Microanal. 24 (S-2) (2018) 502-504. Figure 1

Electrochemical Study of Bi2Se3 Single Crystals

Bi2Se3 single crystals have attracted the attention of an extensive research community because of their many attractive properties: as a model topological insulator (TI), a layered structure and a promising platform for surface catalysis studies. However, despite often being studied under ultrahigh vacuum, there are very few studies of either the surface chemistry at ambient pressure or their electrochemistry. We have already demonstrated the protection and in-situ imaging and modification of bismuth chalcogenide single crystals in an electrochemical environment1,2. The present work shows that different choices of chalcogenide (Se in place of Te) and electrolyte yield differences in the oxidative dissolution process. We also investigate how the charge transfer resistance changes during electrochemical oxidation and reduction processes. Oxidative dissolution significantly increases the Bi2Se3 charge transfer resistance, measured by electrochemical impedance spectroscopy (EIS) using the ferrocyanide/ferricyanide redox couple. The charge transfer resistance only partially recovers during subsequent electrochemical reduction. As a further step in the electrochemical modification of bismuth chalcogenides, we studied metal electrodeposition. For example, we imaged Bi electrodeposition on a bismuth selenide single crystal in-situ for the first time, showing that it gives rise to characteristic triangular structures with kink-free step edges, the motion of which can be followed during island growth. The deposition is also highly reversible.

Metal-Organic Frameworks as a Platform for CO2 Capture and Chemical Processes: Adsorption, Membrane Separation, Catalytic-Conversion, and Electrochemical Reduction of CO2

The continuous rise in the atmospheric concentration of carbon dioxide gas (CO2) is of significant global concern. Several methodologies and technologies are proposed and applied by the industries to mitigate the emissions of CO2 into the atmosphere. This review article offers a large number of studies that aim to capture, convert, or reduce CO2 by using a superb porous class of materials (metal-organic frameworks, MOFs), aiming to tackle this worldwide issue. MOFs possess several remarkable features ranging from high surface area and porosity to functionality and morphology. As a result of these unique features, MOFs were selected as the main class of porous material in this review article. MOFs act as an ideal candidate for the CO2 capture process. The main approaches for capturing CO2 are pre-combustion capture, post-combustion capture, and oxy-fuel combustion capture. The applications of MOFs in the carbon capture processes were extensively overviewed. In addition, the applications of MOFs in the adsorption, membrane separation, catalytic conversion, and electrochemical reduction processes of CO2 were also studied in order to provide new practical and efficient techniques for CO2 mitigation.

Hazardous wastes treatment technologies.

A review of the literature published in 2019 on topics related to hazardous waste management in water, soils, sediments, and air. The review covered treatment technologies applying physical, chemical, and biological principles for the remediation of contaminated water, soils, sediments, and air. PRACTICAL POINTS: This report provides a review of technologies for the management of waters, wastewaters, air, sediments, and soils contaminated by various hazardous chemicals including inorganic (e.g., oxyanions, salts, and heavy metals), organic (e.g., halogenated, pharmaceuticals and personal care products, pesticides, and persistent organic chemicals) in three scientific areas of physical, chemical, and biological methods. Physical methods for the management of hazardous wastes including general adsorption, sand filtration, coagulation/flocculation, electrodialysis, electrokinetics, electro-sorption ( capacitive deionization, CDI), membrane (RO, NF, MF), photocatalysis, photoelectrochemical oxidation, sonochemical, non-thermal plasma, supercritical fluid, electrochemical oxidation, and electrochemical reduction processes were reviewed. Chemical methods including ozone-based, hydrogen peroxide-based, potassium permanganate processes, and Fenton and Fenton-like process were reviewed. Biological methods such as aerobic, anoxic, anaerobic, bioreactors, constructed wetlands, soil bioremediation and biofilter processes for the management of hazardous wastes, in mode of consortium and pure culture were reviewed. Case histories were reviewed in four areas including contaminated sediments, contaminated soils, mixed industrial solid wastes and radioactive wastes.

Insights into the Electrochemical Reduction Products and Processes in Silica Anodes for Next‐Generation Lithium‐Ion Batteries

AbstractThe use of silica as a lithium‐ion battery anode material requires a pretreatment step to induce electrochemical activity. The partially reversible electrochemical reduction reaction between silica and lithium has been postulated to produce silicon, which can subsequently reversibly react with lithium, providing stable capacities higher than graphite materials. Up to now, the electrochemical reduction pathway and the nature of the products were unknown, thereby hampering the design, optimization, and wider uptake of silica‐based anodes. Here, the electrochemical reduction pathway is uncovered and, for the first time, elemental silicon is identified as a reduction product. These insights, gleaned from analysis of the current response and capacity increase during reduction, conclusively demonstrated that silica must be reduced to introduce reversible capacity and the highest capacities of 600 mAh g−1 are achieved by using a constant load discharge at elevated temperature. Characterization via total scattering X‐ray pair distribution function analysis reveal the reduction products are amorphous in nature, highlighting the need for local structural methods to uncover vital information often inaccessible by traditional diffraction. These insights contribute toward understanding the electrochemical reduction of silica and can inform the development of pretreatment processes to enable their incorporation into next‐generation lithium‐ion batteries.

Rapid electro-catalytic reduction of azo dyes and phenolic compounds in the presence of metallic palladium

This paper demonstrates Electro-catalytic reduction (ECR), a novel and highly efficient method of improving Electrochemical reduction (ER) process by introducing spatially suspended Pd0 particles in the cathode compartment of a divided cell. ECR of some aqueous pollutants; Reactive Black 5 (RB5), Methyl Orange (MO), 2-chlorophenol (2-CP), and 4- Nitrophenol (4-NP), was investigated under galvanostatic conditions. The % decolourization and first-order rate constants of ER of RB5 and MO were limited to 80% and 20% and 0.022 min−1 and 0.003 min−1, respectively; which were improved to 99% and 98%, and 0.187 min−1 and 0.160 min−1, respectively by ECR. ECR of 2-CP showed almost a 10-fold improvement over that of ER. Settleable Pd0 particles could be easily recovered and reused more than twenty times without any appreciable attenuation of its catalytic activity. A novel, reusable Pd@PVA beads were prepared and employed for reduction of 4-NP. >98% 4-NP was electro-catalytically reduced to 4-Aminophenol (4-AP), successively for at least ten times. A simple experiment was performed to reveal the presence of nucleophilic species on the surface of Pd0, responsible for enhanced degradation of pollutants. ECR in the presence of highly reusable Pd0 is a novel and promising option for rapid reductive degradation of hazardous pollutants.

Novel plant flavonoid electrochemical sensor based on in-situ and controllable double-layered membranes modified electrode.

Identification and quantification of plant flavonoids are critical to pharmacokinetic study and pharmaceutical quality control due to their distinct pharmacological functions. Here we report on a novel plant flavonoid electrochemical sensor for sensitive and selective detection of dihydromyricetin (DMY) based on double- layered membranes consisting of gold nanoparticles (Au) anchored on reduced graphene oxide (rGO) and molecularly imprinted polymers (MIPs) modified glassy carbon electrode (GCE). Both rGO-Au and MIPs membranes were directly formed on GCE via in-situ electrochemical reduction and polymerization processes step by step. The compositions, morphologies, and electrochemical properties of membranes were investigated with X-ray powder diffractometry (XRD), Fourier transform infrared spectrum (FTIR), Field emission scanning electron microscopy (FESEM) combined with various electrochemical methods. The fabricated electrochemical sensor labeled as GCE│rGO-Au/MIPs exhibited excellent performance in determining of DMY under optimal experimental conditions. A wide linear detection range (LDR) ranges from 2.0×10−8 to 1.0×10−4 M together with a low limit of detection (LOD) of 1.2×10−8 M (S/N = 3) were achieved. Moreover, the electrochemical sensor was employed to determine DMY in real samples with satisfactory results.

A review of electrochemical reduction processes to treat oxidized contaminants in water

Abstract The purpose of this review is to provide a short overview of electrochemical reduction processes for oxidized contaminants in water. The major parameters affecting the electroreduction mechanisms and the impact of electrode choice are discussed with reference to both inorganic and organic pollutants that are either regulated or emerging (e.g., nonmetal oxyanions, perfluoroalkyl and polyfluoroalkyl substances). To conclude, a discussion is presented on the future directions and challenges that must be addressed to develop these electrochemical reduction processes at a larger, commercialized scale.