Effect of dip time on the electrochemical behavior of PPy-Cu(OH)2 hybrid electrodes synthesized using pyrrole and CuSO4

e-Polymers ◽  
2017 ◽  
Vol 17 (2) ◽  
pp. 167-173 ◽  
Author(s):  
Amarsingh V. Thakur ◽  
Balkrishna J. Lokhande
Keyword(s):  
Specific Capacitance ◽  
Electrochemical Behavior ◽  
Charge Transfer Resistance ◽  
Specific Power ◽  
Data Card ◽  
Sem Images ◽  
Transfer Resistance ◽  
X Ray ◽  
Hybrid Energy ◽  
Warburg Impedance

AbstractThe present work in on the successive ionic layer adsorption and reaction (SILAR) mediated synthesis and study of variations in electrochemical behavior of PPy-Cu(OH)2 hybrid electrodes with dip time. In the aqueous route preparation, 0.1 m pyrrole, 0.1 m CuSO4 dissolved in acidified water (using 0.5 m H2SO4) and H2O2 (30 wt %) were used as initial ingredient sources. The peaks observed in the X-Ray diffraction (XRD) pattern of the electrode at 2θ=21.500 oriented along the <110> planes closely match with the peaks of Cu(OH)2 as per JCPDS data card no. 42-0638 indicating the existence of triclinic Cu(OH)2 in the hybrid. The characteristic peak at 1559 cm−1 in the Fourier transform infrared (FTIR) spectrum due to pyrrole ring vibrations confirms the existence of PPy in the hybrid. Energy-dispersive X-ray (EDX) analysis shows the occurrence of C, N, O and Cu in the electrode material which substantiates the formation of the hybrid. The scanning electron microscopy (SEM) images of electrodes with optimum dip time (20 s) in pyrrole show networks of interconnected nanostructures. The specific capacitance increases with the dip time in the source solutions. The electrode prepared with optimum dip time in pyrrole has produced the maximum values of specific capacitance (SC), specific energy (SE) and specific power (SP) as 127.04 F/g, 44.16 Wh/kg and 30 kW/kg, respectively, when analyzed in 0.5 m H2SO4. Impedance study of the electrode explains the mixed capacitive nature and the maximum values of solution resistance (Rs), charge transfer resistance (Rct) and Warburg impedance (Rw) are 1.35 Ω, 143.4 Ω and 2.05 Ω, respectively.

scholarly journals Influence of HAP on the Morpho-Structural Properties and Corrosion Resistance of ZrO2-Based Composites for Biomedical Applications

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 202
Author(s):  
Réka Barabás ◽  
Carmen Ioana Fort ◽  
Graziella Liana Turdean ◽  
Liliana Bizo
Keyword(s):  
Electrochemical Impedance ◽  
Artificial Saliva ◽  
Synergetic Effect ◽  
Composite Layer ◽  
Charge Transfer Resistance ◽  
Processing Route ◽  
Dental Alloys ◽  
Metallic Electrode ◽  
Transfer Resistance ◽  
X Ray

In the present work, ZrO2-based composites were prepared by adding different amounts of antibacterial magnesium oxide and bioactive and biocompatible hydroxyapatite (HAP) to the inert zirconia. The composites were synthesized by the conventional ceramic processing route and morpho-structurally analyzed by X-ray powder diffraction (XRPD) and scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS). Two metallic dental alloys (i.e., Ni–Cr and Co–Cr) coated with a chitosan (Chit) membrane containing the prepared composites were exposed to aerated artificial saliva solutions of different pHs (i.e., 4.3, 5, 6) and the corrosion resistances were investigated by electrochemical impedance spectroscopy technique. The obtained results using the two investigated metallic dental alloys shown quasi-similar anticorrosive properties, having quasi-similar charge transfer resistance, when coated with different ZrO2-based composites. This behavior could be explained by the synergetic effect between the diffusion process through the Chit-composite layer and the roughness of the metallic electrode surface.

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

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.

Facile Preparation of NiO/Ni Nanocomposite and its Electrochemical Capacitive Behaviors

2011 ◽  
Vol 306-307 ◽  
pp. 134-138 ◽  
Author(s):  
Wei Dong Yin ◽  
Gui Lian Li ◽  
Xian Ming Liu
Keyword(s):  
Specific Capacitance ◽  
Oxidation Process ◽  
Aqueous Electrolyte ◽  
High Specific Capacitance ◽  
Cycling Performance ◽  
Charge Transfer Resistance ◽  
Electrochemical Performances ◽  
Composite Electrodes ◽  
Galvanostatic Charge ◽  
Transfer Resistance

NiO/Ni nanocomposites were prepared by chemically reduction-oxidation process in tetra-ethylene glycol (TEG) solution. The structure and morphology of the samples were examined by XRD and SEM. The results indicated the composite consisted of NiO and Ni and exhibited spherical morphology with diameter of 50-200 nm. The electrochemical performances of composite electrodes used in electrochemical capacitors were studied. The electrochemical measurements were carried out using cyclic voltammetry, galvanostatic charge/discharge and impedance spectroscopy in 6M KOH aqueous electrolyte using three-electrode Swagelok systems. The results showed that the composite had a high specific capacitance and excellent capacitive behavior. The specific capacitance of the composite decreased to 192F/g after 500 cycles. Due to the existance of Ni, the charge transfer resistance is lower than 1Ω. It revealed that the composite exhibited good cycling performance.

scholarly journals Facilely Synthesized NiCo2O4/NiCo2O4 Nanofile Arrays Supported on Nickel Foam by a Hydrothermal Method and Their Excellent Performance for High-Rate Supercapacitance

Energies ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1308 ◽  
Author(s):  
Anil Yedluri ◽  
Eswar Araveeti ◽  
Hee-Je Kim
Keyword(s):  
Electrochemical Performance ◽  
Specific Capacitance ◽  
Nickel Foam ◽  
Rate Capability ◽  
Charge Transfer Resistance ◽  
High Rate ◽  
Transfer Resistance ◽  
Electrons And Ions ◽  
Binary Metal Oxides ◽  
Hydrothermal Approach

NiCo2O4 nanoleaf arrays (NCO NLAs) and NiCo2O4/NiCO2O4 nanofile arrays (NCO/NCO NFAs) material was fabricated on flexible nickel foam (NF) using a facile hydrothermal approach. The electrochemical performance, including the specific capacitance, charge/discharge cycles, and lifecycle of the material after the hydrothermal treatment, was assessed. The morphological and structural behaviors of the NF@NCO NLAs and NF@NCO/NCO NFAs electrodes were analyzed using a range of analysis techniques. The as-obtained nanocomposite of the NF@NCO/NCO NFAs material delivered outstanding electrochemical performance, including an ultrahigh specific capacitance (Cs) of 2312 F g−1 at a current density of 2 mA cm−2, along with excellent cycling stability (98.7% capacitance retention after 5000 cycles at 5 mA cm−2). These values were higher than those of NF@NCO NLAs (Cs of 1950 F g−1 and 96.3% retention). The enhanced specific capacitance was attributed to the large electrochemical surface area, which allows for higher electrical conductivity and rapid transport between the electrons and ions as well as a much lower charge-transfer resistance and superior rate capability. These results clearly show that a combination of two types of binary metal oxides could be favorable for improving electrochemical performance and is expected to play a major role in the future development of nanofile-like composites (NF@NCO/NCO NFAs) for supercapacitor applications.

scholarly journals Nitrogen-Doped Graphene: The Influence of Doping Level on the Charge-Transfer Resistance and Apparent Heterogeneous Electron Transfer Rate

Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 1815 ◽  
Author(s):  
Maria Coros ◽  
Codruta Varodi ◽  
Florina Pogacean ◽  
Emese Gal ◽  
Stela M. Pruneanu
Keyword(s):  
Doping Level ◽  
Transfer Rate ◽  
Charge Transfer Resistance ◽  
Electron Transfer Rate ◽  
Transfer Resistance ◽  
X Ray ◽  
Nitrogen Doped ◽  
Heterogeneous Electron Transfer ◽  
Nitrogen Doped Graphene ◽  
Doped Graphene

Three nitrogen-doped graphene samples were synthesized by the hydrothermal method using urea as doping/reducing agent for graphene oxide (GO), previously dispersed in water. The mixture was poured into an autoclave and placed in the oven at 160 °C for 3, 8 and 12 h. The samples were correspondingly denoted NGr-1, NGr-2 and NGr-3. The effect of the reaction time on the morphology, structure and electrochemical properties of the resulting materials was thoroughly investigated using scanning electron microscopy (SEM) Raman spectroscopy, X-ray powder diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), elemental analysis, Cyclic Voltammetry (CV) and electrochemical impedance spectroscopy (EIS). For NGr-1 and NGr-2, the nitrogen concentration obtained from elemental analysis was around 6.36 wt%. In the case of NGr-3, a slightly higher concentration of 6.85 wt% was obtained. The electrochemical studies performed with NGr modified electrodes proved that the charge-transfer resistance (Rct) and the apparent heterogeneous electron transfer rate constant (Kapp) depend not only on the nitrogen doping level but also on the type of nitrogen atoms found at the surface (pyrrolic-N, pyridinic-N or graphitic-N). In our case, the NGr-1 sample which has the lowest doping level and the highest concentration of pyrrolic-N among all nitrogen-doped samples exhibits the best electrochemical parameters: a very small Rct (38.3 Ω), a large Kapp (13.9 × 10−2 cm/s) and the best electrochemical response towards 8-hydroxy-2′-deoxyguanosine detection (8-OHdG).

EFFECT OF TiO2 PARTICLES ON MICRO-HARDNESS, CORROSION, WEAR AND FRICTION OF Ni–P–TiO2 COMPOSITE COATINGS AT DIFFERENT ANNEALING TEMPERATURES

2016 ◽  
Vol 23 (01) ◽  
pp. 1550082 ◽  
Author(s):  
PRASANNA GADHARI ◽  
PRASANTA SAHOO
Keyword(s):  
Wear Resistance ◽  
Corrosion Resistance ◽  
Composite Coatings ◽  
Corrosion Current ◽  
Xrd Analysis ◽  
Charge Transfer Resistance ◽  
Micro Hardness ◽  
Transfer Resistance ◽  
X Ray ◽  
Annealing Temperatures

The present study investigates the effect of titania particles on the micro-hardness, wear resistance, corrosion resistance and friction of electroless Ni–P–TiO2 composite coatings deposited on mild steel substrates at different annealing temperatures. The experimental results confirmed that the amount of TiO2 particles incorporated in the coatings increases with increase in the concentration of particles in the electroless bath. In presence of TiO2 particles, hardness, wear resistance and corrosion resistance of the coating improve significantly. At higher annealing temperature, wear resistance increases due to formation of hard Ni3P phase and incorporation of titania particles in the coated layer. Charge transfer resistance and corrosion current density of the coatings reduce with an increase in TiO2 particles, whereas corrosion potential increases. Microstructure changes and composition of the composite coating due to heat treatment are studied with the help of scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDXA) and X-ray diffraction (XRD) analysis.

scholarly journals From Allergens to Battery Anodes: Nature-Inspired, Pollen Derived Carbon Architectures for Room- and Elevated- Temperature Li-ion Storage

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Jialiang Tang ◽  
Vinodkumar Etacheri ◽  
Vilas G. Pol
Keyword(s):  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Lithium Ion ◽  
Charge Transfer Resistance ◽  
High Rate ◽  
Energy Storage Devices ◽  
Lithium Storage ◽  
Transfer Resistance ◽  
Carbonaceous Particles ◽  
X Ray

Abstract The conversion of allergic pollen grains into carbon microstructures was carried out through a facile, one-step, solid-state pyrolysis process in an inert atmosphere. The as-prepared carbonaceous particles were further air activated at 300 °C and then evaluated as lithium ion battery anodes at room (25 °C) and elevated (50 °C) temperatures. The distinct morphologies of bee pollens and cattail pollens are resembled on the final architecture of produced carbons. Scanning Electron Microscopy images shows that activated bee pollen carbon (ABP) is comprised of spiky, brain-like and tiny spheres; while activated cattail pollen carbon (ACP) resembles deflated spheres. Structural analysis through X-ray diffraction and Raman spectroscopy confirmed their amorphous nature. X-ray photoelectron spectroscopy analysis of ABP and ACP confirmed that both samples contain high levels of oxygen and small amount of nitrogen contents. At C/10 rate, ACP electrode delivered high specific lithium storage reversible capacities (590 mAh/g at 50 °C and 382 mAh/g at 25 °C) and also exhibited excellent high rate capabilities. Through electrochemical impedance spectroscopy studies, improved performance of ACP is attributed to its lower charge transfer resistance than ABP. Current studies demonstrate that morphologically distinct renewable pollens could produce carbon architectures for anode applications in energy storage devices.

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

2016 ◽  
Vol 23 (02) ◽  
pp. 1550111 ◽  
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.

Synthesis and Electrochemical Properties of Y-Doped SnO2/C Composite Materials for Lithium-Ion Battery

2011 ◽  
Vol 197-198 ◽  
pp. 1157-1162 ◽  
Author(s):  
Sheng Kui Zhong ◽  
You Wang ◽  
Chang Jiu Liu ◽  
Yan Wei Li ◽  
Yan Hong Li
Keyword(s):  
Particle Size ◽  
Electrochemical Impedance ◽  
Electronic Conductivity ◽  
Lithium Ion ◽  
Charge Transfer Resistance ◽  
Precipitation Method ◽  
Cyclic Voltammograms ◽  
Sem Images ◽  
Electrochemical Impedance Spectra ◽  
Transfer Resistance

The layered Y-doped SnO2/C anode materials were prepared by a co-precipitation method. The physical properties of the Y-doped SnO2/C were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), and electrochemical measurements. XRD studies showed that the Y-doped SnO2/C has the same layered structure as the undoped SnO2/C. The SEM images exhibited that the particle size of Y-doped SnO2/C is smaller than that of the undoped SnO2/C and the smallest particle size is only about 1µm. The Y-doped SnO2/C samples were investigated on the Lithium extraction/insertion performances by charge/discharge, cyclic voltammograms (CV), and electrochemical impedance spectra (EIS). The results showed that the optimal doping content of Y was that x=0.07 and 2% content of carbon nanotubes samples to achieve high discharge capacity and good cyclic stability. The electrode reaction reversibility and electronic conductivity were enhanced, and the charge transfer resistance was decreased through Y-doping.

scholarly journals Nanoflake Manganese Oxide and Nickel-Manganese Oxide Synthesized by Electrodeposition for Electrochemical Capacitor

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Man Van Tran ◽  
An The Ha ◽  
Phung My Loan Le
Keyword(s):  
Manganese Oxide ◽  
Specific Capacitance ◽  
Deposition Time ◽  
Discharge Rate ◽  
Electrochemical Capacitor ◽  
Charge Transfer Resistance ◽  
Transfer Resistance ◽  
Structure Morphology ◽  
Highly Porous ◽  
Nickel Manganese

Nanoflake structures of electrochemical manganese oxide (EMD) and nickel mixed manganese oxide (NiMD) were directly deposited on a stainless steel by using Chronoamperometry and Cyclic Voltammetry (CV) techniques. The structure, morphology, and capacitive behavior of EMD or NIMD nanoflake were affected by the electrodeposition modes and deposition time. The highest specific capacitance (Csp) was obtained for only two-minute deposition by both methods. EMD nanoflakes electrodeposited by CV technique show higher specific capacitance values than those prepared by Chronoamperometry owing to its homogenous and highly porous surface. All EMD samples exhibited excellent cycle behavior, less than 5% capacitance loss after 1000 cycles. Ni mixed MnO2was prepared at different Mn2+/Ni2+ratios for 2 minutes of electrodeposition. The presence of Ni2+ion enhanced theCspvalue at high charge-discharge rate due to the decrease of the charge transfer resistance. The supercapacitor prototype of 2 cm × 2 cm was assembled using EMD and NiMD as electrode material and tested at 1 A·g−1.

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