Ag AgCl Research Articles

3D-printed Ag–AgCl electrodes for laboratory measurements of self-potential

Abstract. This paper details the design, development, and evaluation of a 3D-printed rechargeable Ag–AgCl electrode to measure self-potential (SP) in laboratory experiments. The challenge was to make a small, cheap, robust, and stable electrode that could be used in a wide range of applications. The new electrodes are shown to offer comparable performance to custom-machined laboratory standards, and the inclusion of 3D printing (fused filament fabrication or FFF and stereolithography or SLA) makes them more versatile and significantly less expensive – of the order of ×40 to ×75 cost reduction – to construct than laboratory standards. The devices are demonstrated in both low-pressure experiments using bead packs and high-pressure experiments using natural rock samples. Designs are included for both male and female connections to laboratory equipment. We report design drawings, practical advice for electrode printing and assembly, and printable 3D design files to facilitate wide uptake.

Fast Ionic Actuators with Silver–Silver Chloride Electrodes and a Mixed Ionic Liquid Electrolyte

Excellent conductivity makes silver (Ag) an attractive electrode and current collector material for a variety of devices, also promising faster soft actuators. However, high reactivity challenges the use of Ag in electrochemical systems, as dendritic growth can create undesired conduction pathways and short‐circuit the oppositely polarized electrodes. The challenge of rapid Ag electrochemical migration is addressed using a mixed mixed‐room temperature ionic liquid (RTIL) system (l‐ethyl‐3‐methylimidazolium bis‐(trifluoromethylsulfonyl)‐imide and trihexyl(tetradecyl)phosphonium chloride) that prevents short‐circuiting by engaging the produced Ag+ ions with Cl− anions. The stability of the system is demonstrated on an ionic actuator using Ag–silver chloride (AgCl) electrodes and a mixed‐RTIL electrolyte. The work demonstrates fast (in 5 s) transfer of a large (0.2 C cm−2) charge to high‐specific‐surface‐area carbon without observable dendritic growth in cycling and good electromechanical performance: 4° s−1 deflection rate at 0.8 V s−1 scan rate. Simple spray‐deposition of the Ag–AgCl electrodes promises scalable and cost‐effective fabrication. The combination of high stability and vast charge capacity encourages the engagement of Ag‐based electrodes for many electrochemical applications involving organic electrolytes also beyond robotics.

Micromotors with Spontaneous Multipattern Motion and Microvortex for Enhanced “On‐the‐Fly” Molecule Enrichment

“On‐the‐fly” molecule enrichment by micro/nanomotors obviously improves heterogeneous catalysis, trace detection, and environmental monitoring, yet faces challenges of the trade‐off between collection range and interaction time. Inspired by the versatile foraging process of predators, this work demonstrates that micromotors doing spontaneous multipattern motion with microvortex can greatly enhance “on‐the‐fly” enrichment, demonstrated by highly sensitive surface‐enhanced Raman scattering detection. It leverages an axis‐asymmetric bowl‐shaped structure and the nonlinear Ag–AgCl reaction, realizing alternating low‐velocity swinging forward and accelerated steering motions for prolonged interaction and large work area. Moreover, the bowl‐shaped microstructure bestows a micro‐vortex above the Ag side due to the competition of electric potential and pressure gradient, also extending interaction time during the acceleration. Consequently, it exhibits at least an order of magnitude larger enhancement of detection signals than the counterparts. This proof‐of‐concept study highlights the significance of motion mode and structure design in guiding flow field, offering substantial benefits for applications.

EOG acquisition system based on ATmega AVR microcontroller

This paper presents a hardware and software of an electrooculogram (EOG) acquisition system based on ATmega AVR microcontroller for the acquisition of vertical and horizontal eye movements. The presented system is used to acquire a dataset of eye movements for volunteers. This system gives two channels representing vertical and horizontal EOG signals. The frequency range of the EOG signal is known to be 0.1 to 10 Hz, and hence this frequency range is isolated with a High-Pass Filter (HPF) with a cutoff frequency of 0.1 Hz followed by a Low-Pass Filter (LPF) with a cutoff frequency of 10 Hz. The EOG acquisition system is interfaced with an ATmega AVR microcontroller to acquire a dataset that can be used for controlling hardware such as Light Emitting Diodes (LEDs), wheelchair, and robot arm. The presented system is composed of EOG signal acquisition, Ag/AgCl electrodes, analog-to-digital converter through Arduino Mega 2560 board microcontroller unit, trainer board, laptop, keypad, and Liquid Crystal Display (LCD). The eye movement is detected by measuring the potential difference between cornea and retina using five Ag–Agcl disposable electrodes. Different volunteers of different ages at different times have been treated with the presented system to obtain data. Classified vertical and horizontal EOG signals and the basic eye movements e.g., open eye, left, right, up, and down can be used to control robots and wheelchairs for rehabilitation purposes.

Quantitative Detection of Ortho-Aminophenol by Using Modified Reduced Graphene Oxide/Indium Tin Oxide Glass Electrode

In this research work the electrochemical oxidation of ortho-aminophenol (oAP) is studied using modified reduced graphene oxide/indium tin oxide (rGO/ITO) glass electrode in acetonitrile medium, tetrabutyl ammonium perchlorate (TBAP) supporting electrolyte. Cyclic voltammetry (CV) and linear-sweep voltammetry (LSV) techniques were used to study the redox behavior of oAP. The graphene oxide-initiated auto-oxidized 2-aminophenoxazine-3-one is irreversibly reduced by modified rGO/ITO glass electrode at −0.048[Formula: see text]V (versus Ag–AgCl electrode). LSV response shows that the cathodic peak current increases notably compared to that of bare rGO/ITO glass electrode and with the increasing concentration of oAP. The oxidized product of oAP was characterized by UV–Visible and FT-IR spectroscopy. The redox behavior of oAP of modified rGO/ITO glass electrode was compared with the electrochemical behavior of oAP at bare glassy carbon electrode.

Effect of Magnesium Chloride in Supporting Electrolyte for Enhancing Sensitive and Selective Electrochemical Sensor: An Approach for Anti-Rheumatic Sulfasalazine Detection

In this work, an electroanalytical evaluation for voltammetric sensing of the anti-rheumatic sulfasalazine (SSZ) at an unmodified screen-printed graphene electrode (SPGE) is demonstrated. By using the differential pulse (DPV) technique, the SSZ produced a well-defined peak of around −0.3 V (vs Ag AgCl−1) in Britton-Robinson (BR) buffer pH 4. Supporting electrolytes, pH, and salts all significantly impact SSZ reduction. Therefore, their impact on the working solutions was assessed. We discovered that using a mixture of Britton–Robinson (BR) buffer with pH 4 and MgCl2 as a supporting electrolyte can enhance SSZ sensitivity by approximately 1.7 times while simultaneously increasing detection selectivity. Under optimal conditions, the proposed assay demonstrated the ultrasensitive determination of SSZ with a broad linear detection range from 0.01 to 100 μM and a low detection limit of 4.7 nM (S/N = 3). To demonstrate the impact of the proposed method, the sensor has been successfully applied for the quantitative determination of SSZ in pharmaceutical, urine, and artificial serum sample. Therefore, this approach could offer simplicity, and rapidity, and serve as an alternative to the SSZ detection in practical applications.

Wireless CardioS framework for continuous ECG acquisition

A first-level textile-based electrocardiogram (ECG) monitoring system referred to as “CardioS” (cardiac sensor) for continuous health monitoring applications is proposed in this study to address the demand for resource-constrained environments. and the signal quality assessment of a wireless CardioS was studied. The CardioS consists of a Lead-I ECG signal recorded wirelessly using silver-plated nylon woven (Ag-NyW) dry textile electrodes to compare the results of wired wearable Ag-NyW textile electrode-based ECG acquisition system and CardioS. The effect of prolonged usage of Ag-NyW dry electrodes on electrode impedance was tested in the current work. In addition, electrode half-cell potential was measured to validate the range of Ag-NyW dry electrodes for ECG signal acquisition. Further, the quality of signals recorded by the proposed wireless CardioS framework was evaluated and compared with clinical disposable (Ag–AgCl Gel) electrodes. The signal quality was assessed in terms of mean magnitude coherence spectra, signal cross-correlation, signal-to-noise-band ratio (S band/N band), crest factor, low and high band powers and power spectral density. The experimental results showed that the impedance was increased by 2.5–54.6% after six weeks of continuous usage. This increased impedance was less than 1 MΩ/cm2, as reported in the literature. The half-cell potential of the Ag-NyW textile electrode obtained was 80 mV, sufficient to acquire the ECG signal from the human body. All the fidelity parameters measured by Ag-NyW textile electrodes were correlated with standard disposable electrodes. The cardiologists validated all the measurements and confirmed that the proposed framework exhibited good performance for ECG signal acquisition from the five healthy subjects. As a result of its low-cost architecture, the proposed CardioS framework can be used in resource-constrained environments for ECG monitoring.

Determination of the Particle Number Concentration, Size Distribution, and Species of Dominant Silver-Containing Nanoparticles in Soils by Single-Particle ICP-MS.

The potential risk of various silver-containing nanoparticles (AgCNPs) in soils is related to the concentration, size, and speciation, but their determination remains a great challenge. Herein, we developed an effective method for determining the particle number, size, and species of dominant AgCNPs in soils, including nanoparticles of silver (Ag NPs), silver chloride (AgCl NPs), and silver sulfide (Ag2S NPs). By ultrasonication wand-assisted tetrasodium pyrophosphate extraction, these AgCNPs were extracted efficiently from soils. Then, multistep selective dissolution of Ag NPs, AgCl NPs, and whole Ag NPs/AgCl NPs/Ag2S NPs was achieved by 1% (v/v) H2O2, 5% (v/v) NH3·H2O, and 10 mM thiourea in 2% (v/v) acetic acid, respectively. Finally, the particle number concentration and size distribution of AgCNPs in the extracts and the remaining AgCNP particle number concentration after each dissolution were determined by single-particle inductively coupled plasma mass spectroscopy for speciation of the dominant AgCNPs. AgCNPs were detected in all five soil samples with the concentrations of 0.23-8.00 × 107 particles/g and sizes of 16-110 nm. Ag2S NPs were the main form of AgCNPs in the examined soils with the percentage range of 53.98-69.19%, followed by AgCl NPs (11.42-23.31%) and Ag NPs (7.78-16.19%). Our method offers a new approach for evaluating the occurrence and potential risk of AgCNPs in environmental soils.

A Room‐TemperatureChloride‐Conducting Metal–Organic Crystal [Al(DMSO)6]Cl3 for Potential Solid‐State Chloride‐Shuttle Batteries

The growing demand for substitutes of lithium chemistries in battery leads to a surge in budding novel anion‐based electrochemical energy storage, where the chloride ion batteries (CIBs) take over the role. The application of CIBs is limited by the dissolution and side reaction of chloride‐based electrode materials in a liquid electrolyte. On the flipside, its solid‐state electrolytes are scarcely reported due to the challenge in realizing fast Cl− conductivity. The present study reports [Al(DMSO)6]Cl3, a solid‐state metal–organic material, allows chloride ion transfer. The strong Al‐Cl bonds in AlCl3 are broken down after coordinating of Al3+ by ligand DMSO, and Cl− in the resulting compound is weakly bound to complexions [Al(DMSO)6]3+, which may facilitate Cl− migration. By partial replacement of Cl− with , the room‐temperature ionic conductivity of as‐prepared electrolyte is increased by one order of magnitude from 2.172 × 10−5 S cm−1 to 2.012 × 10−4 S cm−1. When they are assembled with Ag (anode)/Ag–AgCl (cathode) electrode system, reversible electrochemical redox reactions occur on both sides, demonstrating its potential for solid‐state chloride ion batteries. The strategy by weakening the bonding interaction using organic ligands between Cl− and central metallic ions may provide new ideas for developing solid chloride‐ion conductors.

Comments and Protocols for the Construction and Calibration of Ag AgCl Reference Electrodes

Despite the vital importance of reference electrodes, RE, it is common for PhD students in electrochemistry and other users of electrochemical instruments to lack a thorough understanding of their creation and calibration. This work presents the protocol to construct Ag/AgCl RE with different NaCl concentrations. The experimental RE potentials are measured using two techniques and compared to those obtained using the Nernst equation. The RE potential similarities or differences observed when different NaCl concentrations are present are also discussed. Furthermore, using an electrolytic cell to deposit AgCl onto the silver wire part of the RE and determining the mass of AgCl formed using Faraday’s law of electrolysis are presented. These reference electrodes are easily constructed, and the materials needed are readily available and non-toxic. Furthermore, the reference electrodes exhibit good potential stability as a function of time.

Low-concentration CO2 conversion on AgxNa1−xTaO3-AgCl heterojunction photocatalyst

Photocatalytic conversion of low-concentration CO2 with H2O oxidation indicates an applicable way to achieve sustainable carbon cycling and solve the global warming problem. Enhancing photogenerated charge separation and surface adsorption and catalytic process of photocatalysts is the crucial point to compensate for the mass transfer limitation during low-concentration CO2 conversion. Herein, a highly-crystalline AgxNa1−xTaO3-AgCl heterostructure composite was successfully fabricated via a one-step flux method. The in-situ formation of intimate heterojunction between AgxNa1−xTaO3 and AgCl facilitated the separation and transfer of photogenerated charges. Moreover, the simultaneous introduction of Ag cations and AgCl components promoted the adsorption and activation of CO2 on the photocatalyst surface. When combined with metallic Ag cocatalysts, the AgxNa1−xTaO3-AgCl heterostructure photocatalyst exhibited an improved activity for the overall reaction of CO2 reduction and H2O oxidation at low CO2 concentration condition. The design of photocatalysts active at low CO2 concentration accounts for an alternative way to construct the practical CO2 conversion system in the future.

Structural Engineering of ZnO–SnO2–Ag(AgCl) Nanocomposites for the Medical Applications

Structural Engineering of ZnO–SnO2–Ag(AgCl) Nanocomposites for the Medical Applications

Photo-oxygenation of water media using photoactive plasmonic nanocomposites.

Plasmonic nanocomposites ZnO-Ag and ZnO-SnO2-Ag(AgCl) were prepared by the polymer-salt method, and their structure and morphology were studied using XRD and SEM analyses. It was found that the addition of photoactive inorganic nanocomposites ZnO-Ag and ZnO-SnO2-Ag(AgCl) in pure water significantly enhances the effectiveness of its disinfection and purification during UV treatment and provides the effective water oxygenation. Oxygen photogeneration under blue light (λex. = 405nm) can be related to the plasmon-excitation processes in ZnO-SnO2-Ag(AgCl) composites. Prepared composites demonstrate antibacterial activity against both Gram-positive and Gram-negative bacteria. The increase of Ag content in ZnO-Ag and ZnO-SnO2-Ag(AgCl) composites significantly enhances their antibacterial activity.

An advanced plasmonic photocatalyst containing silver(0) single atoms for selective borylation of aryl iodides

A conventional plasmonic Ag-AgCl photocatalyst consists of Ag nanoparticles (AgNPs) and AgCl. Here, we converted a small amount of Ag+ on the surfaces of AgCl particles into single-atom Ag(0) (SAAg). SAAg was characterized with high-angle annular dark field aberration corrected (HAADF AC)-STEM and quantified with electron spin resonance (ESR). The obtained AgEG/Mg(OH)2 material was efficient and afforded excellent selectivity control between hydrodehalogenation and deiodination-borylation under visible light irradiation. SAAg acted as the 1e−-reducing site of the photocatalyst and its loading is linearly correlated with the initial reaction rate. While the quantity of SAAg was only 6.0 × 10–8 mol g−1, the TOF of SAAg reached 1.4 × 104 h−1. The oxidation state of SAAg retained 0 in both the resting and the working states. This study suggests SAAg may be an effective cocatalyst in general for reductive dehalogenation of organic halides.

Synthesis of Photoactive ZnO–SnO2–Ag(AgCl) Nanomaterials for Medical and Ecological Applications and Study of Their Structure and Properties

Synthesis of Photoactive ZnO–SnO2–Ag(AgCl) Nanomaterials for Medical and Ecological Applications and Study of Their Structure and Properties

Photocatalysis: One‐Pot Bio‐Assisted Synthesis of Stable Ag–AgCl System Using Jellyfish‐Based Scaffold for Plasmonic Photocatalysis Applications (Adv. Sustainable Syst. 7/2021)

In article number 2100099, Koray Aydin, Shachar Richter and co-workers perform a bio-assisted green synthesis of an Ag@AgCl system utilizing the biomass of jellyfish. The as-prepared membrane shows photocatalytic properties in the visible light region for the degradation of methyl orange.

One‐Pot Bio‐Assisted Synthesis of Stable Ag–AgCl System Using Jellyfish‐Based Scaffold for Plasmonic Photocatalysis Applications

AbstractPlasmonic assisted photocatalysis has emerged in the past decade as an efficient, high‐performance methodology. Such a system is often composed of the dispersal of noble metal nanoparticles on a semiconductor. In this architecture, the application of light at the plasmon frequency allows the separation of charge at the Schottky interface between the metal and the semiconductor, which can be further used for efficient catalysis. Here, a one‐pot green bio‐synthesis of Ag antibacterial nanoparticles attached to AgCl crystals while embedded in a jellyfish‐based eco‐friendly scaffold, is reported. The synthesis utilizes the chemical reduction properties of mucin protein found in the Jellyfish biomass, and thus the resulting Ag@AgCl system is firmly bound to the scaffold, making this membrane very stable. The system's photocatalytic activity is investigated by decomposing methyl orange and full electromagnetic simulations.

A Review: Sensory System, Data Processing, Actuator Type on a Hand Exoskeleton Design

A rehabilitation device for a post-stroke is essential because stroke attacks can cause disable to part or half of the human body. An exoskeleton could be a vital device for rehabilitation for a post-stroke patient. Several studies have proposed the exoskeleton design for rehabilitation purposes to a human limb disorder. This study aims to review the state-of-the-art of hand exoskeleton devices based on myoelectric or any other sensors. This paper is expected to contribute to design a hand exoskeleton device using both myoelectric and force sensors. This was achieved by reviewing several articles related to the development of the exoskeleton, especially in the sensor system, data processing, and actuator system. The results show that the use of Ag electrode disposable Ag (AgCl) is still commonly found to detect the movement of the fingers on the hand because this sensor can reduce the artifact noise. The use of myo-armband is also found in several studies because it has wireless properties so that it is easy to use. In terms of processors, Arduino microcontrollers are more widely used than others. In order to activate the hand exoskeleton, servo motors are more widely used to actuate the finger joints, which is more precise than other actuators. In a further development, integration between exoskeleton systems and information systems will be an expected challenge. Furthermore, hopefully, the development of this exoskeleton can be applied as a rehabilitation device for patients with malfunction or hand paralysis.

A MODELING OF EXTENDED KALMAN FILTER TO IMPROVE ACCURACY IN ELBOW JOINT ANGLE ESTIMATION

The essential problem in the estimation of a human elbow angle position using myoelectric or electromyography (EMG) is that the EMG features have non-linearity characteristics. The non-linearity of the EMG features influences the performance of the estimation. The objective of this paper is to develop an extended Kalman filter based on the time domain feature to predict the position of the elbow using a myoelectric signal. The contribution of this study is that the non-linearity of EMG feature can be linearized effectively on flexion and extension motion. This is achieved by linearizing the EMG feature in extended Kalman filter using first-order Tailor series. The Ag(AgCl) was used to collect the myoelectric activities from biceps muscle. In this study, the sign slope feature (SSC) extracted the EMG signal to get the evidence that is associated with the position of the elbow. The extended Kalman filter (EKF) was chosen to linearize and to approximate the elbow position using EMG features. The performance of the proposed method is 12.81% and 9.65 % for periodic and arbitrary motion, respectively. We have confirmed the success of the presented EKF method to improve the performance of the estimation. Further, the proposed method can be implemented to an assistive exoskeleton for elderly people or stroke patients for a better life.

Biosynthesis of Silver–Silver Chloride Nanoparticles Using Fruit Extract of Levisticum Officinale: Characterization and Anticancer Activity Against MDA-MB-468 Cell Lines

In this study, characterization and anticancer activity of synthesized silver and silver chloride nanoparticles (Ag–AgCl NPs) using aqueous fruit extract of Levisticum Officinale were investigated. The first sign of the synthesis of Ag–AgCl NPs was the color change of the solution from yellow to brown due to the addition of plant extract to the silver nitrate (AgNO3) solution, which was confirmed by UV–Vis spectroscopy. The phase and chemical characteristics, size, spherical shape, nanocrystalline structure and stability of Ag–AgCl NPs were evaluated by fourier transform infrared spectroscopy (FT-IR), energy-dispersive X-ray analysis (EDX), transmission electron microscope (TEM), scanning electron microscopy (SEM), dynamic light scattering (DLS), X-Ray diffraction (XRD) and zeta potential analyzes. The results confirmed the formation of spherical nanoparticles with the face centered cubic (FCC) crystalline structure. The cytotoxic effect of Ag–AgCl on MDA-MB-468 cancer cell line was studied by 3-[4,5 dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) colorimetric method at 48 h. Also, MTT assay results prove promising that the Ag–AgCl NPs could be an agent of breast cancer treatment.