Fabrication and EIS Characterization of Titania Nanotube Arrays with Top Non-Tube Layer

TiO2nanotube arrays were fabricated in the electrolyte containing 0.25wt% NH4F, 2.5vol% water and the ethylene glycol for various hours at room temperature by anodization of Ti foil in this paper. Some anodized specimens were annealed at 450°C for 3 hours. Electrochemical Impedance Spectroscopy (EIS) was employed to measure electrochemical parameters of anodized specimens. The morphology and crystalline structure of anodized products were characterized by Field Emission Scanning Electronic Microscopy (FESEM), X-ray Diffraction (XRD) and Transmission Electronic Microscopy (TEM). A non-tube layer appears on nanotube arrays with the increase in anodization time. Anodized TiO2nanotube arrays have an amorphous structure, which transfers to anatase structure after annealing at 450°C. A new equivalent circuit R(CR(R(QR)(CR))) was proposed to fit EIS data. The results show that the charge transfer resistance at the electrode/electrolyte interface controls the electrochemical process of TiO2nanotubes.

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Effect of Zirconium Oxide Reinforcement on Microstructural, Electrochemical and Mechanical Properties of TiNi Alloy Produced Via Powder Metallurgy Route

Journal of Engineering Materials and Technology ◽

10.1115/1.4051308 ◽

2021 ◽

pp. 1-22

Author(s):

Syed Abbas Raza ◽

Muhammad Imran Khan ◽

Muhammad Ramzan Abdul karim ◽

Rashid Ali ◽

Muhammad Umair Naseer ◽

...

Keyword(s):

Electrochemical Impedance ◽

Passive Layer ◽

Charge Transfer Resistance ◽

Tini Alloy ◽

X Ray Diffraction ◽

Zro2 Content ◽

Transfer Resistance ◽

X Ray ◽

Conventional Sintering ◽

Layer Resistance

Abstract Equiatomic TiNi alloy composites, reinforced with 0, 5, 10 and 15 vol. % ZrO2, were synthesized using conventional sintering approach. Equiatomic TiNi pre-alloyed powder and ZrO2 powder were mixed in planetary ball mill for 6 hours followed by cold compaction and pressure-less sintering, respectively. The sintered density was found to vary inversely with the addition of ZrO2 content. The X-Ray diffraction spectra have shown the formation of multiple-phases which were resulted from the decomposition of the B19'and B2 phases of the equiatomic TiNi alloy due to the addition of ZrO2 and higher diffusion rate of Ni than that of Ti in the alloy composite. An increase in hardness was noted due to the addition of ZrO2, measured by micro and nanoindentation techniques. Potentiodynamic polarization scan revealed a 10% decrease in the corrosion rate of the composite containing 10 vol. % ZrO2. Electrochemical impedance spectroscopy results indicated an increase in passive layer resistance (Rcoat) due to the increase in charge transfer resistance (Rct) caused by the reduced leaching of ions from the surface.

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PREPARATION AND INVESTIGATION OF ELECTRODEPOSITED Ni–NANO-Cr2O3 COMPOSITE COATINGS

Surface Review and Letters ◽

10.1142/s0218625x15501115 ◽

2016 ◽

Vol 23 (02) ◽

pp. 1550111 ◽

Cited By ~ 3

Author(s):

JIBO JIANG ◽

CHENQI FENG ◽

WEI QIAN ◽

LIBIN YU ◽

FENGYING YE ◽

...

Keyword(s):

Electrochemical Impedance ◽

Composite Coatings ◽

Charge Transfer Resistance ◽

X Ray Diffraction ◽

Transfer Resistance ◽

X Ray ◽

Potentiodynamic Polarization Curves ◽

Nucleation Sites ◽

Passive Transition ◽

Steel Surfaces

The electrodeposition of Ni–nano-Cr2O3 composite coatings was studied in electrolyte containing different contents of Cr2O3 nanoparticles (Cr2O3 NPs) on mild steel surfaces. Some techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), microhardness, the potentiodynamic polarization curves (Tafel) and electrochemical impedance spectroscopy (EIS) were used to compare pure Ni coatings and Ni–nano-Cr2O3 composite coatings. The results show that the incorporation of Cr2O3 NPs resulted in an increase of hardness and corrosion resistance, and the maximum microhardness of Ni-nano-Cr2O3 composite coatings reaches about 495 HV. The coatings exhibit an active-passive transition and relatively large impedance values. Moreover, the effect of Cr2O3 NPs on Ni electrocrystallization is also investigated by cyclic voltammetry (CV) and EIS spectroscopy, which demonstrates that the nature of Ni-based composite coatings changes attributes to Cr2O3 NPs by offering more nucleation sites and less charge transfer resistance.

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PREPARATION AND CHARACTERIZATION OF A POLY(PYRROLYL METHANE)/MULTIWALLED CARBON NANOTUBES COMPOSITES

NANO ◽

10.1142/s179329201350063x ◽

2013 ◽

Vol 08 (06) ◽

pp. 1350063

Author(s):

JINXIAN LIN ◽

PAN WANG ◽

YUYING ZHENG

Keyword(s):

Electron Microscopy ◽

Carbon Nanotubes ◽

Multiwalled Carbon Nanotubes ◽

Electrochemical Impedance ◽

Charge Transfer Resistance ◽

Electrode System ◽

X Ray Diffraction ◽

Multiwalled Carbon ◽

Transfer Resistance ◽

Transmission Electron

A poly(pyrrolyl methane) (Poly[pyrrole-2, 5-diyl(4-methoxybenzylidane)], PPDMOBA)/multiwalled carbon nanotubes (MWNTs) composites are fabricated by in situ chemical polycondensation of pyrrole and 4-methoxybenzaldehyde on MWNTs. The structure, morphology, thermal stability and electrical property of the resulting composites are investigated via fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and a four-probe method. The electrochemical performance of the composites is determined in a three-electrode system using cyclic voltammetry (CV), galvanostatic charge–discharge (GCD) and electrochemical impedance spectroscopy (EIS) techniques. FTIR, FESEM and TEM confirm that the composites have been successfully prepared, and PPDMOBA is uniformly dispersed in MWNTs. Electrical conductivity of PPDMOBA/MWNTs composites is 1.39 S cm-1, which is significantly larger than that of pristine PPDMOBA. The specific capacitance and charge transfer resistance of the composites is 56 F g-1 (1 mA cm-2) and 0.3Ω, respectively.

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Preparation and electrochemical characterization of PANI/MnCo2O4 nanocomposite as supercapacitor electrode material

Canadian Journal of Chemistry ◽

10.1139/cjc-2017-0423 ◽

2018 ◽

Vol 96 (5) ◽

pp. 477-483 ◽

Cited By ~ 3

Author(s):

Saeid Panahi ◽

Moosa Es’haghi

Keyword(s):

Specific Capacitance ◽

Surface Characterization ◽

Electrochemical Impedance ◽

Rate Capability ◽

Cycling Performance ◽

Charge Transfer Resistance ◽

X Ray Diffraction ◽

Supercapacitor Electrode ◽

Transfer Resistance

In this work, PANI/MnCo2O4 nanocomposite was prepared via in-situ chemical polymerization method. Materials synthesized were characterized by FTIR spectroscopy, X-ray diffraction, and scanning electron spectroscopy. In addition, surface characterization of samples such as specific surface area, pore volume, and pore size distribution was studied. Supercapacitor capability of materials was investigated in 1 mol L–1 Na2SO4 solution using cyclic voltammetry in different potential scan rates and electrochemical impedance spectroscopy (EIS). The specific capacitance of materials was calculated, and it was observed that the specific capacitance of PANI/MnCo2O4 nanocomposite was 185 F g−1, much larger than PANI. Moreover, the prepared nanocomposite exhibited better rate capability in scan rate of 100 mV s−1 with respect to PANI. The EIS experiments revealed that the nanocomposite has lower charge transfer resistance compared with pure PANI. Subsequently, it was shown that the nanocomposite cycling performance was superior to the PANI cycling performance.

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STUDY OF ZN-NI ALLOY COATINGSMODIFIED BY NANO-AL2O3 PARTICLES INCORPORATION

Acta Metallurgica Slovaca ◽

10.12776/ams.v22i3.706 ◽

2016 ◽

Vol 22 (3) ◽

pp. 171 ◽

Cited By ~ 1

Author(s):

Malika Diafi ◽

Said Benramache ◽

Elhachmi Guettaf Temam ◽

Adaika Mohamed Lakhdar ◽

Brahim Gasmi

Keyword(s):

Electrochemical Impedance ◽

Research Work ◽

Charge Transfer Resistance ◽

Diffraction Measurement ◽

X Ray Diffraction ◽

Corrosion Properties ◽

Transfer Resistance ◽

Characterization Methods ◽

Ni Alloy ◽

Steel Substrates

AbstractThe aim of this research work was to codeposit nano-Al2O3 particles into Zn-Ni alloy coatings in order to improve some surface ,properties, the influence of the concentration of Al2O3 is the principal object in order to improve the corrosion resistance of the deposit, which has been made by electroplating on steel substrates previously treated, have been studied by several characterization methods, as the X-ray diffraction, measurement of micro hardness and scanning electron microscopy (SEM), protection against corrosion properties studied in a solution of 3% NaCl in the potentiodynamic polarization measurements (Tafel), electrochemical impedance spectroscopy (EIS) to the potential of corrosion free. The parameters that characterize the corrosion behavior can be determined from the plots and Nyquist plots and chronopotentiometry. Trends of increasing the charge transfer resistance and the decrease of capacitance values. XRD and SEM results and identify any coatings Zn-Ni and Zn-Ni-Al2O3 alloy composition have similar phase ( γ-phase structure) and the addition of Al2O3 in the Zn-Ni matrix increases the microhardness, and we note the maximum hardness is obtained for 50 g/L Al2O3.

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Electrochemical behavior of hydrogen precipitated Zircaloy-4

Modern Physics Letters B ◽

10.1142/s0217984915502000 ◽

2015 ◽

Vol 29 (32) ◽

pp. 1550200 ◽

Cited By ~ 6

Author(s):

Mohsin Rafique ◽

Naveed Afzal ◽

K. M. Deen ◽

Yong-Soo Kim

Keyword(s):

Hydrogen Concentration ◽

Electrochemical Behavior ◽

Electrochemical Impedance ◽

Charge Transfer Resistance ◽

X Ray Diffraction ◽

Transfer Resistance ◽

Corrosion Kinetics ◽

Before And After ◽

Potentiodynamic Anodic Polarization ◽

Kinetics Of

This work investigates the hydrogen precipitation effects on the electrochemical behavior of Zircaloy-4 in acidic saline media. The specimens of Zircaloy-4 were hydrogen charged at 200, 400 and 600 ppm concentrations for 30 min at 400[Formula: see text]C. X-ray diffraction (XRD) studies confirmed the formation of delta hydrides in the material. Scanning electron microscopy (SEM) results also indicated the presence of elongated hydrides whose density and thickness increased with the increase of hydrogen concentration in the alloy. The corrosion kinetics of the specimens were explored before and after hydrogen precipitation using potentiodynamic anodic polarization (PAP) and electrochemical impedance spectroscopy (EIS) techniques. The results showed that hydrogen precipitation shifts the corrosion potential towards more positive and thus improves the corrosion resistance of the alloy. The charge transfer resistance [Formula: see text] of the alloy was found to increase with increasing hydrogen concentration. This indicates an increased polarization tendency of the Zircaloy-4 surface with a limited dissolution tendency in the presence of delta hydrides.

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Synthesis and Electrochemical Properties of Polypyrrole Conducting Polymer in Sheath like Nanotube Arrays Structured over TiO2 for Supercapacitor Energy Storage Devices

MRS Proceedings ◽

10.1557/opl.2015.78 ◽

2015 ◽

Vol 1749 ◽

Author(s):

Navjot K. Sidhu ◽

A.C. Rastogi

Keyword(s):

Energy Storage ◽

Electrochemical Properties ◽

Electrochemical Impedance ◽

Charge Transfer Resistance ◽

Nanotube Arrays ◽

Energy Storage Devices ◽

Transfer Resistance ◽

Capacitance Density ◽

Electrically Conducting ◽

Supercapacitor Energy Storage

ABSTRACTThe vertical TiO2 nanotube arrays constituting the core of 3-D nanoscale electrode architecture were synthesized over Ti sheet by anodization. Such formed TiO2 nanotubes are electrically conducting and amorphous as confirmed by XRD studies. Nanotube morphology is affected by water content and in the present study, close-packed 3-4 μm long TiO2 nanotube arrays of 45-50 nm diameter are formed with 2% water as revealed by the transmission and scanning electron microscopy. The redox active polypyrrole sheath is created by ultra-short pulsed current electropolymerization. Electrochemical properties of the 3-D nanoscaled TiO2 nanotube core-polypyrrole sheath electrodes relevant to the energy storage were investigated using cyclic voltammetry (CV) plots, electrochemical impedance spectroscopy (EIS), Charge discharge (CD) tests. High areal capacitance density of 48 mF cm-2 and low charge transfer resistance 12 Ω cm-2 with least ion diffusion limitation are realized at optimized polypyrrole sheath thickness. The Raman spectra studies reveal anion at specific chain locations involve in the redox process.

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Electrochemical Performances of Yttrium Doped Li3V2–XYX(PO4)3/C Cathode Material for Lithium Secondary Battery

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2015.11197 ◽

2015 ◽

Vol 15 (10) ◽

pp. 8042-8047 ◽

Cited By ~ 5

Author(s):

Minchan Jeong ◽

Hyun-Soo Kim ◽

Dong-Sik Bae ◽

Chang-Woo Lee ◽

Bong-Soo Jin

Keyword(s):

Electrochemical Impedance ◽

Rate Capability ◽

Cycling Performance ◽

Charge Transfer Resistance ◽

Electrochemical Performances ◽

X Ray Diffraction ◽

Lithium Secondary Battery ◽

Capacity Retention ◽

Solid State Method ◽

Transfer Resistance

In this study, the Li3V2–X YX(PO4)3 compounds have been synthesized by a simple solid state method. In addition, a polyurethane was added to apply carbon coating on the surface of the Li3V2–X YX(PO4)3 particles for enhancement of the electrical conductivity. The crystal structure and morphology of the synthesized Li3V2–XYX(PO4)3/C (LVYP/C) was investigated using an X-ray diffraction (XRD) and a scanning electron microscopy (SEM) systematically. The electrochemical performance of synthesized material, such as the initial capacity, rate capability, cycling performance and EIS was evaluated. The sizes of synthesized particle ranged from 1 to 5 μm. The Li3V2–XYX(PO4)3/C (X = 0.02) delivered the initial discharge capacity of 171.5 mAh · g–1 at 0.1C rate. It showed a capacity retention ratio of 73.0% at 1.0C after 100th cycle. The electrochemical impedance spectroscopies (EIS) results revealed that the charge transfer resistance of the material decreases by Y doping.

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Supercapacitor electrodes based on modified titania nanotube arrays on flexible substrates

International Journal of Materials Research (formerly Zeitschrift fuer Metallkunde) ◽

10.1515/ijmr-2020-7828 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Kunnambeth M. Thulasi ◽

Sindhu Thalappan Manikkoth ◽

Anjali Paravannoor ◽

Shajesh Palantavida ◽

Baiju Kizhakkekilikoodayil Vijayan

Keyword(s):

Metal Oxides ◽

Electrochemical Impedance ◽

Titanium Foil ◽

Nanotube Arrays ◽

Metal Foil ◽

X Ray Diffraction ◽

Nanotube Array ◽

Titania Nanotube Arrays ◽

Titania Nanotube ◽

Supercapacitor Performance

Abstract Highly ordered titania nanotube arrays were synthesised on titanium metal foil through electrochemical anodisation. The annealed samples were characterised through scanning electron microscopy and X-ray diffraction analysis. The electrochemical characterisations of the arrays were done through cyclic voltammetry, galvanostatic charge discharge and electrochemical impedance spectroscopy analyses. The titania nanotube arrays exhibited a specific capacitance of 6.8 mF cm–2 at 5 mV s–1 scan rate, which is very much higher than that reported earlier. Pseudocapacitive metal oxides were deposited on these arrays forming composite supercapacitor electrodes and their supercapacitor properties were compared with same deposited on bare titanium foil substrates. Pseudocapacitive metal oxides deposited on these titania nanotube array substrates exhibited improved supercapacitor performance and stability over the same deposited on titanium foil substrates.

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

10.26434/chemrxiv.7991129 ◽

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

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/RuO2–IrO2 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 RuO2 and IrO2 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/RuO2–IrO2 anodes with improved properties that can be further extended to synthesise other MMO compositions.

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