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[Display omitted] • Free-standing composite papers of SFCP@PANI were prepared. • The free-standing SFCP@PANI-2 paper was directly utilized as supercapacitive electrodes. • The SFCP@PANI-2 demonstrated an enhanced electrochemcial capacitive performance. Free-standing composite papers of SFCP@PANI were prepared by in situ polymerization of aniline on the surface of sisal fiber carbon paper (SFCP). The SFCP@PANI papers can be directly built into electrodes without the need for any binders or conductive agents. SFCP@PANI-2 exhibits excellent electrochemical performance in the three-electrode system and the coin-type symmetric supercapacitor (SSC), which indicates that it may be a promising electrode material for supercapacitor. [ABSTRACT FROM AUTHOR]

The combination of electrochemistry and mass spectrometry is a powerful analytical tool for studying redox reaction mechanisms and identifying products or intermediates. However, the previously reported devices all require bespoke fabrication and are too complicated to be assembled and used by others. Crucially, the long ion transport distance and small spray volumes make it difficult to capture the short-lived intermediates. We present a practical mass spectrometric method in which surface-modified carbon fiber paper is innovatively applied to detect electrogenerated intermediates. Treating carbon fiber paper with dilute nitric acid removes its surface impurities, enhancing the capability of electro-redox. Electrospray ionization and redox reaction occur simultaneously on the tip of the paper. Transient electro-redox species generate and transfer into gas phase as soon as the appearance of spray. Rapid transport of quantities of electrogenerated ions to the mass spectrometer inlet makes it possible for mass spectrometric identification on the millisecond scale. The short-lived radical cations and iminium ions were successfully captured, reflecting the starting step of the cross-dehydrogenation coupling reaction. The real-time oxidation and online functionalization reactions of tertiary amines were achieved using this device without additional oxidants and electrolytes. In this way we could achieve in-depth mechanistic understanding and rapid screening of serial reactions. [Display omitted] • Treating carbon fiber paper with dilute nitric acid enhances the capability of detecting electrogenerated intermediates. • A-CFPSI permits the real-time monitoring of electrochemical reaction intermediates on the millisecond scale. • No additional electrolytes and oxidants are required, avoiding interference with the mass spectrum. • A-CFPRSI can be used for rapid screening of electrochemical reactions and mechanism researches. [ABSTRACT FROM AUTHOR]

[Display omitted] • It is easier and cheaper to produce sisal fiber carbon paper supercapacitor electrodes in various shapes. • The free-standing SFCPs were directly utilized as supercapacitive electrodes. • SFCP-900 exhibited relatively good electrochemical properties in supercapacitor. Sisal Fiber Carbon Papers (SFCPs) with high specific surface area was obtained using a simple hydrothermal, pressing and carbonization method. The effects of calcination temperature on morphology, structure, pore structure and electrochemical properties of SFCPs were systematically studied. The free-standing SFCPs were directly utilized as supercapacitive electrodes, and the results revealed that the SFCPs calcinated at 900 °C (SFCP-900) exhibit a better specific capacity than SFCP-800 and SFCP-1000. These results suggested that the SFCP-900 has potential applications in supercapacitors. [ABSTRACT FROM AUTHOR]

Malaria elimination is a major goal to be reached in the next decade. Significant progress were made in the past, and the prevalence decreased in many areas while the positive trend stalled in the last years. The exact number of asymptomatic carriers of Plasmodium parasites is unknown since this population is not detected by conventional diagnosis methods and participate in the maintenance of transmission. Molecular methods to detect low parasitemia are not available at point-of-care in low-income countries of malaria endemic areas. Adaptation of molecular methods such as loop-mediated isothermal amplification of DNA may provide effective tools but it required simplification of DNA detection. Square waves voltammetry, easily imbedded in small device such as cell phone, was largely described for DNA detection but support for reaction was an issue to address. Here we used an efficient functionalization method of paper-based material to facilitate the interactions between isothermal amplification product and methylene blue for easy-to-use DNA detection. The proof-of-concept of qualitative detection of very low parasitemia from malaria infected patients using newly chemically treated paper for square waves voltammetry was obtained with a sensitivity and specificity of 100% and a limit-of-detection of 0.1 parasite. μL−1 corresponding to a parasitemia of 0.000002%. [Display omitted] • Asymptomatic carriers of Plasmodium parasites participate in the maintenance of malaria transmission. • Molecular methods to detect low parasitemia are not available at point-of-care in malaria endemic areas. • Detection of Plasmodium DNA using square waves voltammetry and methylene blue required innovative paper functionalization. • The proof-of-concept of low parasitemia diagnosis using chemically grafted paper for square waves voltammetry was obtained. [ABSTRACT FROM AUTHOR]

This study reports a unique flow-through electrode design for hydrogen production in alkaline water electrolysis. This paper investigates a variety of electrodeposition coatings on the 3D-printed electrodes, including nickel, nickel-copper, and nickel-iron. The catalytic activity and properties of the electrodes are examined through electrochemical measurements involving linear sweep voltammetry, cyclic voltammetry, electrochemical impedance spectroscopy, and surface morphology analysis. An experimental setup is also developed to measure hydrogen production and evaluate the efficiency of the designed electrodes. The study finds the flow-through electrodes coated with nickel-copper and nickel-iron achieve the current densities of 54 mA/cm2 and 45 mA/cm2, respectively. The activation overpotentials for the nickel-copper coated electrode are reported as 539 mV, and 408 mV for the nickel-iron coated electrode, both at a current density of 10 mA/cm2. The highest production rate is obtained within the first 15 minutes, 0.273 μg/s for the Ni-Cu flow-through electrode and 0.255 μg/s for the Ni-Fe flow-through electrode. The study further shows that flow-through electrodes produce hydrogen with an efficiency approximately 74% higher than traditional electrodes, suggesting a potentially better design for better hydrogen production in industrial applications. • This study reports a new flow-through electrode design for hydrogen production. • The electrodes are fabricated using 3D-printing and coated using electrodeposition. • The performance is evaluated using electrochemical and hydrogen measurements. • The study finds that flow-through electrodes perform better than traditional. • The flow-through electrodes consume less energy with the same or higher production. [ABSTRACT FROM AUTHOR]

• The electrochemical synthesis of precursor to biologically active C-nucleosides was carried out. • An enzyme based bioelectrocatalysis for the oxidation of d -ribofuranose to d -ribonolactone, precursor of Remdesivir was developed. • The electrochemical oxidation was carried out on laccase immobilized poly-thiophene supported carbon fiber paper. • The screening of the reaction condition and plausible mechanism of the reaction were established. A modified electrode based on laccase immobilized poly-thiophene-3-carboxylic acid supported on carbon fiber paper was developed for the electrocatalytic oxidation of D-ribofuranose to otherwise difficult-to-access D-ribonolactone, a precursor for C-nucleoside based drug like Remdesivir. The electrochemical oxidation of D-ribofuranose was achieved by the TEMPO-mediated electrochemical process. The experimental parameters were optimized and validated using Design of Experiment (DoE) statistical tool indicating the concentration of TEMPO and stirring as important parameters in bulk electrolysis. The mechanism for the electrochemical oxidation of D-ribofuronose followed single electron anodic oxidation of TEMPO mediated by laccase to the corresponding oxoammonium nitrosonium species which was vital for the mediated electrochemical oxidation. The mechanism for the electrochemical oxidation was established using cyclic voltammetry and computational studies. The plausible interactions of laccase enzyme with TEMPO mediator were studied using molecular docking experiments. This facile method was successfully applied for the oxidation of D-ribofuranose to D-ribonolactone. [Display omitted] [ABSTRACT FROM AUTHOR]

The hydrogen and oxygen bubbles covering the electrode surface will reduce the reaction rate of water electrolysis and increase energy consumption. Adding ultrasonic to the electrolytic cell can improve the escape velocity of bubbles on the electrode surface by oscillation and cavitation effect. In this paper, the effects of ultrasound on the performance of water electrolysis under different working conditions are studied by experiment and numerical simulation. Firstly, the polarization curves and bubble flow patterns under different positions of the ultrasonic vibrator and electrode were obtained through experiments. And then, the flow model of the electrolytic cell with ultrasonic is constructed, which considers the mass transfer between the gas and liquid phases and the acoustic flow phenomenon caused by cavitation. The results revealed that, due to the reflection of the wall and the transmission process of the ultrasonic in the electrolyte, the electrode position has a significant impact on the current density when the ultrasonic vibrator is located on the right side of the electrolytic cell, which can be increased by 2.40%–22.70% at different electrode positions compared with that without ultrasound. The influence of operating parameters on the flow field inside the electrolyzer was obtained through numerical simulation. As a result, appropriate loading methods and operating conditions can maximize the effectiveness of ultrasound. [Display omitted] • Improper ultrasonic loading method increases energy consumption. • Wall conditions have a significant impact on the performance of water electrolysis. • The bubble flow morphology on the electrode surface was observed. • A flow field model of electrolyzer with ultrasonic was constructed. [ABSTRACT FROM AUTHOR]

• The ORR reaction pathway and catalytic mechanism of rare earth-based catalysts are briefly described. • The latest progress of rare earth-based ORR catalysts is systematically summarized. • Rare earth elements play an indispensable role in improving the activity of electrocatalytic materials through the formation of heterostructure interface, doping/substitution engineering, strain effect, etc. Rare earth (RE) metals have special 4f shell electronic configuration and special physical and chemical properties. Therefore, rare-earth-based catalysts are extensive used in the electrochemical cathodic oxygen reduction reaction (ORR) of proton exchange membrane (PEM) fuel cells. However, the low conductivity and low active site density of these catalysts limit their effective application in electrochemistry. The results show that the oxygen reduction activity and stability of rare-earth-based catalysts can be significantly improved by controlling the electronic structure and spatial configuration of active sites through doping of metal/nonmetal elements. In this paper, the main research work on metal/nonmetallic element doping to improve the performance of rare earth-based-catalysts in recent years was reviewed, including noble metal element doping, non-noble metal element doping, non-metallic element doping, perovskite and so on. The paper further summarized and pointed out the problems and challenges faced by rare-earth-based catalysts, and looked forward to their development prospects and future research directions. In recent years, rare earth metals have been widely used in the electrochemical cathodic oxygen reduction (ORR) of fuel cells because of their special 4f shell electronic structure and special physical and chemical properties. However, the low conductivity and low active site density of these catalysts limit their effective application in electrochemistry. The results show that the electronic structure and spatial configuration of the active sites can be significantly improved by doping metal/non-metal elements, which can significantly improve the oxygen reduction activity and stability of the rare-earth based catalysts. In this paper, the main research work on improving the performance of rare earth-based catalysts doped with metal/non-metal elements at home and abroad in recent years is reviewed, and their development prospects and future prospects are also prospected. [Display omitted] [ABSTRACT FROM AUTHOR]

This paper introduces a design strategy for a self-assembled artificial solid electrolyte interface (SEI) layer with adjustable functional group integration, aimed at enhancing the performance of AZIBs. [Display omitted] • The self-assembled artificial SEI layer can securely adhere to the zinc surface through covalent bonding. • The resulting CF 3 -PSiOX layer acts as a hydrophobic shield, effectively isolating water and inhibiting corrosion. • The strong interaction between −CF 3 and Zn2+ guides the diffusion and deposition processes of Zn2+, optimizing the de-solvation process. Commercial applications of aqueous Zn batteries primarily encounter challenges related to surface corrosion and dendrite formation. In this study, a hydrophobic polysilane layer functionalized with −CF 3 groups (CF 3 -PSiO X) is tailored for Zn anode through a two-step process involving self-assembly and condensation. The CF 3 -PSiO X layer functions as a protective barrier, effectively isolating water and inhibiting corrosion. Moreover, the primary interactions between −CF 3 and Zn2+ guides the diffusion and deposition processes of Zn2+ while optimizing the de-solvation process, ultimately resulting in dendrite inhibition. Hence, cells with CF 3 -PSiO X layer boasts a high Coulombic efficiency (∼99.8 % after 1500 cycles), a long lifespan (over 2400 h), and optimized capacity retention (73.3 % over 1000 cycles). The self-assembled polysilane layer with customizable groups offers a novel approach for tuning the interface properties of Zn anodes and establishes a general principle for interface adjustment applicable to alternative metallic electrodes. [ABSTRACT FROM AUTHOR]

[Display omitted] • A PtX technology capable of removing methyl mercaptan from gas has been developed. • Electrochemically regenerated chlorine oxidizes methyl mercaptan and removes it. • The technology can purify gas to a high degree and is adaptable and scalable. • No Chlorine is released into the cleaned exhaust gas. • The final product of the oxidation is sulfate which is dissolved in the solvent. A new electroscrubbing technology has been developed. This Power-to-X process utilizes active chlorine, which oxidizes impurities and is continuously regenerated in an electrochemical cell. The process is primarily intended for hydrogen sulfide capture, but has shown potential in removing other sulfur components as well. In this paper the capability of the process for removing methyl mercaptan has been examined. The electroscrubbing process was able to remove mercaptan to undetectable levels. The capture rate of mercaptan was primarily determined by the applied electrical current. Gas flow and concentration had a negligible effect on the capture while liquid flow had only a minor impact. The primary product of the mercaptan oxidation was found to be sulfate ions. [ABSTRACT FROM AUTHOR]

The zinc powder replacement method for Co removal is characterized by several challenges, such as poor mass transfer and agglomeration. To solve this problem, the ultrasonically enhanced zinc powder replacement method was developed and used to remove Co from the sulfate solution, and a 95.02% removal rate of Co was achieved under the optimized condition. Compared with conventional conditions, the removal rate increased by 24.5%. The behavior and mechanism of zinc powder replacing Co were comprehensively analyzed through electrochemistry and COMSOL Multiphysics. Chronoamperometry curves showed that after the introduction of ultrasound, the reaction current increased by approximately two times compared with the conventional condition. The cyclic voltammetry (CV) curves showed that the reduction potential of Co positively shifted, accompanied by an increase in peak current. The electrochemical impedance spectroscopy (EIS) tests showed that the nuclear transmission resistance decreased by approximately 1.6 times compared with conventional conditions. In addition, the COMSOL simulation revealed that, after the system was subjected to ultrasonic conditions, the temperature, flow rate, and sound pressure physical field increased, which accelerated the heat and mass transfer process in the solution. The removal behavior of the system was studied using scanning electron microscopy and X-ray diffraction. Ultrasonic waves decomposed the insoluble substances on the surface of zinc powder, refined the particles, and improved the removal rate of Co. This provides new insights into the ultrasound-enhanced reaction. In this paper, we introduce an innovative approach by ultrasonic enhanced zinc powder for the replacement removal of cobalt, achieving high-efficiency cobalt elimination. Additionally, the electrochemical kinetics of the zinc powder replacement process is comprehensively investigated. Theoretical validation of ultrasound-enhanced heat and mass transfer processes within the solution was achieved through numerical simulations conducted using COMSOL software. [Display omitted] • Ultrasound was used to improve the efficiency of Co removal from zinc sulfate solution. • The removal rate was increased by 24.65% compared with convention. • The introduction of ultrasound increased the mass transfer in the solution. • Ultrasound decomposed the insoluble substance on the surface of the zinc powder. [ABSTRACT FROM AUTHOR]

• A interdigital flow field plate for PEM was designed based on plant vein system. • Two-phase flow behaviors and influences on electrolysis performance were studied. • Electrolysis performance was improved by eliminating the flow dead zone. Proton exchange membrane (PEM) electrolytic hydrogen production has the advantages of high current density, high operating pressure, wide power regulation range and so on. It has good adaptability to wind and photovoltaic power with high volatility and recognized as an important way to solve the effective utilization of renewable energy. In PEM electrolyzer cell (PEMEC), anode flow field plate plays a crucial role in the process of water electrolysis to produce oxygen, which affects the of gas and liquid transfer. Among them, the channel blockage caused by bubble retention is an important factor limiting the performance of PEMEC. In this paper, an interdigital flow field plate is designed based on the plant leaf vein system. The two-phase flow behaviors within the interdigital flow field channel are studied. The results show that the interdigital flow field plate is superior to the traditional serpentine flow field in terms of electrolytic efficiency and voltage loss. The reaction kinetics rate is accelerated, the overall ohmic resistance is reduced by about 4.8 %, and the hydrogen production is increased by about 9.1 %. The above research can provide guidance for the structural improvement and performance improvement of PEMEC. [Display omitted] [ABSTRACT FROM AUTHOR]

Additive manufacturing is a technique that allows the construction of prototypes and has evolved a lot in the last 20 years, innovating industrial fabrication processes in several areas. In chemistry, additive manufacturing has been used in several functionalities, such as microfluidic analytical devices, energy storage devices, and electrochemical sensors. Theophylline and paracetamol are important pharmaceutical drugs where overdosing can cause adverse effects, such as tachycardia, seizures, and even renal failure. Therefore, this paper aims at the development of miniaturized electrochemical sensors using 3D printing and polylactic acid-based conductive carbon black commercial filament for theophylline and paracetamol detection. Electrochemical characterizations of the proposed sensor were performed to prove the functionality of the device. Morphological characterizations were carried out, in which chemical treatment could change the surface structure, causing the improvement of the analytical signal. Thus, the detection of theophylline at a linear range of 5.00–150 μmol L−1 with a limit of detection of 1.2 μmol L−1 was attained, and the detection of paracetamol at a linear range of 1.00–200 μmol L−1 with a limit of detection of 0.370 μmol L−1 was obtained, demonstrating the proposed sensor effectively detected pharmaceutical drugs. [Display omitted] • A simple and easy printing miniaturized electrochemical device has been developed. • A 3D-printed sensor based on PLA and carbon black filament is constructed. • DMF chemical treatment was effective for exposing carbon black agglomerates. • The optimized method was applied for theophylline detection. • Drug monitoring is performed in pharmaceutical and artificial biological samples. [ABSTRACT FROM AUTHOR]

In the present paper, it was studied the possibility of obtaining nickel oxide (NiO) for developing nanocomposites based on transitional oxides and carbon materials for electrochemical applications. In order to obtain nanostructured NiO, the precipitation method was chosen and the influence of surfactants (e.g. SDS, CTAB, PEG, IGEPAL CA-630 and hydroxypropyl cellulose) on the structural and morphological properties of NiO was established. The oxide precursor was treated at a maximum of 700 °C. The used carbon material is reduced graphene oxide (RGO) and was obtained by the Hummer's method. The ex-situ method was used for obtaining nanocomposites, consisting of the formation of a homogeneous mixture between the fillers (RGO and NiO) and the polymeric matrix polyvinylidene fluoride (PVDF). The influence of filler concentration on the electroactive β-phase of PVDF was evaluated. The developed materials were analyzed from a morphological and structural point of view and the wetting capacity was determined, using characterization techniques, such as FTIR and EDX spectroscopy, X-ray diffraction, SEM microscopy and goniometry. The morphological study shows the synthesis of oxide particles with dimensions below 80 nm, their insertion in the graphene domains and close interaction between composite components took place. Structural studies indicate crystalline purity of the oxide and increased electroactive β phase nucleation by the incorporation of RGO and NiO into the PVDF matrix. The PVDF-RGO-NiO composite has a hydrophilic character. The ability of PVDF-RGO-NiO nanocomposites to store charge was evaluated via cyclic voltammetry. [ABSTRACT FROM AUTHOR]

In support of the energy and feedstock transition, new concepts of producing chemical building blocks are necessary. While currently ethylene is mainly produced from fossil feedstocks, this paper explores its production via the electrochemical conversion of CO 2. Different process routes were reviewed and a most promising route was selected based on Faradaic efficiency, current density, overpotential, and material availability. In this preferred route, syngas is produced electrochemically from CO 2 , which is then converted into methanol before the final conversion into ethylene and other high-value chemicals. On this preferred route, a design has been made which includes process design, unit design and a techno-economic evaluation, with CAPEX and OPEX included. Also the CO 2 emission is evaluated and it was found that a net consumption of 2.5 ton CO 2 per ton high-value chemical can be achieved. As expected, the investment and operational costs are very high with the applied price sets. However, when the electricity price decreases due to developments in renewable energy and a tax is implemented on CO 2 emissions, this process can become economically viable and can contribute to CO 2 emission reduction in view of climate change. [Display omitted] • Electrochemical CO 2 reduction could play a key role in reducing greenhouse gases. • Route was chosen based on carbon efficiency, electricity requirements and complexity. • Electrochemical syngas production, methanol formation and olefin production. • The electrolyzer is a stacked-cell system with a Nafion-424 cation exchange membrane. • Price of ethylene mainly dependent on CO 2 price, current density and electricity price. [ABSTRACT FROM AUTHOR]

Rapid and sensitive determination of pesticide residues in fruits and vegetables is critical for human health and ecosystems. This paper used an Ag-modified CuO sphere-cavity array (CuO@Ag) electrode as a thiram SERS/electrochemical dual readout detection platform. Numerous Raman "hotspots" generated by uniformly distributed silver nanoparticles, charge transfer at the CuO@Ag interface, and the formation of Ag-thiram complexes contribute to the significant enhancement of this SERS substrate, which results in excellent SERS performance with an enhancement factor up to 1.42 × 106. When using SERS as the readout technique, the linear range of the substrate for thiram detection was 0.05–20 nM with a detection limit (LOD) of up to 0.0067 nM. Meanwhile, a correlation between the value of change in current density and thiram concentration was established due to the formation of stable complexes of thiram with Cu2+ generated at specific potentials. The linear range of electrochemical detection was 0.05–20.0 μM, and the detection limit was 0.0167 μM. The newly devised dual-readout sensor offers notable sensitivity and stability. The two signal readout methods complement each other in terms of linear range and detection limit, making it a convenient tool for assessing thiram residue levels in agro-food. At the same time, the combination of commercially available portable equipment makes on-site monitoring possible. Ag-modified CuO cavity arrays have been established as SERS-electrochemical dual-signal platforms for thiram detection. [Display omitted] • CuO@Ag cavity arrays were used as SERS/electrochemical dual-signal sensors. • The EM and CT synergistic effect endow CuO@Ag with excellent SERS performance. • The highly ordered array structure ensures excellent SERS signal reproducibility. • The complex between the electrode and thiram enhances the electrochemical response. • The sensor demonstrated the feasibility of detecting thiram in real samples. [ABSTRACT FROM AUTHOR]

Three-dimensional (3D) architected electrode materials are expected to exhibit advantageous properties such as enlarged surface area, increased mass transfer, enhanced adsorption and more active sites exposed. In this paper, boron-doped diamond (BDD) electrodes on 3D printed patterned silicon carbide (SiC) scaffolds have been fabricated using chemical vapor deposition (CVD). The stabilization of the plasma sphere by using clamshell type CVD reactor, introducing the outer protecting plate, the optimization of CVD parameters, and the design of 3D-SiC scaffolds improved the sp3/sp2 ratio, uniformity and growth rate of BDD. 3D-BDD electrodes exhibit enough electrical conductivity for electrochemical applications. The preliminary test for electrochemical carbon dioxide reduction (CO 2 R) has showed the potential advantages of this type of 3D structured BDD electrodes. [Display omitted] • Three-dimensional BDD electrode was fabricated on 3D-SiC scaffolds using microwave plasma chemical vapor deposition. • The stabilization of plasma improved the diamond growth on the 3D-structure. • 3D-BDD electrodes exhibited enough electrical conductivity for electrochemical applications. [ABSTRACT FROM AUTHOR]

Analysis of trace level metals in environmental samples (e.g., soil, water, and plant samples) is important for assessing environmental quality and food safety. This paper reports a non-toxic, eco-friendly, and cost-effective sensing method, capable of in-situ detection of microgram per liter (µg/L) levels of heavy metal ions in plant and soil solutions using carbon fiber electrodes (CFEs) produced without using any microfabrication. The electrochemical behaviors of the CFEs were characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) measurements. As proof of principle, the CFEs were validated for sensing selected heavy metals in buffer solutions as well as in extracted plant and soil solutions using differential pulse anodic stripping voltammetry (DP-ASV). Experimental results confirm that the CFEs were able to simultaneously measure cadmium (Cd), lead (Pb), and mercury (Hg) with a detection limit of 2.10, 0.93, and 1.85 µg/L respectively in buffer solution, showcasing good selectivity and sensitivity. The ideal pH range for heavy metal detection was also extensively investigated and was found to be between pH 4.0 and pH 5.0. These findings lay a better foundation towards long-term and stable electrochemical analysis for plant and soil solution matrices. [Display omitted] • Carbon fiber electrode fabricated without using any microfabrication facility. • The sensor can detect Cadmium, Lead, and Mercury in a wide range between 10 and 1600 μg/L. • This sensor can detect heavy metals in a wide variety of solutions including buffer, plant, and soil solutions. • This sensor provides repeatability over 100 measurements. [ABSTRACT FROM AUTHOR]

[Display omitted] • The semiconducting properties of chalcopyrite is discussed. • Electrochemical characterization of chalcopyrite leaching passivation is reviewed. • The mechanisms of enhanced leaching of chalcopyrite are discussed. Chalcopyrite is the most important and abundant raw material for copper extraction in which hydrometallurgical leaching is more attractive. However, the leaching rate is limited, which is related to the properties of chalcopyrite and the passive film produced during leaching. Usually, the leaching of chalcopyrite is considered several electrochemical reactions whose redox processes, properties of passive film and substrate, mechanisms, and kinetics can be analysed by electrochemical characterizations (such as impedance plots (including Mott-Schottky curve and EIS plot), redox/open-circuit potential, potentiodynamic curves (including polarization curve and CV/LSV plot), and I - t / E - t curve) which are of easy manipulation, high efficiency, accuracy and credibility, and low cost and requirement. By initially introducing the properties of chalcopyrite and passive film, this paper reviews these recent electrochemical characterizations of chalcopyrite leaching and passivation, and the important electrochemical phenomenon-galvanic effect. The mechanisms of enhanced leaching, including manipulating lattice composition and structure, destroying p-n junction, regulating/attacking/hydrophilizing film, strengthening synergies, activating species/promoting diffusion, stabilizing cupric species by coordination, as well as improving adsorption, solid–liquid/intergranular electron transfer and galvanic effect, are also circumstantially discussed. To obtain more information about leaching and passivation, the joint use of several electrochemical characterizations is encouraged because of their different (dis)advantages. Finally, the prospect of chalcopyrite slurry electrolysis which integrates electrochemical leaching, ions purification and electrodeposition these three steps is envisaged. [ABSTRACT FROM AUTHOR]

In this paper, we synthesized Bi 2 Se 3 -NFs@rGO composite and analyzed electro chemical properties. Bi 2 Se 3 -NFs@rGO composite improved specific capacity, cycle stability and ion conductivity by rGO composite. [Display omitted] • The synthesis of Bi 2 Se 3 nanoflakes(NFs) by organic molecules as selenium precursor. • Synthesized homogenously nanoflakes by oleylamine as surfactant. • Bi2Se3-NFs@rGO composite exhibits high specific capacity compared to previous articles. • Analyzed the mechanism of Bi 2 Se 3 -NFs@rGO composite via Ex-situ TEM and Ex-situ XRD. Metal selenides have gained attention as alternative anode materials for lithium-ion batteries, with increasing demand for electro-vehicles and appliances. Bismuth selenide has significant potential as anode materials in lithium-ion batteries. Nevertheless, metal selenides have essential drawbacks, such as volume expansion and poor cycle performance. In this paper, bismuth selenide synthesized homogeneous morphology-like nanoflakes (NFs) using the wet chemical method. We combined these nanoflakes with reduced graphene oxide to improve their structural stability. The Bi 2 Se 3 -NFs@rGO composite showed enhanced specific capacity from 750 mAhg−1 to 1100 mAhg−1 at 100 mAg−1. Furthermore, at a current density of 500 mAg−1, it reached a specific capacity (819 mAhg−1) after 300 cycles and demonstrated a coulombic efficiency of 96 %. [ABSTRACT FROM AUTHOR]

[Display omitted] In order to meet the growing demand of portable electronic devices and electric vehicles, enhancements in battery performance metrics are required to provide higher energy/power densities and longer cycle lives, especially for anode materials. Alloying anodes, such as Group IVA elements-based materials, are attracting increasing interest as anodes for next-generation high-performance alkali-metal-ion batteries (AMIBs) owing to their extremely high specific capacities, low working voltages, and natural abundance. Nevertheless, alloying-type anodes usually display unsatisfactory cycle life due to their intrinsic violent volumetric and structural changes during the charge–discharge process, causing mechanical fracture and exacerbating side reactions. In order to overcome these challenges, efforts have been made in recent years to manufacture multimetallic anodes that can accommodate the induced strain, thus showing high Coulomb efficiency and long cycle life. Meanwhile, much work has been conducted to understand the details of structural changes and reaction mechanisms taking place by in-situ characterization methodologies. In this paper, we review the various recent developments in multimetallic anode materials for AMIBs and shed light on optimizing the anode materials. Finally, the perspectives and future challenges in achieving the practical applications of multimetallic alloy anodes in high-energy AMIB systems are proposed. [ABSTRACT FROM AUTHOR]

The paper reports a results of series of interlaboratory comparisons of low impedance measurements at frequencies relevant for electrochemical impedance spectroscopy (EIS) of commercial lithium-ion cells. Two comparisons are presented. The first, bilateral comparison has focused on low impedance standards calibration in a full complex plane using digital sampling setups. The second comparison has focused on calibration and use of commercial 4-terminal battery EIS meters. Both comparisons have covered the impedance range from 50 μ ℧ to 100m℧ across the full complex plane in a frequency range from 0.01Hz up to 5kHz. Finally, the paper summarizes practices identified as critical for achieving measurement compatibility among various labs. • Relevant for electrochemical impedance measurements of lithium-ion battery cells. • First interlaboratory comparison of low impedances in full complex plane. • First interlaboratory comparison of low impedance at frequencies down to 0.01Hz. [ABSTRACT FROM AUTHOR]

Most products today have several functions, but these are achieved by integrating different monofunctional devices and/or materials in a system. Having several functions simultaneously in one single material has many potential advantages, such as a structural material that can also store energy, have self-sensing or self-healing capability or any other physical function. This would lead mass and resource savings, being more energy efficient and thus more sustainable. This paper presents a mini review on how carbon fibres can be used for integrating several functions simultaneously in a high-performance load carrying structural material using the electrical and electrochemical properties of carbon fibres. Through this carbon fibre composites can also store energy like a lithium-ion battery, be used as a strain sensor, have electrically controlled actuation and shape-morphing, and be used as an energy harvester. [ABSTRACT FROM AUTHOR]

• The scale inhibition mechanism of HAS was explored from three perspectives. • The main responsible for scale inhibition is carboxyl functional group of HAS. • There is a strong mutual attraction between HAS and the surface of calcite crystal. • The effect of HAS concentration on scale inhibition performance increases first and then decreases. The scale inhibition mechanism of sodium humate (HAS) on Calcium Carbinate (CaCO 3) was investigated by experiments, quantum chemical calculations and molecular dynamics simulations. The changes of electrochemical impedance spectroscopy were analyzed by electrochemical methods at different concentrations (0, 10, 30, 50, 70, 100 mg/L) of HAS. The molecular structure of HAS was optimized by quantum chemical calculation, and the charge distribution, electrostatic potential distribution and frontier orbital energy of HAS were obtained. The interaction simulation system between HAS and the crystal planes of calcite was constructed based on molecular dynamics simulation. The interaction mechanism between specific functional groups in HAS and calcite crystal plane was analyzed. The results show that the capacitance arc and charge transfer resistance increase with the increase of HAS concentration in the range of 0–50 mg. However, In the concentration range of 50–100 mg, the capacitance arc and charge transfer resistance decrease with the increase of concentration. In the optimized structure of HAS, the oxygen atom on the carboxyl group is more negatively charged. There is a strong mutual attraction between HAS and calcite crystal plane. The primary functional group responsible for achieving scale inhibition is formed through the bonding between the carboxyl oxygen atom within its molecular structure and the calcium atom on the calcite crystal plane. The research in this paper provides a strong guidance for the treatment of scale and the development of scale inhibitors. [ABSTRACT FROM AUTHOR]

A novel heterobinuclear heteroleptic μ-carbido-dimer complex (t Bu) 4 PcRu=C=FeTPP is capable of successful decomposing β-carotene without involvement any other reagent due to the activation of dioxygen molecule in some solvents. Interaction between the compound and t BuOOH in dichloromethane, benzene and acetonitrile afford highly reactive species which are catalytically competent in β-carotene, methylene blue and t BuOOH oxidation at room temperature. [Display omitted] Bimetallic µ-bridged complexes supported by macrocycles are worth addressing due to their excellent stability, rich redox chemistry and suitability in catalysis. This paper for the first-time reports on the synthesis and redox properties of an unexplored heterometallic μ-carbido-dimer derivative bearing iron-porphyrin and ruthenium-phthalocyanine parts and a FeIV = C = RuIV unit. The compound is identified by UV–visible, IR, EPR, MALDI TOF, electrochemistry techniques and DFT calculations. The redox activity of the compound toward H 2 O 2 , t BuOOH is examined. The results indicate that under oxidation conditions in dichloromethane, benzene and acetonitrile, the initial complex evolves rapidly via oxidation steps forming intermediates which are competent in β-carotene and methylene blue oxidation at room temperature. The site oxidation accessibility of the initial compound and the nature of high-charged intermediate species are established to depend on the solvent polarity and axial ligands. The findings contribute to a deeper understanding of the significant role of reaction conditions as well as the mixed macrocyclic ligand environment and metal nature in controlling the oxidizing capability and thus can aid the development of new more active and durable catalysts. [ABSTRACT FROM AUTHOR]

In this paper, porous NiTi intermetallic was synthesized via a modified thermal explosion (TE) method, utilizing Ni (74 μm, 38 μm, 5 μm, 100–200 nm) and Al element powders as raw material. The exothermic behavior and phase transition of porous NiTi intermetallic compounds were studied. The results showed that with the refinement of Ni particle size, the heat release decreased, and the Ti-74 μm sample was the product of two eutectic reactions. Their mechanical properties were verified by the Vickers hardness tester and universal testing machine, and the corrosion behavior of porous NiTi intermetallic compounds in phosphate-buffered saline (PBS) solution was studied by electrochemical tests. Among them, Ti-5 μm exhibits the most homogeneous microstructure and favorable mechanical properties, which has a porosity of 31.7 % and a compressive strength of 321.71 MPa. However, corrosion resistance is sacrificed due to the high open porosity. This study holds great promise for precise control microstructural characteristics and optimization of mechanical and electrochemical properties of porous NiTi intermetallics. • Porous NiTi intermetallic compounds were sintered by a rapid TE method. • The refinement of the particle size will limit the heat release of the TE reaction. • The prepared NiTi has a porosity of 31.7 % and a compressive strength of 321.71 MPa. • Reducing porosity contribute to improving corrosion resistance. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel nanomaterial toward (CuCo/CP) electrochemical water splitting. • Facile method for Copper-Cobalt (CuCo) supported on carbon paper (CuCo/CP) composition. • The electrochemical activation of electrode led to improvement of OER and HER kinetics. • Tafel slopes has been calculated for CoCu/CP is 97.7 mV dec−1. • CuCo/CP an emerging material for different energy applications. Electrochemical water splitting is one of the most appealing approaches to produce Hydrogen as a sustainable energy resource. The efficiency of Hydrogen evolution reaction (HER) and Oxygen evolution reaction (OER) largely depends on the activity and stability of any elctrocatalyst. Herein, we have employed a facile and reproducible electrodeposition coating method to synthesize bi-metallic Copper-Cobalt (CuCo) containing electrocatalyst supported on carbon paper (CuCo/CP) for electrochemical splitting of water in neutral medium. We have accomplished superior and improved HER and OER electrocatalytic activity, regardless of lower activity of Cu toward HER and OER. The unique structure and synergistic effect of CuCo/CP displayed better electrocatalytic activity with a low overpotential of 450 mV at 10 mA.cm−2 toward HER and just 80 mV at 10 mA.cm−2 toward Oxygen evolution reaction than other Cu containing electrocatalysts. Moreover, the durability of synthesized electrocatalyst at high applied current density ensure the stable nature of the catalyst. The present study may pave the way for the rational design of electrocatalysts for efficient Oxygen and Hydrogen production applications. [ABSTRACT FROM AUTHOR]

This work presents an all-in-one origami paper-based electrochemical platform for simple and inexpensive l -cysteine (Cys) detection using Cys as a monomer for modifying electrode surfaces. The proposed method combines the steps of electropolymerization and detection into a single device to offer a highly convenient method for the end-user. In comparison, the sensitivity toward Cys detection is a significantly increased using this modified electrode. The developed device provided a linear concentration range of 10–800 μM with a limit of detection of 5.5 μM. For application, the device was successfully applied to detect Cys in different food products such as wheat flour, bread, and cake with satisfactory results, yielding excellent intra-day and inter-day relative standard deviations (1.5–4.9%) and recoveries (84.2–110.8%). This discovery is important from the viewpoint of the development of Cys detection in other applications in the future. [Display omitted] • A novel self-modification of poly(cysteine) for l -cysteine detection was proposed. • New all-in-one origami paper-based analytical device coupled with a novel sensor was developed to offer a convenient procedure over previous methods. • Good selectivity, accuracy, and precision for l -cysteine detection in food samples were demonstrated. [ABSTRACT FROM AUTHOR]

[Display omitted] • We introduce an innovative approach to electrochemical micromachining using a Two-tone sinusoidal signal and investigate the mechanism behind the reduced machining gap with this signal. • Using the Taguchi optimization method, we study the impact of the control variables on the micromachining process during micro-hole drilling, and results show that using the optimized parameters greatly enhanced processing accuracy. • We use this technology to machine the microstructures on 5-μm pure nickel sheet and hard-to-cut super alloy plates, and improve the machining accuracy to the nanometer level. Electrochemical micromachining is an emerging technology in the machining field. This method offers several advantages such as exceptional surface quality, minimal cathode depletion, and a high elimination rate. Often, an ultrashort pulse power supply is employed in electrochemical micromachining to address over-machining in non-processing areas. While reducing the pulse duration can enhance processing accuracy, its high cost and impracticality for regular production limit its development. This paper presents the use of a Two-tone sinusoidal signal as an alternative to ultrashort pulse in electrochemical micromachining. We investigated the mechanism behind the reduced machining gap with this signal. By drilling micro-holes in the nickel sheet to optimize parameters such as voltage, fundamental frequency, and harmonic order. Using the Taguchi optimization method, we studied the impact of these control variables on the micromachining process during micro-hole drilling. The study also focused on fabricating micro-structures using the best processing parameters. Our results showed that using the optimized parameters greatly enhanced processing accuracy. Moreover, we found that high machining accuracy could be achieved when working on hard-to-cut super alloy plates. [ABSTRACT FROM AUTHOR]

In this paper we present an all-solid-state lithium-ion battery (ASSB) model that considers electrochemistry and solid mechanics in a fully coupled manner. The model spatially resolves the three-dimensional microstructure of an ASSB cell and is based on non-linear continuum mechanics. The coupling of electrochemistry and solid mechanics is incorporated via lithiation-dependent volumetric changes of the active materials and the consistent formulation of the electrochemical governing equations on deformed geometries resulting in changed percolation paths. As the volumetric changes due to (de-)lithiation are reported to be large for several active materials, we introduce this effect using a multiplicative split of the deformation gradient. To also allow for large deformations in the mass conservation equation, an Arbitrary Lagrangian–Eulerian formulation is employed. Furthermore, we show the central steps to deduce the finite element formulation of our model as well as the adopted monolithic solution procedure to solve this strongly coupled non-linear problem. The linear solver used for large problem setups is adjusted from the advanced, physics-oriented preconditioning technique published in our previous work. In the numerical examples, we investigate three different geometries with up to about 1.3 million degrees of freedom and thereby prove that our approach is applicable to geometrically large and complex scenarios. Moreover, we show that our approach consistently introduces the mass and charge conservation on deformed meshes. Furthermore, the numerical examples demonstrate the high relevance to incorporate current collectors into the ASSB cell simulations. Finally, we show that solid mechanics and the coupling effects have indeed a large impact on the ASSB cell performance and their incorporation is therefore vital for precise results and predictions. [ABSTRACT FROM AUTHOR]

[Display omitted] • This review covers topical progress in polyaniline composites and their application in energy supply systems. • Polyaniline is a new emerging material for energy storage/conversion for intensive learning and additional progress. • Special attention was paid to polyaniline composites with carbonaceous material (CNTs, graphene, activated carbon, or graphite), transition metals, and metal oxides. • Enlightens an extensive assortment of information, research advancement, and scope of polyaniline-based nano-composite for energy supply devices. • Beneficial to the electrochemical community concerned with conducting polymer of aniline and their cutting-edge applications. Intrinsic conductive polymers have undergone comprehensive surveys due to their several benefits as compared to conventional materials. A wide exploration of polyaniline as an intrinsic conducting polymer has escalated due to its valuable mechanical, optical, and electrical assets thereby intensifying their possibility of applications. The inclusion of pristine polyaniline with fillers (ingredients) such as carbonaceous material, transition metals, and its metal oxides resulted in the fabrication of a multifunctional polyaniline composite with boosted performance using varying energy supply devices. Thanks to this structural stabilization efficiency of polyaniline with various ingredients or fillers, it has an open new window to develop futuristic energy devices. For this reason, we have explored this paper in terms of contemporary scenarios of emerging developments in polyaniline and its nanocomposites which would be beneficial to the electrochemical research community. Here we classified our survey into three categories of energy supply systems such as supercapacitors, solar cells, and OLED. This could be a future breakthrough as well as cooperative for administrative the balanced strategy and staff in command to additionally outfit the practical demand. [ABSTRACT FROM AUTHOR]

[Display omitted] • A POM-based detector for EU. • Organic-inorganic material composite increases electrode stability. • Achieved rapid and sensitive determination of EU. • Successfully compared EU content of different parts of the perch. Food safety concerns caused by the application of spice allergens to fish anaesthesia. In this paper, a chitosan-reduced graphene oxide/polyoxometalates/poly- l -lysine (CS-rGO/P 2 Mo 17 Cu/PLL) modified electrode was constructed by electrodeposition and successfully applied to the quantitative analysis of eugenol (EU). The detection limit was 0.4490 μM in the linear range of 2x10-6 M to 1.4x10-5 M. It was applied to the determination of EU residues in kidney, liver and meat tissues of perch with recoveries ranging from 85.43 to 93.60%. Besides, the electrodes demonstrate high stability (2.56% drop in current value after 70 days at room temperature), high reproducibility (RSD of 4.87% for 6 parallel electrodes) and extremely fast response time. This study provided a new material for the electrochemical detection of EU. [ABSTRACT FROM AUTHOR]

High level of mental stress will lead to negative psychological and health consequences, such as insomnia, depression, and cardiovascular disease, which will increase the suicide rate and affect social stability. Mental stress has been proved to be related to biomarkers cortisol and skin conductance, and reflects the complementary advantages of stress monitoring. Based on electrochemistry and electrophysiology analysis technology, combined with microelectronic design and biosensors, this paper constructed an integrated physiological and biochemical sensing system, and an intelligent user interaction system. Firstly, a molecularly imprinted biosensor with gold nanoparticles (AuNPs), prussian blue (PB), and polypyrrole (PPy), achieved highly sensitive detection of cortisol in the range of 1–10000 ng/mL and demonstrating good specificity. The cortisol detection unit used differential pulse voltammetry (DPV) method by dual power amplifier chip AD8674, which was a precision operational amplifier with low noise, low input bias current, and unit gain stability. Then, the skin conductance detection unit was mainly composed of a pulse width modulation (PWM) drive circuit, which was designed to achieve a 100 Hz voltage output. The integrated system was designed with microcontroller module, transimpedance amplifier (TIA) module, power management module, signal transmission module, cortisol and skin conductance detection module, which was suitable for constructing precision voltage control and weak current signal conditioning. Finally, based on the software and hardware platform of smartphones, an intelligent analysis system was developed to improve the portability and user interaction convenience. Our system achieved the physiological and biochemical joint detection for the first time, showing enormous application potential in future multimode sensing monitoring. • Integrated physiological and biochemical sensing system. • Electrochemistry and electrophysiology combined with microelectronic design and biosensors. • Intelligent user interaction system on smartphone. • Application potential in future multimode sensing monitoring. [ABSTRACT FROM AUTHOR]

The electrochemical method is commonly applied in diagnosing and monitoring diseases. When used in conjunction with optical disease detection systems, it can broaden the detection range, lower the limit of detection and create mutual confirmation. Utilizing the electrochemical-optical dual-mode detection method for disease diagnosis is non-invasive, low-cost, easy-to-use, efficient and accurate compared with the traditional single-mode method. This paper reviews the reports of electrochemistry and optical methods combined in recent years, such as colorimetry, fluorescence, Surface Enhanced Raman Spectroscopy (SERS), surface plasmon resonance (SPR) and spectroelectrochemistry. We cover researches on several electrochemical-optical dual-mode detection methods for identifying disease markers, including biochemistry, cancer, infection, cardiovascular and cerebrovascular disease, and neurological diseases as well. These studies demonstrate the feasibility of electrochemical-optical dual-mode detection and its broad application prospects in the field of disease detection. This paper reviews the popular schemes of electrochemical dual-mode detection in disease diagnosis recently. First of all, five electrochemical dual-mode disease detection are discussed, such as electrochemical-colorimetry mode, electrochemical-fluorescence mode, electrochemical-SERS mode, electrochemical-SPR mode and electrochemical-microfluidics mode. Secondly, we investigate the schemes of various electrochemical dual-mode detection methods for the detection of different types of diseases, such as biochemical detection, cancer detection, infection detection, detection of cardiovascular and cerebrovascular and neurological disease detection. Finally, alternative electrochemical dual-mode detection methods are compared. We also evaluate their detection qualities across a variety of disorders and recommend research avenues that researchers may favor in the future. [Display omitted] • Introducing the research progress of electrochemical-optical dual-mode detection in different kinds of diseases. • Stating the excellent schemes of combining electrochemistry with different kinds of optical methods in disease detection. • An in-depth analysis of the benefits and drawbacks of several electrochemical-optical dual-mode detection methods. • The future prospect of different electrochemical-optical dual-mode detections in disease diagnosis are discussed. [ABSTRACT FROM AUTHOR]

Use of aluminum alloy anodes as metal fuel in electrochemical batteries has specific advantages in numerous applications. In this paper, we report novel Al alloy anodes obtained by adding In and Bi to a reported Al ternary-element alloy, Al-Zn-Sn. An electron probe microanalyzer is used to obtain the elemental composition of Al-5Zn-0.1Sn, Al-5Z-0.1Sn-0.1In, and Al-5Zn-0.1Sn-0.1In-0.1Bi. Tafel analysis, electrochemical impedance spectroscopy, and constant-current chronopotentiometry are performed for electrochemical analysis. In addition, the self-corrosion of the alloys is examined to determine the hydrogen evolution and anode discharge stability. These results indicate that Al-5Zn-0.1Sn-0.1In-0.1Bi has the highest anode performance. On the basis of the scanning electron microscopy and transmission electron microscopy microstructure analysis, we propose that the dissolution and sedimentation process induced by Bi nanoprecipitates may activate a passive Al surface, significantly enhancing the discharge efficiency. • Al-5Zn-0.1Sn-0.1In-0.1Bi alloy is first synthesized which displays high discharging performance in battery applications. • XRD, SEM, and TEM showed the minor crystals and grains in Al-5Zn-0.1Sn-0.1In-0.1Bi. • The self-corrosion is examined indicating a dissolution mechanism of the Al alloy. • In and Bi in the Al alloy collapsed during discharge, which refreshed the passivated Al surface. [ABSTRACT FROM AUTHOR]

• In this paper, we report the corrosion inhibition of amino acid imidazole ionic liquids ([CyVIm][AA]ILs) on mild steel in neutral media, which has not been studied before. • In addition, the corrosion inhibition performance of [CyVIm][AA]ILs in neutral media was evaluated comprehensively by a combination of experiments and simulations as well as an in-depth investigation of the corrosion inhibition mechanism. The corrosion inhibition properties of three amino acid imidazole ionic liquids ([CyVIm][AA]) as corrosion inhibitors for mild steel in a 3.5 wt% NaCl corrosion medium were evaluated by electrochemical measurements. The polarization experiments show that [CyVIm][AA] influences anode reaction processes, demonstrating that [CyVIm][AA] is an anodic inhibitor type corrosion inhibitor. [CyVIm]Try outperforms [CyVIm]His and [CyVIm]Pro in terms of corrosion inhibition. The results of surface analysis and quantum chemical calculations show that [CyVIm]Try can form a protective film on the surface of mild steel and inhibit surface corrosion. Furthermore, by applying molecular dynamics simulations, after investigating the corrosion inhibitor adsorption trends on the Fe (1 1 0) surface, the interaction order between the molecular framework of the Fe corrosion inhibitor and the Fe (1 1 0) surface for entanglement was determined. According to the radial distribution function, the corrosion inhibitor adsorption mode on the metal surface is composite adsorption with chemisorption as the major mode and physical adsorption as the secondary mode. [ABSTRACT FROM AUTHOR]

• Porphyrins with different number of electroactive substituents. • Effect of porphyrin structure on the film formation and film properties. • Mechanism and kinetic of oxygen electroreduction on the films. • Difference in films morphology, activity and, probable, in catalytic site density. The paper analyzes how the structure of porphyrin affects its electrochemical characteristics, film formation process and physicochemical properties of the obtained materials. A comparison of the redox processes of 21H,23H-5,15-bis-(4-aminophenyl)-10,20-di-phenyl porphyrin (Porph I) and 21H,23H-5,10,15-tris-(4-aminophenyl)-20-phenyl porphyrin (Porph II) shows that Porph I is more stable in oxidation and less stable in reduction processes than Porph II. The presence of electrochemically active amino groups in the composition of the porphyrin molecules allows the superoxide-assisted electrochemical deposition method to be applied to successfully form poly-Porph I and poly-Porph II films from dimethyl sulfoxide solutions. Spectral methods confirm that the obtained materials preserve their porphyrin structure. The structure of the initial monomer molecules is demonstrated to affect the film formation and surface morphology of the prepared materials. Oxygen electroreduction in an alkaline medium is shown to have smaller kinetic limitations on poly-Porph II films than that on poly-Porph I ones. [ABSTRACT FROM AUTHOR]

• Similarity between natural corrosion and accelerated experiment is evaluated. • The number and location of corrosion peaks are statistically consistent. • Corrosion configurations are very likely to be similar within the rear region. • Reversal of corrosion configuration in the front region is possible. Concrete structures can be seriously deteriorated by the corrosion of steel reinforcement lasting for decades under realistic environment. It is still controversial whether and how the natural corrosion can be reasonably accelerated in experimental simulation. This paper focuses on the probabilistic similarity of corrosion pattern by comparing the normalized configuration of natural corrosion and galvanic accelerated experiment. The former is obtained by conducting the Monte-Carlo simulation of the electrochemical process based on the meso -scale model of concrete, whist the latter is analysed using digital image correlation method. The results indicated that their number and location of corrosion peaks are statistically consistent. The configurations of corrosion are very likely to be similar within the rear region of steel reinforcement in most cases, whereas possibly to be reversed in the front inward region and front outward region. The similarity is affected by the geometry of designed specimen and humidity of simulated environment. [ABSTRACT FROM AUTHOR]

• In the present paper, we highlight the role of oxophilic Al atom in the Cu(111) surface for the CO 2 adsorption and in the subsequent reduction reactions. • Our periodic density functional theory (DFT) calculations show that introduction of the oxophilic Al atom into the Cu(111) surface effectively improves the CO 2 adsorption ability via formation of a Alδ+- (Cu6)δ- configuration on the Al/Cu(111) surface. • The adsorbed CO2 was easily reduced to CO via a unique dissociated adsorption process induced by the oxophilic Al center. Our energy calculations show that introduction of the Al atom into the Cu(111) surface is both thermodynamically and kinetically favorable for CO dimerization when compared with the pristine Cu(111) surface. And the Al center acts as an electron-transfer medium for the coupling of two CO molecules over Al/Cu(111) surface. Inspired by the work of Sargent et al. (Nature , 2020, 581 , 178–183), the oxophilic Al atom was introduced into the Cu(111) surface to design a Al/Cu(111) bimetallic catalysts for implementing electrochemical CO 2 reduction reaction based on the first-principles calculations. The results indicate that introduction of the oxophilic Al atom into the Cu(111) surface effectively improves the CO 2 adsorption ability via formation of a Alδ+- (Cu 6)δ− configuration on the Al/Cu(111) surface. And the adsorbed CO 2 was easily reduced to CO via a unique dissociated adsorption process induced by the oxophilic Al center. Our energy calculations show that introduction of the Al atom into the Cu(111) surface is both thermodynamically and kinetically favorable for CO dimerization when compared with the pristine Cu(111) surface. And the Al center acts as an electron-transfer medium for the coupling of two CO molecules over Al/Cu(111) surface. Finally, our mechanism investigation shows that the presence of oxophilic Al atom in the Cu(111) surface effectively improves the selectivity of ethanol product via the formation of the Al-O bond along the hydrogenation path. [Display omitted] [ABSTRACT FROM AUTHOR]

• B2 phases in Al 0.3 CoCrFeNi HEAs are purposely controlled by annealing treatment. • Effect of B2 phases on corrosion resistance of Al 0.3 CoCrFeNi HEAs is studied. • The B2 phases deteriorate the pitting corrosion resistance of Al 0.3 CoCrFeNi HEAs. • B2 phases act as preferential pit nucleation sites and facilitate pit propagation. The corrosion resistance of Al-Co-Cr-Fe-Ni high entropy alloys (HEAs) is probably affected by B2 phases. In this paper, the effect of B2 phases on the corrosion behavior of Al 0.3 CoCrFeNi HEAs in 3.5 wt% NaCl solution is clarified in this paper by purposely controlling the formation of B2 phases using annealing treatment. The microstructure characterization reveals that the content of (Al, Ni)-rich and Cr-poor B2 phases increases and the electrochemical measurements show that the pitting corrosion resistance is deteriorated as the annealing temperature decreases. Accordingly, the B2 phase is confirmed to be detrimental to the corrosion resistance of Al 0.3 CoCrFeNi HEAs. It can be attributed to the preferential dissolution of B2 phases causing easier pit initiation, which is evidenced by the corrosion morphology observation and scanning Kelvin probe force microscopy measurements, and to the slower repassivation rate leading to easier pit propagation, as demonstrated by the quantitative analysis of potentiostatic polarization curves. [ABSTRACT FROM AUTHOR]

A new power-to-X desulfurization technology has been examined. The technology uses only electricity to oxidize the hydrogen sulfide (H 2 S) found in biogas to elemental sulfur. The process works by using a scrubber where the biogas comes into contact with a chlorine containing liquid. This process is capable of removing close to 100% of H 2 S in biogas. In this paper a parameter analysis of process parameters has been carried out. In addition a long term test of the process has been performed. It has been found that the liquid flow rate has a small but notable influence on the process' performance on removing H 2 S. The efficiency of the process largely depends on total amount of H 2 S flowing through the scrubber. As the H 2 S concentration increases, the amount of chlorine required for the removal process is also increased. A high amount of chlorine in the solvent may lead to unwanted side reactions. [Display omitted] • A PtX technology capable of removing hydrogen sulfide from gas has been developed. • Electrochemically regenerated chlorine oxidizes hydrogen sulfide to solid sulfur. • The technology can purify gas to a high degree and is quickly adaptable. • The solvent flow has only a small effect on the efficiency of the process. • The process is stable over longer periods of operation. [ABSTRACT FROM AUTHOR]

Metronidazole (MNZ) is non-biodegradable and highly soluble in water, it is easy to accumulate in the aquatic environment, which has toxic effects in clinical applications such as causing peripheral neuritis, cardiogenic shock and pseudomembranous colitis. In this paper, Co/NC@w-NiSO 4 ·NiS 2 nanospheres were successfully constructed by coating w-NiSO 4 ·NiS 2 on the surface of ZIF-67 as the growth substrate via hydrothermal method and subsequent calcination for electrochemical detection of metronidazole (MNZ). The nanostructure and composition of the materials were confirmed by SEM, TEM, FT-IR and XPS. The sensitivity of Co/NC@w-NiSO 4 ·NiS 2 sensor for MNZ detection is 1977.14 μA/(mM·cm2); the limit of detection (LOD) is as low as 0.009 μM and the linear range is 1 ∼ 200 and 200 ∼ 1000 μM. Moreover, the modified sensor can resist the interference from many traditional living substances, and has good reproducibility and stability. High catalytic activity requires effective molecular transport and exposure of active sites. The successful construction of Co/NC@w-NiSO 4 ·NiS 2 nanostructure promotes the dispersion of materials and the migration of reactants on the electrode surface, and the w-NiSO 4 ·NiS 2 coating on the irregular particles of ZIF-67-derived cobalt/nitrogen-doped carbon suppressed the stacking of the w-NiSO 4 ·NiS 2 nanosheets to expose more catalytic sites. These factors are conducive to increasing the catalytic activity of the modified sensor for highly sensitive MNZ detection and ensuring the activity of catalyst in multiple catalytic cycles. [Display omitted] • Co/NC@w-NiSO 4 ·NiS 2 composite was synthesized via hydrothermal method and pyrolysis. • The composite suppressed the stacking of nanosheets to expose more catalytic sites. • The sensitivity of electrochemical sensor is 1977.14 μA/(mM·cm2). • The electrochemical sensor was used for MNZ analysis in human blood plasma samples. [ABSTRACT FROM AUTHOR]

Titanium oxide has been widely studied in the field of electrochromism due to its unique color-changing behavior induced by ion insertion. In this paper, amorphous Gd-doped TiO 2 films were synthesized via the RF magnetron reactive sputtering. The effects of Gd doping on the electrochromic performance of TiO 2 films were explored in detail. The improved coloration efficiency of ∼60% at 540 nm for low Gd-doped TiO 2 film (0.61%) is due to the formation of monoclinic Gd 2 O 3 island nanostructure on the surface of TiO 2 , which enhances the reaction kinetics and charge capacity of the film. The wide optical modulation (73% at 650 nm), large coloration efficiency (59.7 cm2 C−1 at 650 nm) and short response time (coloring time is 16.9 s, bleaching time is 9.1 s) were obtained for the moderately Gd-doped TiO 2 film (0.83%). However, for the high Gd-doped TiO 2 films (≥1.0%), the coloration efficiency reduced, which is due to the excessive Gd 2 O 3 hindered the electrolyte penetration into the TiO 2 active material. By studying the effects of Gd doping on the electrochemical performance of TiO 2 , it can provide a valuable reference for determining the appropriate doping element and content for electrochromic materials. • Amorphous Gd-doped TiO 2 films are prepared by the RF magnetron reactive sputtering. • The effects of Gd doping on the electrochromic properties of the films are explored. • The films exhibit the high optical modulation (73% at 650 nm). • The films also exhibit the large coloration efficiency (59.7 cm2 C−1 at 650 nm). [ABSTRACT FROM AUTHOR]

To achieve superamphiphobic properties on the surface of copper, a novel strategy for fabricating multi-level micro-nano superamphiphobic membranes by laser-electrochemistry subtractive-additive manufacturing method is explored. To test the properties of the metal surface prepared by this method, a variety of testing experiments are carried out. The experiment results shows that the contact angle (CA) of water and oil droplets are 161° ± 4° and 151° ± 4°, while those rolling CAs are 2° and 10°, which shows that the prepared surface had excellent superamphiphobic properties. Through the wettability test at different temperatures, the surface hydrophobicity of the prepared samples at low temperature 5 °C is worse than that at a room temperature 25 °C. According to droplet bounce test, the water drops experiences two complete bouncing processes on the surface of the prepared samples when the laser scanning interval is equal to the laser spot diameter, which indicates that the stable Cassie state is related to the multi-level micro-nano structures. In addition, the superamphiphobic surfaces fabricated in this paper have perfect functionality and stability, which provides a novel method for the potential application in the automotive, aerospace, and shipbuilding industries. [Display omitted] [ABSTRACT FROM AUTHOR]

The separation of the superimposed electrochemical signals of intracellular guanine (G) and xanthine (X) is difficult, which is great obstacle to the application of cell electrochemistry. In this paper, independent functional modules, G-functional module (G-FM) and X-functional module (X-FM), were constructed by molecular imprinting technology for sensitive detection of G and X without mutual interference, then integrated in dual-functional module cellular electrochemical sensing platform (DMCEP) as signal sensing units. DMCEP transmitted signals of G and X in cells synchronously to two windows by two signal sensing channels, and achieved the separation of superimposed signals of G and X in cells. DMCEP exhibited satisfactory reproducibility with relative standard deviation (RSD) of 3.10 and 2.22 %, repeatability with RSD of 3.72 and 3.05 % for G and X detection, and detection limit 0.05 μΜ for G and 0.06 μΜ for X. Good linear relationships between cell concentrations and the signals of G and X on DMCEP were shown in range of 0.75–85 × 106 and 3–85 × 106 cells/mL, respectively. The growth of MCF-7 cells was tracked by DMCEP, and showed consistent trend with the cell counting method, while the change of cell viability from lag to logarithmic phase captured by DMCEP was earlier than that of cell counting method. This strategy provided the foundation for the establishment of the cell viability electrochemical detection method, and new insights into the simultaneous recording of other analyses with superimposed peak positions and the simultaneous tracking of multiple biomarkers. [ABSTRACT FROM AUTHOR]

• Perchlorates in environment rise concerns, sensitive determination techniques needed. • Analysis and critical evaluation of published electrochemical perchlorate sensors. • Voltammetric methods superior over „classical" potentiometric ISE. • Electrochemical impedance and capacitance sensors - the lowest detection limit. • Capability of electrochemical sensors to replace ion/mass chromatography shown. Growing concerns about adverse effects of perchlorate (ClO 4 −) together with its relatively frequent occurrence in the environment demand sensitive analytical methods. It is also anticipated that ClO 4 − sensors will find their application in future extra-terrestrial missions. Ion chromatography (IC) and mass spectroscopy (MS) provide sufficiently low detection limit (LOD) but lack transportability and field analysis possibility that are provided by most electrochemical analytical methods. On the other side, commercially available potentiometric ion-selective electrodes (ISEs) cannot compete with IC or MS in terms of sensitivity. To answer the question whether (and how) such drawback can be overcome, in this paper electrochemical methods of ClO 4 − determination are introduced and evaluated. Starting with potentiometric ISEs which can theoretically reach LOD suitable for assessment of WHO-set limits of ClO 4 −, it is further shown that ISEs operating in voltammetric mode are superior in terms of sensitivity. Next section covers impedimetric and capacitance ClO 4 − sensors, concluding that they can reach detection limits of IC or MS while retaining their advantages. In further sections related issues are discussed including biosensing or direct electrochemical reduction of perchlorate as well as diversity of (nano)materials applicable for perchlorate sensors preparation. This critical review thus shows that electrochemical ClO 4 − sensors can reach sensitivity of standard methods while retaining their portability and ease of operation. [ABSTRACT FROM AUTHOR]

A properly designed sensing interface is crucial for the accurate and sensitive detection of biologically active molecules. Single-atom nanozymes from transition metal and nitrogen-doped carbon materials (M-N-C) have caught attention owing to their large surface area and strong bionic enzyme activity. Herein, a three-dimensional layered electrochemical electrode consisting of a Co–N–C nanoenzyme embedded in a reduced graphene oxide aerogel was prepared for the detection of hydrogen peroxide (H 2 O 2), dopamine (DA) and uric acid (UA). Due to its unique three-dimensional layered structure, rGA has excellent electrical conductivity and high material loading and is used to enhance the electrocatalytic performance of Co–N–C. The combination of single-atom nanozymes and electrochemical detection shows unique advantages in catalytic activity and selectivity. The limit of detection and detection range are 0.74 μM and 3–2991 μM respectively for H 2 O 2. Furthermore, it has been successfully implemented for the in-situ detection of H 2 O 2 in living cells. In addition, their simultaneous detection is also realized by the sensors for DA and UA. And it can accurately capture the signal of UA and DA in the urine. Meanwhile, the electrode displays satisfactory stability and repeatability. Therefore, this paper provides a new detection strategy for a variety of bioactive molecules, showing great potential in cell biology, pathophysiology and diagnostics. A novel electrochemical sensor based on single-atom nanozymes Co–N–C for bioactive molecules detection. [Display omitted] • Single-atom nanozymes Co–N–C exhibited peroxidase activity. • Co–N–C/rGA was used to detect H 2 O 2 in living cells, and successfully realized the simultaneous detection of DA and UA. • It provides a new method for the detection of bioactive molecules. [ABSTRACT FROM AUTHOR]

Extracting rubidium from high reserve salt lakes has been an important measure to cope with the growing demand for rubidium. However, due to the low concentration and high impurity ions in the salt lake, there was no rational method to extract rubidium. Prussian blue and its analogues (PBAs) with specific functional structures have shown good cycling stability for K+ and Rb+ with large ionic radii in the field of batteries and their special affinity (Li+ > Na+ > K+ > Rb+) for rubidium, which provides a new idea for the extraction of rubidium from salt lakes. In this paper, the cyclic electrochemical performance of synthesized copper ferricyanide (Cu 3 [Fe (CN) 6 ] 2) for rubidium was tested. Furthermore, a new method of rubidium extraction from salt lake was proposed by using potassium as the shuttle ion. The (K 2 Cu 3 [Fe (CN) 6 ] 2) obtained by intercalating K+ into copper hexacyanoferrate (Cu 3 [Fe (CN) 6 ] 2) with the electrochemical method was used to extract rubidium from simulated brine and the separation coefficients β Rb: K , β Rb: Na , β Rb: Ca and β Rb: Mg were 63, 1635, 585 and 2543, respectively. After that, rubidium was deintercalated by electrochemical oxidization of Rb 2 Cu 3 [Fe (CN) 6 ] 2 and the deintercalated efficiency can be reached 98 %. Rubidium enrichment can be achieved by repeating the above process with regenerated materials. [Display omitted] • A novel method of rubidium extraction from simulated salt lake brine was proposed. • Rubidium was extracted directly from low concentrations of simulated salt lake brine. • The recycling extraction of rubidium from salt lake was realized. [ABSTRACT FROM AUTHOR]

As one of the most efficient, low-cost, and readily available electrocatalysts for oxygen evolution reaction (OER) in alkaline environments, the nickel-iron electrocatalyst is of great significance to commercial water splitting. In this study, NiFe-layered double hydroxide loaded on nickel foam (NiFe-LDH/NF) was synthesized via a simple one-step hydrothermal method, whose OER catalytic performance could be successfully optimized by further electrochemical reconstruction. The results show that NF is an effective precursor to loading crystallized Ni(OH) 2 nanoparticles during hydrothermal synthesis, leading to the generation of high-performance NiOOH during OER reconstruction. Under the optimal Ni:Fe feeding ratio, Ni 2 Fe 1 -LDH/NF requires an ultra-low OER overpotential of 239 mV at 50 mA cm−2 and 260 mV at 100 mA cm−2, whose Tafel slope is only 64.1 mV dec−1. Impressively, Ni 2 Fe 1 -LDH/NF also achieves an ultra-low voltage of 1.44 V at 10 mA cm−2 with excellent long-term stability for overall water splitting. Unlike the previous viewpoint that only Ni species dominate surface reconstruction of NiFe-LDH, in this article the decisive influence related to Fe species on the reconstruction layers' activity and stability is confirmed by electrochemistry, Raman, and XPS analysis during reconstruction process. During OER reconstruction, the surface Ni:Fe ratios can be "self-adaptively" regulated to an appropriate region, thus the stable reconstruction layers rich in NiOOH can be formed as the protective shells for NiFe-LDH. Furthermore, such "self-adaptive" reconstruction, assisted with appropriate initial Ni:Fe feeding ratios, can also stimulate more Ni3+ active sites for OER, benefitting the outstanding catalytic performance of NiFe-LDH/NF for overall water splitting and prospective large-scale application. [Display omitted] • There are some highlights in this paper may be found interested by the general readers. • Unstable iron-rich phases start self-adaptively electrochemical reconstruction. • Self-adaptive reconstruction promotes the OER catalytic activity and stability. • The optimal electrocatalyst exhibits 260 mV overpotential at 100 mA·cm−2 for OER. • The electrocatalyst only needs 1.44 V at 10 mA·cm−2 for overall water splitting. [ABSTRACT FROM AUTHOR]

In this paper, self-supported and binder-free α-Ni(OH) 2 nanosheet arrays decorated with carbon quantum dots (CQDs/α-Ni(OH) 2) are prepared using one-step hydrothermal method. The optimal electrode exhibits high specific capacitance of 1724.0 F/g at 3 A/g, which is 2.3 times higher than the 750.7 F/g of bare α-Ni(OH) 2. 45.8% of capacitance retention rate is achieved with the current density increasing from 3 to 50 A/g. Hierarchical structure of α-Ni(OH) 2 and the assistance of CQDs endow CQDs/α-Ni(OH) 2 with enhanced reactive sites and improved electrical conductivity, achieving high electrochemical performance. Asymmetric supercapacitors assembled with CQDs/α-Ni(OH) 2 and activated carbon (AC) deliver a high-energy density of 44.0 Wh/kg at 3000 W/kg and retain an energy density of 29.03 Wh/kg at 18,015 W/kg. 99.91% of the initial capacitance and 99.46% of the Coulombic efficiency are maintained after 5000 cycles at 10 A/g. This study provides a new approach to design high-performance electrodes for supercapacitors. [Display omitted] [ABSTRACT FROM AUTHOR]