Base Electrolyte Research Articles

Poly(3‐alkylthiophene) Films as Solvent‐Processable Photoelectrocatalysts for Efficient Oxygen Reduction to Hydrogen Peroxide

Poly(3‐alkylthiophene) films play a central role in various organic devices due to their solvent processability and their remarkable electrical and optical properties. The (photo)electrocatalytic abilities of unsubstituted and solvent‐insoluble polythiophenes in the reduction of O2 to H2O2 in a basic aqueous electrolyte have recently emerged as an advanced function. Herein, the electrocatalytic and photoelectrocatalytic abilities of solvent‐processable poly(3‐alkylthiophene) films at pH 12 are demonstrated, as well as their characteristics are re‐examined from the viewpoints of the polymer structure, electrochemistry, photochemistry, and film nanostructure. A comparison of the above characteristics reveals the requirements for effective (photo)electrocatalytic O2 reduction to H2O2 production. In addition, the addition of an organic salt to the polymer solution changes the formed film characteristics. The thin film of the regioregular poly(3‐hexylthiophene‐2,5‐diyl) containing a small amount of tetramethylammonium bis(trifluoromethanesulfonyl) imide is easily formed by a solvent‐based process and features lower crystallinity, a porous film nanostructure, and high conductivity. This polymer acts as a robust photoelectrocatalyst for the reduction of O2 to H2O2 with a conversion rate of 3.9 × 103 mg (H2O2) gphotocat−1 h−1 or ≈0.040 mg (H2O2) cm−2 h−1 and a high Coulombic efficiency of >95% at 0.1 V bias from the theoretical potential.

Evolution of interfacial coupling interaction of Ni-Ru species for pH-universal water splitting

Designing highly-efficient and pH-universal electrocatalysts for overall water-splitting reactions is important for the sustainable production of hydrogen. Herein, NiRu nanoparticles encapsulated into N-doped carbon (NiRu@NC) are fabricated with the assistance of MOF for hydrogen evolution reaction (HER) and also evolved into core–shell structured nanomaterials with abundant interfaces for oxygen evolution reaction (OER, Ni/RuOx@C). Benefiting from optimized electronic structure, interfacial synergy effect and special core–shell structure (~150 nm), the newly developed electrocatalysts present remarkable electrocatalytic activities with small overpotentials to drive 10 mA cm−2 for the HER (19 mV in alkaline, 80 mV in neutral, 20 mV in acid) and OER (252 mV, 316 mV, 211 mV). Moreover, the obtained electrocatalysts exhibit outstanding catalytic performances for overall water-splitting in a two-electrode system with 1.53 V and 1.67 V to drive 10 mA cm−2 in basic and neutral electrolyte, respectively. Remarkably, a small potential of 1.47 V is required to deliver 10 mA cm−2 in acidic media and no significant decay of the activity is observed. This work paves the way for designing a novel class of electrocatalyst that can not only exhibit remarkable electrocatalytic water splitting performances in various conditions, but also possess excellent stabilities for future generation of clean energy.

(Student Battery Slam Best Presentation Award Winner) “Water-in-Salt” Polymer Electrolyte for Li-Ion Batteries

Lithium ion batteries (LIBs) have been widely applied in multitudinous energy storage systems due to their high energy density, long cycle stability and high energy efficiency. While the public concern over the safety of LIBs increases rapidly with our reliance on this technology in our daily life, for which the nonaqueous and highly flammable electrolyte should bear most of the responsibility. Aqeuous rechargeable lithium ion batteries resolve several challenges of conventional LIBs. However, the electrochemical stability window of aqueous electrolytes is less than 2.0 V, beyond which the electrolysis of H2O with the hydrogen evolution reaction at anode (H2 generated) and oxygen evolution reaction at cathode (O2 generated). Recently, the ground-breaking of “water-in-salt” electrolyte (WiSE) successfully expanded the ESW of water to 3.0 V. To further enhance the energy density of WiSE based batteries, the cathodic limitation of 1.9 V needs to further reduced, and a high Coulombic efficiency (CE) of > 99.9% at a matched areal capacities of cathode/anode is required for a long-term cycling. Here, we designed a solid-state aqueous polymer electrolyte (SAPE) by incorporating WiSE with UV-curable methacrylic polymer. The abundant hydrophilic groups of the polymer stabilized water molecules due to the sluggish water mobility in SAPE and formed a water-less thin passivation interphase between anode and electrolyte. In addition, by pre-coating a strongly basic water-free solid polymer electrolyte on the surface of anode, an artificial passivation interphase was formed. A robust SEI was formed on the surface of anode and the water reduction reaction is suppressed in our electrolyte system. Also, an extended electrochemical stability window of 3.86 V is achieved at 12 mol kg-1 aqueous polymer electrolyte, enabling the 3 V full cells cycled with an unprecedented high initial CE of 90.5% and average CE of 99.97%. The SAPE exhibits intrinsic safety and tolerance of drastic mechanical abuse, the flexible full cell with supper robustness can be widely used for low-cost and high-safety flexible electronic devices. Moreover, the UV-cured polymerization process possesses the merit of facile and high efficiency, and the whole process have the potential to be practical used in a large scale. Overall, this newly developed reduced salt concentration WiSE not only reduces the cost of aqueous electrolyte, but also opens up another perspective on future directions and guidance for the design of aqueous electrolyte for high-energy-density Li-ion batteries in practical applications.

ELECTROLYTIC EXCHANGE FEATURES DURING MYOCARDIAL INFARCTION WITH RECURRENT EPISODES OF ISCHEMIA IN MEN UNDER 60 YEARS OLD

Relevance. Recurrent myocardial infarction and early postinfarction angina negatively effects on the prognosis of myocardial infarction. Aim. To evaluate myocardial infarction sodium, potassium, chlorides, calcium metabolism, features in men under 60 years old with recurrent myocardial infarction and early postinfarction angina to improve prevention and outcomes. Material and methods. The study included men aged 19-60 years old with type I myocardial infarction. Patients are divided into two age-comparable groups: I - the study group, with recurrent myocardial infarction - 110 patients; II - control, without it - 555 patients. A comparative analysis of blood serum electrolyte levels, their dynamics from the first hours to the end of the third week of myocardial infarction in the selected groups were performed. Their impact on the risk of recurrent ischemia and unfavorable outcome was assessed. Results. In the study group, in the first hours of the disease, the levels of chloride were higher (103.7±5.5 and 101.7±4.7 (mmol/l); p=0.002), and total calcium at the end of the third week of myocardial infarction (2.3±0.2 mmol/l) - lower than in the control (2.46±0.16; p=0.001). With an unfavorable outcome in the study group, the sodium level was lower in the first hours of the disease (138.7±4.9 and 142.7±6.6 (mmol/l); p=0.049). Moreover, the risk of its development was associated with sodium levels ≥148.0 mmol/l (absolute risk: 100.0%; relative - 13.8; p<0.0001) and potassium levels ≥5.3 mmol/l (absolute: 71,4%; relative - 12.4; p<0.0001). The risk of developing recurrent episodes of ischemia in the examined increased at chloride levels ≥104.7 mmol/l (absolute: 28.4%; relative: 3.1; p=0.0001) and sodium ≥139.0 mmol/l (absolute: 19.5%; relative: 1.7; p=0.03) in the first hours of myocardial infarction and calcium (<2.4 mmol/l) at the end of the third week of the disease (absolute: 31.0%; relative: 4.9; p=0.003). Conclusions. The listed combinations of levels of basic electrolytes in blood serum are markers of recurrence of ischemia in myocardial infarction and poor outcome. They should be used to identify risk groups with the necessary preventive measures and for predictive modeling.

Li[(FSO2)(n‐C4F9SO2)N]: A Difunctional Salt for Ethylene‐Carbonate‐ and Additive‐Free Electrolyte for Li‐Ion Cells

AbstractAn ethylene carbonate (EC) free and additive‐free base electrolyte, simply comprising a solid‐electrolyte‐interphase (SEI)‐forming salt (i. e., lithium (fluorosulfonyl)(n‐nonafluorobutanesulfonyl)imide (Li[(FSO2)(n‐C4F9SO2)N], LiFNFSI)) and dimethyl carbonate (DMC), for stable cycling graphite||LiNi0.6Mn0.2Co0.2O2 (NMC622) full cells at different temperatures (i. e., 25 °C and 60 °C) is reported. The utilization of the LiFNFSI‐based, EC‐free electrolyte endows the graphite||NMC622 cell with superior cycling performances, especially at an elevated temperature of 60 °C, outperforming the lithium hexafluorophosphate (LiPF6)‐based ones with and without EC. X‐ray photoelectron spectroscopy and electrochemical impedance spectra analyses demonstrate that a thin, compact, and robust Li‐ion conductive SEI film is formed on the overall surface of the graphite anode in LiFNFSI‐DMC, while that formed in LiPF6‐DMC is discrete. These results suggest the potential application of LiFNFSI as a main conducting salt for building high‐performance LIBs with EC‐free electrolytes.

Architectural Design of Electrode Material for Supercapacitor Application Based on a MoS2/CeO2 Heterostructure Synthesized by Facile Hydrothermal Technique

The recent work is based on synthesis of MoS2/CeO2 heterostructure (2D/3D) as electrode material to display its outstanding supercapacitive performance. Herein, we present a two-step facile hydrothermal technique to produce MoS2/CeO2 heterostructure. The characterization tools such as X-ray Diffraction (XRD), Fourier Transform Infrared (FTIR) and UV-Vis spectroscopy evidently confirm the co-existence of MoS2 and CeO2, while the Field-Emission Scanning Electron Microscopy (FESEM) images confirms the unique microstructures of MoS2/CeO2 heterostructure. The objective is to study the electrochemical properties of MoS2/CeO2 heterostructure with different electrolytes viz. Na2SO4 (neutral), H2SO4 (acidic) and NaOH (basic). Remarkably, MoS2/CeO2 heterostructure yield the highest electrical double layer capacitance of 166.6 F g−1 at a scan rate of 5 mV s−1 in an aqueous 1 M NaOH basic electrolyte. The role of ions in NaOH as an electrolyte are explain on the basis of ionic conductivity and mobility to validate the maximum resultant specific capacitance. The ionic conductivity and mobility of all the electrolytes are well studied. Furthermore, the architectural design of 3D interconnected network of a 3D CeO2 nanocubes with 2D MoS2 nanosheets assists the electrochemical properties of heterostructure.

Refining d-band center in Ni0.85Se by Mo doping: A strategy for boosting hydrogen generation via coupling electrocatalytic oxidation 5-hydroxymethylfurfural

Electrochemical oxidation of biomass convert into worthy production is considered to be a prospective alternative to slow kinetic oxygen evolution reaction (OER) in order to facilitate H2 generation. Herein, Mo-doped Ni0.85Se on the Ni foam (denoted as NF@Mo-Ni0.85Se) was prepared as effective bifunctional catalyst to boost H2 production and translate 5-hydroxymethylfurfural (HMF) into 2, 5-furfuran carboxylic acid (FDCA) simultaneously. Operando electrochemical impedance spectroscopy (EIS) and theoretical calculations confirm that the Mo doping could speed the electron transmission within the catalyst and downshift the d-band center of Ni in NF@Ni0.85Se, which is not only conducive to abating H* adsorption energy, but further promotes the hydrogen evolution reaction (HER) and organic hydrogen adsorption process. The as-synthesized electrocatalysts have shown outstanding hydrogen evolution property in acid, neutral, alkaline and seawater. When the NF@Mo-Ni0.85Se||NF@Mo-Ni0.85Se catalyst couple was employed for HER as well as HMF oxidation in basic electrolytes, the potential only required a potential of 1.50 V to obtain the current density of 50 mA cm−2, lower than that of overall water splitting (1.68 V). This present work especially emphasizes the significance of doping transition metals to improve material properties for constructing bifunctional electrocatalysts towards highly efficient energy utilization.

Towards novel calcium battery electrolytes by efficient computational screening

The development of Ca conducting electrolytes is key to enable functional rechargeable Ca batteries. The here presented screening strategy is initially based on a combined density functional theory (DFT) and conductor-like screening model for real solvents (COSMO-RS) approach, which allows for a rational selection of electrolyte solvent based on a set of physico-chemical and electrochemical properties: solvation power, electrochemical stability window, viscosity, and flash and boiling points. Starting from 81 solvents, N,N-dimethylformamide (DMF) was chosen as solvent for further studies of cation-solvent interactions and subsequent comparisons vs. cation-anion interactions possibly present in electrolytes, based on a limited set of Ca-salts. A Ca2+ first solvation shell of [Ca(DMF)8]2+ was found to be energetically preferred, even as compared to ion-pairs and aggregates, especially for PF6− and TFSI as the anions. Overall, this points to Ca(TFSI)2 and Ca(PF6)2 dissolved in DMF to be a promising base electrolyte for Ca batteries from a physico-chemical point-of-view. While electrochemical assessments certainly are needed to verify this promise, the screening strategy presented is efficient and a useful stepping-stone to reduce the overall R&D effort.

The Effect of Normal Saline and Plasmalyte on Acid-Base Status in Patients Undergoing Head-and-Neck Surgery with Free Flap Reconstruction: A Prospective, Observational Cohort Study.

Background:Intraoperative fluid strategy may affect the graft viability in head-and-neck surgeries with free flap reconstruction (HNS-FFR). Studies to guide regarding association of intraoperative fluid with metabolic parameters during such surgeries are infrequent.Aim:This study aimed to compare plasmalyte (PL) and normal saline (NS) (0.9%) in terms of acid–base balance and electrolytes in the peri-operative period along with graft viability during above-mentioned surgeries.Settings and Design:Prospective, observational cohort study was conducted in patients, 18–65 years, undergoing HNS-FFR at a tertiary care center.Materials and Methods:The cohort was categorized into two groups based on the intraoperative fluid used, i.e., PL (Group A) and NS (Group B) group. The primary objective was to compare arterial blood gas parameters at seven time points till the 3rd postoperative day. We studied the effect on graft viability and length of hospital stay.Statistical Analysis Used:The independent t-tests, Chi-square, or Fisher's exact test were used to evaluate the categorical variables with a repeated measures analysis of variance for inter-group comparison with P < 0.05 as significant.Results:Seventy-one (36 in Group A and 35 in Group B) patients were included in the study with comparable baseline characteristics. Group A had a better acid–base status, especially after the conclusion of vascular anastomosis (pH 7.37 ± 0.06 vs. 7.33 ± 0.04, P = 0.014) and in the postoperative period (pH 7.35 ± 0.07 vs. 7.31 ± 0.05, P = 0.013). No statistically significant difference was observed in outcome parameters between the groups.Conclusions:PL may be preferred over NS due to better metabolic milieu during HNS-FFR surgery.

Synthesis of Cobalt Oxide on FTO by Hydrothermal Method for Photoelectrochemical Water Splitting Application

Cobalt oxide thin films were successfully grown directly on fluorine-doped tin oxide glass substrates through a simple, green, and low-cost hydrothermal method. An investigation into the physicochemical characteristics and photoelectrochemical (PEC) properties of the developed cobalt oxide thin film was comprehensively performed. At various annealing temperatures, different morphologies and crystal phases of cobalt oxide were observed. Microflowers (Co3O4) and microflowers with nanowire petals (Co3O4/CoO) were produced at 450 °C and 550 °C, respectively. Evaluation of the PEC performance of the samples in KOH (pH 13), Na2SO4 (pH 6.7), and H2SO4 (pH 1) revealed that the highest photocurrent −2.3 mA cm−2 generated at −0.5 V vs. reversible hydrogen electrode (RHE) was produced by Co3O4 (450 °C) in H2SO4 (pH 1). This photocurrent corresponded to an 8-fold enhancement compared with that achieved in neutral and basic electrolytes and was higher than the results reported by other studies. This promising photocurrent generation was due to the abundant source of protons, which was favorable for the hydrogen evolution reaction (HER) in H2SO4 (pH 1). The present study showed that Co3O4 is photoactive under acidic conditions, which is encouraging for HER compared with the mixed-phase Co3O4/CoO.

Development and Comparative Analysis of Electrochemically Etched Tungsten Tips for Quartz Tuning Fork Sensor.

Quartz Tuning Fork (QTF) based sensors are used for Scanning Probe Microscopes (SPM), in particular for near-field scanning optical microscopy. Highly sharp Tungsten (W) tips with larger cone angles and less tip diameter are critical for SPM instead of platinum and iridium (Pt/Ir) tips due to their high-quality factor, conductivity, mechanical stability, durability and production at low cost. Tungsten is chosen for its ease of electrochemical etching, yielding high-aspect ratio, sharp tips with tens of nanometer end diameters, while using simple etching circuits and basic electrolyte chemistry. Moreover, the resolution of the SPM images is observed to be associated with the cone angle of the SPM tip, therefore Atomic-Resolution Imaging is obtained with greater cone angles. Here, the goal is to chemically etch W to the smallest possible tip apex diameters. Tips with greater cone angles are produced by the custom etching procedures, which have proved superior in producing high quality tips. Though various methods are developed for the electrochemical etching of W wire, with a range of applications from scanning tunneling microscopy (SPM) to electron sources of scanning electron microscopes, but the basic chemical etching methods need to be optimized for reproducibility, controlling cone angle and tip sharpness that causes problems for the end users. In this research work, comprehensive experiments are carried out for the production of tips from 0.4 mm tungsten wire by three different electrochemical etching techniques, that is, Alternating Current (AC) etching, Meniscus etching and Direct Current (DC) etching. Consequently, sharp and high cone angle tips are obtained with required properties where the results of the W etching are analyzed, with optical microscope, and then with field emission scanning electron microscopy (FE-SEM). Similarly, effects of varying applied voltages and concentration of NaOH solution with comparison among the produced tips are investigated by measuring their cone angle and tip diameter. Moreover, oxidation and impurities, that is, removal of contamination and etching parameters are also studied in this research work. A method has been tested to minimize the oxidation on the surface and the tips were characterized with scanning electron microscope (SEM).

Photoluminescence of ZnO:Eu3+ and ZnO:Tb3+ coatings formed by plasma electrolytic oxidation of pure zinc substrate

Eu3+ and Tb3+ doped ZnO optical coatings were formed by the Plasma Electrolytic Oxidation (PEO) method from the pure Zn sheet, with various dopant concentrations. The morphologies show no significant change with the introduced dopant or their concentrations, with typical appearance of PEO formed coatings. All elements are uniformly distributed, and concentration of incorporated dopants is related to the concentrations of the Eu2O3 or Tb4O7 particles added to the basic electrolyte. Wurtzite structure of ZnO was identified in all the samples, with no change induced by the dopants. Under 260 nm excitation ZnO emits broad-band in the visible region attributed to oxygen interstitial defects and oxygen vacancies. Photoluminescence (PL) of ZnO:X3+ (X = Eu, Tb) is a sum of PL from ZnO and 4f–4f dopant emissions. Eu3+ and Tb3+ are most effectively excited in charge-transfer band and 4f5d levels, respectively. By increasing concentrations of the dopants the broad PL decreases in favor of the 4f–4f dopant transitions, an indication of the energy transfer. ZnO:Eu3+ spectra are dominated by the hypersensitive 5D0→7F2 transition. Eu3+ ions are incorporated in a highly asymmetric environment. PL emission at 541 nm is the most intense in ZnO:Tb3+. Judd-Ofelt intensity parameters rise with increasing Eu3+ concentration, up to Ω2 = 7.8·10−42 cm2 and Ω4 = 4.4·10−42 cm2. Radiative lifetime of 5D0 level drops to 1.12 ms. Chromaticity of PL varies with concentration only when the samples are irradiated by UV light, from white to orange-red or green for Eu3+ or Tb3+ doped samples, respectively. Eu3+ under 394 nm and 464 nm irradiation gives 99.5% color-purity.

Multi-applications of new trinuclear Zr-SMI complex

We report on the synthesis route and applications of new solid material Zirconium salicylate methylimidazole. Zirconium based complex was successfully synthesized by a cost-effective, simple stirring method on a hot water bath. The synthesized material arranged in layers with notable properties such as crystalline nature, highly homogeneous topology, and stable oxidation states at room temperature, and large surface area, and thermal stability. As-synthesized zirconium 3D H-bonded complex subjected to multiple applications since it has met desirable characteristics. Zr-SMI electrode has shown rare combination of pseudocapacitor-battery behavior. Supercapacity of 1165 mAhg−1 at 3 Ag−1 was achieved by the Zr-SMI electrode in basic electrolyte. Excellent electrochemical sensing response was found by the Zr-SMI electrode for an organic molecules such as Methylene blue (MB), and L-alanine analytes. In addition, Zr-SMI showed excellent catalytic property towards complete degradation of MB, Methyle orange (MO), and rhodium (RH) dyes. All these results implied the excellent electrochemical and catalytic behavior of Zr-SMI and proved as a promising material for multiple applications.

Influence of ZnO on thermal control property and corrosion resistance of plasma electrolytic oxidation coatings on Mg alloy

Thermal control and corrosion resistant coatings have been fabricated by means of plasma electrolytic oxidation on AZ91 Mg alloy in the present study. The coatings were achieved mainly by in-situ incorporation of nano-sized ZnO particles into the porous layer and optimization of the composition of the base electrolyte. It was found that addition of ZnO nanoparticles influences the absorptance and emissivity of the coatings. The absorptance of the coating is greatly decreased by the inertly incorporated ZnO nanoparticles. This is probably due to the high band gap energy of ZnO, which can reduce the coating absorptance accordingly. The coating emissivity has been increased in the presence of particles since ZnO has high infrared emissivity value. Moreover, the corrosion resistance of PEO coatings has been improved in the presence of ZnO particles, owing to the accumulation of ZnO in the open pores and decrease of the coating porosity.

Tailoring the d-band center of N-doped carbon nanotube arrays with Co4N nanoparticles and single-atom Co for a superior hydrogen evolution reaction

A 3D self-supported integrated electrode, consisting of heteroatomic nitrogen-doped carbon nanotube arrays on carbon cloth with confined ultrafine Co4N nanoparticles and a distribution of anchored single-atom Co, is fabricated via a cobalt-catalyzed growth strategy using dicyandiamide as the nitrogen and carbon source and a layered cobalt hydroxide-nitrate salt as the precursor. The abundance of exposed active sites, namely, the Co4N nanoparticles, single-atom Co, and heteroatomic N-doped carbon nanotubes, and multiple synergistic effects among these components provide suitable tailoring of the d-band center for facilitating vectorial electron transfer and efficient electrocatalysis. Benefiting from the merits of its structural features and electronic configuration, the prepared electrode exhibits robust performance toward the hydrogen evolution reaction with overpotentials of only 78 and 86 mV at 10 mA cm−2 in acidic and basic electrolytes, respectively. Density functional theory calculations and X-ray photoelectron spectroscopy valence band measurements reveal that the effective tailoring of the d-band center by Co4N nanoparticles plays a crucial role in optimizing the hydrogen adsorption free energy to a more thermoneutral value for efficient electrocatalysis.

Development of photocatalytically active coating on cp-Ti by anodization

TiO2 has emerged as an excellent photocatalyst over the last few decades. TiO2 based photocatalysts find application in pollutant control, dye degradation, self-sterilizing coatings, self-cleaning materials, and so on. The present work focuses on the development of TiO2 coatings on a commercially pure titanium substrate (cp-Ti) with a nanotubular morphology by the process of anodization and aims to characterize the coatings formed and to study the effect of anodization process parameters (voltage, time and electrolyte concentration) on the morphology of the coatings. The anodization circuit consists of the cp-Ti sample as the anode, a platinum cathode, and an organic electrolyte with fluoride ions. The base electrolyte used in this work was a 9:1 by volume mixture of ethylene glycol and H2O. Experiments were conducted at combinations of 25 V, 30 V, and 40 V at 1 h and 1.5 h. The coated samples were heat-treated at 500 °C for 1 h in ambient conditions. The thickness of the coatings was measured, after which FESEM was performed to study the morphology of the coatings formed. The phases present in the coating were studied using XRD. The bandgap of the samples was measured using UV–Vis diffuse reflectance spectrometry. The FESEM images clearly showed the formation of a nanotubular coating. The diameters of the tubes increased with an increase in the voltage while the XRD results confirmed the presence of the anatase TiO2 phase.

High performance acid–base junction flow batteries using an asymmetric bipolar membrane with an ion-channel aligned anion exchange layer

An acid–base junction flow battery (ABJFB) is a new type of energy conversion system using neutralization and water dissociation in the presence of acid and base electrolytes.

Вплив складу електроліту на характеристики синтезованого під час твердого анодування алюмінію оксидного шару

The aim of the study. By introducing strong oxidizers to the electrolyte form anode layers on the surface of aluminum with increased mechanical characteristics. To determine the effect of the duration of the formation of an anode layer to change its properties. Hard anodizing was performed at a temperature of –4...0C for 60 min. A 20% aqueous solution of H2SO4 was used as the base electrolyte. During anodizing, the current density was 5 A/dm2. To determine the effect of strong oxidants on the characteristics of the anode layers (oxide), 30 were added to the electrolyte; 50; 70 and 100 г/лof hydrogen peroxide (H2O2). In some cases, it was purged with an ozone-air mixture at a rate of 5 mgmin/l of ozone. It was found that the oxide layer (Al2O3H2O) during hard anodizing on aluminium alloys forms not only oxygen ions, which are formed by the decomposition of water, but also neutral oxygen atoms, which are formed by the decomposition of hydrogen peroxide and ozone. It was found that hydrogen peroxide, as well as blowing the electrolyte with an air-ozone mixture increase the thickness and microhardness of the anodized layer by 50% due to the reduction of the number of water molecules in alumina by half. Hydrogen peroxide and ozone apparently also reduce the thickness of the barrier layer of the coating, through which oxygen and aluminium ions penetrate and which, when combined, form an oxide layer. Conclusions. 1. It has been established that aluminum anodizing for 60 minutes. provides an increase in its properties. Changing the composition of the electrolyte contributes to the growth of microhardness in 1.2 ... 1.7 times. The resistance of abrasive wear increases with the content of different amounts of applications in the electrolyte and the maximum is at 30 g / l H2O2. Blowing the base electrolyte ozone provides an increase in the microhardness of the layer from 380 to 510 HV. The higher loss of mass for higher microhardness is caused by an increase in porosity of coatings. 2. It is determined that an increase in the anodization time in the baseline electrolyte to 120 and 180 minutes contributes to the growth of microhardness to 640 HV compared to an anodized layer for 60 minutes. Loss of mass in the study of abrasive wear is less than 3-4 times with longer anodation than at 60 minutes in the baseline electrolyte.

Effect of electron irradiation on the crystallite size, grain size and band gap energy of electrodeposited cadmium sulfide thin films

Here, cadmium sulfide (CdS) thin films have been prepared by electrodeposition method using aqueous basic electrolyte. The electrodeposition of CdS thin films has been carried out by varying the concentrations. The deposition potential of the compound was studied by cyclic voltammetry. The as-deposited and irradiated CdS thin films were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), and optical absorption technique for different bath concentration. The XRD shows multi crystalline phases having (110) major peak. The band gap was found to be 2.3 and 2.4 eV was as deposited and irradiated flim. The layers were subjected to irradiation with 6 MeV electrons.

A facile, inexpensive and green electrochemical sensor for sensitive detection of imidacloprid residue in rice using activated electrodes.

The development of sensitive, facile, cost-effective and eco-friendly sensors is essential for monitoring imidacloprid (IDP) residue on a large scale. Compared with popular modification of electrodes with advanced materials, electrochemical activation is promising at this point. In this paper, we found that strongly basic electrolytes (e.g. KOH and K3PO4) and applying cyclic potential during the activating process are beneficial to greatly amplify the electro-reduction response of IDP by nearly 16 times. Combining the characterization of activated electrodes with electrochemical behavior analysis of IDP, it is speculated that specific oxygen-contained functional groups were formed to bond with IDP molecules, leading to fast electron transfer kinetics. Then a sensitive IDP sensor has been developed with a low limit of detection (LOD) of 0.03 μM in the range of 0.1-100 μM. The methodological evaluation including reproducibility, stability and recovery has been also carefully studied, verifying the potential of proposed activated electrodes for application in rice samples.