Ultrasensitive Electrochemical Impedance Detection of Mycoplasma agalactiae DNA by Low-Cost and Disposable Au-Decorated NiO Nanowall Electrodes

2020 ◽  
Vol 12 (44) ◽  
pp. 50143-50151 ◽  
Author(s):  
Mario Urso ◽  
Serena Tumino ◽  
Elena Bruno ◽  
Salvo Bordonaro ◽  
Donata Marletta ◽  
...  
Keyword(s):  
Electrochemical Impedance ◽  
Low Cost ◽  
Mycoplasma Agalactiae

Improvement of Ti/RuO2–IrO2 Anode Lifetime and Electrocatalytical Properties by Using an Eco-Friendly Thermal Decomposition Method Using Polyvinyl Alcohol as Solvent

2019 ◽  
Author(s):  
Charlys Bezerra ◽  
Géssica Santos ◽  
Marilia Pupo ◽  
Maria Gomes ◽  
Ronaldo Silva ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Polyvinyl Alcohol ◽  
High Efficiency ◽  
Electrochemical Impedance ◽  
Pechini Method ◽  
Low Cost ◽  
Charge Transfer Resistance ◽  
Transfer Resistance ◽  
Calcination Temperatures ◽  
Service Lifetime

<p>Electrochemical oxidation processes are promising solutions for wastewater treatment due to their high efficiency, easy control and versatility. Mixed metal oxides (MMO) anodes are particularly attractive due to their low cost and specific catalytic properties. Here, we propose an innovative thermal decomposition methodology using <a>polyvinyl alcohol (PVA)</a> as a solvent to prepare Ti/RuO<sub>2</sub>–IrO<sub>2</sub> anodes. Comparative anodes were prepared by conventional method employing a polymeric precursor solvent (Pechini method). The calcination temperatures studied were 300, 400 and 500 °C. The physical characterisation of all materials was performed by X-ray diffraction and scanning electron microscopy coupled with energy dispersive spectroscopy, while electrochemical characterisation was done by cyclic voltammetry, accelerated service lifetime and electrochemical impedance spectroscopy. Both RuO<sub>2</sub> and IrO<sub>2</sub> have rutile-type structures for all anodes. Rougher and more compact surfaces are formed for the anodes prepared using PVA. Amongst temperatures studied, 300 °C using PVA as solvent is the most suitable one to produce anodes with expressive increase in voltammetric charge (250%) and accelerated service lifetime (4.3 times longer) besides reducing charge-transfer resistance (8 times lower). Moreover, the electrocatalytic activity of the anodes synthesised with PVA toward the Reactive Blue 21 dye removal in chloride medium (100 % in 30 min) is higher than that prepared by Pechini method (60 min). Additionally, the removal total organic carbon point out improved mineralisation potential of PVA anodes. Finally, this study reports a novel methodology using PVA as solvent to synthesise Ti/RuO<sub>2</sub>–IrO<sub>2</sub> anodes with improved properties that can be further extended to synthesise other MMO compositions.</p>

scholarly journals A Facile and Green Synthesis of a MoO2-Reduced Graphene Oxide Aerogel for Energy Storage Devices

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 594 ◽  
Author(s):  
Mara Serrapede ◽  
Marco Fontana ◽  
Arnaud Gigot ◽  
Marco Armandi ◽  
Glenda Biasotto ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Chemical Reduction ◽  
Low Cost ◽  
Xps Analysis ◽  
3D Scaffold ◽  
Energy Storage Devices ◽  
Reduced Graphene

A simple, low cost, and “green” method of hydrothermal synthesis, based on the addition of l-ascorbic acid (l-AA) as a reducing agent, is presented in order to obtain reduced graphene oxide (rGO) and hybrid rGO-MoO2 aerogels for the fabrication of supercapacitors. The resulting high degree of chemical reduction of graphene oxide (GO), confirmed by X-Ray Photoelectron Spectroscopy (XPS) analysis, is shown to produce a better electrical double layer (EDL) capacitance, as shown by cyclic voltammetric (CV) measurements. Moreover, a good reduction yield of the carbonaceous 3D-scaffold seems to be achievable even when the precursor of molybdenum oxide is added to the pristine slurry in order to get the hybrid rGO-MoO2 compound. The pseudocapacitance contribution from the resulting embedded MoO2 microstructures, was then studied by means of CV and electrochemical impedance spectroscopy (EIS). The oxidation state of the molybdenum in the MoO2 particles embedded in the rGO aerogel was deeply studied by means of XPS analysis and valuable information on the electrochemical behavior, according to the involved redox reactions, was obtained. Finally, the increased stability of the aerogels prepared with l-AA, after charge-discharge cycling, was demonstrated and confirmed by means of Field Emission Scanning Electron Microscopy (FESEM) characterization.

scholarly journals Electrodeposition of Iridium-Nickel Thin Films on Copper Foam: Effects of Loading and Solution Temperature on HER Performance of Electrocatalyst in Alkaline Water

2020 ◽  
Author(s):  
Jianwen Liu ◽  
Wangping Wu ◽  
Xiang Wang
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Hydrogen Evolution ◽  
Electrocatalytic Activity ◽  
Electrochemical Impedance ◽  
Low Cost ◽  
Solution Temperature ◽  
High Deposition Rate ◽  
Hydrogen Energy ◽  
Copper Foam

Developing novel hydrogen evolution reaction (HER) catalysts with high activity, high stability and low cost is of great importance for the applications of hydrogen energy. In this work, iridium-nickel (Ir-Ni) thin films were electrodeposited on a copper foam as electrocatalyst for HER, and electrodeposition mechanism of Ir-Ni film was studied. The morphology and chemical composition of thin films were determined by scanning electron microscopy and energy-dispersive spectroscopy, respectively. The electrocatalytic performances of the films were estimated by linear sweep voltammograms, electrochemical impedance spectroscopy and cyclic voltammetry. The results show that Ir-Ni thin films were attached to the substrate of porous structure and hollow topography. The deposition of Ni was preferable in the electrolyte without the addition of additives, and Ir-Ni thin film was alloyed, resulting in high deposition rate for Ir42Ni58 thin film, and subsequently an increase of Ir content in the thin films of Ir80Ni20 and Ir88Ni12. Ir-Ni thin films with Tafel slopes of 40-49 mV·dec-1 exhibited highly efficient electrocatalytic activity for HER. The electrocatalytic activity of Ir-Ni thin films showed a loading dependence. As the solution temperature raised from 20 oC to 60 oC, the hydrogen evolution performance of Ir-Ni thin films improved. The apparent activation energy value of Ir88Ni12 film was 7.1 kJ·mol-1. Long-term hydrogen evolution tests exhibited excellent electrocatalystic stability in alkaline solution.

scholarly journals The influence of chromium as a diffusive additive in the boronizing treatment of AISI 4140 steel on the corrosion resistance of the coating evaluated by Electrochemical Impedance Spectroscopy (EIS)

2020 ◽  
Vol 318 ◽  
pp. 01040
Author(s):  
Dimitrios I. Zagkliveris ◽  
Azarias Mavropoulos ◽  
Efstathios Ntovinos ◽  
Georgios K. Triantafyllidis
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Low Cost ◽  
Industrial Applications ◽  
Pack Cementation ◽  
Boride Phase ◽  
Corrosion Resistant ◽  
Aisi 4140 Steel ◽  
Aisi 4140

A large variety of protective coating is being used in industrial applications to improve the resistance of the metallic substrates against corrosion. The pack-cementation method for boronizing and borochromizing is effective to produce extremely hard and corrosion resistant thick coatings and, additionally, is a low-cost and simple technique. In the present study, AISI 4140 steel specimens underwent boronizing and afterwards chromizing by the pack-cementation method using B4C as boron source and Fe-Cr as chromium source, respectively. In both treatments the appropriate activators were used. After chromizing the boronized substrate, a mixed boride phase FeCrB was formed, as it was confirmed by X-ray Diffractometry (XRD). The boronized and the borochromized specimens were subjected to Electrochemical Impedance Spectroscopy (EIS). From the analysis of the frequency response of the coating systems (Bode and Nyquist display), the conclusion that the borochromized specimens were significantly more corrosion resistant was extracted. Finally, data of optical and electron microscopy contribute to the validity of the conclusions.

scholarly journals Dependence of Capacitive Properties of an EDLC on Exfoliation Time of Graphite Electrodes

2021 ◽  
Author(s):  
Dinithi S. K. Rajaguru ◽  
Kamal Vidanapathirana ◽  
Kumudu S. Perera
Keyword(s):  
Electrochemical Impedance ◽  
Low Cost ◽  
Gel Polymer Electrolyte ◽  
Storage Device ◽  
Graphite Electrodes ◽  
Discharge Capacitance ◽  
Capacitive Properties ◽  
Device Applications ◽  
Specific Discharge ◽  
Electrochemical Double Layer

Abstract The scientific focus has been directed through the production and application of ‘wonder material- graphene’ after its discovery in 2004. But the mass production cost has become a huge disadvantage towards commercializing graphene based manufactures. As alternative low cost material, exfoliated graphite (EG) has emerged to be a novel nanostructured carbon material with a potential for electrochemical energy storage device applications owed to its unique characteristics similar to graphene. In this study a series of EG samples were prepared by a surfactant mediated liquid phase exfoliation method by changing the exfoliation time. Electrochemical double layer capacitors (EDLCs) were fabricated using different EG samples as an electrode material and a gel polymer electrolyte (GPE). They were characterized by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and galvanostatic charge discharge (GCD) techniques. EDLC having EG electrodes of 10 h exfoliation time showed the highest results with single electrode specific capacitance (Csc) of 4.12 F g− 1, single electrode specific discharge capacitance (Csd) of 1.10 F g− 1 and relaxation time of 0.22 s from CV, GCD and EIS respectively.

Design of Automatic Measurement System of Lithium Battery Electrochemical Impedance Spectroscopy Based on Microcomputer

2012 ◽  
Vol 241-244 ◽  
pp. 259-264 ◽  
Author(s):  
Wang Li ◽  
Gen Wang Liu ◽  
Fu He Yang
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
High Precision ◽  
Measurement System ◽  
Lithium Battery ◽  
Electrochemical Impedance ◽  
Low Cost ◽  
Automatic Measurement ◽  
Response Curves ◽  
High Level

A system of miniaturized lithium battery electrochemical impedance spectroscopy (EIS) measurement is designed with high precision impedance converter chip AD5933 as its core. The measurement range of the system is from 0.010Hz to 100 KHz. Meanwhile, by using a high-level programming language of C#, an interface is developed which can real-time graphic display of EIS information. Through measurement and analysis of two types of impedance, the results show that detection precision of the system is less than 3.5%. Finally, amplitude-frequency response curves and Nyquist plots of HL-18650 M lithium battery at different state of charge (SOC) levels are measured. Compared with lithium battery EIS measurement system by traditional division, this system has the outstanding advantages of small size, high level of integration, low cost, simple operation and high precision. It is helpful to the mass production and application of lithium battery EIS measurement system.

scholarly journals A Facile Fabrication of a Potentiometric Arrayed Glucose Biosensor Based on Nafion-GOx/GO/AZO

Sensors ◽  
2020 ◽  
Vol 20 (4) ◽  
pp. 964
Author(s):  
Jung-Chuan Chou ◽  
Si-Hong Lin ◽  
Tsu-Yang Lai ◽  
Po-Yu Kuo ◽  
Chih-Hsien Lai ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Electrochemical Impedance ◽  
Limit Of Detection ◽  
Low Cost ◽  
Glucose Biosensor ◽  
Average Sensitivity ◽  
Glucose Biosensors ◽  
Coating Method ◽  
Aluminum Doped Zinc Oxide ◽  
Screen Printing Technology

In this study, the potentiometric arrayed glucose biosensors, which were based on zinc oxide (ZnO) or aluminum-doped zinc oxide (AZO) sensing membranes, were fabricated by using screen-printing technology and a sputtering system, and graphene oxide (GO) and Nafion-glucose oxidase (GOx) were used to modify sensing membranes by using the drop-coating method. Next, the material properties were characterized by using a Raman spectrometer, a field-emission scanning electron microscope (FE-SEM), and a scanning probe microscope (SPM). The sensing characteristics of the glucose biosensors were measured by using the voltage–time (V-T) measurement system. Finally, electrochemical impedance spectroscopy (EIS) was conducted to analyze their charge transfer abilities. The results indicated that the average sensitivity of the glucose biosensor based on Nafion-GOx/GO/AZO was apparently higher than that of the glucose biosensor based on Nafion-GOx/GO/ZnO. In addition, the glucose biosensor based on Nafion-GOx/GO/AZO exhibited an excellent average sensitivity of 15.44 mV/mM and linearity of 0.997 over a narrow range of glucose concentration range, a response time of 26 s, a limit of detection (LOD) of 1.89 mM, and good reproducibility. In terms of the reversibility and stability, the hysteresis voltages (VH) were 3.96 mV and 2.42 mV. Additionally, the glucose biosensor also showed good anti-inference ability and reproducibility. According to these results, it is demonstrated that AZO is a promising material, which could be used to develop a reliable, simple, and low-cost potentiometric glucose biosensor.

scholarly journals Diazonium-Modified Screen-Printed Electrodes for Immunosensing Growth Hormone in Blood Samples

Biosensors ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 88 ◽  
Author(s):  
Nan Li ◽  
Ari M. Chow ◽  
Hashwin V. S. Ganesh ◽  
Melanie Ratnam ◽  
Ian R. Brown ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Low Cost ◽  
High Sensitivity ◽  
Sample Volume ◽  
Screening Methods ◽  
Serum Samples ◽  
Potential Applicability ◽  
Screen Printed

Altered growth hormone (GH) levels represent a major global health challenge that would benefit from advances in screening methods that are rapid and low cost. Here, we present a miniaturized immunosensor using disposable screen-printed carbon electrodes (SPCEs) for the detection of GH with high sensitivity. The diazonium-based linker layer was electrochemically deposited onto SPCE surfaces, and subsequently activated using covalent agents to immobilize monoclonal anti-GH antibodies as the sensing layer. The surface modifications were monitored using contact angle measurements and X-ray photoelectron spectroscopy (XPS). The dissociation constant, Kd, of the anti-GH antibodies was also determined as 1.44 (±0.15) using surface plasmon resonance (SPR). The immunosensor was able to detect GH in the picomolar range using a 20 µL sample volume in connection with electrochemical impedance spectroscopy (EIS). The selectivity of the SPCE-based immunosensors was also challenged with whole blood and serum samples collected at various development stages of rats, demonstrating the potential applicability for detection in biological samples. Our results demonstrated that SPCEs provided the development of low-cost and single-use electrochemical immunosensors in comparison with glassy carbon electrode (GCE)-based ones.

Corrosion protection performance of titania nanoparticles filled poly(4-methyl-5-vinylthiazole) applied on mild steel in 3.5% sodium chloride solution

2020 ◽  
pp. 875608792093930 ◽  
Author(s):  
I Pugazhenthi ◽  
S Mohammed Ghouse
Keyword(s):  
Mild Steel ◽  
Electrochemical Impedance ◽  
Low Cost ◽  
Nano Particles ◽  
Titania Nanoparticles ◽  
X Ray Diffraction ◽  
Corrosive Media ◽  
X Ray ◽  
Polymer Hybrid ◽  
Transmission Electron

Mild steel materials have wide applications in marine construction, because they are low cost, available and easy to handle. However, they have to be protected from corrosive media by coating with polymer hybrid materials. This paper focuses on the anticorrosive properties of poly(4-methyl-5-vinylthiazole) PVTZ coatings on mild steel. Further the coating resistance is enhanced by incorporating Titania Nano particles (TiO2NPs). The nanoparticles were evaluated using X-ray diffraction studies (XRD) and transmission electron microscopy (TEM). PVTZ and its TiO2 nanocomposite were coated on mild steel. Their anticorrosive behavior was analyzed by potentiodynamic polarization and electrochemical impedance spectroscopy in 3.5% (w/v) NaCl.

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