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Bis(diimino)metal complex nanosheets composed of metal ions and hexaaminobenzene ligands (MHABs) are fascinating two-dimensional materials which have been gaining significant attention as electrode materials and electrocatalysts owing to their electrical conductivities, redox properties, and porous structures obtained by the π-conjugated system and regular metal complex arrangement. Although electrochemical oxidation enables the simple and direct formation of MHABs on electrodes within a couple of minutes only, the obtained MHABs are relatively rough and of low crystallinity. This study investigated the effects of the applied potential during the synthesis, the type of base, and the concentrations of bases and building blocks on the synthesis of NiHAB nanosheets. Optical microscopy (OM), atomic force microscopy (AFM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and grazing-incidence X-ray scattering (GIXS) results revealed that a low oxidation potential, high concentration of the ammonia solution, and low concentration of the building blocks in the reaction solution provided a nanometre-thick NiHAB layer. Under the optimal reaction conditions, NiHAB nanosheets were successfully synthesized in a face-on orientation manner on gold electrodes using electrochemical oxidation methods. Furthermore, the anisotropic electrochemical synthesis of CuHAB was achieved under the optimised conditions. The mechanism of the MHAB growth process with an anisotropic orientation and nanometre thickness was proposed and attributed to the flat adsorption of p-conjugated oligomers composed of bis(diamino)metal moieties in a solution onto an electrode surface and the electrochemical oxidation and deprotonation of the adsorbates on the electrode. [ABSTRACT FROM AUTHOR]

Developing non-precious, stable, and highly efficient electrocatalyst materials is crucial for large-scale practical HER applications. Ni3S2 is a prominent catalyst due to its high efficiency and ease of preparation. Nevertheless, its usability is restricted by poor Ni site water molecule adsorption and strong hydrogen bonding between sulphur and hydrogen. The concentration of precursors and samples' morphology significantly affect the electrochemical performance of electrodes intended for the hydrogen evolution reaction (HER) application. This study examines how Mo transition metal sulfide concentration influences the Mo–Co–Ni3S2/NF catalyst's structural aspects and its subsequent electrochemical performance. In situ hydrothermal processing is used to prepare the samples through a two-step process. The samples exhibit enhanced electrocatalytic properties. Specifically, comparatively low overpotentials of 215 mV and 332 mV were observed at current densities of 10 mA cm−2 and 50 mA cm−2, respectively. Additionally, a Tafel slope of 104 mV dec−1 was recorded at a 75 : 25 ratio of molybdenum to cobalt concentration. The samples also demonstrate excellent stability. [ABSTRACT FROM AUTHOR]

In this work, nickel-catecholate (Ni-CAT) nanorods were in situ compounded on graphene oxide (GO) to form a composite Ni-CAT@GO (NCG) with a special "blanket-shape" structure, which was used as an electrode material for supercapacitors. The morphology of Ni-CATs in situ grown on GO was modulated by introducing various contents of GO. With increasing GO, the length of nanorods of Ni-CATs is obviously shortened, and the charge transfer resistance of NCG is significantly reduced as the GO content is relatively low while it increases with further addition of GO, because excessive GO in NCG results in smaller crystal sizes accompanied by smaller stacking pores. Both the over-long Ni-CAT nanorods and the smaller stacking pores can restrict the accessible surface areas for the electrolyte. Optimal nanorod sizes are crucial to achieve good electrochemical performance for electrode materials. Galvanostatic charge–discharge analysis of NCG electrodes shows that their capacity initially increases and then decreases with the addition of more and more GO, and Ni-CAT@GO-0.5 (NCG0.5) with minimal charge transfer resistance exhibits the best electrochemical performance. The results demonstrate that the NCG0.5 electrode with optimal morphology possesses an excellent capacitance of 563.8 F g−1 at 0.5 A g−1 and a good rate performance of 61.9% at 10 A g−1, indicating that Ni-CAT@GO is a new type of promising electrode material for supercapacitors based on conductive metal–organic frameworks. [ABSTRACT FROM AUTHOR]

NaVPO4F has become a focal point in the realm of sodium-ion battery cathode materials owing to its robust structure, elevated voltage platform, and considerable theoretical capacity. Nonetheless, the limited conductivity of NaVPO4F poses a challenge to its practical utilization. In this study, we introduce a straightforward one-step ball milling process to address this issue by creating NaVPO4F/G (G stands for graphite) and enhancing electronic conductivity through the incorporation of polyethylene glycol 6000 (PEG6K). Graphite has the capability to enhance electrochemical properties and markedly enhance electronic conductivity. Furthermore, the incorporation of PEG6K can enhance the transport stability of sodium ions at the interface of sodium-ion batteries. After optimization, NaVPO4F/G@P (P stands for PEG6K) delivers a high capacity of 128.5 mA h g−1 at 0.2C and a high rate capacity of 105.0 mA h g−1 at 10C, with a capacity retention rate of 116.0 mA h g−1 after 200 cycles. Moreover, when coupled with a HC anode (HC as the negative electrode), the full cell still displays an outstanding performance of 76.0 mA h g−1 at 20C. A simple approach is provided in our study that has the potential to significantly improve the performance of sodium-ion batteries. [ABSTRACT FROM AUTHOR]

Electro-osmotic drainage technology is especially suitable for low-permeability clay soil. The electrode–clay interface is believed to play a crucial role in electro-osmosis. Previous documents have highlighted the importance of the electrochemical processes at the electrode–clay interface, but few studies exist with respect to the influencing mechanisms. Therefore, the influencing mechanisms of the electrochemical processes on the electrode–clay interface have been thoroughly studied herein, both theoretically and experimentally. An interfacial resistance model in the electro-osmotic system is proposed based on the interfacial kinetic reactions of metal electrodes and graphite electrodes according to electrochemical theory. The reliability of the proposed model is demonstrated by chamber tests. The proposed model states that the most critical factor influencing interfacial resistance is the current density on the electrode surface. Other crucial influencing factors for interfacial resistance include the electrode material, surface status, pH of the pore solution, soil void ratio, conductive properties and adsorption properties. [ABSTRACT FROM AUTHOR]

Due to the low price and high specific capacity, sodium ion batteries (SIBs) have become a crucial candidate for the future large‐scale energy storage power station, providing strong support for energy transition. Layered transition metal oxides (LTMOs), as one of the most promising cathode materials for SIBs, are usually accompanied by the sodiation/de‐sodiation during charging/discharging, which leads to the slippage and deformation of the layered structure, and consequently causes to the degradation of electrochemical performance. The degradation mechanisms of LTMOs attributed to the structural change are important references for improving the electrochemical performance of cathode materials. Here, this paper presents the main degradation mechanisms such as irreversible anion redox reaction, Na+/vacancy ordering transition and poor air stability as well as the corresponding modification means. It also summarizes the challenges faced by sodium‐ion LTMOs cathode materials, and gives an outlook on the key issues that need to be solved for future development. [ABSTRACT FROM AUTHOR]

BACKGROUND: Nickel foam (NF) is widely used as battery electrode matrix and electrochemical process cathode. However, the surface of NF is prone to oxidation, which may affect its ability to reduce oxygen and produce H2O2, but the influence mechanism is still unclear. In this paper, surface oxidation of the NF was regulated by pickling and drying pretreatment, and the surface oxides were characterized by X‐ray photoelectron spectroscopy (XPS) and energy dispersive X‐ray spectrometry (EDS). The NF was used as the substrate, graphite powder as the catalyst, and PTFE as the binder to prepare graphite‐coated NF composite electrodes. The effect of NF surface oxidation on their ability to generate H2O2 was investigated. RESULTS: The results demonstrated that after pickling and drying, the NF surface generated a large amount of NiO, which increased the charge transfer resistance of the NF by 20.3%, and accelerated further reduction decomposition of H2O2. The rotating ring‐disk electrode (RRDE) tests further confirmed that NiO can reduce the two‐electron oxygen reaction selectivity, which was detrimental to H2O2 electrosynthesis. The graphite‐coated NF composite electrode with pristine NF as the substrate can produce 869.1 mg L−1 of H2O2 and maintain relatively good reusability. CONCLUSION: Overall, the surface oxidation of NF is not conducive to H2O2 electrosynthesis, and it is necessary to prevent oxidation during electrode preparation. This study provides a valuable reference for the preparation of NF electrodes and can promote the further study of in situ H2O2 electrosynthesis. © 2023 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

Organic electrochemical transistors (OECTs) hold great potential in various applications, including biosensing and neural network computation. Traditional "all-in-one" OECT device architecture faces the problems of unclear amplification mechanisms and complex side reactions, to name a few. The reaction cell OECT (RC-OECT) device architecture, proposed by Ting et al. [Adv. Funct. Mater. 31(19), 2010868 (2021)], effectively resolves these problems. Furthermore, in many applications of OECTs, such as high throughput (bio)sensing, an OECT device array instead of a single OECT is needed. Therefore, the size (area) of the OECT device, which represents the amount of occupied chip real estate and the integration of the device, matters. In this paper, we developed a hydrogen peroxide sensor based on the RC-OECT. We utilized an RC cathode modified by the poly(3,4-ethylenedioxythiophene) polystyrene sulfonate film and a Ag/AgCl OECT gate electrode for facilitating device integration, varied RC anode area, and achieved optimization of at least one of the two parameters, sensitivity and lower limit of detection (LLoD), in conjunction with the level of integration of the device. Multiple quantitative sensitivity metrics have been adopted in this work. We also evaluated the correlation between RC anode area and LLoD. In addition, a mechanistic analysis of the RC-OECT device structure, in terms of faradic and non-faradaic currents, was carried out to illustrate the interplay between sensing performance and the electrode area of the reaction cell. This mechanistic analysis provides insights for miniaturizing OECT devices with the RC-OECT architecture. [ABSTRACT FROM AUTHOR]

In this study, in-situ cerium-assembled tungsten oxide carbon nanofibers were successfully prepared via simple electrospinning and calcination technology and were used as flexible electrodes without conductive agent and adhesive. It was confirmed that the introduction of Ce has better maintained the continuous morphology of one-dimensional fibers to provide a continuous uninterrupted reaction position by the SEM TEM and XPS results. The addition of cerium improved the wettability of the material, which was propitious to the penetration of the electrolyte, made the electrolyte more fully contact with the active site, and enhanced the interface transmission effectiveness by the liquid contact angle test. Otherwise, the XRD and XPS results exhibited that the addition of cerium has caused the lattice expansion of the tungsten oxide, which generated the self-adjustable strain relaxation ability of electrode material in the process of continuous constant voltage charge and discharge. It proved that the introduction of cerium has promoted electron transfer, which improved the electrochemical performance of electrode material. In this paper, compared with WO 3 -CNFs without Ce, the Ce/WO 3 -CNFs have wide lattice spacing and hydrophilicity, fully contact with the electrolyte in the electrochemical reaction, and provide high electron transfer ability. The Ce/WO 3 -CNFs shows the maximum specific capacitance (407 F g−1) and excellent cycling stability (10,000 cycles at 5 A g−1 with a retention rate of 80 %). Otherwise, the flexible asymmetric supercapacitor device was prepared using the Ce/WO 3 -CNFs as cathode, and the CNFs as the anode, which exhibited the maximum energy density was 35.75 Wh kg−1 and a power density was 362.54 W kg−1 at 0.5A g−1. The results show that rare earth doping is an effective way and that the Ce/WO 3 -CNFs are promising electrode materials for supercapacitors. For the first time, in-situ cerium-assembled tungsten oxide carbon nanofibers were successfully prepared via simple electrospinning and calcination technology, which could directly serve as a flexible electrode without conductive agent and adhesive. And then, the flexible solid-state asymmetric supercapacitor was prepared using the Ce/WO 3 -CNFs as the cathode, the CNFs as the anode, and a PVA/KOH gel as electrolytes. [Display omitted] • The Ce/WO 3 -CNFs is used as binder-free electrode for supercapacitor. • Cerium improves the electrochemical performance of WO 3. • The improvement of electrode material wettability promotes the transportation of ions and electron between electrode and electrolyte. [ABSTRACT FROM AUTHOR]

The development prospects of conventional Li-ion batteries are limited by the paucity of Li resources. Mg–Li hybrid batteries (MLIBs) combine the advantages of Li-ion batteries and magnesium batteries. Li+ can migrate rapidly in the cathode materials, and the Mg anode has the advantage of being dendrite-free. In this study, a type of Li4Ti5O12 composite material doped with Sn4+ and a conductive carbon skeleton (Li4Ti4.9Sn0.1O12/C, Sn0.1-LTO/C) was prepared by a simple one-pot sol–gel method. The doped Sn4+ replaces part of Ti4+ in the crystal lattice, which makes Ti3+ require charge compensation, thus improving the ionic conductivity. The intervention of the conductive carbon skeleton further improves the conductivity of the Sn0.1-LTO/C composite material. The performance of Sn0.1-LTO/C as the cathode of MLIBs is explored. The initial discharge capacity was 159.1 mA h g−1 at 0.5 C, and it was maintained at 105 mA h g−1 even after 500 cycles. The excellent electrochemical performance is attributed to a small amount of Sn doping and the involvement of the conductive carbon skeleton, which indicated that the Sn0.1-LTO/C composite material provides great potential application in MLIBs. [ABSTRACT FROM AUTHOR]

NASICON‐type sodium vanadium phosphate (Na3V2(PO4)3, or NVP) cathode materials have great potential for fast charging and long cycling sodium‐ion batteries (SIBs) similar to lithium iron phosphate (LiFePO4, or LFP) cathode materials used in lithium‐ion batteries (LIBs). However, the cycle life and energy density in the full cell using NVP materials need to be significantly improved. This paper investigates the degradation mechanisms of NVP‐based SIBs and identifies the Na loss from the cathode to the anode solid electrolyte interphase (SEI) reactions as the main cause of capacity degradation. A new Na‐rich NVP cathode (e.g., Na4V2(PO4)3, or Na4VP) is developed to address the Na loss problem. Conventional NVP can be easily transformed into the Na4VP by a facile and fast chemical solution treatment (30 s). Na‐free‐anode Na4VP and hard carbon‐Na4VP full cells are assembled to evaluate the electrochemical properties of the Na‐rich NVP cathode. The Na4VP cathode provides excess Na to compensate for the Na loss, resulting much longer cycle life in the full cells (>400 cycles) and a high specific energy and power density. Good low‐temperature performance is also observed. [ABSTRACT FROM AUTHOR]

As a soluble dietary fiber, pectin has the functions of lowering cholesterol, reducing weight and improving human immunity. However, nowadays, many studies have been reported on the extraction of pectin, but few on its quantitative analysis. In this paper, graphene modified copper foam and copper sheet were used as working electrodes, respectively. Pt electrode as counter electrode and Ag/AgCl (saturated KCl solution) electrode was used as reference electrode to build electrochemical detection system. The electrochemical responses to pectinose solution were measured by voltammetry (CV) and chronoamperometry (i-t). The detection data were analyzed to develop pectinose quantitative analysis model. Results indicated that the proposed method could determine pectinose concentration in solution, and graphene modified copper foam presented better responses. The sensitivity was 0.68851A cm−2 mmol/L, the detection limit was 0.24825 mol/L. This method presents some advantages including fast response, easy operation, and low cost. It provides a new method for pectinose quantitative detection. [ABSTRACT FROM AUTHOR]

Lithium vanadium oxide (Li3VO4, LVO) is a promising anode material for lithium-ion batteries (LIBs) due to its high theoretical capacity (394 mAh g−1) and safe working potential (0.5–1.0 V vs. Li+/Li). However, its electrical conductivity is low which leads to poor electrochemical performance. Graphene (GN) shows excellent electrical conductivity and high specific surface area, holding great promise in improving the electrochemical performance of electrode materials for LIBs. In this paper, LVO was prepared by different methods. SEM results showed the obtained LVO by sol-gel method possesses uniform nanoparticle morphology. Next, LVO/GN composite was synthesized by sol-gel method. The flexible GN could improve the distribution of LVO, forming a high conductive network. Thus, the LVO/GN composite showed outstanding cycling performance and rate performance. The LVO/GN composite can provide a high initial capacity of 350.2 mAh g−1 at 0.5 C. After 200 cycles, the capacity of LVO/GN composite remains 86.8%. When the current density increased from 0.2 C to 2 C, the capacity of LVO/GN composite only reduced from 360.4 mAh g−1 to 250.4 mAh g−1, demonstrating an excellent performance rate. [ABSTRACT FROM AUTHOR]

Micro and nano interdigitated electrode array (µ/n-IDEA) configurations are prominent working electrodes in the fabrication of electrochemical sensors/biosensors, as their design benefits sensor achievement. This paper reviews µ/n-IDEA as working electrodes in four-electrode electrochemical sensors in terms of two-dimensional (2D) planar IDEA and three-dimensional (3D) IDEA configurations using carbon or metal as the starting materials. In this regard, the enhancement of IDEAs-based biosensors focuses on controlling the width and gap measurements between the adjacent fingers and increases the IDEA's height. Several distinctive methods used to expand the surface area of 3D IDEAs, such as a unique 3D IDEA design, integration of mesh, microchannel, vertically aligned carbon nanotubes (VACNT), and nanoparticles, are demonstrated and discussed. More notably, the conventional four-electrode system, consisting of reference and counter electrodes will be compared to the highly novel two-electrode system that adopts IDEA's shape. Compared to the 2D planar IDEA, the expansion of the surface area in 3D IDEAs demonstrated significant changes in the performance of electrochemical sensors. Furthermore, the challenges faced by current IDEAs-based electrochemical biosensors and their potential solutions for future directions are presented herein. [ABSTRACT FROM AUTHOR]

In order to meet the growing energy demand, it is of great significance to develop high-performance electrochemical energy storage materials. In this paper, mesoporous Co-Fe nanowires binary hydroxide electrode materials were synthesized by a simple and effective hydrothermal method. Co-Fe binary hydroxide electrode materials are composed of a large number of nanowires with specific surface area of 7.34 m2 g−1 and the average pore size of 12.78 nm. The discharge-specific capacity of the electrode materials is 130.85 mA h g−1 at the current density of 1 A g−1. After charging and discharging at a current density of 5 A g−1 for 1000 time, the discharge-specific capacity retention rate of Co-Fe binary hydroxide electrode materials is 56.5%, and the Coulombic efficiency is almost 100%. Co-Fe binary hydroxide electrode materials show excellent electrochemical performance, indicating that doping with elements with similar chemical properties and multivalent states can effectively improve the electrochemical performance of electrode materials. This idea of doping with elements with similar chemical properties and multivalent states has a certain reference value for improving the performance of electrode materials. [ABSTRACT FROM AUTHOR]

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Carbon materials, including graphite, hard carbon, soft carbon, graphene, and carbon nanotubes, are widely used as high‐performance negative electrodes for sodium‐ion and potassium‐ion batteries (SIBs and PIBs). Compared with other materials, carbon materials are abundant, low‐cost, and environmentally friendly, and have excellent electrochemical properties, which make them especially suitable for negative electrode materials of SIBs and PIBs. Compared with traditional carbon materials, modifications of the morphology and size of nanomaterials represent effective strategies to improve the quality of electrode materials. Different nanostructures make different contributions toward improving the electrochemical performance of electrode materials, so the synthesis of nanomaterials is promising for controlling the morphology and size of electrode materials. This paper reviews the progress made and challenges in the use of carbon materials as negative electrode materials for SIBs and PIBs in recent years. The differences in Na+ and K+ storage mechanisms among different types of carbon materials are emphasized. [ABSTRACT FROM AUTHOR]

Since there exist discharge problems in gas insulated metal-enclosed switchgear due to internal metal particle movement, the study in this paper thus, conducted an experiment and simulation research on the movement characteristics of particles, where the charge on particle and the collision recovery coefficient (CRC) was obtained. When the electrode is brass, the charge on the particle is close to the theory one and the CRC of aluminum, stainless steel and particle are 0.52, 0.75 and 0.79 respectively. Accordingly, the study, in order to take the particle charge and its collision process into consideration, established a particle movement model, and conducted a test has thereof. The results show that there exists excellent consistency between charge and its collision. According to the research, the relationship between particle size, material and collision characteristics was revealed. The result shows that under DC voltage the metal particle collision frequency decreases with the increase of particle size when the material of the particles is the same. The time difference between particles' moving to high voltage electrode and ground electrode becomes greater with the increase of the size of the particle. When the particle material is different, the collision characteristics are influenced by its density and collision recovery coefficient of restitution. Particle motion velocity loss becomes less before and after the collision when its collision recovery coefficient of restitution is larger. So the collision frequency is higher. The research results in this paper can offer some reference value to particles suppression measures in gas insulated metal-enclosed transmission line. [ABSTRACT FROM PUBLISHER]

Li/Mn‐rich layered oxide is an attractive cathode material for Li‐ion battery due to its low cost, high specific capacity, and high working potential. In this paper, the high capacity layered Li/Mn‐rich NMC cathode (Li1.2Mn0.6Ni0.1Co0.1O2) and nanocomposite blend gel polymer electrolytes (NBGPEs) are synthesized by using the sol‐gel method and solution casting technique, respectively. XRD results confirm that the cathode material has a well‐defined hexagonal layered structure. It is observed that the synthesized NBGPE containing 2 wt.% SiO2 nanofiller exhibits maximum ionic conductivity (5.2 mS cm−1), Li‐ion conductivity (~2.40 mS cm−1), and wide electrochemical stability (~5.4 V vs Li/Li+) at 30°C. The electrochemical performance of the cell (Li/NBGPE#1/Li1.2Mn0.6Ni0.1Co0.1O2) has been investigated by cyclic voltammetry and galvanostatic charge–discharge measurement. The cell delivers maximum specific discharge capacity of 212.0 mAh g−1 at 0.1C and good rate performance within 2.0‐4.8 V. At 0.2C, the cell shows stable coulombic efficiency ~98% after 200th cycle due to better interfacial stability between NBGPE#1 and the electrode. [ABSTRACT FROM AUTHOR]

Various growth processes have been utilized for the development of lithium iron phosphate including microwave treatment, spray thermal decomposition, sol-gel and the hydrothermal route. However, microwave treatment, spray process and sol-gel suffer from high costs and difficulties in controlling growth parameters. In this review paper, recent synthetic strategies, including the raw materials utilized for the hydrothermal growth of lithium iron phosphate, their effect on the basic characteristics and, as a consequence, the electrochemical performance of cathodes, are reported. The advantages of the hydrothermal process, including high material stability, eco-friendliness, low production costs and material abundance, are explained along with the respective processing parameters, which can be easily tuned to modify lithium iron phosphate characteristics such as structure, morphology and particle size. Specifically, we focus on strategies that were applied in the last three years to improve the performance and electrochemical stability of the cathode utilizing carbon-based materials, N-doped graphene oxide and multi-wall carbon nanotubes (MWCNTs), along with the addition of metallic nanoparticles such as silver. Finally, future perspectives on the hydrothermal process are discussed including the simultaneous growth of powders and solid-state electrodes (i.e., growth of lithium iron phosphate on a rigid substrate) and the improvement in morphology and orientation for its establishment and standardization for the growth of energy storage materials. [ABSTRACT FROM AUTHOR]

Lithium-ion capacitors (LICs) are a novel and promising form of energy storage device that combines the electrode materials of lithium-ion batteries with supercapacitors. They have the potential to deliver high energy density, power density, and long cycle life concurrently. Due to the good electrochemical performance of lithiated manganese-based materials in LICs, they have received extensive attention in recent years. The latest advancements in lithiated manganese-based materials as electrode materials in lithium-ion capacitors are presented here, including LiMnPO4, LiMn2O4, and Li2MnSiO4. These electrode materials have a lot of potential as high-performance energy storage materials. Apart from capacitive-type electrodes, lithiated manganese-based materials are also used in the creation of LIC battery-type electrodes. The LICs based on lithiated manganese-based electrode materials demonstrated energy density, power density, and cycle life, which are relatively comparable with various electrode material values reviewed in this paper. The electrochemical performance of lithiated manganese-based materials is attributed to the synergistic effect of the doping and the conductive carbon coating which provided new pathways for the movement of Li+ ions and electrons, thus facilitating charge transfer reactions. Although much effort has gone into synthesizing lithium-ion battery electrode materials and contracting LICs based on them because of their higher energy density, there is still work to be carried out. Additionally, the potential barriers and opportunities for LIC-based future research in energy applications are explored. [ABSTRACT FROM AUTHOR]

Nitrites are widely used in the food industry, particularly for the preservation of meat products. Controlling the nitrate content in food is an important task to ensure people's health is not at risk; therefore, the search for, and research of, new materials that will modify the electrodes in the electrochemical sensors that detect and control the nitrate content in food products is an urgent task. In this paper, we describe the electrochemical behavior of a glass carbon electrode (GCE), modified with a Fe(II) tetra-tert-butyl phthalocyanine film (FePc(tBu)4/GCE), and decorated with gold nanoparticles (Au/FePc(tBu)4/GCE); this electrode was deposited using gas-phase methods. The composition and morphology of such electrodes were examined using spectroscopy and electron microscopy methods, whereas the main electrochemical characteristics were determined using cyclic voltammetry (CV) and amperometry (CA) methods in the linear ranges of CV 0.25–2.5 mM, CA 2–120 μM in 0.1 M phosphate buffer (pH = 6.8). The results showed that the modification of bare GCEs, with a Au/FePc(tBu)4 heterostructure, provided a high surface-to-volume ratio, thus ensuring its high sensitivity to nitrite ions of 0.46 μAμM−1. The sensor based on the Au/FePc(tBu)4/GCE has a low limit of nitrite detection at 0.35 μM, good repeatability, and stability. The interference study showed that the proposed Au/FePc(tBu)4/GCE exhibited a selective response in the presence of interfering anions, and the analytical capability of the sensor was demonstrated by determining nitrite ions in real samples of meat products. [ABSTRACT FROM AUTHOR]

Cellulose fibers (CFs) are used as a substrate to fabricate the flexible supercapacitor electrodes of PPy@MnMoO4/CFs via double in situ deposition method. The fabricated MnMoO4/CFs (MC), PPy@CFs (PMC0) and PPy@MnMoO4/CFs (PMC6) are characterized by SEM, XRD, FTIR and XPS, and the electrochemical tests are implemented to reveal the structure–property relationship of paper samples. The results show that the electrochemical performance of PPy@MnMoO4/CFs have positive correlation with the concentrations of the precursor solutions of generated MnMoO4. The PMC6 fabricated at equal molar concentration (0.06 mol L−1) of Mn(CH3COO)2 and Na2MoO4 has the best electrochemical performance, and the specific capacitance achieves 440.1 F g−1 at a current density of 0.2 A g−1, retaining about 83.0% after 1000 cycles at a current density of 2 A g−1. However, the specific capacitance of PMC0 reaches merely 236.8 F g−1 and maintains about 74.0% under the same conditions. The PMC6 electrode has excellent electrochemical performance when compared with PMC0, which is due to the interaction between PPy molecular chains and MnMoO4 submicron rods. MnMoO4 submicron rods not only act as the PPy deposition template to modify the morphology of PMC6 composite, but also create more paths for the transfer of electrolyte ions, to ensure a higher reaction rate and a specific capacitance. [ABSTRACT FROM AUTHOR]

This paper reports the comparison of the electrochemical properties of 3D PLA-graphene electrodes (PLA-G) under different activation conditions and through different processes. In this work, the performance of the electrodes was evaluated after polishing, electrochemical and chemical treatments and a combination of them. The best results were obtained with hydroxide activation using 1.0 mol L−1 NaOH for 30 min of immersion, which promoted the saponification of PLA exposing the graphene nanoribbon structures. The improvement was more evident also after electrochemical activation, which led to a great increase in surface area, defects, electron transfer rate and amount of edge sites. The analytical performance of the proposed PLA-GNaOH-30-EC electrode was evaluated in the presence of dopamine (DA) by three electrochemical techniques, presenting a broad linear range, and limits of detection of 3.49, 2.17 and 1.67 μmol L−1 were obtained by cyclic voltammetry (CV), differential pulse voltammetry (DPV) and square wave voltammetry (SWV), respectively. The separation and quantification of DA in the presence of AA and UA was also reported. The sensor showed good repeatability and reproducibility and was successfully applied to DA determination in synthetic urine and human serum, showing good recovery, from 88.8 to 98.4%. Therefore, the activation methods were essential for the improvement in the 3D PLA-G electrode properties, allowing graphene surface alteration and electrochemical enhancement in the sensing of molecular targets. [ABSTRACT FROM AUTHOR]

Tatyana Alexandrovna Kryukova, a Russian scientist and electrochemist, made significant contributions to electroanalytical chemistry. She worked closely with Professor Aleksandr Naumovich Frumkin, a renowned Russian scientist in the field of electrochemistry. Kryukova is best known for developing the theory of polarographic maxima, which explains the sharp increase in current observed during polarographic measurements under certain conditions. She also discovered the "Kryukova effect," which is characterized by a sudden decrease in current at very negative potentials during the polarographic reduction of anionic species. Kryukova's research had both theoretical and practical implications, including its relevance to the Russian uranium project. She published numerous research papers and co-authored a comprehensive textbook on polarographic analysis. [Extracted from the article]

In situ monitoring of endogenous amino acid loss through sweat can provide physiological insights into health and metabolism. However, existing amino acid biosensors are unable to quantitatively assess metabolic status during exercise and are rarely used to establish blood-sweat correlations because they only detect a single concentration indicator and disregard sweat rate. Here, we present a wearable multimodal biochip integrated with advanced electrochemical electrodes and multipurpose microfluidic channels that enables simultaneous quantification of multiple sweat indicators, including phenylalanine and chloride, as well as sweat rate. This combined measurement approach reveals a negative correlation between sweat phenylalanine levels and sweat rates among individuals, which further enables identification of individuals at high metabolic risk. By tracking phenylalanine fluctuations induced by protein intake during exercise and normalizing the concentration indicator by sweat rates to reduce interindividual variability, we demonstrate a reliable method to correlate and analyze sweat-blood phenylalanine levels for personal health monitoring. The in-depth study on the sweat–blood partitioning mechanisms of amino acids is promising for noninvasive metabolic monitoring. Here, the authors develop a wearable biochip for sweat phenylalanine multimodal analysis aimed at tracking exercise metabolic risk and exploring the sweat–blood correlation. [ABSTRACT FROM AUTHOR]

In order to solve the problem of gap flow field divergence and poor forming accuracy in the electrochemical machining (ECM) titanium alloy inner helix, the pull reverse flow and pull downstream cathode physical models as well as the simulation models of machining gap flow field are established respectively in this paper. Different inclination angles of the liquid supply hole effected on the pull downstream cathode rotational flow field uniformity were explored. The results showed that the gap flow field distribution of the pull downstream cathode is better than pull reverse flow cathode, and the distribution of the rotational flow field formed when the inclination angle of the liquid supply hole achieves 40° is relatively uniform. Under the condition of voltage 12 V, cathode feed speed 15 mm/min, composite electrolyte 3%NaCl + 10%NaNO3 + 6%NaClO3, electrolyte temperature 30 °C, and electrolyte inlet pressure 2 MPa, the 800-mm length of titanium alloy inner helix sample was machined stably and reliably by the pull downstream cathode structure, which surface roughness is Ra0.8 μm. [ABSTRACT FROM AUTHOR]

Lithium–sulfur (Li–S) batteries have attracted the attention of researchers because of their excellent theoretical capacity and the advantages of cost-saving and environmental friendliness of their cathode materials. However, due to the shuttling of soluble intermediate polysulfides and other issues, the performance of current Li–S batteries is far from satisfactory. Herein, a sulfur-containing polymer (S-TVTCSi4) synthesized by the copolymerization of sulfur with 2,4,6,8-tetravinyl-2,4,6,8-tetramethylcyclotetrasiloxane (TVTCSi), was combined with carbon nanotubes (CNTs) to obtain a sulfur-containing polymer/carbon nanotube composite cathode material for Li–S batteries. S-TVTCSi4 can effectively anchor lithium polysulfide through covalent bonding, and CNTs can improve the electrochemical reaction kinetics inside the battery. As a result, the S-TVTCSi4-CNT-based battery exhibited prominent rate capacity and stable cycling performance at different current densities, the reversible capacity of 980 mA h g−1 can be achieved after 100 cycles at 0.3C, with the capacity retention of 88.3%, and even at a high current density of 1C, 64.6% of the initial capacity can be retained after 1000 cycles, with a capacity decay of only 0.035% per cycle. The impressive cycling performance demonstrated the enormous potential of the S-TVTCSi4-CNT composite cathode in high-energy Li–S batteries. [ABSTRACT FROM AUTHOR]

Over the past few years, lithium-ion batteries have gained widespread use owing to their remarkable characteristics of high-energy density, extended cycle life, and minimal self-discharge rate. Enhancing the exchange current density (ECD) remains a crucial challenge in achieving optimal performance of lithium-ion batteries, where it is significantly influenced the rate of electrochemical reactions at the electrodes of a battery. To enhance the ECD of lithium-ion batteries, the Taguchi method is employed in this study. The Taguchi method is a statistical approach that allows for the efficient and systematic evaluation of a large number of experimental factors. The proposed method involves varying six input factors such as positive and negative electrode thickness, separator thickness, current collector area, and the state of charge (SOC) of each electrode; five levels were assigned for each control factor to identify the optimal conditions and maximizing the ECD at the positive electrode. Also, main effect screener analysis and sensitivity analysis were conducted to confirm Taguchi analysis results. The results show that the Taguchi method is an effective approach for optimizing the exchange current density of lithium-ion batteries. This paper shows that the separator thickness followed by the positive electrode thickness play the major role in determining the lithium-ion batteries response. The main effect screener analysis and sensitivity analysis show the same effect of the chosen control factor which validate the Taguchi analysis results. By identifying the optimal conditions, it is possible to improve the performance of lithium-ion batteries and potentially extend their use in a variety of applications. As case study, lithium-ion batteries with ECD at positive electrode of 6 A/m2 is designed and simulated using COMSOL multiphasic within a frequency range of 10 mHz to 1 kHz. Electrochemical impedance spectroscopy (EIS) analysis using is carried out. As the frequency increased, the real part of the impedance of the simulated battery relative to the ground decreased because the charge transfer mechanism shifted from ionic to electronic conductivity. Additionally, the imaginary part of the impedance of the simulated battery relative to the ground decreased at higher frequencies due to a reduction in capacitive effects, with only minor inductive effects. This study opens the door widely in front of researchers and manufactures to design a lithium-ion batteries at specific exchange current density that suits specific applications in forward and direct way instead of trial and error approach. [ABSTRACT FROM AUTHOR]

Developing eco-friendly and low-cost advanced anode materials, such as Fe2O3 and Mn3O4, is fundamental to improve the electrochemical performance of lithium-ion batteries (LIBs). The rational engineering of the microstructure of Fe2O3 and Mn3O4 to endow it with one-dimensionally and hierarchically porous architecture is a feasible way to further improve and optimize the electrochemical performance of the anode materials. Herein, we demonstrate a facile strategy to prepare nanotubular Fe2O3 and Mn3O4 as advanced anode materials for high-performance LIBs. By combining the merits of the one-dimensionally nanotubular morphology and hierarchically porous structure, limitations in the lithiation activity of Mn3O4 and Fe2O3 anode materials, such as low electrical conductivity, large volume expansion, and sluggish lithium-ion diffusion within the materials, have been effectively overcome. When used as anode materials, t-Fe2O3 and t-Mn3O4 exhibited outstanding electrochemical performances, including a high reversible discharge capacity (859.7 and 901.4 mA h g−1 for t-Fe2O3 and t-Mn3O4, respectively), excellent rate performance, and ultra-stable cycling stability. Such superior electrochemical performances proved the exceptional potential of the materials for the real-world application in LIBs. [ABSTRACT FROM AUTHOR]

Herein, a dual-mode detection system was constructed for efficient and accurate detection of bisphenol A (BPA) with the assistance of the BPA-induced hybridization chain reaction (HCR). The captured DNA (cDNA) was first modified on the surface of magnetic spheres modified with gold nanoparticles and polydopamine and then hybridized with the BPA aptamer to form double-stranded DNA (dsDNA). In the presence of the BPA target, the BPA aptamer was released from the surface of the magnetic sphere. The free cDNA triggered a HCR to construct a DNA duplex. Methylene blue (MB), as a bifunctional probe, was intercalated into the double-stranded DNA to amplify the photocurrent (IPEC) of the CdS-modified electrode and generate an electrochemical current (IEC) at the same time. Under the optimized conditions, the PEC and EC signal responses of the system were linear to the logarithm of BPA concentration in the range of 1.0 × 10−10 M to 1.0 × 10−5 M. The detection limits were found to be 1.27 × 10−11 M and 3.0 × 10−11 M using the PEC and EC methods, respectively. The constructed dual-mode biosensor exhibited good performance for real sample analysis, demonstrating its promising potential for practical applications. In addition, this dual-mode detection strategy provides more accurate and reliable detection results. [ABSTRACT FROM AUTHOR]

In order to synthesize distinctive ternary nanocomposites, this study combines nanostructured lanthanum oxide (La2O3), reduced graphene oxide (rGO), and quantum size (5–6 nm) silver nanoparticles (AgNPs). La2O3 does not aggregate when AgNPs are introduced with rGO, which also increases bioactivity for the immobilization of biomolecules. Further, effective surface contacts are made possible by the functional groups of rGO and hexagonal La2O3 nanoparticles and the large surface area of rGO increases the electrical conductivity of its electron clouds. The rGO and La2O3 (L) are conjugated with AgNPs using an ex situ hydrothermal technique to create L-rGO/Ag nanocomposites. Prepared ternary L-rGO/Ag nanocomposites have been confirmed using various characterization methods, such as XRD, FT-IR, UV-visible, PL, Raman, SEM, TEM, and EDAX. Further, the tyrosinase enzyme has been immobilized onto the L-rGO/Ag/ITO electrode for electrochemical dopamine biosensing via DPV analysis. Standard dopamine samples were investigated in the range of 1 to 95 μM and the bioelectrode displayed outstanding sensitivity of 24.32 × 10−4 mA μM−1 cm−2 for lower concentrations (1–35 μM) and 20.88 × 10−4 mA μM−1 cm−2 for higher concentrations (40–95 μM), and limit of detection (LOD) of 0.34 μM. In addition to this, the bioelectrode exhibits 40 days of stability, minimal interference, and 8 cycles of reusability without significant deterioration. Its low Michaelis–Menten constant (Km) value of 3.70 μM emphasizes its great dopamine sensitivity and affinity. Hence, the use of this bioelectrode in real sample analysis is motivated by the encouraging results in standard sample analysis of dopamine, opening possibilities for a variety of useful practical applications for timely monitoring and managing neurodegenerative disordered. [ABSTRACT FROM AUTHOR]

Gear involute artifact (GIA) is an indispensable tool in the detection of high-precision gears. In this paper, a new method of horizontal electrode wire electrochemical contour evolution machining (HE-WECEM) was proposed to machine GIA. Compared with traditional circular interpolation for machining involute, HE-WECEM simulates the evolving process of involute to greatly improve the machining accuracy. Firstly, the machining mechanism of GIA by HE-WECEM was studied through mathematical models and electric field simulations. Secondly, reciprocating feed and two-way flushing fluid system was used, and its effectiveness in updating the electrolyte in the machining slit was analyzed through a flow-field simulation. And then, comparative experiment was designed to further validate the effectiveness of the flushing fluid system. The results indicate that the flushing system can effectively improve the stability of HE-WECEM. Finally, single-factor experiments were designed to investigate the effects of electrical parameters on machining. Based on the single-factor experiments, the Box–Behnken experiment was conducted on the electrical parameters. The response surface methodology (RSM) was used to analyze the composite effects of electrical parameters and obtain the optimal combination of machining parameters. A GIA blank with base circle radius of 50 mm was fabricated on an 8-mm-thick GCr15 workpiece, and the maximum deviation of tooth profile can reach 17.18 μm. The average surface roughness Sa reaches 1.435 μm. It is proved that HE-WECEM is a reliable method for machining GIA blank. [ABSTRACT FROM AUTHOR]

The electrochemical transformation of sustainable feedstocks such as biomass derived species can help to electrify the chemical industry and reduce reliance on petroleum. Furfural (FF), one such biomass derived species, can be electrochemically reduced to form furfuryl alcohol (FA) and 2-methylfuran (MF) which are used to produce thermally stable molds and resins, and a fuel candidate or additive, respectively. Using Cu electrodes allows for selective production of FA or MF, dependent on the pH of solution, with MF requiring a low pH. The highly acidic conditions to produce MF also drive homogeneous side reactions and foul the Cu electrode with time. To better understand the nature of the build up on the electrodes, accelerated fouling conditions of high initial concentrations of FF and very low pH were investigated. At concentrations of 200 mM FF in 0.5 M H2SO4, we observed fouling of the Cu electrode during electrochemical hydrogenation and hydrogenolysis (ECH) of FF. The fouling of the electrode was also shown to be potential dependent, with poly(furfuryl alcohol) (pFA) forming at −560 mV RHE while an amorphous carbon resembling soot was observed more significantly at −700 mV RHE. The fouling of the Cu electrodes was shown to increase the polarization resistance during FF reduction, hindering the rates of reactions to FA and MF. Through control studies, it was found that the fouling is electrochemically-driven and requires the starting reactant FF to be present. By investigating and understanding the fouling of Cu electrodes during the electrochemical hydrogenation and hydrogenolysis of FF, catalysts can be better designed to inhibit fouling and be used for longer durations or for more cycles before requiring a treatment to regain activity or replacement. Additionally, while this work shows the detriment of carbon fouling on the electrode, pFA is a desirable product. Process intensification through development of a FF to pFA electrochemical step could be achieved through electroreduction with high concentration of FF in 0.5 M H2SO4. [ABSTRACT FROM AUTHOR]

Electrochemical performance of cathode active materials (CAMs) is dependent on the properties of coprecipitated precursors (pCAMs). This is a sensitive process affected by several reaction parameters such as temperature, pH, concentration of reactants, agitation rate, and residence time. In this paper, the effect of parameters influencing the particle size growth and the physical properties, such as particle morphology and tapped density, was studied in the coprecipitation of Ni(OH)2. Formation of a homogeneous population with narrow particle size distribution was observed, followed by a more heterogeneous population of dense particles. Ammonia concentration and residence time had significant effects on particle size growth and morphology, but agitation rate also had an impact. [ABSTRACT FROM AUTHOR]

In this paper, Al/TiB2 + 10%Ti4O7/PbO2-xCeO2 composite electrode materials were prepared by thermal spraying technology and electrochemical deposition method. The microstructure of the coatings with different contents of Ce3+ was observed by scanning electron microscope, and the phase composition of the coatings was analyzed by X-ray diffractometer. The electrochemical properties of the electrodes were studied by Tafel, EIS, LSV, and CV. The results show that with the increase of Ce3+ concentration, the overall performance of the electrode is improved, but when the content exceeds 1.5 g/L, it will cause agglomeration and reduce the electrode performance. Therefore, when the Ce3+ concentration is 1.5 g/L, the comprehensive performance and effect of the electrode are the best. Moreover, it can be seen from the SEM image that after adding Ce3+, the grains are denser than that of the composite anode without addition. [ABSTRACT FROM AUTHOR]

Lithium metal is the key anode material for solid‐state‐batteries as its successful implementation will drastically increase their energy and power densities. However, anode contact loss during stripping leads to dendrites upon plating and subsequent cell failure. Design strategies to mitigate these issues are crucial to enable the use of lithium metal anodes. This paper reports the dissolution kinetics of composite anodes made of lithium metal and carbon nanotubes (CNTs) with a garnet‐type solid electrolyte (SE). In addition to an enhancement of the effective diffusion within the anode, its dissolution is fundamentally changed from being 2D to 3D. By maintaining contact with the SE, the CNTs facilitate lithium transport to the interface, which yields more than 20 mAh cm−2 discharge capacity at 100 µA cm−2 without the application of external stack pressure (>1 MPa). Conclusions drawn from electrochemical data on the anode microstructure are validated using cryo‐focused‐ion‐beam scanning electron microscopy and correlated with the mechanical properties. Micro‐indentation, acoustic analysis, and stress–strain testing show that mechanical properties of the anode, like yield strength and hardness, are adjustable. Overall, it is shown that the mechanical and electrochemical properties of Li–CNT composite electrodes can be tailored to suit the requirements of a practical cell. [ABSTRACT FROM AUTHOR]

The demand for energy storage devices with high energy and power densities has increased tremendously in this rapidly growing world. Conventional capacitors, fuel cells, and lithium‐ion batteries have been used as energy storage devices for the long term. However, supercapacitors are one of the most promising energy storage devices because of their high specific capacitance, high power density, and longer cycle life. Recent research has focused on synthesizing transition‐metal oxides/hydroxides, carbon materials, and conducting polymers as supercapacitor electrode materials. The performance of supercapacitors can be improved by altering electrolytes, electrode materials, current collectors, experimental temperatures, and film thickness. Thousands of papers on supercapacitors have already been published, reflecting the significance and elucidating how much demanding such energy storage devices for this fast‐growing generation. This review aims to illustrate the electrode materials loaded on various conductive substrates by electrochemical deposition employed for supercapacitors to provide broad knowledge on synthetic pathways, which will pave the way for future research. We also discussed the basic parameters involved in supercapacitor studies and the advantages of the electrochemical deposition techniques through literature analysis. Finally, future trends and directions on exploring metals/metal composites toward designing and constructing viable, high‐class, and even newly featured flexible energy storage materials, electrodes, and systems are presented. [ABSTRACT FROM AUTHOR]

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Cochlear implants are neural implant devices that aim to restore hearing in patients with severe sensorineural hearing impairment. Here, the main goal is to successfully place the electrode array in the cochlea to stimulate the auditory nerves through bypassing damaged hair cells. Several electrode and electrode array parameters affect the success of this technique, but, undoubtedly, the most important one is related to electrodes, which are used for nerve stimulation. In this paper, we provide a comprehensive resource on the electrodes currently being used in cochlear implant devices. Electrode materials, shape, and the effect of spacing between electrodes on the stimulation, stiffness, and flexibility of electrode-carrying arrays are discussed. The use of sensors and the electrical, mechanical, and electrochemical properties of electrode arrays are examined. A large library of preferred electrodes is reviewed, and recent progress in electrode design parameters is analyzed. Finally, the limitations and challenges of the current technology are discussed along with a proposal of future directions in the field. [ABSTRACT FROM AUTHOR]

The development of nickel-rich and low-cobalt cathode materials is currently an effective way to improve the energy density and reduce the cost of lithium-ion batteries. However, as Ni content increases, Ni-rich layered oxides have some problems, such as difficult precursor synthesis, structural instability, and high interfacial activity, which hinder the promotion of Ni-rich layered oxide cathode materials. In this paper, a structurally stable LiNi0.8 Mn0.1 Co0.1 O2 (NCM811) cathode material was prepared by an optimized co-precipitation method, while a fast ionic conductor Li1.5 Y0.5 Zr1.5 (PO4)3 coating was uniformly wrapped on the surface of NCM811 material to overcome the difficulties of interfacial structural instability and electrolyte corrosion. At a high cut-off voltage of 4.5 V, the discharge specific capacity of the modified sample is 214.2 mAh⋅g-1 at 0.2 C and up to 158.8 mAh ⋅ g-1 at 10 C, which is much higher than the 203.7 mAh⋅g-1 (0.2 C) and 82.7 mAh ⋅ g-1 (10 C) of the original sample. Meanwhile, the capacity retention rate of the modified sample after 200 cycles of 1 C at 4.3 V is as high as 84.7%, which is higher than that of the original sample (61.94%). [ABSTRACT FROM AUTHOR]

With the increasing demand for sustainable and green energy, electric energy storage technologies have received enough attention and extensive research. Among them, Li-ion batteries (LIBs) are widely used because of their excellent performance, but in practical applications, the electrochemical performance of electrode materials is not satisfactory. Carbon-based materials with high chemical stability, strong conductivity, high specific surface area, and good capacity retention are traditional anode materials in electrochemical energy storage devices, while cobalt-based nano-materials have been widely used in LIBs anodes because of their high theoretical specific capacity. This paper gives a systematic summary of the state of research of cobalt-containing nanomaterials, carbon nanomaterials, and their composites in LIBs anodes. Moreover, the preparation methods of electrode materials and measures to improve electrochemical performance are also summarized. The electrochemical performance of anode materials can be significantly improved by compounding carbon nanomaterials with cobalt nanomaterials. Composite materials have better electrical conductivity, as well as higher cycle ability and reversibility than single materials, and the synergistic effect between them can explain this phenomenon. In addition, the electrochemical performance of materials can be significantly improved by adjusting the microstructure of materials (especially preparing them into porous structures). Among the different microscopic morphologies of materials, porous structure can provide more positions for chimerism of lithium ions, shorten the diffusion distance between electrons and ions, and thus promote the transfer of lithium ions and the diffusion of electrolytes. [ABSTRACT FROM AUTHOR]

It is well known that the electrochemical performances of electrode material as supercapacitor are related to the contact area between electrolyte and electrode material, which is determined by the microscopic morphology of the electrode material. Because of the large surface of nanoarray electrode for excellent electrochemical performances, CeO2/ZnO nanoarray electrodes were synthesized successfully for energy storage by the developed two kinds of different schemes in this paper. CeO2/ZnO nanorod array (C/Z NRA) and CeO2/ZnO nanosheet array (C/Z NSA) could be modulated by ZnO-rod sol–gel method and ZnO-seed hydrothermal method, respectively. The C/Z NRA owned a specific capacitance of 406.75 F g−1 and an energy density of 119.21 Wh kg−1. However, the specific capacitance and energy density of C/Z NSA were 991.43 F g−1 and 222.82 Wh kg−1, respectively. The electrochemical performances of C/Z NSA were about twice as large as the ones of C/Z NRA. The result is due to the fact that the castle-like C/Z NSA has a large number of voids to ensure its larger contact area with the electrolyte compared with cluster-like C/Z NRA. The difference of the performances of C/Z NRA and C/Z NSA is caused by the difference in their controlled microstructures. The structure–function relationship could be explained by from their SEM and XRD. The ultraviolet–visible (UV–Vis) analysis of C/Z NRA and C/Z NSA could be subjected to guiding effect on the subsequent photoelectric properties that will be relative to their electrochemical properties. The study implies that the idea has become a reality that nanostructure modulation of electrode material could be made to enhance its electrochemical properties for better energy storage according to one's design and intention. [ABSTRACT FROM AUTHOR]

This paper reports the development of a simple electroanalytical method for imazethapyr (IMT) determination in rice samples based on molecularly imprinted polymer and functionalized carbon black paste electrode (MIP‐fCBPE). Carbon black (CB) was functionalized by the insertion of oxygenated functional groups upon acid treatment with HNO3 and H2SO4. The functionalized carbon black (fCB) presented higher performance for IMT determination than the CB without functionalization. The insertion of molecularly imprinted polyvinylimidazole (MIP‐VN) in the fCBPE promoted a significant increase in the cathodic peak current even at low proportions (7.5 % w/w) due to the specific binding sites for IMT recognition. For IMT determination, DPV parameters were optimized by the Doehlert matrix applying 0.1 V for 60 s as pre‐treatment in acetate buffer solution (pH 3.0) as supporting electrolyte. The proposed method showed low limit of detection (0.03 μmol L−1), a wide linear range (0.10–70.00 μmol L−1), and good precision in terms of repeatability of intraday measures (RSD%=3.6). The method was applied in rice samples after microwave‐assisted extraction of IMT and the accuracy of the method was evaluated by addition/recovery assays (96.3–105.7 %), being statistically attested using HPLC‐DAD as reference technique. [ABSTRACT FROM AUTHOR]

This paper reports the results obtained from the determination of ascorbic acid with platinum-based voltammetric sensors modified with potassium hexacyanoferrate-doped polypyrrole. The preparation of the modified electrodes was carried out by electrochemical polymerization of pyrrole from aqueous solutions, using chronoamperometry. Polypyrrole films were deposited on the surface of the platinum electrode, by applying a constant potential of 0.8 V for 30 s. The thickness of the polymer film was calculated from the chronoamperometric data, and the value was 0.163 μm. Cyclic voltammetry was the method used for the Pt/PPy-FeCN electrode electrochemical characterization in several types of solution, including KCl, potassium ferrocyanide, and ascorbic acid. The thin doped polymer layer showed excellent sensitivity for ascorbic acid detection. From the voltammetric studies carried out in solutions of different concentrations of ascorbic acid, ranging from 1 to 100 × 10−6 M, a detection limit of 2.5 × 10−7 M was obtained. Validation of the analyses was performed using pharmaceutical products with different concentrations of ascorbic acid, from different manufacturers and presented in various pharmaceutical forms, i.e., intravascular administration ampoules, chewable tablets, and powder for oral suspension. [ABSTRACT FROM AUTHOR]

Intermetallic alloys were synthetized during aluminum underpotential deposition onto a vanadium metal that was previously deposited on the glassy carbon electrode. Advancements in technologies related to the electrorefining and electrodeposition of metals - as important manufacturing process steps - continue to receive significant attention. The morphology and corrosion resistance of the electrolytically synthesized novel ceria-doped Zn-Co composite coatings were examined and compared with pure Zn-Co coatings obtained under the same conditions. [Extracted from the article]

[Display omitted] • 1,10-Phenanthroline is electropolymerized in aqueous solutions. • The PPhen/CP has a high specific capacity in 1 M H 2 SO 4 and in 1 M KOH. • The solid-state device delivers the energy density of 19.44 Wh kg−1 at the power density of 899.5 W kg−1. Research on novel conducting polymer material is essential in designing high-performance electrodes for the electrochemical energy storage systems. 1,10-phenanthroline is, for the first time, electropolymerized in aqueous solutions on carbon paper, and the resulting electrodes (PPhen/CP) are utilized to store energy electrochemically. The influence of the electropolymerization time and intercalated anions to the morphology and charge storage performance is investigated, and the results show that PPhen/CP with 20 min electropolymerization time and intercalated sulfate ions (PPhen/CP-20) exhibits the best performance, with the specific capacities estimated by galvanostatic charge–discharge of 111.5 mAh g−1 at 1 A g−1 in 1 M H 2 SO 4 , and of 97.1 mAh g−1 at 1 A g−1 in 1 M KOH. The solid-state supercapacitor assembled using two PPhen/CP-20 and the H 2 SO 4 /PVA gel electrolyte can deliver the energy density of 19.44 Wh kg−1 at the power density of 899.5 W kg−1, and can retain 80.76% of the initial capacity after cycling at 5 A g−1 for 4000 cycles. The charge storage mechanism involves dihydroxyl/diketone groups redox process and double layer charging, and the charge storage performance is affected by the electrochemically active surface area and diffusion processes which are related to the morphology of the electropolymerized film. This study shows that the electropolymerized 1,10-phenanthroline film is a promising candidate as the electrode material for aqueous supercapacitors. [ABSTRACT FROM AUTHOR]

Bisphenol A (BPA), a known endocrine-disrupting chemical, has been the subject of widespread bans in food packaging and baby bottles. Due to the potential health risks associated with BPA exposure, precise detection methods are crucial for toxicity assessments, ensuring food safety, and monitoring environmental pollutants. To address this imperative, we have developed an electrochemical sensor utilizing a composite material composed of copper-organic framework (Cu-MOF), cetyltrimethylammonium bromide (CTAB), and graphene (GN). This modified composite, known as CTAB-GN-Cu-MOF, was successfully synthesized and characterized via SEM, FT-IR, XPS, XRD, Zeta, and Size analyses. The integration of Cu-MOF, CTAB, and GN resulted in a synergistic effect, enhancing the electron transport rate and accumulation efficiency for BPA. This technological advancement led to increased signals in differential pulse voltammetry and a substantial electroactive surface area (0.031 cm2). The sensor exhibited a linear response range from 0.100 to 800 μmol L−1 with a detection limit of 35.0 nmol L−1 (signal-to-noise ratio of 3). The sensitivity was measured at 0.890 μA μM−1 cm−2 within the concentration range of 25.0–800 μmol L−1 and 8.87 μA μmol−1 cm−2 within the range of 0.10–10.0 μmol L−1. The device demonstrated stable and satisfactory recovery rates between 96.56% and 103.88% when detecting BPA in various plastic samples, highlighting its potential for practical applications.An electrochemical sensing platform with good performance based on a CTAB-GN-Cu-MOF modified electrode was fabricated in this paper for simultaneous detection of Bisphenol A (BPA). This modified composite, CTAB-GN-Cu-MOF, was successfully synthesized and characterized via SEM, FT-IR, XPS, XRD, Zeta, and Size analyses. The integration of Cu-MOF, CTAB, and GN resulted in a synergistic effect, enhancing the electron transport rate and accumulation efficiency for BPA. This technological advancement increased signals in differential pulse voltammetry and a substantial electroactive surface area (0.031 cm2). The sensor exhibited a linear response range from 0.100 to 800 μmol L−1 with a detection limit of 35.0 nmol L−1. The device demonstrated stable and satisfactory recovery rates between 96.56% and 103.88% when detecting BPA in various plastic samples, highlighting its potential for practical applications.Graphical Abstract: Bisphenol A (BPA), a known endocrine-disrupting chemical, has been the subject of widespread bans in food packaging and baby bottles. Due to the potential health risks associated with BPA exposure, precise detection methods are crucial for toxicity assessments, ensuring food safety, and monitoring environmental pollutants. To address this imperative, we have developed an electrochemical sensor utilizing a composite material composed of copper-organic framework (Cu-MOF), cetyltrimethylammonium bromide (CTAB), and graphene (GN). This modified composite, known as CTAB-GN-Cu-MOF, was successfully synthesized and characterized via SEM, FT-IR, XPS, XRD, Zeta, and Size analyses. The integration of Cu-MOF, CTAB, and GN resulted in a synergistic effect, enhancing the electron transport rate and accumulation efficiency for BPA. This technological advancement led to increased signals in differential pulse voltammetry and a substantial electroactive surface area (0.031 cm2). The sensor exhibited a linear response range from 0.100 to 800 μmol L−1 with a detection limit of 35.0 nmol L−1 (signal-to-noise ratio of 3). The sensitivity was measured at 0.890 μA μM−1 cm−2 within the concentration range of 25.0–800 μmol L−1 and 8.87 μA μmol−1 cm−2 within the range of 0.10–10.0 μmol L−1. The device demonstrated stable and satisfactory recovery rates between 96.56% and 103.88% when detecting BPA in various plastic samples, highlighting its potential for practical applications.An electrochemical sensing platform with good performance based on a CTAB-GN-Cu-MOF modified electrode was fabricated in this paper for simultaneous detection of Bisphenol A (BPA). This modified composite, CTAB-GN-Cu-MOF, was successfully synthesized and characterized via SEM, FT-IR, XPS, XRD, Zeta, and Size analyses. The integration of Cu-MOF, CTAB, and GN resulted in a synergistic effect, enhancing the electron transport rate and accumulation efficiency for BPA. This technological advancement increased signals in differential pulse voltammetry and a substantial electroactive surface area (0.031 cm2). The sensor exhibited a linear response range from 0.100 to 800 μmol L−1 with a detection limit of 35.0 nmol L−1. The device demonstrated stable and satisfactory recovery rates between 96.56% and 103.88% when detecting BPA in various plastic samples, highlighting its potential for practical applications. [ABSTRACT FROM AUTHOR]

Cathode materials based on carbon substrates are of high interest for the electrochemical generation of hydrogen peroxide (H2O2) for wastewater treatment because of their low cost, chemical stability and high selectivity. However, the H2O2 selectivity of carbon materials can be significantly reduced in presence of surfactants, which are frequent contaminants in wastewater. Therefore, the development of surfactant-tolerant cathode materials is highly important. In this paper, composite electrodes comprising of polytetrafluoroethylene and carbon black on a carbon felt substrate were prepared. The effect of sodium dodecyl sulphate on the electrode activity was investigated. It was found that the electrodes prepared with high bulk density carbon black featured a high H2O2 Faradaic efficiency of 95% in surfactant-free solutions. These electrodes also showed significant surfactant tolerance having a 70% Faradaic efficiency in the presence of 1 mM sodium dodecyl sulphate. The enhanced surfactant tolerance is attributed to the hydrophobic properties of the electrode surface.Graphical abstract: Cathode materials based on carbon substrates are of high interest for the electrochemical generation of hydrogen peroxide (H2O2) for wastewater treatment because of their low cost, chemical stability and high selectivity. However, the H2O2 selectivity of carbon materials can be significantly reduced in presence of surfactants, which are frequent contaminants in wastewater. Therefore, the development of surfactant-tolerant cathode materials is highly important. In this paper, composite electrodes comprising of polytetrafluoroethylene and carbon black on a carbon felt substrate were prepared. The effect of sodium dodecyl sulphate on the electrode activity was investigated. It was found that the electrodes prepared with high bulk density carbon black featured a high H2O2 Faradaic efficiency of 95% in surfactant-free solutions. These electrodes also showed significant surfactant tolerance having a 70% Faradaic efficiency in the presence of 1 mM sodium dodecyl sulphate. The enhanced surfactant tolerance is attributed to the hydrophobic properties of the electrode surface. [ABSTRACT FROM AUTHOR]