scholarly journals The role of the concentration profile of titanium oxide on the electrochemical behavior of RuO2-TiO2 coatings obtained by the sol-gel procedure

2003 ◽  
Vol 68 (12) ◽  
pp. 979-988 ◽  
Author(s):  
Vladimir Panic ◽  
Aleksandar Dekanski ◽  
Vesna Miskovic-Stankovic ◽  
Slobodan Milonjic ◽  
Branislav Nikolic
Keyword(s):  
Electrochemical Behavior ◽  
High Frequency ◽  
Electrochemical Impedance ◽  
Sol Gel ◽  
Tio2 Coating ◽  
Tio2 Layer ◽  
Low Frequencies ◽  
Tio2 Coatings ◽  
Overall Resistance

In order to understand the role of TiO2 in the deactivation mechanism of an active RuO2?TiO2 coating, an additional TiO2 layer was introduced in the support coating interphase of regular Ti//[RuO2?TiO2 anode in one case and on the surface of the coating in the other. The electrochemical behavior of these, with TiO2 enriched, anodes was compared with the behavior of anodes with regular RuO2?TiO2 coatings, which were subjected to an accelerated stability test. A high-frequency semicircle in the complex plane plot obtained by electrochemical impedance spectroscopy, for a regular RuO2?TiO2 coating corresponds to TiO2 enrichment in the coating as a consequence of anode corrosion. In the case of the coatings with additional TiO2 layers, a high-frequency semicircle was not observed. The additional TiO2 layers increase the coating overall resistance and influence the coating impedance behavior at low frequencies. Similar equivalent electrical circuits were used to analyze the impedance behavior of coatings having an additional TiO2 layer at different position within RuO2?TiO2 coating.

Surface treatment and its effect on the electrochemical behavior of Ti–15Mo–3Nb–3Al alloy

RSC Advances ◽  
2016 ◽  
Vol 6 (43) ◽  
pp. 36345-36355 ◽  
Author(s):  
R. V. Lakshmi ◽  
Parthasarathi Bera ◽  
Chinnasamy Anandan
Keyword(s):  
Chemical Composition ◽  
Surface Morphology ◽  
Surface Treatment ◽  
Electrochemical Behavior ◽  
Sol Gel

The effect of alkaline and acidic treatments on the surface morphology, chemical composition and electrochemical behavior of Ti β–21S alloy is studied. Also, the role of GPTMS–TIP sol–gel coating in obviating the effects is explored.

Wood derived biochar as electron donor and its influence on microbial denitrification: Role of extracellular polymeric substances in extracellular electron transfer

2020 ◽  
Author(s):  
Kuppusamy Sathishkumar ◽  
Yi Li ◽  
Rana Muhammad Adnan Ikram
Keyword(s):  
Electron Transfer ◽  
Electron Donor ◽  
Electrochemical Behavior ◽  
Nitrate Reduction ◽  
Extracellular Polymeric Substances ◽  
Electrochemical Impedance ◽  
Electrochemical Analysis ◽  
Extracellular Electron Transfer ◽  
Microbial Denitrification

<p>Biochar is extensively used in environmental pollutant remediation because of its diverse property, however the effect of biochar on microbial nitrate reduction and electrochemical behavior of biochar remain unknown. Also electron transfer from the microbial cells to electron donor or acceptor have been transport across the extracellular polymeric substances (EPS), however it was unclear whether extracellular polymeric substances captured or enhance the electrons.  Hence, aim of the present study is to investigate the electrochemical behavior of biochar and its effects on microbial nitrate reduction and elucidate the role of extracellular polymeric substances in extracellular electron transfer (EET).  The biochar was prepared at different pyrolysis temperatures (400 °C, 500 °C and 600 °C) and their electrochemical behavior was characterized by electrochemical analysis (cyclic voltammetry, electrochemical impedance spectrum, chronoamperometry). Results demonstrated that all the biochars could donate and accept the electrons, impact of biochar on microbial nitrate reduction was studied and the results showed that biochar prepared at 400 °C significantly enhances microbial nitrate reduction process. Phenol O-H and quinone C=O surface functional groups on the biochar contributes in the overall electron exchange which accelerated the nitrate reduction. The role of EPS in EET by electrochemical analysis results reveals that outer membrane c-type cytochrome and flavin protein from the biofilm was involved in electron transfer process, and EPS act as transient media for microbial EET. Overall, present study suggested that biochar could be used as eco-friendly material for the enhancement of microbial denitrification.</p>

scholarly journals Dielectric Relaxation Behavior of BTO/LSMO Heterojunction

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1109
Author(s):  
Guoqiang Song ◽  
Yuanyuan Zhang ◽  
Sheng Li ◽  
Jing Yang ◽  
Wei Bai ◽  
...  
Keyword(s):  
Dielectric Relaxation ◽  
High Frequency ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Composite Films ◽  
Hysteresis Loops ◽  
Frequency Range ◽  
Magnetoelectric Composite ◽  
Polarization Switch

The BaTiO3 (BTO)/La0.7Sr0.3MnO3 (LSMO) magnetoelectric composite films were prepared by sol-gel method on STO (001) substrates. The heterojunction has highly preferred orientation and exhibits well ferroelectric properties with perfect hysteresis loops and microscopic polarization switch behaviors. The most interesting thing is the abnormal dielectric relaxation phenomenon in the dielectric spectra at high frequency range and around the phase transition temperature of LSMO. By analyzing the resistance properties of LSMO films, it is indicated that charge-based interfacial coupling, Maxwell-Wagner effect due to the JT polaron and fast resistivity rise in LSMO layer is the main reason. This work emphasizes the crucial role of resistivity exchanges and of carrier accumulation at interfaces for the application of magnetoelectric heterojunction.

Effect of LaCoO3 Additive on the Electrochemical Behavior of Zinc Anode in Alkaline Solution

2010 ◽  
Vol 663-665 ◽  
pp. 596-599 ◽  
Author(s):  
Rabat Boonpong ◽  
Attera Worayingyong ◽  
Marisa Arunchaiya ◽  
Atchana Wongchaisuwat
Keyword(s):  
Zinc Oxide ◽  
Electrochemical Behavior ◽  
Electrochemical Impedance ◽  
Shape Change ◽  
Sol Gel ◽  
Weight Ratio ◽  
Schiff Base Complex ◽  
Cyclic Voltammogram ◽  
Zinc Anode ◽  
Zinc Oxide Powder

The utilization of zinc anode for zinc-based battery is limited due to low cycling life, shape change and ZnO passivation on the electrode surface. The electrochemical behavior of zinc anode in the presence of the additives added to the electrodes or the electrolytes have been reported. In this work, LaCoO3 was used as an additive to improve the electrochemical properties of the zinc oxide anode. LaCoO3 synthesized by sol gel method (Schiff base complex) was added to zinc oxide powder (99.9%) with the weight ratio of 1:0.001, 1:0.002 and 1:0.003. The relative ZnO/LaCoO3 ratios were confirmed by particle induced x-ray emission (PIXE) technique.The electrochemical behavior of the ZnO/LaCoO3 electrodes in 6M KOH solution were investigated by voltammetry and electrochemical impedance spectroscopy (EIS). The cyclic voltammogram showed that ZnO/LaCoO3 gave higher anodic current and ZnO passivation delayed. The EIS spectra showed that charge transfer resistances of the ZnO/LaCoO3 anodes due to zinc oxidation were higher than that of ZnO electrode

THE ROLE OF SOL-GEL PROCEDURE CONDITIONS IN ELECTROCHEMICAL BEHAVIOR AND CORROSION STABILITY OF Ti/[RuO2-TiO2] ANODES

2005 ◽  
Vol 20 (1) ◽  
pp. 89-103 ◽  
Author(s):  
V. Panić ◽  
A. Dekanski ◽  
V. B. Mišković-Stanković ◽  
B. Nikolić ◽  
S. Milonjić
Keyword(s):  
Electrochemical Behavior ◽  
Sol Gel ◽  
Corrosion Stability

scholarly journals Role of Al and Ti doping in modulating electrical properties of BIVOX system

2019 ◽  
Vol 8 (4) ◽  
pp. 489-499
Author(s):  
Diptimayee Tripathy ◽  
Amarjyoti Saikia ◽  
Gyati Tachang Tado ◽  
Arvind Pandey
Keyword(s):  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Parent Compound ◽  
Differential Scanning Calorimetric ◽  
X Ray Diffraction ◽  
Intermediate Temperature Range ◽  
Growth Phenomenon ◽  
Ft Ir ◽  
Overall Resistance

AbstractThe doubly-doped bismuth vanadate with Al and Ti having formula unit, Bi2V1−xAlx/2Titx/2O5.5-δ (0.10 ⩽ x ⩽ 0.25) was synthesized. The specimens were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR), differential scanning calorimetric (DSC), UV-Vis, and electrochemical impedance spectroscopy (EIS) for their structural, thermal, optical, and electrical studies. Influence of both dopant cations (Al and Ti) was observed in the gradual stabilization of the tetragonal phase of Bi2VO5.5-δ with dopant amount. A non-uniform grain growth phenomenon was observed up to x = 0.175, with dopant addition. UV-Vis study revealed the comparatively higher order of oxide ion vacancies for the composition x = 0.175. Impedance spectroscopy measurements indicate a significant decrease of both the grain (Rg) and grain boundary resistances (Rgb) with the rise in temperature and the overall resistance is found to be dominated by the grain interior contribution. Enhancement of ionic conductivity was found in all the compositions in the intermediate temperature range as compared to the parent compound, and the single Al-doped system and the highest value were obtained for x = 0.175.

Calculation-and-experimental estimation of the role of the frequency ratio in changing the endurance at two-frequency deformation modes

2019 ◽  
Vol 85 (1(I)) ◽  
pp. 64-71 ◽  
Author(s):  
M. M. Gadenin
Keyword(s):  
High Frequency ◽  
Experimental Studies ◽  
Low Frequency ◽  
Reduction Factor ◽  
Single Frequency ◽  
Cyclic Loads ◽  
Small Ratio ◽  
Harmonic Components ◽  
Deformation Modes

The cycle configuration at two-frequency loading regimes depends on the number of parameters including the absolute values of the frequencies and amplitudes of the low-frequency and high-frequency loads added during this mode, the ratio of their frequencies and amplitudes, as well as the phase shift between these harmonic components, the latter having a significant effect only with a small ratio of frequencies. Presence of such two-frequency regimes or service loading conditions for parts of machines and structures schematized by them can significantly reduce their endurance. Using the results of experimental studies of changes in the endurance of a two-frequency loading of specimens of cyclically stable, cyclically softened and cyclically hardened steels under rigid conditions we have shown that decrease in the endurance under the aforementioned conditions depends on the ratio of frequencies and amplitudes of operation low-frequency low-cycle and high-frequency vibration stresses, and, moreover, the higher the level of the ratios of amplitudes and frequencies of those stacked harmonic processes of loading the greater the effect. It is shown that estimation of such a decrease in the endurance compared to a single frequency loading equal in the total stress (strains) amplitudes can be carried out using an exponential expression coupling those endurances through a parameter (reduction factor) containing the ratio of frequencies and amplitudes of operation cyclic loads and characteristic of the material. The reduction is illustrated by a set of calculation-experimental curves on the corresponding diagrams for each of the considered types of materials and compared with the experimental data.

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