Combination Of Electrodes Research Articles

Brain-to-brain communication during musical improvisation: a performance case study

Understanding and predicting others' actions in ecological settings is an important research goal in social neuroscience. Here, we deployed a mobile brain-body imaging (MoBI) methodology to analyze inter-brain communication between professional musicians during a live jazz performance. Specifically, bispectral analysis was conducted to assess the synchronization of scalp electroencephalographic (EEG) signals from three expert musicians during a three-part 45 minute jazz performance, during which a new musician joined every five minutes. The bispectrum was estimated for all musician dyads, electrode combinations, and five frequency bands. The results showed higher bispectrum in the beta and gamma frequency bands (13-50 Hz) when more musicians performed together, and when they played a musical phrase synchronously. Positive bispectrum amplitude changes were found approximately three seconds prior to the identified synchronized performance events suggesting preparatory cortical activity predictive of concerted behavioral action. Moreover, a higher amount of synchronized EEG activity, across electrode regions, was observed as more musicians performed, with inter-brain synchronization between the temporal, parietal, and occipital regions the most frequent. Increased synchrony between the musicians' brain activity reflects shared multi-sensory processing and movement intention in a musical improvisation task.

Combined Depth and Subdural Electrodes for Lateralization of the Ictal Onset Zone in Mesial Temporal Lobe Epilepsy with Hippocampal Sclerosis.

(1) Objective: This study aimed to explore the efficacy of conventional invasive techniques in confirming unilateral seizure onset localization in mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS) and to investigate the association between electrode type and intracranial electroencephalography (EEG) pattern. (2) Methods: This retrospective study encompasses patients diagnosed with MTLE-HS who underwent an invasive study prior to an anterior temporal lobectomy (ATL). Intracranial EEG features were assessed for 99 seizure events from 25 selected patients who achieved seizure remission with ATL after an invasive study using bilateral combined depth and subdural electrodes. Their findings were compared to those of 21 seizure events in eight patients who exhibited suboptimal seizure outcomes. (3) Results: For the distribution of electrodes that recorded the ictal onset, hippocampal depth electrodes recorded 96% of all seizure events, while subdural electrodes recorded 52%. Among the seizures recorded in subdural electrodes, 49% were localized in medial electrodes, with only 8% occurring in lateral electrodes. The initiation of seizures exclusively detected in hippocampal depth electrodes was associated with successful seizure remission, whereas those solely recorded in the lateral strip electrodes were often linked to refractory seizures after ATL. (4) Conclusions: These findings emphasize the importance of employing a combination of depth and subdural electrodes in invasive studies for patients with MTLE-HS to enhance the accuracy of lateralization. This also cautions against sole reliance on subdural electrodes without depth electrodes, which could lead to inaccurate localization.

Comprehensive analysis of the integrated electro-coagulation and membrane filtration process for semiconductor wastewater treatment

Dissolved silica poses a significant challenge in semiconductor wastewater treatment due to its propensity to cause scaling and its resistance to removal, particularly due to its low molecular weight and its uncharged nature under neutral pH conditions. This study thus focuses on optimizing the integrated electro-coagulation (EC) and microfiltration (MF) membrane process, which involves the rapid coagulation of dissolved silica and the subsequent removal of the resulting coagulated EC flocs using a membrane. Various anode-cathode combinations were assessed in the EC process to determine the most effective electrode pairing for dissolved silica removal and system maintenance. Our findings revealed that an AlAl electrode combination facilitated efficient dissolved silica removal, reducing concentrations to levels that prevent scaling under charge loadings exceeding 450 C/L. Additionally, different types of polymeric or ceramic membranes were assessed downstream of the EC process to investigate further removal of coagulated dissolved silica flocs and to compare associated membrane fouling. Ceramic membranes exhibited superior fouling resistance, highlighting the role of EC flocs as a major contributor to membrane fouling. This study explores diverse operational conditions for the integrated EC and MF membrane process to achieve the effective removal of dissolved silica. Collectively, our findings provide valuable insights for the rapid removal of other hazardous contaminants commonly found in semiconductor wastewater, thus paving the way for more effective wastewater treatment processes.

Electrolyte design for lithium-ion batteries with a cobalt-free cathode and silicon oxide anode

Lithium-ion batteries (LIBs) to power electric vehicles play an increasingly important role in the transition to a carbon neutral transportation system. However, at present the chemistry of LIBs requires, among other elements, cobalt (Co), which will probably become scarce over time in addition to posing supply chain risks related to its single source, human rights and mining practices. To address this problem, we construct a LIB pairing a Co-free cathode with a silicon suboxide (SiOx) anode that possesses a high cut-off voltage of 4.9 V and sustains unprecedented 1,000 cycles. Underlying this favourable electrode combination is a rational electrolyte design based on 3.4 M LiFSI/FEMC featuring a shifted potential, which serves to aid formation of robust passivation layers on the anode and promote electrolyte stability against both reductive and oxidative degradations. Our electrolyte formulation offers a pathway towards both sustainable and high-performing LIBs, while the concept could be applied to other electrochemical energy technologies.

Unlocking long-chain hydrocarbons (C2–7) via direct electrochemical CO2 and CO reduction on balanced Au/Ni electrodes

Electrochemical (EC) CO2 reduction method has been widely used as a green energy and environmental solution strategy. The use of Au/Ni electrodes was introduced to showcase a new concept of the direct EC Fischer-Tropsch (dEC F-T) synthesis pathway. This pathway involves the combination of electrodes that produce H2 and CO (syngas) during electrochemical CO2 reduction. The introduction of Au on the Ni electrode surface led to an increase in CO production and a gradual decrease in H2 production. When the interface was balanced, a pronounced F-T synthesis pathway was observed, resulting in the production of a series of hydrocarbons (CnH2n and CnH2n+2, n = 2–7). The dEC F-T synthesis was evaluated under different conditions, including electrolytes, concentrations, metal supports (Co and Fe), various overlayer metals (Ag and Cu), light irradiation, and isotope effects. The process was elucidated through surface C−C coupling polymerization reactions based on Anderson-Schulz-Flory weight distribution analysis. Additionally, the F-T synthesis was demonstrated through EC CO reduction via direct CO and H adsorption. The dEC F-T path provides a novel strategy for energy and environment by producing high-value long-chain hydrocarbons.

Self-protection soft fluidic robots with rapid large-area self-healing capabilities

Soft fluidic robots have attracted a lot of attention and have broad application prospects. However, poor fluidic power source and easy to damage have been hindering their development, while the lack of intelligent self-protection also brings inconvenience to their applications. Here, we design diversified self-protection soft fluidic robots that integrate soft electrohydrodynamic pumps, actuators, healing electrofluids, and E-skins. We develop high-performance soft electrohydrodynamic pumps, enabling high-speed actuation and large deformation of untethered soft fluidic robots. A healing electrofluid that can form a self-healed film with excellent stretchability and strong adhesion is synthesized, which can achieve rapid and large-areas-damage self-healing of soft materials. We propose multi-functional E-skins to endow robots intelligence, making robots realize a series of self-protection behaviors. Moreover, our robots allow their functionality to be enhanced by the combination of electrodes or actuators. This design strategy enables soft fluidic robots to achieve their high-speed actuation and intelligent self-protection, opening a door for soft robots with physical intelligence.

Synergistic two-dimensional metal sulfide heterostructures from ZIF-67: A promising catalyst for efficient overall water splitting

The morphology of nanomaterials plays a significant role in electrocatalytic water splitting. Metal–organic frameworks (MOFs) offer several advantages, including high porosity, large specific surface area, adjustable structure and various morphologies. Among the various MOFs, zeolitic imidazolate framework-67 (ZIF-67) is a cobalt-based MOF that can produce carbon-containing metal sulfides through appropriate sulfurization and annealing processes. Since the control of the morphology of nanostructured electrocatalysts plays a crucial role in optimizing catalytic activity, in this study, we synthesized rhombic dodecahedral, cubic, and plate-shaped ZIF-67 nanocrystals and utilized them as templates to fabricate Co3S4@CoMoS3 nanomaterials with various morphologies. These materials were characterized and subjected to electrochemical tests to evaluate their performance in the hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and electrocatalytic water splitting. The electrochemical measurements revealed that the plate-shaped Co3S4@CoMoS3–P exhibited the low overpotential for OER at 20 mA cm−2, with a value of 200 mV and a Tafel slope of 173 mV dec−1. Similarly, for HER at 10 mA cm−2, it showed an overpotential of 240 mV and a Tafel slope of 93 mV dec−1. Moreover, in the water splitting setup employing a dual electrode configuration, the plate-shaped Co3S4@CoMoS3–P achieved a voltage of 1.61 V at 20 mA cm−2, outperforming a commercial electrode combination (10% Pt/C//RuO2) in terms of water-splitting efficiency.

An Electrochemical Approach to Recycle and Extraction of Metals from Electronic Waste

Scraped e-waste is a result of increased production and demand for Electrical and Electronic Appliances (EEA). Because the discarded EEA contains heavy metals, it must be carefully disposed of in order to prevent any environmental harm. Researchers and pollution control boards in the relevant nations are taking notice of this rapid increase in e-waste in order to properly dispose of and recycle the garbage. A variety of materials, including gold, silver, copper, iron, etc., are included in e-waste. For research, it is crucial to safely and sustainably remove all of those metals from old electrical and electronic products. Electrochemical, pyrometallurgical, hydrometallurgical, and bioleaching methods for extracting metals from waste scrap have all evolved in the development of environmentally friendly and sustainable technologies. Among all the methods for extracting metals that are accessible, electrochemical extraction is one of the most admired. One of the reported most effective techniques among all of these is electrochemical. (80-95%) of the metal is reported to have been extracted using the previously stated procedure and various electrolytes. Additionally, after processing and chemical leaching of the Waste, various combinations of electrodes are employed to independently recover the metals from E-Waste is presented in the paper. The study presents an electrolysis method for copper extraction. In order to achieve the highest Cu extraction efficiency, a variety of electrode and electrolyte combinations are used in this study work, along with an energy model for the process. adjusting the electrolyte content to examine the Cu extraction rate for improved extraction efficiency. It is possible to extract copper with 99% efficiency using this electrolysis method.

Magnetic molecules lose identity when connected to different combinations of magnetic metal electrodes in MTJ-based molecular spintronics devices (MTJMSD)

Understanding the magnetic molecules’ interaction with different combinations of metal electrodes is vital to advancing the molecular spintronics field. This paper describes experimental and theoretical understanding showing how paramagnetic single-molecule magnet (SMM) catalyzes long-range effects on metal electrodes and, in that process, loses its basic magnetic properties. For the first time, our Monte Carlo simulations, verified for consistency with regards to experimental studies, discuss the properties of the whole device and a generic paramagnetic molecule analog (GPMA) connected to the combinations of ferromagnet-ferromagnet, ferromagnet-paramagnet, and ferromagnet-antiferromagnet metal electrodes. We studied the magnetic moment vs. magnetic field of GPMA exchange coupled between two metal electrodes along the exposed side edge of cross junction-shaped magnetic tunnel junction (MTJ). We also studied GPMA-metal electrode interfaces’ magnetic moment vs. magnetic field response. We have also found that the MTJ dimension impacted the molecule response. This study suggests that SMM spin at the MTJ exposed sides offers a unique and high-yield method of connecting molecules to virtually endless magnetic and nonmagnetic electrodes and observing unprecedented phenomena in the molecular spintronics field.

Treatability Studies of Dairy Wastewater by Electrocoagulation Process

The dairy industry generates wastewater with high levels of pollution, including Biochemical Oxygen Demand (BOD5), Chemical Oxygen Demand (COD), and Total Suspended Solids (TSS). This study aimed to assess the impact of various operational parameters, such as voltage, pH, and reaction time, on treating real dairy wastewater using the electro-coagulation process. Stainless Steel electrodes were employed with Sodium chloride as an electrolyte. The research focused on removing COD, BOD5, and TSS. Initially, experiments were conducted with different voltages (10V, 20V, and 30V) while keeping the electrode distance constant and using 0.5gms of NaCl. In the second stage, experiments varied the initial pH (4, 6, 8, and 10) under optimal contact time, maintaining 1.5cm electrode spacing. Initially, a 2mm electrode thickness was tested but resulted in high energy consumption, so subsequent experiments used a 0.5mm electrode thickness. The electrode dimensions remained consistent at 150mm X 250mm X 10mm. The highest removal efficiencies for COD, BOD5, and TSS were achieved with a 30V applied voltage and SS-SS electrode combination, reaching 96%, 93%, and 94%, respectively. This study concludes that the SS-SS electrode combination with a 0.5mm thickness was the most effective in reducing COD, BOD5, and TSS, while also generating comparatively less sludge.

Enhancing fog collection by optimizing wettability combination and fork-row collector arrangement: light and heavy fog

Fog collection is essential to alleviate water scarcity in arid areas. However, the vast majority of existing fog collectors only work effectively in heavy fog. To broaden the fog concentration range for efficient work, an optimization strategy based on wettability combination and fork-row arrangement is proposed in this work. Single-layer experiment results show that a hydrophilic (HL) surface with high deposition capacity collects droplets at a faster rate in light fog (25–80 g h−1), while the collection rate of a hydrophobic (HB) surface with high drainage capacity is higher in heavy fog (220–500 g h−1). Double-layer experiment results show that in light fog, the best combination of double-layer collection electrodes is HL–HL, while HB–HL performs best in heavy fog. A 35% improvement in collection rate can be obtained simply by changing the arrangement from smooth-row (S) to fork-row (F), which is attributed to the increased effective collision area of droplets. In our series of experiments, at 50 g h−1, the collection rate of double-layer combination HL–HL(F) is 56.7% higher than that of single-layer HL. In particular, the collection rate of HB–HL(F) reaches 1434.7 mg cm−2 h−1 at 500 g h−1. Such a good performance is attributed to the force imbalance of hanging droplets caused by wettability differences, which tends to transport small droplets on HB towards HL directionally, resulting in a rapid droplet slippage. Therefore, the HB–HL accelerates drainage and refreshes capture points. Furthermore, fog collection performance is also influenced by layer spacing, which has an optimal distance. These findings provide a promising method for practical applications of fog collectors in a wide range of fog flow quantities, enhancing adaptability to variable environments.

Cross-street electrical resistivity imaging for environmental applications

Road collapse has always been an important safety hazard for urban traffic, causing a serious threat to the safety of passing vehicles and citizens. However, the complex urban surface environment with obstacles such as huge buildings, hardened roads, and river network limits the application of ERT in cities. Here we present an innovative cross-street electrical resistivity imaging method. This method abandons the mandatory electrode grid layout that conventional 3D ERT required. Only two survey lines are required to be laid along sides of the street parallelly, gathering the apparent resistivity data set by the combination of current supply and potential electrodes across the street and obtaining the 3D resistivity imaging under street. It is well suitable for detecting and monitoring of hardened road and enhances the feasibility and the adaptability of ERT in urban. A series of numerical models and comparisons among this method and conventional ERT had been done. The modeling results show that this cross-street method reaches the resolution of the conventional 5-lines ERT, and its resolution to objects cross road are better than the conventional ERT. This method can both satisfy the exploration needs with difficult surface conditions such as roads, and greatly reduce the exploration workload. It shows well application prospects, such as hidden geological problem monitoring while combining with time-lapse ERT instruments.

Investigation on corrosion tendency behaviour of TA2 titanium alloy welded joints under flow scouring conditions using the array electrode method

PurposeThe corrosion behaviour of titanium alloy surface when fluid with different flow rates flows through welded joints with different residual heights was explored.Design/methodology/approachThe experiment uses a combination of array electrodes and simulation.FindingsIt is found that when the weld reinforcement exists, the corrosion tendency of both ends of the weld metal is greater than that of other parts of the welded joint due to the influence of high turbulence kinetic energy and shear stress. The presence of weld reinforcement heights makes the fluid behind it fluctuate greatly. The passivation films of both the base metal (BM) at the rear and the heat-affected zone (HAZ) are more prone to corrosion than those of the front BM and HAZ, and the passivation film is rougher.Originality/valueThe combination of test and simulation was used to explore the influence of electrochemical and hydrodynamic factors on the corrosion behaviour of titanium alloy-welded joints when welding residual height existed.

Electrochemical Production of Formate Directly from Amine-Based CO2 Capture Media

Introduction There is an urgency for the development and establishment of technologies to deal with the effects of climate change and increasing temperature of the planet.1 The decrease in the CO2 emissions is a possible path, and the capture of CO2 from the atmosphere is another alternative to try and tackle the effects of climate change.2 The combination of capture and conversion of CO2 is a potential approach to achieve the net-zero emission goals and a circular economy for the future.3 Amine scrubbing is an industrially established capture technology that utilizes mainly monoethanolamine (MEA) as the capture solution to capture CO2 from post-combustion flue gases. The process has the disadvantage of a high energy demand, which prevents its wider application.2 This study proposes a novel capture and utilization (CCU) combination: the use of the MEA capture solution as electrolyte for the electrochemical CO2 reduction (eCO2R). In that way, the CO2 capture and conversion will be combined in the same medium, avoiding the energy-intensive regeneration step, thus saving energy, as well as generating products of industrial interest. Sn-based catalysts were primarily chosen due to their selectivity towards formate, one of the most straightforward reduction products from CO2. Results The eCO2R from the capture media (30 wt% MEA solutions, saturated with CO2) was promoted in a zero-gap type reactor, composed of an Sn-based cathode, a Ni foam anode and a bipolar membrane (BPM) separating the cathode and anode compartments. The BPM is responsible for providing protons to the cathode side of the electrolyzer, which promote the hydrolysis of the carbamate on the surface of the catalyst and thus enhances the CO2 availability and consequently the eCO2R. Figure 1 presents a scheme of the zero-gap electrolyzer, highlighting the hydrolysis of the carbamate in contact with the catalyst, and compares the faradaic efficiencies (FE) towards formate obtained by different setups of the zero-gap electrolyzer, at -50 mA cm-2.The Sn nanoparticle (SnNP)-based catalysts show a low efficiency for the eCO2R from the capture media (up to 5%). As published in the literature, surfactants are capable to inhibit the hydrogen evolution reaction (HER) in electrochemical systems and thus promote the eCO2R.4 The surfactant cetyltrimethylammonium bromide (CTAB) was therefore added to the system and the FE towards formate increased, although merely up to 6.43%. To further increase the surface area available for the eCO2R, a metal gauze was introduced as support for the working electrode (WE). Here, a Cu gauze with electrodeposited Sn (SnED) was used as WE and the obtained FE was 70% higher than for the carbon supported SnNP catalysts, up to 8.49%, without the addition of the surfactant. The hydrophilic nature of the metal surface (in comparison to the carbon paper substrate of the NPs) and a bigger surface area could be the reasons behind this enhancement in the FE using metal WE. Future studies will focus on the further enhancement of the FE towards formate. Conclusion This study shows the feasibility of a novel CCU technology: the electrochemical reduction of CO2 to formate from an amine-based capture medium. Sn-based catalysts lead to an FE of up to 8.49%. The use of a metallic electrode lead to a larger enhancement of the FE, in comparison to the addition of a surfactant to the electrolyte for the SnNP-based catalyst. There is yet room for further improvement of the faradaic efficiency by the combination of the metal electrode and the use of surfactants to inhibit the HER, as well as the use of catalysts with higher selectivity towards the product, such as Bi. The use of a zero-gap electrolyzer shows the feasibility of scaling up the system to industrially relevant dimensions and the easiness of incorporating the electrochemical system to the end of pre-existing capture plants. References Ghiat, I., & Al-Ansari, T. (2021). Journal of CO2 Utilization, 45.Gutiérrez-Sánchez, O., Bohlen, B., et al. (2022). ChemElectroChem, 9(5), e202101540.Li, M., Irtem, E., et al. (2022). Nature Communications 2022 13:1, 13(1), 1–11.Chen, L., Li, F., et al. (2017). ChemSusChem, 10(20), 4109–4118. Figure 1

Decolorization, COD and turbidity removal of the raw vinasse effluent by a one-step electro-oxidation process on a Pb/PbO2 anode.

In this research, and for the first time, the application of anode Pb/PbO2 (prepared from combined thermal oxidation and electrochemical oxidation method) and steel cathode in a flow sample electrochemical treatment process of vinasse and in the wastewater of alcohol factories, has been investigated. The combination of electrodes of Pb/PbO2 as an anode, steel, and/or graphite as a cathode was used in the proposed electrochemical treatment setup. The efficiency of the proposed electrochemical treatment was determined by the removal percentage of chemical oxygen demand (COD), turbidity and color of vinasse samples. The response surface method (RSM) by Minitab 18 was used to determine the effect of the studied factors as well as to detect the relationship between variables. The results showed that under optimum conditions (Pb/PbO2 electrode as the anode and steel electrode as the cathode, a voltage of 30 V, pH 6.5, and reaction time of 45 min), the percentage reduction values of COD, turbidity and color were 97.7, 77.3 and 92.7%, respectively.

A systematic study to achieve cleaner and sustainable manufacturing process by using bio-degradable dielectrics

Inconel 600 is widely used in aeronautical and aerospace industry owing to its excellent mechanical, wear and corrosion characteristics. This high strength alloy requires a special machining environment which justifies the use of Electric Discharge Machining (EDM). However, low cutting rate, which accounts for the productivity aspect, and emission of toxic fumes generated by thermal breakdown of kerosene dielectric currently limit the use of EDM. Moreover, since EDM is an energy intensive machining process, industry has a stringent emphasis to make this process sustainable and eco-friendly. In this context, the potentiality of six bio-degradable dielectrics was comprehensively investigated here for the first time ever to achieve cleaner and sustainable production of Inconel 600. Each biodegradable dielectric was coupled to four electrode materials to find the best tool-dielectric combinations for the EDM processing of this Ni-based super alloy. The responses were defined considering the three key ingredients of sustainability: i.e. productivity (assessed in terms of material removal rate and tool wear ratio), quality (expressed in terms of surface finish and dimensional deviation) and power consumption (expressed in terms of specific energy consumption). Experimentation was performed with a full factorial design taking dielectric type and electrode material as input variables. The EDM configuration including amla oil as dielectric and brass electrode was the best in terms of maximum MRR (19.8 mm3/min), 560% better than the standard EDM configuration including the same brass tool and kerosene dielectric. The lowest surface roughness SR (quality aspect) was obtained by the EDM configuration including a brass electrode and the sunflower oil dielectric: surface quality improved by 30.6% with respect to standard EDM using the same electrode and kerosene dielectric. Considering the specific energy consumption, the EDM setup with brass electrode and amla oil dielectric was 6.6 times more efficient than standard EDM with the same electrode and kerosene dielectric. The combination of coconut dielectric and Cu electrode results in a 5.4 times lower tool wear ratio than the traditional dielectric. In terms of achieving a better dimensional control, graphite electrode is a preferred choice against olive oil dielectric. Based on the measured values for EDM responses, it was revealed that relative percentage of carbon dioxide emissions reduces by 83.95% if amla oil is used in comparison to the CO2 emissions noted for standard kerosene oil considering brass as electrode. Finally, an optimal combination of the best biodegradable dielectric fluid and electrode material to satisfy all performance indicators was proposed through MOGA technique. Experimental data were properly fitted by using artificial neural networks. The EDM setup with copper electrode and amla oil dielectric achieved the best global performance with respect to all responses.

Integrated Construction of a Long-Life Stretchable Zinc-Ion Capacitor.

The major challenge in achieving high-performance stretchable zinc-ion energy-storage devices is the combination of stretchable dendrite-free zinc negative electrodes and sufficient bonding between components (current collector, electrode, separator, and package). Herein, based on a series of physicochemically tunable self-healing polyurethanes, an elastic current collector is prepared through a swelling-induced wrinkling method, and then a stretchable zinc negative electrode prepared through in situ confined electroplating. The elastic current collector has a nano-network structure with polyurethane encapsulation, and exhibits both geometric and intrinsic stretchability. The stretchable zinc negative electrode formed in situ has high electrochemical activity and exhibits an excellent cycle life under the protection of a Zn2+ -permeable coating. Furthermore, fully polyurethane-based stretchable zinc-ion capacitors are assembled through in situ electrospinning and hot-pressing techniques. Due to the high stretchability of the components and the interfusion of the matrixes, the integrated device exhibits excellent deformability and desirable electrochemical stability. This work provides a systematic construction plan for stretchable zinc-ion energy-storage devices in three aspects: material synthesis, component preparation, and device assembly.

Synthesis of CuMoS micro‐rods material as efficient bifunctional electrocatalyst for overall water splitting

AbstractIn oxygen evolution reactions (OER) metal sulfides are the subject of extensive research. Copper‐molybdenum sulfides (CuMoS) that can be made a simple hydrothermal treatment are designed to reduce catalyst costs even more. Here, we demonstrate that binder free electrode composed of micro‐rod structure copper‐molybdenum sulfides on nickel foam (CuMoS/NF) can be employed as an active and robust bifunctional electrocatalyst for water splitting. CuMoS/NF catalyst displays an overpotential for OER of 358 mV (121 mV dec−1) and HER of 129 mV (101 mV dec−1) at current density of 10 mA cm−2. CuMoS/NF is stable for 60 hours with potential deviations in OER and HER of 2.8 % and 3.2 %, respectively. The active bifunctional CuMoS/NF electrode combination helps to fabricate a water electrolyser with 10 mA cm−2 current density at 1.65 V. CuMoS/NF//CuMoS/NF shows good stability over 60 hours with a potential deviation of 2.7 %. The earth‘s abundant non‐precious metal‐based electrode, and solar cell delivered continuous hydrogen and oxygen (1.65 V), making it possible to produce a significant quantity of hydrogen at a low‐cost and on a large‐scale.

Selective Analysis of Redox Processes at the Electrode Interface with Time-Resolved Raman Spectroscopy.

Electrochemistry and electrochemical reactions are increasingly important in the transition to a sustainable chemical industry. The electron transfer that drives such reactions takes place within nanometers of the electrode surface, and follow-up chemical reactions take place within the diffusion layer. Hence, understanding electrochemical reactions requires time-, potential-, and spatially resolved analysis. The confocal nature of Raman spectroscopy provides high spatial resolution, in addition to detailed information on molecular structure. The intrinsic weakness of nonresonant Raman scattering, however, is not sensitive enough for relatively minor changes to the solution resulting from reactions at the electrode interface. Indeed, the limit of detection is typically well above the concentrations used in electrochemical studies. Here, we show that surface-enhanced Raman scattering (SERS) and resonance Raman (rR) spectroscopy allow for spatially and time-resolved analysis of solution composition at (<1-2 nm) and near (within 5 μm) the electrode surface, respectively, in a selective manner for species present at low (<1 mM) concentrations. We show changes in concentration of species at the electrode surface, without the need for labels, specific adsorption, or resonance enhancement, using a SERS-active gold electrode prepared readily by electrochemical surface roughening. A combination of smooth and roughened gold electrodes is used to distinguish between surface and resonance enhancement using the well-known redox couples ferrocene and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). We discuss the impact of specific adsorption on the spectral analysis with the ruthenium(II) polypyridyl complex, [Ru(bpy)3]2+. The dual function of the electrode (surface enhancement and electron transfer) in the analysis of solution processes is demonstrated with the reversible oxidation of TMA (4,N,N-trimethylaniline), where transient soluble species are identified in real time, with rapid spectral acquisition, making use of localized enhancement. We anticipate that this approach will find use in elucidating electro(catalytic) reactions at electrode interfaces.

Optimization of ear electrodes for SSVEP-based BCI

Objective. Current ear electrodes often require complex placing or long stimulation durations to achieve good detection of steady-state visual evoked potential (SSVEP). To improve the practicability of ear electrode-based SSVEP-BCI (brain-computer interface) system, we developed a high-performance ear electrode that can be easily placed. Approach. Hydrogel based disposable and replaceable semi-dry electrodes are developed to improve the contact impedance and wear feeling. The best combination of electrodes for SSVEP-BCI application around the ear is optimized by assessing the electrode on volunteers, and the performance of the electrode was compared with that of the occipital electrode. Main results. The developed ear hydrogel electrode can achieve an impedance close to that of the wet electrode. Three combinations of ear electrode groups demonstrate high information transfer rate (ITR) and accuracy in SSVEP-BCI applications. According to the rating of the comprehensive assessment and BCI performance in the online session, the behind-aural electrode is the best electrode combination for recording SSVEP in the ear region. The average preparation time is the shortest, and the average impedance is the lowest. The ITR of the behind-aural electrode based SSVEP-BCI system can reach 37.5 ± 18 bits min−1. The stimulus duration was as low as 3 s compared to 5 s or 10 s in other studies. Significance. The accuracy, ITR, and wear feeling can be improved by introducing a semi-dry ear electrode and optimizing the position and the combination of ear electrode. By providing a better trade-off between performance and convenience, the ear electrode-based SSVEP-BCI promises to be used in daily life.