Nickel Mesh Research Articles

Grain boundaries derived from layered Fe/Co di-hydroxide porous prickly-like nanosheets as potential electrocatalyst for efficient electrooxidation of hydrazine

Constructing a potentially stable and highly active nanostructured catalyst for hydrazine electro-oxidation is of substantial importance in direct-hydrazine fuel cells (DHFCs) application. In this work, we grow layered prickly-like Fe/Co di-hydroxide porous nanostructures as bifunctional catalysts on the surface of nickel mesh (Fe/Co/NiMn D-HPNs) via controllable electroplating method for an efficient electrooxidation reaction of hydrazine. The layered prickly-like Fe/Co/NiMn D-HPNs samples are explored as potential catalysts for electrooxidation of hydrazine with the enhanced catalytic current response (32.4 mA cm−2), which is higher than the mono-hydroxide nanostructured electrodes (Fe@ D-HPNs and Co@ D-HPNs). The obtained higher catalytic activity is mainly attributed to layered prickly-like nanostructures with a large electroactive surface area (116.5 cm−2), Fe and Co elements that promoted synergetic effect, and the presence of grain-boundaries on the surface of prickly-like porous layers. The layered prickly-like Fe/Co/NiM30 D-HPNs catalyst displayed a low Tafel slope (67.4 mV dec−1) and longer stability of its original morphology of layered prickly-like porous nanostructures toward the electrooxidation of hydrazine even after >10000 sec. Thus, the layered prickly-like Fe/Co/NiM30 D-HPNs are considered as a potential and robust catalyst, and provide new insights in the construction of highly-active and low-cost alternative non-noble nanostructured materials for DHFCs applications.

Rational Design of Trimetallic Sulfide Electrodes for Alkaline Water Electrolysis with Ampere-Level Current Density.

Electrochemical water splitting is considered an environmentally friendly approach to hydrogen generation. However, it is difficult to achieve high current density and stability. Herein, we design an amorphous/crystalline heterostructure electrode based on trimetallic sulfide over nickel mesh substrate (NiFeMoS/NM), which only needs low overpotentials of 352 mV, 249 mV, and 360 mV to achieve an anodic oxygen evolution reaction (OER) current density of 1 A cm-2 in 1 M KOH, strong alkaline electrolyte (7.6 M KOH), and alkaline-simulated seawater, respectively. More importantly, it also shows superior stability with negligible decay after continuous work for 120 h at 1 A cm-2 in the strong alkaline electrolyte. The excellent OER performance of the as-obtained electrode can be attributed to the strong electronic interactions between different metal atoms, abundant amorphous/crystalline hetero-interfaces, and 3D porous nickel mesh structure. Finally, we coupled NiFeMoS/NM as both the anode and cathode in the anion exchange membrane electrolyzer, which can achieve low cell voltage and high stability at ampere-level current density, demonstrating the great potential of practicability.

Nickel-based alloy nanoparticles anchored on nickel mesh towards excellent and sustainable water electrolysis

Mixed metallic alloys have gained significant attention as favorable electrocatalytic materials for water splitting due to their high conductivity and stability. Here, NiCox and NixFe bimetallic alloys with rich pore structures were prepared by electrodeposition on the nickel mesh (NM), which exhibited high electrocatalytic activity for hydrogen evolution reaction (HER) and oxygen evaluation reaction (OER), respectively. At the same time, the synergistic effect of bimetal atoms greatly improved the electrochemical performance compared to monometallic electrodes. When the NiCo4/NM electrode performed as a cathode, the current density reached 10 mA cm−2 at an overpotential of 43 mV, which was comparable to that of the precious metal Pt/C. On the other hand, the Ni4Fe/NM electrode showed an overpotential of only 201 mV at 10 mA cm−2 OER current density. In addition, the electrolyzer assembled with Ni4Fe/NM || NiCo4/NM electrodes afforded low cell voltages of 1.50 and 1.76 V at 10 and 100 mA cm−2, respectively, and excellent long-term stability of more than 80 h. This would be a promising study for replacing the precious benchmark electrocatalysts.

(Digital Presentation) The Effects of Sulfur-Oxygen Ratio at the Heterogeneous Interface on Oxygen Evolution Reaction Performance of Ni3S2@Ni3Fe Catalysts for Alkaline Water Electrolysis

Alkaline water electrolysis is the important pathway for the green hydrogen generation, where oxygen evolution reaction (OER) kinetics is limited due to the sluggish proton-coupled electron transfer in the four-electron reaction. It’s very important for the design of high-performance OER catalysts in order to improve its kinetics performance. Here, porous heterogeneous Ni3S2@Ni3Fe catalysts are prepared on nickel mesh (NM) by the electrodeposition process. Oxygen atoms are introduced into Ni3S2 by the vulcanization processes, and different S-O atom ratios are adjusted by varying vulcanization temperature. The influence of S-O ratio at heterogeneous interface on OER performance of Ni3S2@Ni3Fe is systematacially investigated. The results indicate that high S-O ratio improves the OER performance of Ni3S2-xOx@Ni3Fe, which is attributed to H2O adsorption ability enhancement on Ni3Fe surface due to the formation of unique heterogeneous electronic structure by density functional theory (DFT) calculation analysis. The prepared NM/Ni3S2-xOx@Ni3Fe (vulcanization temperature at 300 oC) electrode exhibits the improved OER performance in 30 wt% KOH solutions at high current density up to 1000 mA cm-2. It provides the guidance for the design of high-performance Ni3S2-based heterogeneous catalysts by introducing oxygen atom and increasing the sulfur-oxygen ratio.

Orange peel-derived activated carbon as an electrode material for supercapacitor application using nickel mesh

Orange peel-derived activated carbon as an electrode material for supercapacitor application using nickel mesh

Ni-Co-P nanosheets in-situ grown at macroporous nickel mesh with promising performance for hydrogen evolution reaction in alkaline medium

Ni-Co-P nanosheets in-situ grown at macroporous nickel mesh with promising performance for hydrogen evolution reaction in alkaline medium

Spatially Formed Tenacious Nickel-Supported Bimetallic Catalysts for CO2 Methanation under Conventional and Induction Heating

The paper introduces spatially stable Ni-supported bimetallic catalysts for CO2 methanation. The catalysts are a combination of sintered nickel mesh or wool fibers and nanometal particles, such as Au, Pd, Re, or Ru. The preparation involves the nickel wool or mesh forming and sintering into a stable shape and then impregnating them with metal nanoparticles generated by a silica matrix digestion method. This procedure can be scaled up for commercial use. The catalyst candidates were analyzed using SEM, XRD, and EDXRF and tested in a fixed-bed flow reactor. The best results were obtained with the Ru/Ni-wool combination, which yields nearly 100% conversion at 248 °C, with the onset of reaction at 186 °C. When we tested this catalyst under inductive heating, the highest conversion was observed already at 194 °C.

Multifunctional smart window based on transparent embedded Ni-mesh electrodes

Flexible electrochromic devices (ECDs) are a future technology with huge impact on wearable displays, energy saving, and adaptive camouflage. In this work, we used embedded nickel (Ni) mesh transparent electrodes combined with a thin polymer film of poly(3,4-ethylenedioxythiophene): polystyrene sulfonate (PEDOT:PSS) to build a multifunctional flexible electrochemical device that integrates the functions of electrochromic and supercapacitor devices. The multi-layer architecture improves the device performance in terms of optical contrast and mechanical strength. Ni-mesh electrodes have a high optical transparency (84.8%), good mechanical flexibility, and low resistance (0.5 Ω/sq), which is conducive to efficient electron injection, benefiting to the response time of the constructed device. The thin polymer film of PEDOT:PSS is an electrochromic (EC) material that also uniformly distributes electrons for a uniform coloration. The fabricated device shows fast response to coloring and bleaching (1.2 and 0.8 s, respectively), an absolute transmittance contrast ratio of 40%, and area capacitance of up to 2.48 mF/cm2. Furthermore, the device exhibits excellent flexibility, and the electrochromic and electrochemical properties of the device are only partially diminished upon folding, which is beneficial for the construction of multifunctional flexible electrochromic devices. With its response time, working stability, and bending ability, our multifunctional device paves the way for the next generation of flexible electronics.

Ultra-low Pt-loaded catalyst based on nickel mesh for boosting alkaline water electrolysis

Green hydrogen produced by water electrolysis is an important form of energy storage for centralized, large-scale and long-cycle scenarios. Cost efficiency is crucial in promoting this green energy storage approach; hence, developing a low-cost and efficient catalyst for water electrolysis is essential. This study describes a method to improve the catalytic activity of nickel wire mesh by using ultra-low Pt (0.06 mg cm−2) doped Ni(OH)2 arrays, which improves the charge kinetics, active surface area and intrinsic activity of the active sites. The target electrode requires only 68 and 269 mV @ 100 mA cm−2 for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), respectively, in alkaline electrolyte. The two-electrode water-splitting system assembled by the proposed electrode outperformed the noble-metal pair Pt/C@NM || RuO2 @NM. The performance of the assembled alkaline water electrolyzer is also outstanding (required only 1.87 V to reach 400 mA cm−2) with excellent durability (> 600 h).

Replacing carbon cloth by nickel mesh as substrate for air-diffusion cathodes: H2O2 production and carbenicillin degradation by photoelectro-Fenton

The development of air-diffusion electrodes (ADEs) that electrocatalytically produce H2O2 for its decomposition by Fenton’s reaction is gaining relevance. However, attention has been paid to improve the catalytic layer using standard carbonaceous substrates like Ccloth. This work clearly proves the superior endurance of 3 cm2 ADEs fabricated with Nimesh as substrate, achieving stable H2O2 accumulation up to 60 mM at 100 mA for 48 h in an undivided cell. Consequently, the antibiotic carbenicillin could be totally degraded in 13 min by photoelectro-Fenton (PEF) process using the Nimesh|C-PTFE ADE at 20 mA in an acidic model solution. This high performance was confirmed by PEF treatment in urban wastewater, reaching total drug disappearance in 18 min with >80 % TOC abatement. The time course of OH and toxicity was monitored, whereas chromatographic analysis of treated solutions revealed the formation of 32 aromatic and 16 aliphatic byproducts, including 7 linear carboxylic acids.

A hierarchical nickel-iron hydroxide nanosheet from the high voltage cathodic polarization for alkaline water splitting

Developing efficient and stable oxygen evolution reaction (OER) electrocatalysts is a promising method to relieve the pressure of noble metals for catalyzing water splitting. Among the prominent candidates, nickel-iron layered double hydroxides (NiFe-LDH) have been found excellent catalytic activity, but their poor conductivity and stability seriously impede their performance. Herein, we report hierarchical NiFe-LDH nanosheets prepared from NiFe-Alloy on nickel mesh (NM) by high voltage cathodic polarization. The resultant NiFe-LDH/NM exhibits a remarkable OER activity and stability, which has a low overpotential of 340 mV at a current density of 10 mA cm−2, and maintains a current density of 15 mA cm−2 at a constant voltage of 1.56 V for 50 h if the NiFe-Alloy/NM is used as the cathode. The successful conversion of NiFe-LDH nanosheets originating from NiFe-Alloy nanoparticles would open a new avenue for synthesizing transition metal-based LDH compounds.

EFFECT OF THE JOINT SATURATION CONDITIONS OF STEEL WITH CHROMIUM AND NICKEL ON THE DIFFUSION LAYER DEPTH

The destruction of parts of machines and mechanisms made of carbon and structural steels, as a rule, begins with surface corrosion, which can be prevented by applying protective coatings, in particular, by chemical-thermal treatment. The results of laboratory studies on the joint thermal diffusion saturation of steel 35Х2Н3 with chromium and nickel at a temperature of 1000°C for 24 hours are presented. A technique for analyzing the resulting coating based on the possibilities of X-ray spectral microanalysis (EDXA) of the diffusion layer on transverse microsections of the obtained samples is presented. The elemental composition of the diffusion layer was monitored using a JEOL JSM-6460 LV universal scanning electron microscope. Additionally, an experiment was carried out, which made it possible to fix the occurrence of an electric current in the system due to the thermal emission of electrons from the metals of the saturating mixture. It is shown that the complex saturation of structural steel with chromium and nickel has a favorable effect on the depth of the diffusion layer. An effective way to increase the depth of diffusion of chromium and nickel is to use an electron gun (nickel mesh). The diffusion depth of nickel increases by 2 times and chromium by 1.3 times. The fact of electron emission and the occurrence of their directed flow (current strength up to 0.15 mA) from the backfill to the saturated part has been experimentally confirmed. It was established that the magnitude of the emerging current depends on the number of emitted electrons and it is higher when the work function of electrons for the metal in the filling is lower.

Preparation of nanosheets of Ni5P2@Ni9S8/CoS1.097 heterostructure for aqueous asymmetric supercapacitors with high electrochemical performance

In recent years, transition metal sulfides, especially nickel-cobalt sulfide materials play a crucial role for supercapacitor applications. In this work, the Ni5P2@Ni9S8/CoS1.097 (Ni-P@NCS) core-shell material has been synthesized by simply phosphating the nickel mesh and subsequent electrodeposition of NCS to obtain a nanosheet heterostructure on nickel foam. The Ni-P@NCS composite material has a higher gravimetric capacitance of 2445.7 F g−1 than pure Ni-P of 1116.6 F g−1 and NCS materials of 1104.3 F g−1 at 1 A g−1. At the same time, Ni-P@NCS electrode yields excellent cycling stability (91.4% capacitance retention after 5000 charge–discharge cycles). An asymmetric supercapacitor (ASC) device assembled from Ni-P@NCS and activated carbon electrodes can deliver a highest energy/power density of 42.8 Wh kg−1/799.8 W kg−1, with 94.3% capacitance retention after 10,000 cycles at 5 A g−1. The improvement of electrochemical performance makes it possible to use it as an electrode material.

(Invited) Leak Current Analysis of Stop Operation and Its Modeling for the Development of Bipolar Alkaline Water Electrolyzer Electrodes

Introduction Water electrolysis is expected a key device to introduce large-scale renewable electricity under management of power grid and electrification of non-electric sector. While alkaline water electrolysis (AWE) systems are well-developed large system, degradation under fluctuated operation with start and stop operation is significant issue to combine photovoltaic and/or wind turbine generation is significant issue. In this study, we have been investigated reverse current, which is leak current through manifold of bipolar alkaline water electrolyzers, and electrode potential behavior of stop operation, and proposed accelerated durability test (ADT) protocol for start and stop operation. Experimental and modeling Figure 1 shows configuration of 4-cells bipolar alkaline water electrolyzer that was consisted with end plates of EP(-) and EP(+), bipolar plates of BP1 to BP3, anodes, separators, and cathodes with principle of reverse current. The end and bipolar plates were made of nickel. Anodes and cathodes were commercially available oxygen and hydrogen electrocatalyst coated nickel mesh electrodes (De Nora Permelec Ltd) with 27.8 cm2 of projected area. Zirfon Perl UTP500 (Agfa) was used for separators. Manifolds were made of Teflon tubes and 15 mL/min of 7 M (= mol/dm3) was circulated for each anolyte and catholyte chambers during measurements. An anode and a cathode set on a bipolar plate. During operation anodes and cathodes are oxidized and reduces, respectively. After stop, the anode and the cathode on a bipolar plate connects both electronically and ionically, so oxidized anode and reduced cathode surface discharges to same potential. In this study, we measured electrode potential and reverse current after 1 h water electrolysis of 80oC at 0.6 A/cm2. The reverse current was measured ionic current through communicating tube with D. C. clamp meter (KEW2510, Kyoritsu).Reverse current behavior was analyzed with COMSOL Multiphysics version 5.5 based 2-dimensional model of stack and height direction using experimentally anode and cathode potentials as functions of discharge for anode and cathodes. Results and discussion Figure 2 shows cell performances in the stacks and a picture of the lab-scale zero-gap configuration electrolyzer. All cells in a stack showed almost the same performance. The cell voltage was 2 V at 400 mA/cm2 at 30oC and was 1.8 V at 500 mA/cm2 at 80oC. Therefore, we think all cells and parts work well.Figure 3 shows reverse currents and electrode potentials as a function of time after 1 h electrolysis under 600 mA/cm2 at 30 or 80 oC. Here, the dashed lines in Fig. 3-a) were simulated value and were almost same after 20 s. The measured reverse current increased around 20 s. At this moment, outlet manifolds filled with electrolyte to increase ionic conduction among the chambers, which was not considered in the simulation. After degassed of manifolds, the reverse current decreased with time with the largest reverse current for the BP2. The reverse current at 80oC was significantly larger than that at 30oC. This difference could be explained the dependence of ionic resistance of manifold on temperature. At same moment, anode and cathode potentials on the end plates were almost constant. The anode cathode potentials on the bipolar plates decreased and increased with time, respectively. Both anode and cathode showed significantly potential change region. The final potentials of all electrodes were around 0.9 V vs. RHE. The potential change regions of the electrodes on the BP2 were earlier than others. Here, the anode and cathode potentials as functions of discharge were almost same for the electrode on all bipolar plates. Therefore, the average discharge functions for anode and cathode were treated as characteristics of electrodes of this study. Using this function, reverse current as a function of time could be expressed accurately using the developed model. From this model, reverse current, and electrode potentials as a function of time would be expected with discharge function of each electrode and ionic resistance of manifold.Figure 4 shows that a start & stop operation simulated ADT protocol based on bipolar electrolyzer measurements. We propose the combination of constant current electrolysis, potential sweep, and chronoamperometry as the inset of illustration in Fig. 4, because constant current measurement is easier to get reproductivity in high current that need accurate iR correction for constant potential measurement and current control measurement never simulate stop operation. Acknowledgements This study was based on results obtained from the Development of Fundamental Technology for Advancement of Water Electrolysis Hydrogen Production in Advancement of Hydrogen Technologies and Utilization Project (P14021) commissioned by the New Energy and Industrial Technology Development Organization (NEDO). Figure 1

Silver decorated hydroxides electrocatalysts for efficient oxygen evolution reaction

Electrocatalysts play a pivotal role in electrochemical water splitting, where the development of efficient oxygen evolution reaction (OER) electrocatalysts remains challenging. Here, we report a facile one-step blending approach to synthesize efficient and durable OER electrocatalysts of silver decorated hydroxides (Ag@hydroxides). The general efficacy of this methodology is demonstrated in five hydroxides, in form of powders or self-supported electrodes. The decoration of Ag lowers the overpotentials by 41–56 mV, rendering Ag@NiFe LDH among the most active OER catalysts. It requires an overpotential of 246 mV only to deliver a current density of 10 mA cm−2. Under industrial electrolysis conditions (30 wt% KOH and 80 °C), the cell voltage is 1.76 V for 500 mA cm−2. It is 270 mV lower than the intact nickel mesh, corresponding to a 9% improvement in the energy conversion efficiency. Furthermore, by combining spectroscopic analysis and theoretical calculation we unravel that the strong interfacial charge transfer is the root cause for the promoting catalytic activity, where the binding energies of catalytic intermediates are optimized. This work provides a facile and ease-to-scale-up approach for the synthesis of efficient and durable electrocatalysts and demonstrates the power of regulating the interface in improving electrocatalytic kinetics.

Ascorbic acid-induced structural defect in photocatalytic graphitic carbon nitride to boost H2O2 fuel cell performance

In this study, porous g-C3N4 with structural defects of oxygen atom and cyano group (COCN) prepared by thermal polymerization of directly calcinating the mixture of urea and ascorbic acid, is firstly applied in the H2O2 fuel cell. By employing a nickel mesh coated with COCN as the photoanode and iron phthalocyanine (FeIIPc) mixed with g-C3N4 on carbon paper as the cathode, this COCN-based cell exhibits a maximum power density of 0.298 mW·cm−2 in the water solution including 0.1 M HCl under AM 1.5G solar light at air atmosphere, which has an approximate 5.0 times enhancement compared with that of pristine g–C3N4–based one. The corresponding solar-to-electricity conversion efficiency (SECE) of above cell is estimated to be 0.248%. In addition, the photocatalytically produced H2O2 (chemical energy) is stored in water with the electrodes disconnected under light irradiation for 3 h, and then is directly used as the fuel in an H2O2 fuel cell by connecting the electrodes in the dark, yielding a specific capacitance of 5900 mF·cm−2. After 6 h of cell operation, the retention rate of specific capacitance is still as high as 76.9%. The primary results provide a facile strategy to introduce structural defects in g-C3N4 for boosting H2O2 fuel cell performance.

Rheological Abnormalities in Human Erythrocytes Subjected to Oxidative Inflammation.

Erythrocytes are oxygen carriers and exposed to redox cycle in oxygenation and deoxygenation of hemoglobin. This indicates that circulating erythrocytes are vulnerable to the oxidative injury occurring under the imbalance of redox homeostasis. In this review article, two topics are presented concerning the human erythrocytes exposed to the oxidative inflammation including septic and sterile conditions. First, we demonstrate rheological derangement of erythrocytes subjected to acute oxidative injury caused by exogenous generators of reactive oxygen species (ROS). Erythrocyte filterability as whole-cell deformability has been estimated by the gravity-based nickel mesh filtration technique in our laboratory and was dramatically impaired in a time-dependent manner after starting exposure to the ROS generators, that is associated with concurrent progression of membrane protein degradation, phospholipid peroxidation, erythrocyte swelling, methemoglobin formation, and oxidative hemolysis. Second, we introduce an impairment of erythrocyte filterability confirmed quantitatively in diabetes mellitus and hypertension of animal models and patients under treatment. Among the cell geometry, internal viscosity, and membrane property as the three major determinants of erythrocyte deformability, erythrocyte membrane alteration is supposed to be the primary cause of this impairment in these lifestyle-related diseases associated with persistent oxidative inflammation. Excessive ROS trigger the inflammatory responses and reduce the erythrocyte membrane fluidity. Oxidative inflammation increasing erythrocyte membrane rigidity underlies the impaired systemic microcirculation, which is observed in diabetic and/or hypertensive patients. On the other hand, elevated internal viscosity caused by sickle hemoglobin polymerization is a primary cause of impaired erythrocyte filterability in sickle cell disease (SCD). However, oxidative inflammation is also involved in the pathophysiology of SCD. The physiologic level of ROS acts as signaling molecules for adaptation to oxidative environment, but the pathological level of ROS induces suicidal erythrocyte death (eryptosis). These findings provide further insight into the ROS-related pathophysiology of many clinical conditions.

Facile strategy for the construction of a robust underbrine superoleophobic membrane for highly efficient oil-brine separation

Developing an effective and sustainable method for the separation of oil and brine mixture is highly necessary for the restoration of environmental pollution caused by the loss of organic solvents during the lithium extraction process from brine. Herein, we report a facile and cost-efficient method to fabricate an underbrine superoleophobic mesh by one-step hydrothermal method. The synthesized CrOx(OH)3–2x/nickel mesh possesses flower-like nanostructure, exhibiting superior superhydrophilicity/underbrine superoleophobicity for different ratios of tributyl phosphate and sulfonated kerosene mixtures. Simultaneously, the CrOx(OH)3–2x /nickel mesh manifests high efficiency for oil and brine separation with an ultrahigh permeation flux (78136 L∙m−2∙h−1) and excellent oil rejection efficiency (>99.17%). Furthermore, the as-prepared mesh exhibits high chemical stability, outstanding salt tolerance, and excellent mechanical properties. Importantly, the surface wettability can be changed from superhydrophilicity to superoleophobicity for several times only by ignition of the CrOx(OH)3–2x/NM on an alcohol burner for 10 s or modified by OTS. Altogether, the CrOx(OH)3–2x/nickel mesh has tremendous potential in practical oil-brine applications.

Sol-gel synthesized nickel oxide nanostructures on nickel foam and nickel mesh for a targeted energy storage application

The nickel-based oxides are treated as favourable pseudocapacitive electrode materials for energy storage application owing to their inexpensive nature, well-defined redox activity, as well as liberty in tuning the microstructures by changing the synthesis process optimizing its vital parameters. However, a real challenge for fabricating nickel-based materials is to sustain the uniform morphology onto a conductive substrates like FTO, ITO, stainless steel, nickel foam, nickel mesh, and copper foam etc. Herein, nickel oxide (NiO) nanostructures (NSs) with high pseudocapacitive performance have been prepared via the sol-gel technique for energy storage application. The structural identity of NiO-NSs is documented by X-ray diffraction, which confirmed the monoclinic crystal structure of the synthesized NSs. The X-ray photoelectron spectroscopy confirmed the valence state of the nickel as ‘+2′ and oxygen as ‘-2′. The field-emission scanning electron microscopy of NiO-NSs revealed non-uniform large spherical clusters agglomerated onto the surface. The NiO-NSs manifested the mesoporous channels and exhibit a surface area of 31.4 m2g-1, which is evaluated through Brunauer-Emmett-Teller analysis. The fabricated NiO-nickel foam (NF) electrode exhibit a high specific capacitance of 871 Fg−1 at a scan rate of 5 mVs−1 in 4 M KOH solution. Moreover, the NiO−NF electrode displayed the cyclic retention of 86.5 % after 10,000 cycles. The mesoporous channels of the electrode material afford plentiful, accessible, active sites to the effective charge transportation of electrolyte charges over the electrolyte-electrode interface and boost the electrochemical performance of NiONF −electrodes. Moreover, an asymmetric supercapacitor device constructed with NiO−NF as the anode and AC−NF as the cathode delivers high specific energy and specific power (24 Whkg−1 at 2.9 kWkg−1), and good cycling stability (retention of 89.7 % over 5 000 cycles)

An industry-applicable hybrid electrode for large current density hydrogen evolution reaction

The performance evaluation on water splitting electrodes is usually conducted in laboratory at current density range of 10–100 mA cm−2, and this is far from satisfactory for the industrial practices that require the operating current density larger than 400 mA cm−2. In this work, an efficient hybrid electrode is developed by firstly electro-etching the nickel mesh (E-NM) in actual seawater and then in-situ depositing nickel nanowires (NWs) onto E-NM substrate under the externally applied magnetic field. The results show that NWs are integrated into the defective E-NM structure. The assembled NWs/E-NM hybrid electrode achieves a high current density of 800 mA cm−2 at 2.0–2.1 V, which outperforms the commercial NM electrode. Moreover, the current density does not decay after 100 h stability test at 500 mA cm−2.