scholarly journals Characterization of Pure Face-Shear Strain in Piezoelectric α-Tellurium Dioxide (α-TeO2)

Crystals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 939
Author(s):  
Guillaume Boivin ◽  
Pierre Bélanger ◽  
Ricardo J. Zednik
Keyword(s):  
Piezoelectric Coefficient ◽  
Microelectromechanical Systems ◽  
Electrochemical Impedance ◽  
Symmetry Class ◽  
Tellurium Dioxide ◽  
Considerable Uncertainty ◽  
Mems Actuators ◽  
Novel Applications ◽  
Piezoelectric Behavior ◽  
First Time

Paratellurite, also known as α-tellurium dioxide, is a ceramic that is primarily employed for its interesting optical properties. However, this material’s crystal structure belongs to the 422 symmetry class that allows a unique piezoelectric behavior to manifest itself: deformation in pure face-shear. This means that crystal symmetry necessitates the piezoelectric tensor to have only a single non-zero coefficient, d123 = d14: such unique behavior has the potential to enable novel gyroscopic sensors and high-precision torsional microelectromechanical systems (MEMS) actuators, as pure face-shear can be used to induce pure torsion. Although α-TeO2 is one of the few known materials belonging to this symmetry class, considerable uncertainty in its single piezoelectric coefficient exists, with the few reported literature values ranging from 6.13 to 14.58 pC/N; this large uncertainty results from the difficulty in using conventional piezoelectric characterization techniques on paratellurite, limiting measurements to indirect methods. The novel applications that would be enabled by the adoption of this extraordinary material are frustrated by this lack of confidence in the literature. We therefore leverage, for the first time, a first-principles analytical physical model with electrochemical impedance spectroscopy (EIS) to determine, directly, the lone piezoelectric coefficient d123 = d14 = 7.92 pC/N.

Torsional Piezoelectric Strain in Monocrystalline Paratellurite

2016 ◽  
Vol 879 ◽  
pp. 637-641 ◽  
Author(s):  
Guillaume Boivin ◽  
Pierre Bélanger ◽  
Ricardo J. Zednik
Keyword(s):  
Electrochemical Impedance ◽  
Three Dimensional ◽  
Alpha Phase ◽  
Symmetry Class ◽  
Large Uncertainty ◽  
Mems Actuators ◽  
Piezoelectric Strain ◽  
Piezoelectric Behavior ◽  
Doppler Interferometer ◽  
Excitation Conditions

Crystals of the 422 symmetry class exhibit interesting piezoelectric behavior, as their piezoelectric tensor has only a single non-zero coefficient, d123 = d14: such unique behavior has the potential to enable novel gyroscopic sensors and high-precision torsional MEMS actuators. Although alpha-phase tellurium dioxide (paratellurite, alpha-TeO2) is one of the few materials belonging to this symmetry class, this material has been primarily studied for its interesting optical properties. Indeed, a large uncertainty in the piezoelectric coefficient of paratellurite exists, with d123 measurements on single crystals ranging from 8.13 pC/N to 14.58 pC/N; this large uncertainty results from the difficulty in using conventional piezoelectric characterization techniques on paratellurite, and impedes adoption of this extraordinary material. The present study characterizes the piezoelectric behavior of this interesting material using two independent techniques, (1) a three dimensional laser Doppler interferometer system, and (2) electrochemical impedance spectroscopy (EIS). The experimental results are analyzed using numerical simulations for dynamic excitation conditions over a frequency range of 20 Hz to 200 kHz.

scholarly journals Protection of Petroleum Pipeline Carbon Steel Alloys with New Modified Core-Shell Magnetite Nanogel against Corrosion in Acidic Medium

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Gamal A. El Mahdy ◽  
Ayman M. Atta ◽  
Amro K. F. Dyab ◽  
Hamad A. Al-Lohedan
Keyword(s):  
Carbon Steel ◽  
Sulfonic Acid ◽  
Electrochemical Impedance ◽  
Electrochemical Techniques ◽  
Core Shell ◽  
Magnetite Nanoparticle ◽  
Potassium Peroxydisulfate ◽  
Redox Initiator ◽  
Initiator System ◽  
First Time

New method was used to prepare magnetite nanoparticle based on reduction of Fe(III) ions with potassium iodide to produce Fe3O4nanoparticle. The prepared magnetite was stabilized with cross-linked polymer based on 2-acrylamido-2-methylpropane sulfonic acid (AMPS to prepare novel core-shell nanogel. In this respect, Fe3O4/poly(2-acrylamido-2-methylpropane sulfonic acid) (PAMPS) magnetic nanogels with controllable particle size produced via free aqueous polymerization at 65°C have been developed for the first time. The polymer was crosslinked in the presence of N,N-methylenebisacrylamide (MBA) as a crosslinker and potassium peroxydisulfate (KPS) as redox initiator system. The structure and morphology of the magnetic nanogel were characterized by Fourier transform infrared spectroscopy (FTIR) and transmission and scanning electron microscopy (TEM and SEM). The effectiveness of the synthesized compounds as corrosion inhibitors for carbon steel in 1 M HCl was investigated by various electrochemical techniques such as potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The results showed enhancement in inhibition efficiencies with increasing the inhibitor concentrations. The results showed that the nanogel particles act as mixed inhibitors. EIS data revealed thatRctincreases with increasing inhibitor concentration.

scholarly journals A High Capacity, Room Temperature, Hybrid Flow Battery Consisting of Liquid Na-Cs Anode and Aqueous NaI Catholyte

Batteries ◽  
2018 ◽  
Vol 4 (4) ◽  
pp. 60 ◽  
Author(s):  
Caihong Liu ◽  
Leon Shaw
Keyword(s):  
Room Temperature ◽  
Electrochemical Impedance ◽  
Coulombic Efficiency ◽  
High Capacity ◽  
High Energy ◽  
Flow Battery ◽  
Membrane Interfaces ◽  
Number Of Cycles ◽  
Novel Concept ◽  
First Time

In this study, we have proposed a novel concept of hybrid flow batteries consisting of a molten Na-Cs anode and an aqueous NaI catholyte separated by a NaSICON membrane. A number of carbonaceous electrodes are studied using cyclic voltammetry (CV) for their potentials as the positive electrode of the aqueous NaI catholyte. The charge transfer impedance, interfacial impedance and NaSICON membrane impedance of the Na-Cs ‖ NaI hybrid flow battery are analyzed using electrochemical impedance spectroscopy. The performance of the Na-Cs ‖ NaI hybrid flow battery is evaluated through galvanostatic charge/discharge cycles. This study demonstrates, for the first time, the feasibility of the Na-Cs ‖ NaI hybrid flow battery and shows that the Na-Cs ‖ NaI hybrid flow battery has the potential to achieve the following properties simultaneously: (i) An aqueous NaI catholyte with good cycle stability, (ii) a durable and low impedance NaSICON membrane for a large number of cycles, (iii) stable interfaces at both anode/membrane and cathode/membrane interfaces, (iv) a molten Na-Cs anode capable of repeated Na plating and stripping, and (v) a flow battery with high Coulombic efficiency, high voltaic efficiency, and high energy efficiency.

scholarly journals Electrochemical Impedance of Hydrogenated Phases of ZnO and CuO Nanoparticles for Electrode Applications

2020 ◽  
pp. 1-6
Author(s):  
L. I. Menegbo ◽  
J. L. Konne ◽  
N. Boisa
Keyword(s):  
Electrochemical Impedance ◽  
Sol Gel ◽  
Low Frequency ◽  
High Gain ◽  
High Frequency Region ◽  
Nyquist Plots ◽  
Eis Measurements ◽  
Xrd Patterns ◽  
Straight Lines ◽  
First Time

The Electrochemical Impedance Spectroscopy (EIS) measurements of Sol-gel synthesized ZnO, CuO and their respective hydrogenated phases (ZnO:H and CuO:H) for  a proton-type battery model has been reported for the first time. The XRD patterns confirmed that CuO and ZnO were phase pure with minor impurities. However, that of CuO:H showed mixed phases of CuO and Cu2O with the later  appearing prominent. The estimated particle sizes of ZnO, ZnO:H, CuO and CuO:H obtained using Scherrers’ equation were 17.83, 17.75, 21.63 and 15.42 nm respectively, showing remarkable particle size reductions upon hydrogenation as oxygen vacancies were substituted with smaller hydrogen ions. Nyquist plots from the EIS experimental data recorded over a frequency range of 100 kHz – 5 mHz showed expected flat semicircles at the high frequency region and straight lines at the low frequency regions while resistance estimations from the intercepts of the Bode plots were 12.10, 7.80, 16.00 and 10.80 Ω for ZnO, ZnO:H, CuO and CuO:H respectively. It also indicated high gain margins suggesting impressive electrochemical properties for battery applications.

scholarly journals Evaluation of the Corrosion Resistance of WC-Co Coating on AZ91 Applied by Electro Spark Deposition

2020 ◽  
Vol 20 (1) ◽  
pp. 30-40
Author(s):  
Arvin Taghizadeh Tabrizi ◽  
Maryam Pouzesh ◽  
Farhad Farhang Laleh ◽  
Hossein Aghajani
Keyword(s):  
Corrosion Rate ◽  
Room Temperature ◽  
Electrochemical Impedance ◽  
Bulk Sample ◽  
Az91 Alloy ◽  
Corrosion Performance ◽  
Surface Microhardness ◽  
Optimum Parameters ◽  
Temperature Polarization ◽  
First Time

Abstract In order to enhance the surface properties of a magnesium-based substrate, WC-Co coating was applied on AZ91 alloy by electro spark deposition (ESD), successfully for the first time. The optimum parameters of the ESD process were achieved, based on the corrosion behavior and calculated corrosion rate of the coated samples when 5kHz and 25 A were chosen. For evaluation of the corrosion performance of the achieved WC-Co layers, polarization, and electrochemical impedance spectroscopy tests were carried out in the 3.5 wt % Na3PO4 solution at room temperature. Polarization results show that the corrosion rate (mpy) is in the optimum condition almost half of a bulk sample of uncoated AZ91. Field emission scanning electron microscopy (FE-SEM) was used to examine the surface morphology of applied coatings. These results show that at a lower current, the amount of deposited WC-Co was reduced. The maximum surface microhardness obtained was 193 HV0.2.

One-Pot Electrodeposition of NiS Nanoparticles as an Efficient Electrode for Nonenzymatic H2O2 and Glucose Sensors

NANO ◽  
2019 ◽  
Vol 14 (01) ◽  
pp. 1950010
Author(s):  
Zhiheng Huang ◽  
Chunchuan Gu ◽  
Jiajun Wen ◽  
Langlang Zhu ◽  
Mingzhen Zhang ◽  
...  
Keyword(s):  
Metal Ion ◽  
Electrochemical Impedance ◽  
Glucose Sensors ◽  
Cyclic Voltammograms ◽  
Impedance Spectra ◽  
Electrochemical Impedance Spectra ◽  
One Pot ◽  
X Ray ◽  
First Time ◽  
Nis Nanoparticles

In this paper, a new and one-pot electrodeposition method was expanded for the preparation of NiS nanoparticles-based electrochemical biosensor using metal-ion complexes as a precursor. Thioacetamide was used to control the production rate of NiS nanoparticles for the first time. The proposed electrochemical sensor was characterized by energy dispersive X-ray spectroscopy (EDX), field emission scanning electron microscope (FESEM), cyclic voltammograms (CV), and electrochemical impedance spectra (EIS). Experiment parameters were optimized. Under the optimized condition, the prepared NiS-based biosensor exhibited excellent electrocatalytic oxidation of H2O2 and glucose due to their small size. It provided fast and sensitive strategy for detecting H2O2 and glucose in the range of 1–5000 and 1–1000[Formula: see text][Formula: see text]M. The detection limit of 0.257 and 0.3[Formula: see text][Formula: see text]M was obtained for H2O2 and glucose. The mechanisms were also analyzed. The proposed biosensor exhibited excellent anti-interference and repeatability. Furthermore, it was applied in the actual sample analysis, such as human blood serum.

Electrochemical pesticide sensor based on Langmuir–Blodgett film of cobalt phthalocyanine-anthraquinone hybrid

2015 ◽  
Vol 19 (05) ◽  
pp. 708-718 ◽  
Author(s):  
Yeliz İpek ◽  
M. Kasım Şener ◽  
Atıf Koca
Keyword(s):  
Electrochemical Impedance ◽  
Measurement Techniques ◽  
Modified Electrodes ◽  
Cobalt Phthalocyanine ◽  
Blodgett Film ◽  
Langmuir Blodgett ◽  
Lb Film ◽  
Electrochemical Catalyst ◽  
Nano Gold ◽  
First Time

A cathode active and selective pesticide electrochemical sensor based on Langmuir–Blodgett (LB) film of cobalt phthalocyanine-anthraquinone hybrid (CoPc-AQ) was constructed for the first time in this study. Cobalt-based, Pc ring-based, and anthraquinone-based reduction processes of CoPc-AQ indicated suitability of the complex as a possible electrochemical catalyst and sensor for detection of target species. LB film of CoPc-AQ on ITO (ITO/CoPc-AQ electrode) was titrated with eserine and carbofuran pesticides and interaction of the electrode with these pesticides was tested with square wave voltammetry (SWV), electrochemical impedance spectroscopy (EIS), and double potential step chronocoulometry (DPSCC) techniques. ITO/CoPc-AQ electrode selectively sensed carbofuran and eserine pesticides. While ITO/CoPc-AQ electrode senses carbofuran with the voltammetric responses recorded at anodic potentials (1.20 V), eserine sensing affected antraquinone based reduction peaks recorded at cathodic potentials (-0.80 V). Modification of ITO/CoPc-AQ electrode with nano-platinum and nano-gold particles (ITO/CoPc-AQ-n Pt and ITO/CoPc-AQ-n Au ) increased the sensitivity of the electrode. All basic sensor parameters of modified electrodes were derived with different measurement techniques and compared with each other. The lowest detection limit (2.30 × 10-9 M) was recorded with EIS techniques on ITO/CoPc-AQ-n Pt electrode for sensing of eserine.

A Direct Comparison of Glassy Carbon and PEDOT-PSS Electrodes for High Charge Injection and Low Impedance Neural Interfaces

2016 ◽  
Vol 102 ◽  
pp. 68-76 ◽  
Author(s):  
Maria Vomero ◽  
Elisa Castagnola ◽  
Emma Maggiolini ◽  
Francesca Ciarpella ◽  
Irene Rembado ◽  
...  
Keyword(s):  
Electrochemical Performance ◽  
Glassy Carbon ◽  
Cultured Cells ◽  
Electrochemical Impedance ◽  
Neural Interfaces ◽  
Somatosensory Stimulation ◽  
Brain Surface ◽  
First Time

For neural applications, materials able to interface with the brain without harming it while recording high-fidelity signals over long-term implants are still sought after. Glassy Carbon (GC) and Poly (3,4-ethylenedioxythiophene)-poly (styrenesulfonate) (PEDOT-PSS) have proved to be promising materials for neural interfaces as they show – compared to conventional metal electrodes - higher conductivity, better electrochemical stability, very good mechanical properties and therefore seem to be very promising for in vivo applications. We present here, for the first time, a direct comparison between GC and PEDOT-PSS microelectrodes in terms of biocompatibility, electrical and electrochemical properties as well as in vivo recording capabilities, using electrocorticography microelectrode arrays located on flexible polyimide substrate. The GC microelectrodes were fabricated using a traditional negative lithography processes followed by pyrolysis. PEDOT-PSS was selectively electrodeposited on the desired electrodes. Electrochemical performance of the two materials was evaluated through electrochemical impedance spectroscopy and cyclic voltammetry. Biocompatibility was assessed through in-vitro studies evaluating cultured cells viability. The in vivo performance of the GC and PEDOT-PSS electrodes was directly compared by simultaneously recording neuronal activity during somatosensory stimulation in Long-Evans rats. We found that both GC and PEDOT-PSS electrodes outperform metals in terms of electrochemical performance and allow to obtain excellent recordings of somatosensory evoked potentials from the rat brain surface. Furthermore, we found that both GC and PEDOT-PSS substrates are highly biocompatible, confirming that they are safe for neural interface applications.

Reactivity of carbon black diamond electrode during the electro-oxidation of Remazol Brilliant Blue R

RSC Advances ◽  
2016 ◽  
Vol 6 (5) ◽  
pp. 3690-3699 ◽  
Author(s):  
Mohammed A. Ajeel ◽  
Mohamed Kheireddine Taeib Aroua ◽  
Wan Mohd Ashri Wan Daud
Keyword(s):  
Cyclic Voltammetry ◽  
Carbon Black ◽  
Electrochemical Impedance ◽  
Brilliant Blue ◽  
Remazol Brilliant Blue R ◽  
Diamond Electrode ◽  
Electro Oxidation ◽  
First Time

This article reports for the first time, the reactivity of Carbon Black Diamond (CBD) electrode using cyclic voltammetry and electrochemical impedance techniques in 0.25 M H2SO4 solution containing 0.5 mM K4Fe(CN)6.

SPINEL Li2MTi3O8(M = Mg, Mg0.5Zn0.5) NANOWIRES WITH ENHANCED ELECTROCHEMICAL LITHIUM STORAGE

2011 ◽  
Vol 04 (01) ◽  
pp. 65-69 ◽  
Author(s):  
ZHENSHENG HONG ◽  
TONGBIN LAN ◽  
YONGZAN ZHENG ◽  
LILONG JIANG ◽  
MINGDENG WEI
Keyword(s):  
Solid State ◽  
Anode Materials ◽  
Electrochemical Impedance ◽  
Impedance Spectra ◽  
Li Ion Battery ◽  
Lithium Storage ◽  
Electrochemical Impedance Spectra ◽  
Titanate Nanowires ◽  
Li Ion ◽  
First Time

Spinel structural Li2MTi3O8 ( M = Mg, Mg0.5Zn0.5 ) nanowires have been successfully synthesized using titanate nanowires as a precursor and then have been used for the first time as anode materials in a rechargeable Li -ion battery. The cell composed of Li2MgTi3O8 nanowires exhibited a discharge capacity of 232 mAhg-1 at the second cycle, while only 159 mAhg-1 was obtained for the bulk prepared by a solid state reaction. The results of electrochemical impedance spectra indicate that spinel structural Li2MTi3O8 ( M = Mg, Mg0.5Zn0.5 ) nanowires can significantly reduce the charge transfer impedance, leading to enhanced capability of electrochemical lithium storage.

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