Surface Morphology Of Electrode Research Articles

Economical iron-based catalyst electrode for highly stable catalytic industrial-scale overall seawater splitting

The development of economical and stable catalyst electrodes for industrial-scale seawater splitting is one of the current challenges in hydrogen production. The economical transition metals possess high electrical conductivity and offer the potential for designing electrodes with high intrinsic activity through appropriate modifications, thus holding promising applications in industrial contexts. Herein, a durable and economical self-supported bifunctional electrode (Fe@Ni) with high efficiency and large area is successfully constructed by one step in-situ deposition of iron on the porous structure of nickel foam (NF) via mild (298 K) electroplating method. Transition metals like iron and nickel offer high electrical conductivity and can be properly modified to achieve electrodes with high intrinsic activity. Due to the in-situ growth of cost-effective iron on the NF surface, the electrode surface morphology and electronic structure are reconstructed, which significantly improves the electrochemical activity surface area and electron transfer capability of the electrode. The hydrogen/oxygen evolution reaction (HER/OER) in simulated seawater (1 M KOH + 0.5 M NaCl) require only 129 mV and 323 mV overpotentials to achieve a current density of 100 mA cm−2. Overall seawater splitting (OWS) achieves 10 mA cm−2 at a low voltage of 1.49 V and with a faradaic efficiency of nearly 100%. More importantly, the bifunctional electrodes remain stable at industrial-level current density (1.0 A cm−2) for more than 50 days. More attractively, this work realizes the universal construction of large-area electrode for multiple metals (e.g., Fe, Cu, Al, etc.) with mild and simple process, which provides a new strategy for the current research of energy and materials.

Au‐Free Ti/Al/Ni/TiN Ohmic Contact to AlGaN/GaN Heterostructure: Ti/Al Thicknesses at an Optimized Ratio

Although a few studies report that tuning Ti/Al thicknesses at a fixed ratio can further improve the Ohmic contact to AlGaN/GaN heterostructure, systematic physical mechanisms have not been reported. In this work, after determining the optimal Ti/Al ratio of 1/4, two metal stacks with varying Ti/Al thicknesses and fixed Ni/TiN thicknesses are deposited to investigate how tuning Ti/Al thicknesses at an optimized ratio enhances the Ohmic contact performance. At the optimal annealing condition (950 °C, 45 s) of samples with Ti/Al thicknesses of 20/80 nm, samples with Ti/Al thicknesses of 35/140 nm exhibit a reduction of 48% in contact resistance and 70% in specific contact resistivity (ρc). By correlating the results from ρc–T measurements, time‐of‐flight secondary ion mass spectrometry, and high‐resolution X‐ray diffraction, it has been determined that this method effectively enables N‐vacancies doping into the heterostructure, thereby increasing the carrier concentration and reducing both the height and width of the interfacial potential barrier, achieving a more efficient carrier transport. By avoiding the use of Au with high solubility and ductility, this approach significantly improves contact performance without adversely affecting the electrode surface morphology, demonstrating good adaptability for optimizing Au‐free Ohmic contacts.

Exploring Platinum Thin Films as Electrodes for High‐Temperature and ‐Pressure Electrochemical Studies in Aqueous Systems

ABSTRACTThis work reports a methodology for the fabrication of Pt thin‐film electrodes for electrochemical studies in hydrothermal systems. The research process was meticulous, with particular attention paid to the multilayer Ti/Pt/Ti/Al2O3 film structure and annealing conditions that are expected to impact the morphology of the films, surface composition and electrochemical response. The findings of this study are significant, as they provide valuable insights into the behaviour of Pt thin‐film electrodes in various media and conditions. Two different approaches were adopted for the preparation of the electrodes: in one case, the Ti/Pt/Ti/Al2O3 films deposited on sapphire wafers were exposed to rapid thermal annealing at 900°C under argon for 5 min, followed by argon ion milling to etch the final electrode pattern (Pt‐RA(900)), while in the other case, uncapped Pt films were annealed, after etching, in a tubular oven under argon at specific temperatures between 200°C and 900°C (Pt‐TO). Rapid annealing at 900°C on capped films resulted in the formation of a Pt3Ti intermetallic alloy with remarkable mechanical and chemical stability even after 10 h of immersion in deionised water, acid (0.1 M H2SO4) and alkaline media (0.1 M KOH) conditions at temperatures up to 150°C, despite the dissolution of the Al2O3 top layer at 150°C and long immersion times (> 10 h). In the case of uncapped Pt films, diffusion and oxidation of Ti through the Pt film at high temperature resulted in the formation of TiO2 on the surface of Pt. The results were confirmed by using a comprehensive suite of ex‐situ characterisation techniques to follow changes in the Pt electrode surface morphology and composition before and after immersion in H2O, 0.1 M H2SO4 and 0.1 M KOH solutions under argon. Ex‐situ electrochemical characterisation studies were also conducted to correlate the changes in the electrode surface properties, including the electrochemical surface area, with different annealing conditions and after various hydrothermal treatments in neutral, alkaline and acidic media.

Correlation of residual stress on piezoresistive properties of boron-doped diamond films

To investigate the influence of residual stress on the piezoresistive behavior of boron-doped diamond (BDD) films, BDD films with varying doping concentrations were synthesized using a hot-filament chemical vapor deposition (HFCVD) system on silicon and diamond substrates. The relationship between the surface morphology, structural composition, resistivity, and piezoresistive properties of BDD electrodes was examined, along with an in-depth analysis of the impact of boron doping level on these properties. The microstructure and bonding state of the BDD films were characterized using scanning electron microscopy (SEM), atomic force microscopy (AFM), and Raman spectroscopy. The piezoresistive properties of the BDD films were evaluated employing a cantilever beam bending method. Our findings demonstrate that the level of boron doping not only affects resistivity but also directly influences residual stress in BDD films, both factors having an impact on their piezoresistive properties. Despite significantly larger grain sizes observed in BDD films grown on diamond substrates compared to those grown on silicon substrates at identical boron doping concentrations, they exhibit consistent variations in residual stress and gauge factor (GF) values. With increasing doping levels, the absolute residual stress decreases initially before increasing again; moreover, at 2000 ppm doping level, it transitions from compressive to tensile stress. The GF value is closely associated with both the magnitude and type of residual stress. By utilizing a doping concentration of 2000 ppm for growth on diamond substrates, we achieved a peak GF value of 257 for BDD films which highlights their promising potential for pressure sensor applications.

Substrate and potential-driven surface morphology of bifunctional Ni-Fe electrode for efficient alkaline water electrolysis

Nickel-iron (Ni-Fe) alloy electrodes are synthesized using chronoamperometry. The influence of substrate type (copper, stainless steel, and nickel) and deposition potential on the structural, morphological, and electrocatalytic characteristics are systematically investigated. X-ray diffraction (XRD) analysis revealed the formation of a face-centered cubic (FCC) Ni-Fe alloy. Electrodeposition at higher potential (−1.45 V) forms well-defined nanoflakes, whereas electrodeposition at lower potential (−1.00 V) results aggregated Ni-Fe particles. The Ni-Fe alloy electrodes having well-defined nanoflakes demonstrated superior electrocatalytic performance, exhibiting a overpotential of −168 mV vs. RHE for the hydrogen evolution reaction (HER) and 236 mV vs. RHE for the oxygen evolution reaction (OER), at current density of 10 mA/cm2. The enhanced electrocatalytic activity of the nanoflakes based Ni-Fe alloy is attributed due to their larger catalytic surface area, porous morphology and higher Fe concentration. The Ni-Fe alloy electrodes displayed bifunctional electrocatalytic behavior, making them highly suitable for both HER and OER processes.

Voltammetric Sensor Based on Titania Nanoparticles Synthesized with Aloe vera Extract for the Quantification of Dithiophosphates in Industrial and Environmental Samples

In this work, TiO2 spherical nanoparticles with a mean diameter of 10.08 nm (SD = 4.54 nm) were synthesized using Aloe vera extract. Rutile, brookite, and anatase crystalline phases were identified. The surface morphology of a carbon paste electrode does not change in the presence of nanoparticles; however, the surface chemical composition does. The voltammetric response to dicresyl dithiophosphate was higher when the electrode was modified with TiO2 nanoparticles. After an electrochemical response study from pH 1.0 to 12.0, pH 7.0 was selected for the electroanalysis. The electroactive area of the modified sensor was 0.036 cm2, while it was 0.026 cm2 for the bare electrode. The oxidation process showed mixed adsorption-diffusion control. The charge transfer resistance of the modified sensor (530.1 Ω, SD = 4.08 Ω) was much lower than that of the bare electrode (4298 Ω, SD = 8.53 Ω). The linear quantitative range by square wave voltammetry was from 5 to 150 μmol/L, with a limit of detection of 1.89 μmol/L and a limit of quantification of 6.26 μmol/L under optimal pulse parameters of 50 Hz frequency, 1 mV step potential, and 25 mV pulse amplitude. The sensor response was repeatable and reproducible over 30 days. The results on real flotation and synthetically contaminated soil samples were statistically equivalent to those obtained by UV-vis spectrophotometry. A dithiocarbamate showed an interfering effect on the sensor response to dithiophosphate.

Influence of Bi3+ Doping on Electrochemical Properties of Ti/Sb-SnO2/PbO2 Electrode for Zinc Electrowinning.

Bi3+ doped Ti/Sb-SnO2/PbO2 electrode materials were fabricated by electrodeposition to improve their electrochemical performance in zinc electrowinning. The surface morphology, chemical composition, and hydrophilicity of the as-prepared electrodes were characterized using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and contact angle. An electrochemical measurement and an accelerated lifetime experiment were also conducted to investigate the electrocatalytic performance and stability of the electrodes. The results show that the Bi3+ modification electrode has an important effect on the coating morphology, the crystal structure, the surface hydrophilicity, the electrocatalytic activity, and the stability. The electrode prepared from the solution containing 2 mmol·L-1 Bi(NO3)3 (marked as the Ti/Sb-SnO2/2Bi-PbO2 electrode) exhibits the best hydrophilicity performance (θ = 21.6°) and the longest service life (1196 h). During the electrochemical characterization analysis, the Ti/Sb-SnO2/2Bi-PbO2 electrode showed the highest oxygen evolution activity, which can be attributed to it having the highest electroactive surface (qT* = 21.20 C·cm-2) and the best charge-transfer efficiency. The DFT calculation demonstrated that the doping of Bi3+ leads to a decrease in the OER reaction barrier and an increase in the DOS of the electrode, which further enhances the catalytic activity and the conductivity of the electrode. Moreover, the simulated zinc electrowinning experiment demonstrated that the Ti/Sb-SnO2/2Bi-PbO2 electrode consumes less energy than other electrodes. Therefore, it is expected that the Bi3+ modified electrode will become a very promising electrode material for zinc electrowinning in the future.

Balancing current density and electrolyte flow for improved zinc-air battery cyclability

Zinc-air batteries (ZABs), known for their high energy density and environmental friendliness, are emerging as promising solutions for sustainable energy storage. However, the irregular deposition of zinc on electrodes hinders the widespread utilization of rechargeable ZABs due to limited durability and stability. This study investigates the role of electrolyte flow in enhancing zinc electrodeposition and overall performance in zinc-air flow batteries (ZAFBs) at high current densities. We explore the interplay between current density, flow rate, and their influence on electrode surface morphology and the removal of the passivating zinc oxide layer to improve battery efficiency and lifespan. Using advanced in-situ synchrotron radiation x-ray tomography, we found that incorporating flowing electrolyte at specific current densities results in rounded dendrite tips, thinner and more uniform deposition layers, and improved zinc adhesion. Imaging and electrochemical analyses further reveal that flowing electrolyte enhances zinc morphology, reduces charge transfer resistance, diminishes passivation, and lowers galvanostatic charge/discharge polarization across various current densities, thereby improving battery cycling performance. Notably, the impact of flowing electrolyte is more pronounced at a moderate current density of 50 mA/cm2 compared to lower or higher currents. Our findings underscore the importance of electrolyte flow and current density management in developing high-performance ZAFBs, providing valuable insights for their future commercialization.

Nitrate reduction on bimetallic (Pd0.09Sn0.91) electrodes: Effects of calcination temperature, electrode support, and quenching

The effects of fabrication process, namely, calcination temperature, electrode support, and quenching, on electrochemical nitrate reduction were investigated, exemplified by Pd0.09Sn0.91 electrode. The electrode was characterized by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, energy-dispersive X-ray spectroscopy, and cyclic voltammetry. Results showed that electrode surface morphology, crystalline formation, and chemical composition, which were influenced by the electrode fabrication process, controlled nitrogen selectivity and nitrate reduction reactivity. The Pd0.09Sn0.91/SS electrodes were calcined at different temperatures (from 100 to 700 °C) for 3 h in air and the results showed that high calcination temperature rendered electrode oxidized, and decreased nitrogen selectivity and nitrate reduction capability. Electrode supports affected nitrate reduction following the order of Ni ≈SS > G > Ti. Quenching electrode in ice water decreased nitrate reduction capability. Porous surface with small oxygen content, less degree of metal oxidation (i.e., higher fraction of Pd0 and Sn0), and Sn crystals favored nitrogen selectivity and nitrate removal.

Mechanism of overscreening breakdown by molecular-scale electrode surface morphology in asymmetric ionic liquids

The interfacial nature of the electric double layer (EDL) assumes that electrode surface morphology significantly impacts the EDL properties. Since molecular-scale roughness modifies the structure of EDL, it is expected to disturb the overscreening effect and alter differential capacitance (DC). In this paper, we present a model that describes EDL near atomically rough electrodes with account for short-range electrostatic correlations. We provide numerical and analytical solutions for the analysis of conditions for the overscreening breakdown and DC shift estimation. Our findings reveal that electrode surface structure leads to DC decrease and can both break or enhance overscreening depending on the relation of surface roughness to electrostatic correlation length and ion size asymmetry.

Exoelectrogenic behaviors of Shewanella oneidensis MR-1 and cytochrome knock-out mutants on smooth electrodes of different materials

The development of anodes supporting a high rate of current generation stands as a crucial and challenging aspect in microbial electrochemical systems. A well-defined electrode surface morphology is essential for comprehending the impact of material intrinsic properties on microbial current generation, offering molecular insights into the respiration of exoelectrogens with electrodes made of diverse materials. We fabricated smooth electrodes (root mean square roughness below 10 nm) using four materials, each representing a distinct class of materials commonly utilized to construct bioanodes. These electrodes were employed to investigate current generation, electrochemical characteristics, and biofilm formation by Shewanella oneidensis MR-1 and mutants lacking cytochromes MtrC (ΔmtrC), MtrA (ΔmtrA), or CymA (ΔcymA). In reactors inoculated with MR-1, the poly(3,4-ethylenedioxythiophene) polystyrene sulfonate electrodes demonstrated a current density of 12.5 ± 1.1 μA cm-2, surpassing the 3.57 ± 0.50 μA cm-2 observed with indium tin oxide electrodes, while current generation levels by gold and glassy carbon electrodes fell in between. This disparity was not attributed to distinct biofilm formations by MR-1, as it formed stable monolayer biofilms on all types of working electrodes. At least five electron transfer pathways were identified in the MR-1 Vammograms, with the activities of these pathways depending on the electrode materials. The effectiveness of both endogenous and exogenous electron mediators varied with the electrode materials involved. Additionally, a phenazine compound exhibited diverse formal potentials when interacting with the biofilm and different types of electrodes. The mutants displayed varying degrees of impaired current generation and biofilm formation capabilities, with ΔmtrA and ΔcymA being the most affected regardless of the electrode used. However, for a specific mutant, the overall current generation, relative contribution by individual pathways, and biofilm formations underwent significant changes based on the electrode materials employed.

Electrodeposition of NiCo on stainless steel substrate using deep eutectic solvent for efficient hydrogen evolution and methanol oxidation reactions

The electrodeposition of NiCo on a stainless-steel substrate using Deep eutectic solvent (DES) was carried out using constant current methods. A 1:2 mol ratio of ChCl (Choline chloride) and crystalline urea was used to prepare DES. The XRD analysis of the fabricated NiCo@SS showed a highly crystalline nature, and the SEM image revealed the fabricated electrode surface morphology. The composition and oxidation state of the deposited material were confirmed by EDAX and XPS techniques. The prepared electrodes were subjected to LSV and CV studies with 1 M KOH using a three-electrode system to analyse its catalytic ability in the Hydrogen evolution reaction (HER) and methanol oxidation reaction (MOR). Among all the deposited electrocatalysts, NiCo@SS demonstrated the highest catalytic activity and excellent stability for the hydrogen evolution reaction (HER), achieving an overpotential of 257 mV at a current density of 100 mA/cm2. Additionally, NiCo@SS exhibited a remarkable current density of 240 mA at a potential of 0.8 V towards the MOR. The synthesized NiCo@SS possessed excellent low overpotential, low charge transfer resistance, high current density, and large surface area. The explored catalyst of NiCo@SS was examined with different concentrations of methanol using the CV technique. Finally, the stability of NiCo@SS, as examined by chronoamperometry and LSV with 3000 cycles, revealed it to be a robust, stable catalyst towards HER and OER.

Highly transparent and conductive Ga-doped InWO multi-component electrodes for Perovskite photovoltaics

Wide-bandgap Ga-doped InWO (GIWO) transparent conductive electrodes (TCE) were fabricated by co-sputtering IWO and Ga2O3, followed by rapid thermal annealing (RTA), with the effects of the Ga dopant content on the electrical, optical, structural, and morphological properties of the GIWO multi-component electrodes investigated to optimize the GIWO electrode. According to the figure of merit (FOM), the GIWO film with a Ga content of 2.1 at% exhibited a low sheet resistance of 9.9 Ohm/square and high transmittance of 91.71 % at a wavelength of 550 nm. The presence of a high Lewis acid strength (LAS) dopant of Ga (1.16) and W (3.15) led to an increase in the carrier mobility of GIWO and transmittance in the near infrared wavelength region. In addition, the strongly preferred (222) and (400) orientations of the GIWO grains increase the carrier mobility and improve the surface morphology of the GIWO electrodes. The successful operation and superior performance of the planar p-i-n structured perovskite solar cells (PSC) fabricated on GIWO electrodes indicate the feasibility of GIWO as a substitute for conventional Sn-doped In2O3 electrodes. The highest-performing PSC with GIWO electrodes exhibited reliable hysteresis with an efficiency difference of less than 1 % depending on the scan direction under standard AM1.5 G conditions.

Nickel Disulfide (NiS2): A Sustainable Low‐Cost Electrode Material for High‐Performance Supercapacitors

In the family of transition metal sulfides, nickel disulfide (NiS2) received significant attention in the recent past, particularly as an electrode‐active material for supercapacitors due to its high specific capacitance, high power density, long cyclic stability, and low cost. A detailed overview on the supercapacitor applications of NiS2 is lacking in the literature. In this review article, the unique features of NiS2 in terms of its various methods of synthesis, characterizations, and electrochemical performance evaluations are described. This review provides an in‐depth understanding on the unique properties of ultrathin nanostructured NiS2 such as structural properties, electronic properties, optical properties, and so on. Later, the various methods of synthesis including hydrothermal method, solvothermal method, solvent‐free approach, and so on are reviewed. Further, the strategies are discussed to improve the electrochemical performance of NiS2 by preparing hybrids or nanocomposites with other types of electrode‐active materials. The influence of electrode nanostructure and surface morphology on the charge storage is discussed with the help of specific examples. Furthermore, the potential challenges and future perspectives of NiS2 for commercial supercapacitors are examined. This review proclaims the development of novel approaches and strategies for the effective utilization of NiS2‐based electrodes for high‐performance low‐cost supercapacitors.

Enhanced Supercapacitive Performance in Catalyst‐Free Binary Composite SnO2–RuO2 Nanostructured Thin Films for Symmetric Supercapacitor Device

In the present work, thin film electrodes of ruthenium oxide (RuO2), tin oxide (SnO2), and their composite SnO2–RuO2 are deposited on 304 stainless steel substrates using pulsed laser deposition (PLD). These nanostructured electrodes are then evaluated for their suitability in electrochemical energy storage applications. A symmetric supercapacitor device (SSD) is constructed using the SnO2–RuO2 composite electrodes. Compared to individual SnO2 and RuO2 electrodes, the composite electrodes exhibit enhanced specific capacitance and cycle life. This improvement is attributed to modifications in surface morphology and electronic properties. This modified surface morphology of the composite electrode, creates favourable conditions for electrolyte interaction and ion transport, ultimately contributing to the observed increase in specific capacitance. Specifically, the composite electrode demonstrates a specific capacitance of 170.2 Fg−1 at a current density of 0.1 mA cm−2, outperforming SnO2 (37.4 Fg−1). The SnO2–RuO2//SnO2–RuO2 SSD exhibites a specific capacitance of 70.0 Fg−1 at a current density of 0.1 mA cm−2, coupled with energy density and power density values of 19.05 Wh kg−1 and 645 W kg−1, respectively, within a voltage window of 1.4 V. The SSD displays an impressive capacitive retention of 81.27% over 10 000 cycles, indicating its potential for practical energy storage applications.

Functionalization of Carbon Electrode Surface Using Polyaniline and Gold Nanoparticles for Protein Immobilization

This study presents a screen-printed carbon electrode surface functionalization to immobilize proteins. The process involves the deposition of gold nanoparticles on the carbon electrode and subsequent surface modification to immobilize bovine serum albumin–fluorescein isothiocyanate conjugate (BSA-FITC). A combination of conducting polymer and gold nanoparticles was employed to enhance the electrode contact area and current transmission. The electrode surface morphology and properties were evaluated by scanning electron microscopy (SEM) and Raman spectroscopy, showing the porous polyaniline (PANI) film has been formed on the carbon electrode surface with the network of dendritic nanofibers. Gold nanoparticles were evenly distributed on the PANI film to form a nanocomposite material layer on the carbon electrode. The observed size of these gold nanoparticles was significantly smaller than those on the electrode without a PANI film. Additionally, the current transmission of this composite material layer has been verified by cyclic voltammetry (CV). The results show that the amplitude of the redox peak was doubled compared to the bare carbon electrode and gold nanoparticle-only deposited electrode. Moreover, the success of the process was verified by fluorescence and cyclic voltammetry. The fluorescent green color observed under the microscope indicated that BSA-FITC was on the electrode surface. The change of CV signal after each step verified the formation of a new layer on the electrode surface. These results are anticipated to play an important role in developing high-sensitivity immunosensors in the future.

Efficient chlorine evolution of CuO modified RuO2 electrode and its application in preparation of electrochemical disinfectant

Electrochemical chlorine evolution reaction (CER) is one of the most important practical applications of electrochemical reaction, which can be used for electrochemical disinfection. The electrochemical disinfectant of acidic electrolyzed water (AEW) is obtained by electrolyzing extremely dilute chlorine-containing solution in ion-exchange membrane electrolyzer. In the anode area, HClO is produced by CER, which has a strong bactericidal effect. Due to the low concentration of chloride ion, it is necessary to improve the CER selectivity of the electrode in order to improve the efficiency of chlorine electrolysis. In this paper, CuO/RuO2 electrode was prepared by the two-step thermal decomposition method, and the surface morphology and electronic structure of RuO2 electrode were modified. Compared with the ordinary RuO2 electrode, the CER activity of CuO/RuO2 electrode is improved. For the oxygen evolution reaction (OER), the activity of CuO/RuO2 electrode is significantly lower than that of RuO2 electrode. The CER mechanism of CuO/RuO2 electrode is the second electron transfer, and the OER mechanism is the formation and transformation of OHads. The potential difference between CER and OER of CuO/RuO2-3 electrode is 105 mV, which is 52 mV higher than that of RuO2 electrode, so the selectivity of CER of CuO/RuO2 electrode is remarkably improved. During the preparation of AEW, the HClO of AEW2 (prepared by CuO/RuO2-3 electrode) is 0.72 mmol/L, which is 2.5 times that of AEW1 (prepared by RuO2 electrode). In the sterilization experiments on E. coli and B. subtilis, the germicidal efficacy of AEW2 (3.71 and 2.99 log10 CFU/mL) is obviously superior to that of AEW1 (0.76 and 0.61 log10 CFU/mL).

Effect of atomization amounts on electrical discharge ablation machining and electrochemical machining

ABSTRACT This study investigated the impact of varying atomization amounts on composite machining involving both atomized electrical discharge ablation machining and electrochemical machining (EDAM-ECM). Additionally, this study examined the effects of different atomization amounts on the material removal rate, relative electrode wear rate, processing waveforms, surface roughness, surface morphology and elements, and the EDAM-to-ECM ratio. Moreover, a theoretical model for describing the material removal process in composite processing was developed. Furthermore, the effect of the ECM ratio on the processing results was quantitatively analyzed through the integration of statistical circuits with a formula for calculating recast layer thickness. The model was used to predict and select the optimal atomization amounts required to achieve recast layer removal during processing. The results revealed that at an atomization amount of 200 mL/min, 16.7% of the total material removal was attributable to ECM, indicating the successful removal of the recast layer. At this atomization amount, the fabricated sample maintained a machining precision of 0.02 mm.

Synthesis of nanoporous solid polymer electrolyte AuNiCe/NC hydrogenation membrane electrode

In this study, using graphite fiber cloth as the support, gold-based solid polymer electrolyte (SPE) membrane electrodes were synthesized by high-vacuum ion beam sputtering, nitrogen doping of the support, combined electrochemical dealloying, and hot-pressing technology. The application of the SPE membrane electrode to couple hydrogen evolution and liquid organic hydrogen storage is of significant importance for sustainable hydrogen energy and efficient carbon dioxide conversion. Using various characterization techniques, we systematically analyzed the phase structure, surface morphology, porous structure, and electrocatalytic performance of the membrane electrode for the hydrogenation of cyclohexene. The results indicated that doping the carbonaceous support with nitrogen (NC), doping with cerium as catalyst promoter, and combined electrochemical dealloying can all enhance the activity of the catalyst. Cerium doping provides the catalyst with oxygen vacancies for accelerated electron transfer. After combined electrochemical dealloying, AuNiCe/NC formed a three-dimensional bicontinuous porous structure. The electrochemically active surface area increased by 23.94 times, the energy consumption of catalytic cyclohexene hydrogenation decreased by 35.7%, and current efficiency and the formation rate of cyclohexane increased by 54.9% and 29.4%, respectively.

Arcing Stabilization Effect and Ablation Characteristics for C–Cu Electrodes at Low Air Pressure

Arc ablation is a widespread problem in electrical contact systems. The fault of the system caused by arc ablation significantly restricts its lifespan. Facing the development goal of electrified aircraft and low vacuum high-speed railways, the problem of arc ablation at low air pressure cannot be ignored. In this paper, an experimental platform for arcing and ablation at low air pressure is built. The influence of low air pressure on the characteristics of arc ablation is explored. The results show that the stability of the arc column at low air pressure varies significantly. Under the condition of different air pressures, the traces and morphology in the ablation region of the electrode differ significantly. These are caused by Rayleigh-Taylor instability between the arc and air, and by the motion of the arc root which is driven by the arc column. Importantly, the low-pressure stabilization effect for the arc is found. The corresponding relationship between electrode ablation traces, surface morphology, and air pressure is revealed. The action mechanism of air pressure on the arcing process and ablation characteristics of the electrode are clarified. This research provides theoretical support for restraining arc ablation and prolonging the lifespan of the electrical contact system.