Current Electrolysis Research Articles

Coupling of photovoltaics with neurostimulation electrodes—optical to electrolytic transduction

Objective. The wireless transfer of power for driving implantable neural stimulation devices has garnered significant attention in the bioelectronics field. This study explores the potential of photovoltaic (PV) power transfer, utilizing tissue-penetrating deep-red light—a novel and promising approach that has received less attention compared to traditional induction or ultrasound techniques. Our objective is to critically assess key parameters for directly powering neurostimulation electrodes with PVs, converting light impulses into neurostimulation currents. Approach. We systematically investigate varying PV cell size, optional series configurations, and coupling with microelectrodes fabricated from a range of materials such as Pt, TiN, IrO x , Ti, W, PtO x , Au, or poly(3,4 ethylenedioxythiophene):poly(styrene sulfonate). Additionally, two types of PVs, ultrathin organic PVs and monocrystalline silicon PVs, are compared. These combinations are employed to drive pairs of electrodes with different sizes and impedances. The readout method involves measuring electrolytic current using a straightforward amplifier circuit. Main results. Optimal PV selection is crucial, necessitating sufficiently large PV cells to generate the desired photocurrent. Arranging PVs in series is essential to produce the appropriate voltage for driving current across electrode/electrolyte impedances. By carefully choosing the PV arrangement and electrode type, it becomes possible to emulate electrical stimulation protocols in terms of charge and frequency. An important consideration is whether the circuit is photovoltage-limited or photocurrent-limited. High charge-injection capacity electrodes made from pseudo-faradaic materials impose a photocurrent limit, while more capacitive materials like Pt are photovoltage-limited. Although organic PVs exhibit lower efficiency than silicon PVs, in many practical scenarios, stimulation current is primarily limited by the electrodes rather than the PV driver, leading to potential parity between the two types. Significance. This study provides a foundational guide for designing a PV-powered neurostimulation circuit. The insights gained are applicable to both in vitro and in vivo applications, offering a resource to the neural engineering community.

Facile Synthesis of U2Ti Intermetallic by Direct Electrochemical Reduction of UO2-TiO2 Composite in LiCl-Li2O Melt

Alloys of U with Ti are of importance in nuclear industry as fuel for Gen IV fast reactors, hydrogen isotope storage medium for fusion reactors, super conductors, and also as corrosion resistant material for use in various applications. Here, preparation of U2Ti intermetallic compound was investigated by the direct electrochemical reduction of mixed oxide of UO2-TiO2 in LiCl-0.5% Li2O molten salt at 650 °C. The mixed oxide pellet of UO2-TiO2 sintered at 1500 °C was found to be a mixture of UTi2O6 and UO2 as evidenced by X-ray diffraction (XRD) analysis. Direct electro-lithiothermic reduction of UO2, TiO2, and a mixture of sintered UO2-TiO2 and UTi2O6 coupled with cyclic voltammetry of these oxides in the melt was performed to understand the electro-reduction mechanism. Potentials of reduction of these oxides in the melt, w.r.t Ni/NiO reference electrode, obtained by analysis of CV data of these oxides contained in metallic cavity electrodes and XRD analysis of partially electro-reduced oxides were used to arrive at the electro-reduction mechanism. Results indicate that U2Ti can be prepared conveniently by the electro-lithiothermic reduction of sintered pellet of UO2-TiO2 cathode by constant current electrolysis in a two-electrode cell.

3D transition metal boride monolithic electrode for industrial hectoampere-level current anion exchange membrane water electrolysis

High performance, cost-efficient anion exchange membrane water electrolysis (AEMWE) is of great current interest for industrial-level hydrogen production. However, the lack of active and robust catalytic electrode severely impedes the development of this technology. Herein, a versatile strategy of 3D hierarchical porous monolithic electrode enabling industrial hectoampere-level current AEMWE is successfully explored for the first time. By a facile electroless plating technique coupled with corrosion engineering process, a series of low-cost and highly active 3D transition metal boride (etched-TMB, TM=Ni, Co, NiP, NiMo, CoP, CoMo, CoNi) catalytic electrodes have been prepared. A distinctive hierarchically structured etched-NiPB@MS alloy monolithic electrode exhibits a superior bifunctional hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) catalytic activity and large-current stability, which derive from enhanced intrinsic activity, sufficient electrochemical active sites, mechanical stability as well as efficient gas/liquid transport pathways. An AEMWE electrolyzer with 10×10 cm2 etched-NiPB@MS as both anode and cathode works efficiently at large current of 100 A (1 A cm−2) and reaches a H2 production rate of 41.78 L h−1, verifying its huge potential for industrial hydrogen production. This study paves out a new approach for high-efficient catalytic electrode and industrial-level current AEMWE.

Electrochemically Mediated Atom Transfer Radical Polymerization Driven by Alternating Current.

Alternating current (AC) and pulsed electrolysis are gaining traction in electro(organic) synthesis due to their advantageous characteristics. We employed AC electrolysis in electrochemically mediated Atom Transfer Radical Polymerization (eATRP) to facilitate the regeneration of the activator CuI complex on Cu0 electrodes. Additionally, Cu0 served as a slow supplemental activator and reducing agent (SARA ATRP), enabling the activation of alkyl halides and the regeneration of the CuI activator through a comproportionation reaction. We harnessed the distinct properties of Cu0 dual regeneration, both chemical and electrochemical, by employing sinusoidal, triangular, and square-wave AC electrolysis alongside some of the most active ATRP catalysts available. Compared to linear waveform (DC electrolysis) or SARA ATRP (without electrolysis), pulsed and AC electrolysis facilitated slightly faster and more controlled polymerizations of acrylates. The same AC electrolysis conditions could successfully polymerize eleven different monomers across different mediums, from water to bulk. Moreover, it proved effective across a spectrum of catalyst activity, from low-activity Cu/2,2-bipyridine to highly active Cu complexes with substituted tripodal amine ligands. Chain extension experiments confirmed the high chain-end fidelity of the produced polymers, yielding functional and high molecular-weight block copolymers. SEM analysis indicated the robustness of the Cu0 electrodes, sustaining at least 15 consecutive polymerizations.

Electrochemically Mediated Atom Transfer Radical Polymerization Driven by Alternating Current

AbstractAlternating current (AC) and pulsed electrolysis are gaining traction in electro(organic) synthesis due to their advantageous characteristics. We employed AC electrolysis in electrochemically mediated Atom Transfer Radical Polymerization (eATRP) to facilitate the regeneration of the activator CuI complex on Cu0 electrodes. Additionally, Cu0 served as a slow supplemental activator and reducing agent (SARA ATRP), enabling the activation of alkyl halides and the regeneration of the CuI activator through a comproportionation reaction. We harnessed the distinct properties of Cu0 dual regeneration, both chemical and electrochemical, by employing sinusoidal, triangular, and square‐wave AC electrolysis alongside some of the most active ATRP catalysts available. Compared to linear waveform (DC electrolysis) or SARA ATRP (without electrolysis), pulsed and AC electrolysis facilitated slightly faster and more controlled polymerizations of acrylates. The same AC electrolysis conditions could successfully polymerize eleven different monomers across different mediums, from water to bulk. Moreover, it proved effective across a spectrum of catalyst activity, from low‐activity Cu/2,2‐bipyridine to highly active Cu complexes with substituted tripodal amine ligands. Chain extension experiments confirmed the high chain‐end fidelity of the produced polymers, yielding functional and high molecular‐weight block copolymers. SEM analysis indicated the robustness of the Cu0 electrodes, sustaining at least 15 consecutive polymerizations.

Nonconductive Metal Oxide Gas Diffusion Layer for Mitigating Electrowetting during CO2 Electrolysis.

Gas diffusion electrodes (GDEs) are extensively used for high current density electrochemical CO2 electrolysis (ECO2R), enabled by significantly reducing mass transfer resistance of CO2 to the catalyst layer. Conventionally, these GDEs are based upon hydrophobic carbon-based gas-diffusion layers (GDLs) that facilitate the gas transport; however, these supports are prone to flood with electrolyte during electrolysis. This potential-induced flooding, known as electrowetting, is related to the inherent conductivity of carbon and limits the activity of ECO2R. To investigate the effect of electrical conductivity more carefully, a GDE is constructed based on a Cu mesh with a nonconductive microporous GDL applied to this substrate, the latter composed of a mixture of metal oxide and polytetrafluoroethylene. With alumina as the metal oxide, a stable operation is obtained at -200 mA cm-2 with 70% selectivity for ECO2R (with over half toward C2+ products) without flooding as observed by in situ microscopy. On the contrary, with a Vulcan carbon-based GDL, the initial activity is rapidly lost as severe flooding ensues. It is reasoned that electrowetting is averted by virtue of the nonconductive nature of alumina, providing a new perspective on alternative GDL compositions and their influence on ECO2R performance.

Two-Phase Electrosynthesis of Dihydroxycoumestans: Discovery of a New Scaffold for Topoisomerase I Poison.

Coumestan represents a biologically relevant structural motif distributed in a number of natural products, and the rapid construction of related derivatives as well as the characterization of targets would accelerate lead compound discovery in medicinal chemistry. In this work, a general and scalable approach to 8,9-dihydroxycoumestans via two-electrode constant current electrolysis was developed. The application of a two-phase (aqueous/organic) system plays a crucial role for success, protecting the sensitive o-benzoquinone intermediates from over-oxidation. Based on the structurally diverse products, a primary SAR study on coumestan scaffold was completed, and compound 3 r exhibited potent antiproliferative activities and a robust topoisomerase I (Top1) inhibitory activity. Further mechanism studies demonstrates that compound 3 r was a novel Top1 poison, which might open an avenue for the development of Top1-targeted antitumor agent.

Superior decomposition of xenobiotic RB5 dye using three-dimensional electrochemical treatment: Response surface methodology modelling, artificial intelligence, and machine learning-based optimisation approaches

The highly efficient electrochemical treatment technology for dye-polluted wastewater is one of hot research topics in industrial wastewater treatment. This study reported a three-dimensional electrochemical treatment process integrating graphite intercalation compound (GIC) adsorption, direct anodic oxidation, and ·OH oxidation for decolourising Reactive Black 5 (RB5) from aqueous solutions. The electrochemical process was optimised using the novel progressive central composite design–response surface methodology (CCD–NPRSM), hybrid artificial neural network–extreme gradient boosting (hybrid ANN–XGBoost), and classification and regression trees (CART). CCD–NPRSM and hybrid ANN–XGBoost were employed to minimise errors in evaluating the electrochemical process involving three manipulated operational parameters: current density, electrolysis (treatment) time, and initial dye concentration. The optimised decolourisation efficiencies were 99.30%, 96.63%, and 99.14% for CCD–NPRSM, hybrid ANN–XGBoost, and CART, respectively, compared to the 98.46% RB5 removal rate observed experimentally under optimum conditions: approximately 20 mA/cm2 of current density, 20 min of electrolysis time, and 65 mg/L of RB5. The optimised mineralisation efficiencies ranged between 89% and 92% for different models based on total organic carbon (TOC). Experimental studies confirmed that the predictive efficiency of optimised models ranked in the descending order of hybrid ANN–XGBoost, CCD–NPRSM, and CART. Model validation using analysis of variance (ANOVA) revealed that hybrid ANN–XGBoost had a mean squared error (MSE) and a coefficient of determination (R2) of approximately 0.014 and 0.998, respectively, for the RB5 removal efficiency, outperforming CCD–NPRSM with MSE and R2 of 0.518 and 0.998, respectively. Overall, the hybrid ANN–XGBoost approach is the most feasible technique for assessing the electrochemical treatment efficiency in RB5 dye wastewater decolourisation.

HyPLANT100: Industrialization from Assembly to the Construction Site for Gigawatt Electrolysis

The global push for sustainable energy has heightened the demand for green hydrogen, which is crucial for decarbonizing heavy industry. However, current electrolysis plant capacities are insufficient. This research addresses the challenge through optimizing large-scale electrolysis construction via standardization, modularization, process optimization, and automation. This paper introduces H2Giga, a project for mass-producing electrolyzers, and HyPLANT100, investigating large-scale electrolysis plant structure and construction processes. Modularizing electrolyzers enhances production efficiency and scalability. The integration of AutomationML facilitates seamless information exchange. A digital twin concept enables simulations, optimizations, and error identification before assembly. While construction site automation provides advantages, tasks like connection technologies and handling cables, tubes, and hoses require pre-assembly. This study identifies key tasks suitable for automation and estimating required components. The Enapter Multicore electrolyzer serves as a case study, showcasing robotic technology for tube fittings. In conclusion, this research underscores the significance of standardization, modularization, and automation in boosting the electrolysis production capacity for green hydrogen, contributing to ongoing efforts in decarbonizing the industrial sector and advancing the global energy transition.

S, N, and O tri-doped graphite nanosheets-based gas diffusion electrode boosts highly selective electrosynthesis of H2O2

Electrochemical synthesis of hydrogen peroxide (H2O2) via oxygen reduction reaction (ORR) is a promising environmentally friendly approach for on-site production of H2O2. The development of economically feasible cathodes with high activity and selectivity is of utmost importance to enable the large-scale application of the process of H2O2 electrosynthesis. Herein, a novel electrocatalyst of sulfur, nitrogen, and oxygen tri-doped graphite nanosheets (SNOGNSs) was developed, which exhibited the selectivity of up to 97.4 % for the electrosynthesis of H2O2, significantly higher than that of flake graphite (FG, 51.4 %), OGNSs (72.8 %) and NOGNSs (90.9 %). The gas diffusion electrode (GDE) was fabricated using SNOGNSs as catalysts, and the accumulation of H2O2 reached 732.8–1044.4 mg/Lh−1 at 0.3–0.5 A electrolytic current. The mechanism of the synergistic enhancement of two-electron ORR by S, N, and O tri-doping was revealed utilizing density functional theory (DFT) calculations. This work offers a suitable alternative for on-site clean production of H2O2 that can be applied in electrochemical advanced oxidation processes.

Recent Advances and Challenges in Anion Exchange Membranes Development/Application for Water Electrolysis: A Review.

In recent years, anion exchange membranes (AEMs) have aroused widespread interest in hydrogen production via water electrolysis using renewable energy sources. The two current commercial low-temperature water electrolysis technologies used are alkaline water electrolysis (AWE) and proton exchange membrane (PEM) water electrolysis. The AWE technology exhibited the advantages of high stability and increased cost-effectiveness with low hydrogen production efficiency. In contrast, PEM water electrolysis exhibited high hydrogen efficiency with low stability and cost-effectiveness, respectively. Unfortunately, the major challenges that AEMs, as well as the corresponding ion transportation membranes, including alkaline hydrogen separator and proton exchange membranes, still face are hydrogen production efficiency, long-term stability, and cost-effectiveness under working conditions, which exhibited critical issues that need to be addressed as a top priority. This review comprehensively presented research progress on AEMs in recent years, providing a thorough understanding of academic studies and industrial applications. It focused on analyzing the chemical structure of polymers and the performance of AEMs and established the relationship between the structure and efficiency of the membranes. This review aimed to identify approaches for improving AEM ion conductivity and alkaline stability. Additionally, future research directions for the commercialization of anion exchange membranes were discussed based on the analysis and assessment of the current applications of AEMs in patents.

Coupled amorphous NiFeP/cystalline Ni3S2 nanosheets enables accelerated reaction kinetics for high current density seawater electrolysis

Rational designing efficient, low-cost and corrosion resistant electrocatalysts is a crucial priority for seawater electrolysis to give impetus to the development of hydrogen energy and carbon neutrality. Herein, an amorphous NiFeP/crystalline Ni3S2 (NiFeP/Ni3S2) heterojunction catalyst is legitimately constructed for seawater electrolysis. Such structure improves the conductivity of amorphous NiFeP and optimizes the electronic structure by keeping the metal active sites in a relatively high valence state. In situ/ex situ experimental and theoretical calculation results reveal that the amorphous/crystal heterostructure accelerates the reconstruction and reaction kinetics of catalysts, reducing the energy barrier for potential-determining step and leading to improved intrinsic activity. The constructed NiFeP/Ni3S2 shows the overpotential of 354 mV to drive current density of 800 mA cm−2 in the alkaline medium. Besides, under 100 mA cm−2, NiFeP/Ni3S2 can run stably for 600 hours in seawater electrolyte without any hypochlorite production, demonstrating its excellent chemical stability and corrosion resistance.

Theoretical Understanding of Effects of Operating Modes on the Performance Durability of Solid Oxide Cells: A Comparison between Potentiostatic and Galvanostatic Operations

In solid oxide cells (SOCs), the choice between galvanostatic (constant current) and potentiostatic (constant voltage) modes does not significantly affect the performance of SOCs as long as the cell components remain unchanged and intact. However, the degradation of cell components, which leads to changes in electrochemical and physical properties of the cell, elevates the importance of the selected operating mode. This paper aims to investigate the effects of galvanostatic and potentiostatic operating modes on the evolving properties of SOCs and their subsequent influence on performance durability. Employing non-equilibrium thermodynamic analysis, a crucial approach for understanding the degradation phenomena within an active electrochemical system, this study aims to provide in-depth insights into how these operating modes affect the longevity and efficacy of SOCs. Key findings include: In cases where oxygen electrode (OE) degradation is accelerated by higher partial pressure of oxygen ( pO2 ), operating under constant voltage electrolysis can mitigate the high pO2 at the OE|electrolyte (OE|EL) interface. Conversely, if OE degradation occurs more rapidly under a lower pO2, constant current electrolysis is more effective in suppressing degradation by achieving a high pO2 at the OE|EL interface. For degradation of the fuel electrode (FE) due to higher pO2, constant current electrolysis is beneficial for more stable performance, which helps maintain low pO2 at the FE|EL interface. When FE degradation is accelerated by lower pO2, constant voltage electrolysis can avert low pO2 at the FE|EL interface. In practical scenarios, more complex degradation mechanisms come into play, especially when pO2 significantly deviates from initial conditions. Degradation in one electrode can influence pO2 in the other electrode, a phenomenon more pronounced in potentiostatic than in galvanostatic electrolysis.

Electron Redistribution of Ru Site on MoO2@NiMoO4 Support for Efficient Ampere-Level Current Density Electrolysis of Alkaline Seawater.

Seawater electrolysis is a promising but challenging strategy to generate carbon-neutral hydrogen. A grand challenge for hydrogen evolution reaction (HER) from alkaline seawater electrolysis is the development of efficient and stable electrocatalysts to overcome the limitation of sluggish kinetics. Here, a 3D nanorod hybrid catalyst is reported, which comprises heterostructure MoO2@NiMoO4 supported Ru nanoparticles (Ru/ MoO2@NiMoO4) with a size of ≈5nm. Benefitting from the effect of strongly coupled interaction, Ru/MoO2@NiMoO4 catalyst exhibits a remarkable alkaline seawater hydrogen evolution performance, featured by a low overpotential of 184mV at a current density of 1.0 A cm-2, superior to commercial Pt/C (338mV). Experimental observations demonstrate that the heterostructure MoO2@NiMoO4 as an electron-accepting support makes the electron transfer from the Ru nanoparticles to MoO2, and thereby implements the electron redistribution of Ru site. Mechanistic analysis elucidates that the electron redistribution of active Ru site enhances the ability of hydrogen desorption, thereby promoting alkaline seawater HER kinetics and finally leading to a satisfactory catalysis performance at ampere-level current density of alkaline seawater electrolysis.

Anodic Oxidation of Aliphatic and Aromatic Amides, Bisamides and Related Derivatives

AbstractThe current comprehensive review covers four main parts, of which some are presented in the form of a personal account. 1. Anodic oxidation of a) N‐alkyl and N,N‐diallyl carbonyl moieties, b) Azacycloalkyl amides and the effect of ring‐size on the outcome, c) Lactams, d) Sulfonamides, and e) The effect of a substituent R attached to carbonyl (N−CO−R) or sulfonamides (N−SO2R) on their oxidation potentials. 2. Anodic oxidation of aromatic amides, in particular of type Ph2CHCONHAr, lacking hydrogen(s) at the α‐position to nitrogen. They undergo three types of bond‐cleavage, yielding a variety of fragmentation products. 3. a) Anodic oxidation of symmetrical bisamides of type ZCONH(CH2)nNHCOZ (Z=Me, Ph, Ar; n=2–4) under constant current electrolysis, in methanol. For n=3, 4 they afford mostly mono‐ and dimethoxylation products. For n=2 they undergo ′CH2−CH2′ bond cleavage to yield fragmentation products. b) Anodic oxidation of symmetrical bisamides of type ArCONH(CH2)2NHCOAr under controlled potential electrolysis, in acetonitrile, leads to gem‐unsymmetrical bisamides of type ArCONHCH2NHCOMe as the major product, in fair yields. 4. Utilization of the anodic process in organic synthesis to form C−C bonds by both intra‐ and inetrmolecular processes; as well as C−O and C−N bonds for generating heterocycles.

Electrochemical CO2 conversion in eutectic Li-Ba and Li-Ca carbonate mixtures

Here, the impact of electrolyte selection and electrolysis temperature on carbon morphology, energy consumption, and voltage efficiency in molten Li2CO3-BaCO3 and Li2CO3-CaCO3 electrolytes during 90 min 10 A constant current electrolysis are investigated. The scarcity of experimental investigations into these binary electrolytes, coupled with a lack of systematic investigation of temperature effects, necessitates further examination. The comprehensive analysis of the produced carbon reveals that both electrolyte composition and temperature influence carbon morphology. At lower temperatures the effect of electrolyte composition to the morphology is a more significant. The type and amount of metallic impurities mixed with the carbon vary depending on the electrolyte composition and electrolysis temperatures. The results from Li2CO3-CaCO3 electrolyte show more promising compared to results from Li2CO3-BaCO3 electrolyte in terms of product quality. Regarding electrolysis power and voltage efficiency, Li2CO3-CaCO3 proves equal or superior to other electrolytes, depending on temperature. Heat generation occurs in all the experiments, which emphasizes the importance maintaining a constant electrolysis temperature in industrial processes to manage heat generation effectively.

Hyperchaotic power with wide current variation for efficient manganese electrodeposition

A practical hyperchaotic circuit has been designed, which has further been successfully applied to the manganese metal electrolysis system, replacing the traditional direct current power to alter the dynamic system of electrolysis process. The results illustrate that the hyperchaotic current can significantly suppress the electrochemical oscillation. Therefore, the growth of manganese (Mn) dendrites in the cathode can be significantly suppressed by the ultra − wide chaotic current fluctuation because of the regulation of electronic dynamic system. In addition, the distribution of manganese dendrites is quantified for the first time through image analysis, processing, and calculation. Besides, the hyperchaotic current can also considerably improve the current efficiency with 2 % increasing and reduce the energy consumption about 0.3 kW·h/kg simultaneously. It also demonstrates some advantages of chaotic current electrodeposition technology by conducting a larger-scale chaotic current electrolysis experiment.

Study on the air atmosphere molten salt electrolytic extraction of tungsten and cobalt from cemented carbide scrap

In this study, tungsten and cobalt were extracted from cemented carbide scrap by three-stage electrodeposition in Na2WO4 molten salt at 900 °C in air atmosphere. The cemented carbide scrap was used as the consumable anode, while the cemented carbide calcined material was used as the electrolytically active substance additive. The composition of the cemented carbide calcined material was determined by thermodynamic calculations combined with XRD phase analysis. The study investigated the promoting effect of air atmosphere on anode oxidation and the effect of varying the molar ratio of tungsten to cobalt in the molten salt on product composition. Cyclic voltammetry was used to analysed the cathodic reduction behaviour of tungsten and cobalt. The nucleation mechanism of tungsten and cobalt was determined to be instantaneous by chronoamperometry. Finally, metallic tungsten and cobalt were successfully separated and extracted by three-stage constant current electrolysis.

Construction and Evaluation of Cheap and Robust Miniature Ag/AgCl Reference Electrodes for Aqueous and Organic Electrolytes

AbstractStable reference electrodes (REs) are crucial for reliable voltammetry, controlled potential electrosynthesis, or spectro‐electrochemistry. Yet, inferior pseudo‐REs, such as plain Ag wire are often used, because commercial REs are expensive, may degrade or contaminate under required conditions, or don't fit geometric restrictions of custom setups. Addressing such cases, we report construction, benchmarking and utilization of easy to make, cheap (<1 €), and robust miniature REs from pasteur pipettes, molecular sieve beads and Ag wire. Excellent potential precision and accuracy with at least 1 week device stability was obtained for aqueous Ag/AgCl REs with 3 M NaCl in H2O and anhydrous 0.1 M TBACl in MeCN inner‐electrolytes. Even in alkaline 1 M NaOH electrolyte, where initial Ag/AgCl REs quickly convert to Ag/Ag2O (1 M NaOH) REs, perfect potential precision, accuracy, and at least 1 week stability are demonstrated. According to experimental needs, miniature REs can be built with many organic and aqueous electrolytes. For these custom use‐cases, we report guidelines to calibrate absolute RE potential, and to assess device precision, accuracy and stability. Finally, electro‐hydrogenation of styrene on nickel electrodes exemplifies superiority of Ag/AgCl REs over Ag wire pseudo‐REs, affording more reliable electrolysis current, cell potential and potential dependent Faraday efficiency.

Nitrogen-doped carbon layer encapsulating NiFeP nanosheet arrays as high-performance electrocatalyst for oxygen evolution reaction

With water electrolysis restricted to the slow kinetics of oxygen evolution reaction (OER), developing catalysts with both high activity and durability has become an urgent requirement for the development of current water electrolysis technology. Herein, we successfully prepared nitrogen-doped carbon layer encapsulating NiFe phosphide nanosheet arrays (denoted as N-C@NiFeP) catalysts by using a simple hydrothermal method combined with low temperature plasma technique. Phosphating conversion, carbonization, and nitrogen doping were realized by the same high-efficiency plasma treatment process. The nitrogen-doped carbon-coated structure modifies the NiFeP electronic structure, resulting in remarkable OER performances of N-C@NiFeP nanosheet arrays. The N-C@NiFeP nanosheet arrays possessed a tiny Tafel slope value of 27 mV dec−1 and a low overpotential of 229 mV at 10 mA cm−2. Meanwhile, the N-C@NiFeP nanosheet arrays also exhibited impressive long-term durability of 100 h under sequential OER testing at 100 mA cm−2. Our work was instrumental in paving new pathways for the construction of efficient and stable OER electrocatalysts.