Glass Electrode Research Articles

Variation of current density with time as a novel method for efficient electrochemical treatment of real dyeing wastewater with energy savings.

Electro-oxidation is a promising technology for wastewater treatment with biorefractory organic and nitrogen pollutants; however, the high energy demand hinders its wide application. In this study, a novel method by regulating significant parameter during the electro-oxidation process in a timely manner for real dyeing wastewater treatment with energy savings was studied. Operating factors (i.e., flow rate, initial pH value, electrode distance, and current density) were investigated for chemical oxygen demand (COD) and ammonia removal, and the results indicated that current density was the key factor that obviously influenced the electrochemical performance. Indirect oxidation by active chlorine was then confirmed as the main reaction pathway for pollutant oxidation, and the relationship between the current density and the generation of active chlorine was established, suggesting that a large part of the generated active chlorine was not utilized effectively. Subsequently, a novel method of varying the current density in a timely manner based on the reaction mechanism was proposed; the results indicated that, with similar pollutant removal efficiencies, energy consumption could be reduced from 31.6 to 20.5 kWh/m3. Additionally, the novel system was further optimized by Box-Behnken design: The COD removal efficiency could reach 71.8%, and the energy demand could be reduced by 45.6%.

Investigating the variation in the optical properties of TiO2 thin-film utilized in bifacial solar cells using machine learning algorithm

Among various solar cell architectures, dye-sensitized solar cells (DSSCs) and perovskite solar cells have demonstrated the capability of being bifacial as both can be fabricated on conducting glass electrodes. In both cells, TiO2 plays a key role in the optoelectronic properties of the cell. Various studies have reported a range of recipes and deposition techniques for TiO2 thin films. Such variety introduces some uncertainties into the optical properties of the prepared films as well as in the process repeatability. Here, we utilized machine learning methods to correlate the film porosity to the film refractive index, making it capable of studying the impact of varying the fabrication and deposition techniques. Image postprocessing for scanning electron microscope measurements was utilized to estimate the film porosity, and the refractive index was calculated from the T–λ spectra. Four sets of samples with complete bifacial DSSCs were fabricated and characterized. They recorded a maximum current of 23.42 mA. They were fabricated using carboxymethyl cellulose-based suspension and deposited via the spin-coating sol-gel method. The fabricated cells showed an overall conversion efficiency of 7.9% under optical injection of the AM1.5G spectrum from the front side and LED indoor lighting from the counter electrode.

Pharmaceutical versus Over-the-Counter Potassium Citrate: A Benchtop Comparison.

Potassium citrate has been shown to significantly reduce kidney stone recurrence by alkalinizing urine and increasing citrate excretion. However, the cost of potassium citrate can be prohibitive. Thus, over-the-counter use of potassium citrate supplements has gained interest from patients and providers due to reported decreased cost. Prior studies show that fluids such as orange juice, Crystal Light and certain sodas are reasonable sources of alkali citrate; however, the true alkali citrate content among leading over-the-counter supplements is unknown. We investigate popular supplements and compare them to pharmaceutical potassium citrate. The top 6 potassium citrate supplements were purchased from Amazon.com in October 2020 and April 2021. These supplements and Urocit®-K were dissolved in deionized water and diluted before measurement with a colorimetric citrate assay kit. A pH electrode was used to measure the pH of each sample and the alkali citrate content of each supplement was calculated. Urocit-K and Thorne® had the highest percentage of alkali citrate per gram. NOW® supplements and Nutricost® offered the cheapest alkali citrate at less than 1 cent per mEq. Citrate supplements vary widely in their cost and citrate content. Patients and providers may find this information useful depending on their individual preferences for cost and pill size. Pharmaceutical Urocit-K was not the most cost-effective option; however, it may be the more convenient option as it requires fewer pills.

Versatile, low-cost, non-toxic potentiometric pH-sensors based on niobium

A low-cost potentiometric pH electrode based on niobium/niobium oxide was developed with excellent stability over several months under various storage conditions. Three fast and simple preparation routes including thermal growth as well as chemical and electrochemical deposition were tested. Our data demonstrates that the electrochemical manufacturing method produces pH electrodes with high reproducibility and a sensitivity of −41 mV/pH. OCP (Open Circuit Potential) measurements showed that the pH electrode can be used over a wide pH range from pH 2 to 12. Furthermore, the oxide layer of all produced electrodes was characterized and compared via SEM (Scanning Electron Microscopy), EDX (Energy-Dispersive X-Ray Spectroscopy) and EIS (Electrochemical Impedance Spectroscopy). It was shown that the electrochemical fabrication route leads to the highest porosity, which is in turn linked to the highest sensitivity. The hysteresis of this pH sensor was determined to be 2 mV in a pH region between 4 and 10. In long-term experiments a drift of 1.1 mV/h was obtained. Negligible interference was observed with NaCl and KCl ions, whereas sensitivity and linearity were affected by Li-ions.

Recent progress in the development of glass and glass-ceramic cathode/solid electrolyte materials for next-generation high capacity all-solid-state sodium-ion batteries: A review

The lithium-ion battery (LIB) has been the dominant technology in the rechargeable energy storage market for more than twenty years. However, to meet the increasing need for electric vehicles, stationary electricity storage, and portable electronics, there is an emerging demand for alternative battery technologies. One promising candidate is an all-solid-state sodium-ion battery (ASSSIB) that can provide high power density with good safety and cycle durability, making it a potential next-generation battery technology. Recently the development of glass and glass-ceramic cathode/solid electrolytes showed specific interest in developing all-solid-state sodium-ion batteries (ASSIBs) due to optimization of their crystalline structure for fast Na+ ion diffusion, high cycle performance, excellent thermal stability, high electronic and ionic conductivity. Until now, there are no reports on the research progress in the development of ASSIBs based on glass or glass-ceramic cathode/solid electrolyte. The challenges and opportunities associated with these glass and glass-ceramic systems are reviewed in this paper. In addition, this review will focus on a better understanding of glass and glass-ceramic electrode and electrolyte materials for used to development of ASSIBs.

Characterization and comparison of glass electrodes

This paper presents the study on the characterization of glass electrodes, which are one of the main components of detectors like Resistive Plate Chambers (RPCs). The RPCs are being used in various ongoing High Energy Physics experiments, e.g., BELLE at KEK, CMS at LHC, and would be used in the near future experiments e.g., INO-ICAL in India. The characterization of glass electrodes has been done to understand the factors like quality of glass that can help in improving the detector's performance. The glass samples chosen were procured locally Asahi (A), Saint Gobain (S), Modi (M) that are easily available in Indian industry. The characterization includes the tests to study the optical, surface, physical, electrical properties, the composition of glass samples, and leakage currents. This paper adds new information to the existing body of research on the subject. Based on the techniques discussed in the paper a comparison of the measurements among the three different types of glass electrodes has been done. This study helps us to determine the best quality of glass that can be chosen for better operation of the detectors.

Quantitative assessment of Critic acid present in various soft drinks available in India.

Carbonated and non-carbonated are the two categories of soft/energy drinks are very commonly available. The non -carbonated soft drinks contain citric acid as a major component. In addition, some other acids such as Ascorbic, Malic, Caffeic acid are added in minute quantity as an as anti-oxidants, flavours and preservatives. In the current study the critic content is determined using two parallel methods for the same sample; one is visual titration and another by using pH-metre with combined glass electrode. The overall range for citric acid content is 1.445 to 9.722 g/L by visual titration whereas 1.577 to 1.577 by pH metric titration

A water-soluble glass-based temporary restorative resin inhibited bacteria-induced pH reductions at the bacteria-material interface

This study aimed to evaluate the inhibitory effects of a water-soluble glass based temporary restorative resin (WSG-TRR) on bacteria-induced pH reductions at the bacteria-material interface. Each material (WSG-TRR, glass-ionomer cement, resin composite and conventional temporary restorative resin) was fixed to the bottom of the well of the experimental apparatus. The well was filled with pelleted cells of Streptococcus mutans, and the pH at the bacteria-material interface was monitored using a miniature pH electrode. The concentration of ions released from WSG-TRR and the effect of fluoride and zinc ions on bacteria-induced pH reduction was evaluated. The buffering capacities of WSG-TRR and WSG were also evaluated. At 90 min after the glucose addition, WSG-TRR exhibited the highest pH (5.29±0.12). Fluoride ion was detected at the interface between bacteria and WSG-TRR. Moreover, WSG were found to confer high buffering capacity. A WSG-TRR reduced bacteria-induced pH reductions at the bacteria-material interface.

High anti-interference ability induced by the SP/SiOx/ImIL composite film on IrOx pH electrodes

High concentrations of redox substances in the solution may cause severe electrode potential drift, resulting in the inaccuracy of in situ measurements. Sulfide anion, a highly reductive substance, is the killer of all metal oxide electrodes because of its small size and strong surface activity. We first proposed to use SPEEK (SP) with silica-stabilized imidazole-type ionic liquid (ImIL) to fabricate a composite film (SP/SiOx/ImIL) to achieve a high anti-interference ability for metal electrodes. The composite film was especially designed to address the interference caused by sulfide anions and other small-sized anions (i.e., I−, F− and ascorbic acid). The reduced proton conductivity was restored by introducing ImIL into SPEEK matrix. Open circuit potential tests showed that the potential of the SP/SiOx/ImIL modified IrOx electrode fluctuated within 0.3 mV in 30 min continuous test at a concentration of 10−3 M Na2S, exhibiting good stability in moderately high sulfide solution. It also exhibited fast response and good reversibility. In addition, no potential drift was measured under other anions interferences. XPS survey verified that the Ir4+/Ir3+ ratio of the IrOx electrode did not change before and after application in sulfide-containing solution, indicating that the SP/SiOx/ImIL composite film has good anion isolation capacity.

Minimalizing Non-point Source Pollution Using a Cooperative Ion-Selective Electrode System for Estimating Nitrate Nitrogen in Soil.

Nitrate nitrogen ( -N) in the soil is one of the important nutrients for growing crops. During the period of precipitation or irrigation, an excessive -N readily causes its leaching or runoff from the soil surface to rivers due to inaccurate fertilization and water management, leading to non-point source pollution. In general, the measurement of the -N relies upon the laboratory-based absorbance, which is often time-consuming, therefore not suitable for the rapid measurements in the field directly. Ion-selective electrodes (ISEs) support the possibility of -N measurement by measuring the nitrate () ions in soil quickly and accurately due to the high water solubility and mobility of ions. However, such a method suffers from a complicated calibration to remove the influences caused by both temperature and other ions in the measured solution, thus limiting field use. In this study, a kind of all-solid ISE system combined with a temperature sensor and a pH electrode is proposed to automatically measure the concentrations of the -N. In this study, a soil water content calibration function was established, which significantly reduces a relative error (RE) by 13.09%. The experimental results showed that the stabilization time of this electrode system was less than 15 s with a slope of −51.63 mV/decade in the linear range of 10–5–10–2.2 mol/L. Both the limit of detection of 0.5 ppm of the -N and a relative SD of less than 3% were obtained together with the recovery rate of 90–110%. Compared with the UV-Vis spectroscopy method, a correlation coefficient (R2) of 0.9952 was obtained. The performances of this all-solid ISE system are satisfied for measuring the -N in the field.

Rapid colorimetric methods for analysis of pH, extractable aluminium and Colwell phosphorus in soils

Context Analytical procedures and technologies for soil analyses can be prohibitively expensive for small laboratories and researchers in developing countries. There is a need for low cost and high-throughput methods for assaying pH, extractable aluminium and phosphorus when conducting field trials on acid soils. Aims We investigated methods to develop rapid yet inexpensive colorimetric assays for the assay of pH, extractable aluminium and Colwell phosphorus in soil extracts. Methods We developed a colorimetric method to measure soil pH enabling pH to be quantified in a high-throughput assay. Similarly, two existing methods for extractable aluminium and Colwell P were modified for high throughput assays also using microtiter plates. Key results All three methods yielded linear relationships when using absorbance to quantify the parameters with the high throughput methods. Furthermore, there was a strong correlation between pH values of the soil samples obtained with the colorimetric assay and pH values measured with a glass electrode. Conclusions We demonstrated that the rapid assays for all three methods can be implemented to characterise field sites through the mapping of distributions for extractable Al, Colwell P and pH. Implications The high-throughput methods described here will be useful for researchers who conduct field trials to map variations in soil pH, soluble Al and Colwell P. Although the focus of the current work was on acid soils, the colorimetric pH and Colwell P methods can also be applied to non-acid soils.

Inhibition of cytochrome P450 with proadifen alters the excitability of brain catecholamine-secreting neurons.

The concentrations of circulating glucocorticoids are regulated by their synthesis and metabolism. Cytochrome P450 (CYP), primarily expressed in the liver, is one of the main metabolizers of glucocorticoids. Since glucocorticoids, as well as monoamines, are fundamental in stress, the link between hepatic glucocorticoid metabolism and central monoamine transmission might be important in pathophysiology of stress-related disorders. We had previously reported that CYP inhibition by proadifen (SKF525) led to the inhibition of central serotonin (5-HT) neurons. The aim of this study was to investigate the effect of SKF525 on the excitability of central catecholamine neurons. Adult male Wistar rats were administered SKF525 forty-eight, twenty-four, and one hour before electrophysiological assessments. Control animals were injected saline. Rats were anesthetized with chloral hydrate and glass electrodes were inserted into the locus coeruleus (LC) or ventral tegmental area (VTA). Noradrenaline neurons of the LC and dopamine of the VTA neurons were identified, and their firing activity was recorded. It was found that the SKF525 enhanced the excitability of noradrenaline and reduced the excitability of dopamine neurons. We suggest that corticosterone-induced inhibition of 5-HT neurons underlines, at least in part, the ability of SKF525 to stimulate noradrenaline neurons. The inhibitory effect of SKF525 on dopamine neurons might be in turn secondary to the stimulatory effect of this compound on noradrenaline neurons.

Ion Selective Electrode Determination of Ammonia Nitrogen in Passaic River Waste Water in New Jersey Essex County Area

The percent ammonia nitrogen was determined in Passaic River waste water using Ion-Selective Electrode EPA Method 350.3. The intelligent ammonia sensor integrates ammonia electrode, pH electrode and Ammonia Ion electrode together to realize the in situ detection of ammonia. The test results have shown that the sensor is easy operation, low cost and no pollution. The ammonia is determined potentiometrically using an ammonia ion selective electrode and a pH/mV meter, having an expanded millivolt scale. The ammonia selective electrode uses a hydrophobic gas-permeable membrane to separate the sample solution from an electrode internal solution of ammonium chloride. Dissolved ammonia is converted to NH3 gas by raising the pH to above 11.0 with a strong base. NH3 gas diffuses the membrane and changes the internal solution pH that is sensed by the electrode. In single laboratory test results have been found 1.001 NH3-/L and 0.897 mg NH3-N/L, recoveries were 77.3% and 83.1%, respectively.

Sol-Gel Derived, Inkjet Printed, and Flash Lamp Annealed Ta2o5 on Flexible, Interdigitated Electrodes for Capacitive Ph Sensing at High Ionic Strength

Sol-Gel Derived, Inkjet Printed, and Flash Lamp Annealed Ta2o5 on Flexible, Interdigitated Electrodes for Capacitive Ph Sensing at High Ionic Strength

Chemical Detection by Analyte-Induced Change in Electrophoretic Deposition of Gold Nanoparticles

The electrophoretic deposition (EPD) of citrate-stabilized Au nanoparticles (cit-Au NPs) occurs on indium tin oxide (ITO)-coated glass electrodes upon electrochemical oxidation of hydroquinone (HQ) due to the release of hydronium ions. Anodic stripping voltammetry (ASV) for Au oxidation allows the determination of the amount of Au NP deposition under a specific EPD potential and time. The binding of Cr3+ to the cit-Au NPs inhibits the EPD by inducing aggregation and/or reducing the negative charge, which could lower the effective NP concentration of the cit-Au NPs and/or lower the electrophoretic mobility. This lowers the Au oxidation charge in the ASV, which acts as an indirect signal for Cr3+. The binding of melamine to cit-Au NPs similarly leads to aggregation and/or lowers the negative charge, also resulting in reduction of the ASV Au oxidation peak. The decrease in Au oxidation charge measured by ASV increases linearly with increasing Cr3+ and melamine concentration. The limit of detection (LOD) for Cr3+ is 21.1 ppb and 16.0 ppb for 15.1 and 4.1 nm diameter cit-Au NPs, respectively. Improving the sensing conditions allows for as low as 1 ppb detection of Cr3+. The LOD for melamine is 45.7 ppb for 4.1 nm Au NPs.

Feasibility of multifunction calibration of H+-responsive glass electrodes in seawater (IUPAC Technical Report)

Article Feasibility of multifunction calibration of H+-responsive glass electrodes in seawater (IUPAC Technical Report) was published on January 1, 2022 in the journal Chemistry International (volume 44, issue 1).

Excellent physicochemical and sensing characteristics of a Re x O y based pH sensor at low post-deposition annealing temperature.

pH monitoring in clinical assessment is pivotal as pH imbalance significantly influences the physiological and extracellular functions of the human body. Metal oxide based pH sensors, a promising alternative to bulky pH electrodes, mostly require complex fabrication, high-temperature post-deposition treatment, and high expenses that inhibit their practical applicability. So, there is still room to develop a straightforward and cost-effective metal oxide based pH sensor comprising high sensitivity and reliability. In this report, a novel solution-processed and low-temperature annealed (220 °C) mixed-valence (vii/vi) oxide of rhenium (RexOy) was applied in an electrolyte–insulator–semiconductor (EIS) structure. The annealing effect on morphological, structural, and compositional properties was scrutinized by physical and chemical characterizations. The post-annealed RexOy exhibited a high pH sensitivity (57.3 mV pH−1, R2 = 0.99), a lower hysteresis (4.7 mV), and a reduced drift rate (1.7 mV h−1) compared to the as-prepared sample for an analytically acceptable pH range (2–12) along with good stability and reproducibility. The magnified sensing performance originated due to the valence state of Re from Re6+ to Re7+ attributed to each electron transfer for a single H+ ion. The device showed high selectivity for H+ ions, which was confirmed by the interference study with other relevant ions. The feasibility of the sensor was verified by measuring the device in real samples. Hence, the ease-of-fabrication and notable sensing performance of the proposed sensor endorsed its implementation for diagnosing pH-related diseases.

Generation of Atmospheric Pressure Dielectric Barrier Discharge (DBD) Using Water Electrode

In this experiment, an atmospheric pressure dielectric barrier discharge (DBD) generated with a water electrode is investigated by means of optical measurements and imaging. The discharge was generated using a high voltage (0-20kV) power supply operating at 10-30 kHz with water as one of the electrode and borosilicate glass as a dielectric barrier of 2.5mm thickness. This paper reports the generation and characterization of atmospheric pressure plasma in nitrogen environment and its application in the surface modification of polyethylene terephthalate (PET). The generated plasma has been characterized by image analysis and optical emission spectroscopy. Our results showed that the distribution of micro-discharges depends significantly on the inter electrode gap and applied voltage. In order to characterize the discharge, electron temperature has been determined by using line intensity ratio method. The results showed that Te depends on applied voltage and pressure inside the chamber. The values of Te were found to be 1.40 eV and 0.95 eV applied at 1kV and 10kV voltage using 1% concentration. The discharge was produced at various conditions for the study of effectiveness of treatment on the surface property of Polyethylene terephthalate (PET). After the treatment of the sample in different treatment time: 10s, 20s, 40s, and 60s, the hydrophobic properties of sample changed to the hydrophilic. To investigate the effect of plasma treatment on Polyethylene terephthalate (PET) polymer contact angle was measured by using goniometer with water as a testing liquid. The surface properties of the untreated and plasma treated PET samples were characterized by contact angle measurement, and surface energy analysis. Before treatment the contact angle for untreated sample was 77.1° and after treatment its contact angle becomes 38.7° , 35.04° , 33.6° and 31.6° respectively.

Copper oxide nanoleaves covered with loose nickel oxide nanoparticles for sensitive and selective non-enzymatic nitrite sensors

In this work, we developed a new method for preparing copper oxide (CuO) nanostructures, designed and prepared a CuONiO modified fluorine-doped SnO2 transparent conductive glass (FTO) electrode for electrochemical sensor to effectively detect the nitrite. The leaf-shaped CuO nanostructures grow uniformly on the FTO electrode, resulting in the increased contact area and reduced transfer resistance. The NiO nanoparticles effectively dispersed in the gaps between the leaves can further improve the electron transfer and reduce the diffusion resistance. The electrochemical results demonstrated that the prepared electrode exhibited high sensitivity (7.2 mA mM−1 cm−2), broad linear range (0.001–1.8 mM) and low detection limit (0.013 μM). Moreover, the prepared sensor also reflected good reproducibility, stability and anti-interference in the detection of actual samples, which provides a good application prospect for metal oxides used in water quality and environmental monitoring.

Efficiently Regulating the Electrical Properties of Flexible Fabric‐Based Cu3(BTC)2 Thin Film by Introducing Various Guest Molecules

AbstractRecently, the flexibility of 2D conductive metal–organic frameworks (MOFs) is an important precondition for manufacturing high‐performance smart electronic devices. Preparation of MOFs thin film has drawn much attention, and increasingly more MOF thin films have been deposited on different rigid substrates like glass, silicon, and metal electrodes. However, they do not meet the requirements for flexible materials, such as wearable electronic devices. Here, the fabric‐based composites (the integration of MOFs and fabric materials) can solve this problem. Insulating polyester fabric is chosen as a flexible substrate and atom layer deposition (ALD) and the layer‐by‐layer (LBL) method (also called the liquid phase epitaxy method) are combined to synthesize Cu3(BTC)2 thin film. 7,7,8,8‐tetracyanoquinodimethane (TCNQ) and polypyrrole (PPy) are chosen to improve the conductivity of the MOF thin films. The conductivity of Cu3(BTC)2 thin film is improved by more than four orders of magnitude compared to that of the original sample. This research shows that the large‐area lightweight fabric‐based Cu3(BTC)2 thin films, which possess excellent uniformity and flexibility and controllable thickness, can be prepared at room temperature; this allows MOFs to be applied in more areas, such as large‐area electronic devices and smart wearable sensing equipment.