scholarly journals Differences in the electrochemical behavior of ruthenium and iridium oxide in electrocatalytic coatings of activated titanium anodes prepared by the sol-gel procedure

2010 ◽  
Vol 75 (10) ◽  
pp. 1413-1420 ◽  
Author(s):  
Vladimir Panic ◽  
Aleksandar Dekanski ◽  
Vesna Miskovic-Stankovic ◽  
Slobodan Milonjic ◽  
Branislav Nikolic
Keyword(s):  
Sol Gel ◽  
Potential Range ◽  
Electrochemical Characteristics ◽  
H2so4 Solution ◽  
Metal Chlorides ◽  
Impedance Characteristics ◽  
Voltammetric Behavior ◽  
Redox Transitions ◽  
Surface Redox ◽  
Hydrolysis Of

The electrochemical characteristics of Ti0.6Ir0.4O2/Ti and Ti0.6Ru0.4O2/Ti anodes prepared by the sol-gel procedure from the corresponding oxide sols, obtained by force hydrolysis of the corresponding metal chlorides, were compared. The voltammetric properties in H2SO4 solution indicate that Ti0.6Ir0.4O2/Ti has more pronounced pseudocapacitive characteristics, caused by proton-assisted, solid state surface redox transitions of the oxide. At potentials negative to 0.0 VSCE, this electrode is of poor conductivity and activity, while the voltammetric behavior of the Ti0.6Ru0.4O2/Ti electrode is governed by proton injection/ejection into the oxide structure. The Ti0.6Ir0.4O2/Ti electrode had a higher electrocatalytical activity for oxygen evolution, while the investigated anodes were of similar activity for chlorine evolution. The potential dependence of the impedance characteristics showed that the Ti0.6Ru0.4O2/Ti electrode behaved like a capacitor over a wider potential range than the Ti0.6Ir0.4O2/Ti electrode, with fully-developed pseudocapacitive properties at potentials positive to 0.60 VSCE. However, the impedance characteristics of the Ti0.6Ir0.4O2/Ti electrode changed with increasing potential from resistor-like to capacitor-like behavior.

scholarly journals Sol-gel prepared active ternary oxide coating on titanium in cathodic protection

2007 ◽  
Vol 72 (12) ◽  
pp. 1393-1402 ◽  
Author(s):  
Vladimir Panic ◽  
Branislav Nikolic
Keyword(s):  
Cathodic Protection ◽  
Sol Gel ◽  
Oxide Coating ◽  
Molar Ratio ◽  
Ternary Oxide ◽  
Electrochemical Characteristics ◽  
Accelerated Corrosion ◽  
Metal Chlorides ◽  
Corrosion Stability ◽  
The Stability

The characteristics of a ternary oxide coating, on titanium, which consisted of TiO2, RuO2 and IrO2 in the molar ratio 0.6:0.3:0.1, calculated on the metal atom, were investigated for potential application for cathodic protection in a seawater environment. The oxide coatings on titanium were prepared by the sol-gel procedure from a mixture of inorganic oxide sols, which were obtained by forced hydrolysis of metal chlorides. The morphology of the coating was examined by scanning electron microscopy. The electrochemical properties of activated titanium anodes were investigated by cyclic voltammetry and polarization measurements in a H2SO4- and NaCl-containing electrolyte, as well as in seawater sampled on the Adriatic coast in Tivat, Montenegro. The anode stability during operation in seawater was investigated by the galvanostatic accelerated corrosion stability test. The morphology and electrochemical characteristics of the ternary coating are compared to that of a sol-gel-prepared binary Ti0.6Ru0.4O2 coating. The activity of the ternary coating was similar to that of the binary Ti0.6Ru0.4O2 coating in the investigated solutions. However, the stability in seawater is found to be considerably greater for the ternary coating.

Synthesis and Charge-Discharge Characteristics of Polycrystalline LiNi1-xCoxO2 (0 ≤ x ≤ 0.5) as a Cathode Material for Lithium Rechargeable Batteries

2007 ◽  
Vol 280-283 ◽  
pp. 443-446 ◽  
Author(s):  
Xin Lu Li ◽  
Fei Yu Kang ◽  
Wan Ci Shen ◽  
Xiu Juan Shi
Keyword(s):  
Sol Gel ◽  
Hexagonal Lattice ◽  
Chelating Agent ◽  
Rechargeable Batteries ◽  
Potential Range ◽  
Electrochemical Characteristics ◽  
X Ray Diffraction ◽  
Soft Chemistry ◽  
Capacity Fading ◽  
Lithium Rechargeable Batteries

The synthesis and electrochemical characteristics of LiNi1-xCoxO2 (0 £ x £ 0.5) used as the promising cathode materials for lithium rechargeable batteries were investigated. The LiNi1-xCoxO2 was prepared by a soft chemistry route in which citric acid was used as the chelating agent to make the sol-gel precursor, then was calcined in oxygen atmosphere at the calcination temperature of 800°C for 12 h. Polycrystalline LiNi1-xCoxO2 possesses a hexagonal lattice of the α-NaFeO2 type characterized by using X-ray diffraction. The discharge capacity of LiNi0.8Co0.2O2 was 169.1 mAh/g with the efficiency of 90.5% in the first cycle and 162.1 mAh/g with only 4% capacity fading in the 10th cycle at 0.2 C rate over a potential range of 3.0-4.2 V.

scholarly journals Activity and stability of RuO2-coated titanium anodes prepared via the alkoxide route

2006 ◽  
Vol 71 (11) ◽  
pp. 1173-1186 ◽  
Author(s):  
Vladimir Panic ◽  
Aleksandar Dekanski ◽  
Slobodan Milonjic ◽  
Vesna Miskovic-Stankovic ◽  
Branislav Nikolic
Keyword(s):  
Degradation Mechanism ◽  
Sol Gel ◽  
Active Material ◽  
Coating Surface ◽  
Coating Mass ◽  
Voltammetric Behavior ◽  
Forced Hydrolysis ◽  
The Stability ◽  
Hydrolysis Of ◽  
Alkoxide Route

Titanium anodes with an active RuO2 coating of two different thicknesses were prepared from the oxide suspended in ethanol ("ink" method), while the oxide itself was synthesized by the hydrolysis of ruthenium ethoxide in an ethanolic solution (alkoxide route). The morphology of prepared oxide was examined by scanning electron microscopy. The electrochemical properties of the prepared Ti/RuO2 anodes, involving their cyclic voltammetric behavior in H2SO4 and NaCl solutions, activity in the chlorine and oxygen evolution reaction, impedance behavior in H2SO4, and stability during electrolysis in dilute chloride solutions, were investigated. The performances of the anodes are compared to those of a Ti/RuO2 anode prepared by the sol-gel procedure from an oxide sol obtained by the forced hydrolysis of ruthenium chloride in acid solution. The anodes prepared via the alkoxide route showed a higher capacitance and activity for the chlorine evolution reaction than the anode prepared by the inorganic sol-gel procedure. The results of the stability test showed that the utilization of the coating active material is better when the anodes were prepared via the alkoxide route than via the inorganic sol-gel procedure, particularly for anodes with a smaller mass of coating. The different rates of loss of activity indicate a degradation mechanism for the anodes prepared via the alkoxide route in which electrochemical dissolution of RuO2 from the coating surface prevails over the growth of an insulating TiO2 layer in the coating/Ti substrate interphase. The effect of RuO2 dissolution from the coating surface increases with increasing coating mass.

scholarly journals Electrocatalytic properties and stability of titanium anodes activated by the inorganic sol-gel procedure

2008 ◽  
Vol 73 (11) ◽  
pp. 1083-1112 ◽  
Author(s):  
Vladimir Panic ◽  
Branislav Nikolic
Keyword(s):  
Electrochemical Impedance ◽  
Sol Gel ◽  
Open Circuit ◽  
Stability Test ◽  
Electrochemical Characteristics ◽  
Potential Region ◽  
Metal Chlorides ◽  
Transmission Electron ◽  
Accelerated Stability ◽  
Activity Loss

The properties of activated titanium anodes, RuO2-TiO2/Ti and RuO2--TiO2-IrO2/Ti, prepared from oxide sols by the sol-gel procedure, are reviewed. RuO2 and TiO2 sols were synthesized by forced hydrolysis of the corresponding chlorides in acid medium. The morphology of the prepared sols was investigated by transmission electron microscopy. The chemical composition of the RuO2 sol was determined by X-ray diffraction and thermogravimetric analysis. The loss of electrocatalytic activity of a RuO2-TiO2/Ti anode during an accelerated stability test was investigated by examination of the changes in the electrochemical characteristics in the potential region of the chlorine and oxygen evolution reaction, as well as on the open circuit potential. These electrochemical characteristics were investigated by cyclic voltammetry, electrochemical impedance spectroscopy and polarization measurements. The changes in electrochemical characteristics of the anode prepared by the sol-gel procedure were compared to the changes registered for an anode prepared by the traditional thermal decomposition of metal chlorides. The comparison indicated that the main cause for the activity loss of the sol-gel prepared anode was the electrochemical dissolution of RuO2, while in the case of thermally prepared anode the loss was mainly caused by the formation of an insulating TiO2 layer in the coating/Ti substrate interphase. The results of an accelerated stability test on RuO2-TiO2/Ti and RuO2--TiO2-IrO2/Ti anodes showed that the ternary coating is considerably more stable than the binary one, which is the consequence of the greater stability of IrO2 in comparison to RuO2.

EPR of Cu(II) in Sol-Gel Prepared SiO2 Glass

1986 ◽  
Vol 73 ◽  
Author(s):  
S. Dave ◽  
R. K. Maccrone
Keyword(s):  
Local Structure ◽  
Copper Ions ◽  
Sol Gel ◽  
Epr Spectra ◽  
Sio2 Glass ◽  
Structural Probe ◽  
Hydrolysis Of

ABSTRACTSiO2 glass has been prepared by the hydrolysis of TEOS in alcohol using HCl and NH4OH to control the pH. Copper ions were incorporated from the acetate to act as structural probe ions during the process of gellation and calcination. The local structure of copper ions was investigated using EPR determined at 300 K and 10 K.It was found that the pH of the solution had a profound effect on the EPR spectra of the copper in the gels and glasses, indicating differences in the local structure.

Investigation on Structure and Electrochemical Properties of Li[Ni1/3Co1/3Mn1/3]O2 for Lithium Ion Batteries

2007 ◽  
Vol 336-338 ◽  
pp. 455-458
Author(s):  
Xiu Juan Shi ◽  
Yong Ping Zheng ◽  
Fei Yu Kang ◽  
Xin Lu Li ◽  
Wan Ci Shen
Keyword(s):  
Cathode Material ◽  
Lithium Ion Batteries ◽  
Sol Gel ◽  
Lithium Ion ◽  
Hexagonal Structure ◽  
Oxidation States ◽  
Potential Range ◽  
Xps Analysis ◽  
Electrochemical Behaviors ◽  
Charge Discharge

Cathode material Li[Ni1/3Co1/3Mn1/3]O2 for lithium-ion batteries with layered hexagonal structure was successfully synthesized in sol-gel way. The influences of calcination temperature (from 700° to 1000°C) on the structure and electrochemical behaviors of Li[Ni1/3Co1/3Mn1/3]O2 were extensively investigated. The results of XRD show that all samples are isostructural with α-NaFeO2 with a space group R-3m. XPS analysis shows that the oxidation states of Co and Mn were Co3+ and Mn4+ respectively, while Ni exists as Ni2+ and Ni3+. The charge-discharge experiments show that the sample calcined at 850°C delivers 194.8mAh/g in the first cycle at C/5 rate in 2.5-4.3V potential range.

scholarly journals STRUCTURAL, SURFACE AND ELECTROCHEMICAL CHARACTERISTICS OF TiO2 FOR LITHIUM-ION BATTERIES

2020 ◽  
Vol 86 (9) ◽  
pp. 14-27
Author(s):  
Nataliy Globa ◽  
Tatyana Lisnycha ◽  
Yurii Shmatok ◽  
Vitalii Sirosh ◽  
Sviatoslav Kirillov
Keyword(s):  
Heat Treatment ◽  
Lithium Ion ◽  
Total Pore Volume ◽  
Treatment Temperature ◽  
Electrolyte Composition ◽  
Electrochemical Characteristics ◽  
Kinetic Characteristics ◽  
Anatase Structure ◽  
Structural Surface ◽  
Hydrolysis Of

The paper presents structural, surface, thermodynamic and kinetic characteristics of titanium dioxide samples obtained by means of alkaline hydrolysis of TiCl4 by LiOH solutions and further heat treatment. TiO2 samples have the anatase structure with crystallite size of 7–10 nm. An increase in the heat treatment temperature from 150 °C to 470 °C leads to a decrease in the specific surface area from 404 to 80 m2/g and the total pore volume from 0.340 to 0.152 cm3/g. The influence of electrolyte composition and surface properties of TiO2 on its behavior in cells with lithium anode investigated by means of galvanostatic cycling and impedance spectroscopy is discussed.

Synthesis of Hollow Titania Photocatalytic Particles Using Yeast as Templates

2013 ◽  
Vol 699 ◽  
pp. 126-132 ◽  
Author(s):  
Toshiyuki Nomura ◽  
Syota Tanii ◽  
Hayato Tokumoto ◽  
Yasuhiro Konishi
Keyword(s):  
Pore Diameter ◽  
Sol Gel ◽  
Solid Particles ◽  
Core Shell ◽  
Average Pore ◽  
Inorganic Particles ◽  
Sol Gel Process ◽  
Yeast Powder ◽  
Titania Precursor ◽  
Hydrolysis Of

Hollow inorganic particles have attracted considerable interest for a variety of applications. In this work, yeast powder was used as a bio-template to fabricate yeast/titania core-shell spheres. A titania precursor was deposited via the hydrolysis of tetraisopropyl titanate. Triethanolamine was employed to control the reaction rate of the sol-gel process. The hollow titania particles with a diameter of approximately 4 m and a thickness of approximately 54 nm were successfully obtained after calcination of the core-shell spheres at 700 °C. The crystal structure of the particles was anatase. The specific surface area and the average pore diameter were 21.4 m2/g and 1.6 nm, respectively. The photocatalytic activity of the hollow particles was higher compared with that of solid particles.

Sign in / Sign up

Export Citation Format

Share Document