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1.
Yingwu Yao Haishu Dong Naichuan Yu Xin Chen Limiao Jiao Chunmei Zhao 《Russian Journal of Electrochemistry》2017,53(4):411-416
PbO2–CeO2 nanocomposite electrodes were prepared by pulse electrodeposition method in the lead nitrate solution containing CeO2 nanoparticles with different peak current density. The content of CeO2 nanoparticles in the electrodes increase with the increase of peak current density. The effects of peak current density on the morphology and structure of PbO2–CeO2 nanocomposite electrodes were studied by scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. The SEM and XRD results show that the increase of peak current density can make the morphology finer and more compact, and the crystal size decreases with the increase of peak current density. The oxygen evolution overpotential and stability of PbO2–CeO2 nanocomposite electrodes enhance with the increase of peak current density. The electrocatalytic property of PbO2–CeO2 nanocomposite electrodes was examined for the electrochemical oxidation of rhodamine B (RhB). The results show that the RhB removal efficiency on PbO2–CeO2 nanocomposite electrodes increase with the increase of peak current density, which can be attributed to the higher oxygen evolution overpotential and CeO2 content in the composite electrodes. 相似文献
2.
A. B. Velichenko V. A. Knysh T. V. Luk’yanenko D. Devilliers F. I. Danilov 《Russian Journal of Electrochemistry》2008,44(11):1251-1256
The regularities of electrodeposition of composite materials based on PbO2 containing zirconium dioxide particles are studied. The contents of various phases in the composite depend on the electrolyte composition and conditions of deposition. When a dispersed phase is incorporated into the composite coating, the dimensions of lead dioxide crystals decrease to submicrons. 相似文献
3.
A. B. Velichenko V. A. Knysh T. V. Luk’yanenko D. Devilly F. I. Danilov 《Russian Journal of Applied Chemistry》2008,81(6):994-999
Fundamental aspects of electro deposition of PbO2-based composites containing titanium dioxide particles were studied. The content of the dispersed phase in the composite depends on the electrolyte composition and deposition conditions. Incorporation of titanium dioxide particles into PbO2 leads to significant changes in the morphology and structure of the deposit. 相似文献
4.
Longjian Ma Yongxiang Li Xiaofeng Yu Nanfei Zhu Qunbao Yang Chang-Ho Noh 《Journal of Solid State Electrochemistry》2008,12(11):1503-1509
In this work, 3-methylthiophene (MeT) was electrochemically incorporated with nano- and mesoporous TiO2 films to form poly(3-methylthiophene) (PMeT)/TiO2 nanocomposite electrochromic electrodes. TiO2 films, which were previously coated on the ITO glass sheets through a well-established technique, were introduced to enhance
the adhesion of the polymers to the substrates and thus increase the long-term stability of the devices. With this effort,
the nanocomposite electrodes were found to retain up to 60% of their optical response after 3,500 deep and double potential
steps and retain up to 50% of their electroactivity after 104 same steps, exhibiting enhanced long-term stability. Switching time and the maximum optical contrast (ΔT%) of the nanocomposite electrodes were found to be 0.6 s and 45%, respectively. Moreover, our work showed that electrochemically
incorporating conductive polymers (CPs) with TiO2 mesoporous films was an effective method to form high-quality CP/TiO2 nanocomposite electrodes, which can be used widely in battery cathodes, photovoltaic cells, photocatalytic reaction, and
photoelectrochromic cells and were supposed to enhance their performances. 相似文献
5.
A PbO2-SnO2 composite anode with interconnected structure is prepared for organics electro-incineration through a two-step method, thermal-decomposition
process and subsequent low-current density electrodeposition process. The element mapping, together with the impedance spectra
of the composite electrode, confirms that an interconnected architecture of SnO2 and PbO2 grains, instead of a lamellar structure, was obtained on the Ti substrate. A lower electrodeposition current density (≤10
mA cm−2) is very crucial for the formation of a porous surface and an interconnected architecture of two oxides inside. The asprepared
electrode exhibits an enhanced electrocatalytic activity on the mineralization of phenol and a long service life due to the
interconnected architecture, which helps to utilize the merits of these two metal oxides simultaneously. This two-step method
also provides us a novel and facile way to fabricate a series of composite material such as oxide-oxide, oxide-metal composite
electrodes. 相似文献
6.
In this paper, a new highly sensitive potentiometric pH electrode is proposed based on the solid-state PbO2 film electrodeposited on carbon ceramic electrode (CCE). Two different crystal structures of PbO2, α and β were examined and the similar results were obtained. Moreover, the experimental results obtained for the proposed
pH sensor and a conventional glass pH electrode were in good agreement. The electromotive force (emf) signal between the pH-sensitive
PbO2-coated CCE and SCE reference electrode was linear over the pH range of 1.5–12.5. Near-Nernstian slopes of −64.82 and −57.85 mV/pH
unit were obtained for α- and β-PbO2 electrodes, respectively. The interferences of some mono-valence and multi-valence ions on potentiometric response of the
sensor were studied. The proposed pH sensor displayed high ion selectivity with respect to K+, Na+, Ca2+, and Li+, with log values around −12 and has a working lifetime of about 30 days. Key parameters important for the pH sensor performance, including
kind of PbO2 film, selectivity, response time, stability, and reproducibility, have been characterized. The proposed electrode showed
a good efficiency for direct pH-metry after calibration and pH-metric titrations without calibration step. The response time
was about 1 s in acidic medium and less than 30 s in alkaline solutions. The pH values of complex matrix samples such as fruit
juices measured by the proposed sensor and a conventional glass pH electrode were in good agreement. 相似文献
7.
A. B. Velichenko V. A. Knysh T. V. Luk’yanenko F. I. Danilov D. Devilliers 《Russian Journal of Electrochemistry》2009,45(7):778-782
In the work, the regularities of electrodeposition of composite materials based on PbO2 containing the valve metal particles are considered. The content of dispersed phase in the composite depends on the electrolyte composition and conditions of deposition. The incorporation of titanium particles into PbO2 considerably changes the deposit morphology. It is found that the service life of electrodes containing dispersed Ti phase increases by 4 times as compared with the conventional anodes made of pure PbO2. 相似文献
8.
R. Amadelli A. De Battisti L. Doubova A. B. Velichenko 《Russian Journal of Electrochemistry》2008,44(1):131-137
An electrochemical kinetic investigation of nitrite oxidation to nitrate on RuO2 is discussed. The process is studied by cyclic voltammetry, steady-state measurements and potential step measurements. The
overall oxidation reaction is a two-electron process where the first step involves a reversible charge transfer: NO2− ⇔ NO2 + e− The one-electron oxidation of nitrite yields adsorbed NO2 which is further oxidized to adsorbed (NO2)+ and subsequently desorbed via a chemical reaction. In the general case, fit of experimental data is obtained with adsorption
described by a Temkin isotherm unless the electrode is pre-treated at a cathodic potential where the (NO2)ads is removed. This treatment lowers the degree of coverage by intermediates but not the nature of the slow step.
Published in Russian in Elektrokhimiya, 2008, Vol. 44, No. 1, pp. 142–149.
The text was submitted by the authors in English. 相似文献
9.
Possibility of layer-by-layer synthesis by colloidal layering of Sb2S3-SiO2 nanocomposite layers from colloid solutions of {[H x Sb2S5] m ?}mNa+ and SiO2 was studied. The composition of the layers synthesized was examined by Raman spectroscopy, transmission spectroscopy in the UV and visible spectral ranges, energy-dispersion micro analysis, and scanning electron microscopy. 相似文献
10.
11.
R. Machado M. L. Santiago M. G. Stachiotti A. Frattini N. Pellegri R. Bolmaro O. de Sanctis 《Journal of Sol-Gel Science and Technology》2008,48(3):294-302
Ferroelectric thin films of strontium bismuth tantalate (SBT) have been fabricated by a chemical solution deposition technique
using non-hydrolyzing precursors. Strontium acetate, bismuth nitrate and tantalum ethoxide were used as precursor materials,
with methanol and glacial acetic as solvents. We investigate the effects of the precursor chemistry, by the selection of the
chelating agent, on the elimination of residual organic compounds, thermal evolution of phase formation, and microstructure
evolution of derived films. We found that the utilization of alkanolamines as chelating agent produce the segregation of metallic
bismuth in as-prepared powders. On the other hand, acetoin, one of the hydroxyketones, showed the elimination of residual
organics at low temperature, an earlier onset of crystallization, and no segregation of secondary phases during the whole
crystallization process. A comparative investigation of the surface microstructure, grain size distribution, crystallinity,
and degree of crystal orientation of films fabricated with the different chelating agents is presented. The dielectric and
ferroelectric properties of films prepared with acetoin are investigated. 相似文献
12.
Li Chen Haixia Shen Zhen Lu Cang Feng Su Chen Yanru Wang 《Colloid and polymer science》2007,285(13):1515-1520
TiO2–SiO2 composite nanoparticles were prepared by a sol–gel process. To obtain the assembly of TiO2–SiO2 composite nanoparticles, different molar ratios of Ti/Si were investigated. Polyurethane (PU)/(TiO2–SiO2) hybrid films were synthesized using the “grafting from” technique by incorporation of modified TiO2–SiO2 composite nanoparticles building blocks into PU matrix. Firstly, 3-aminopropyltriethysilane was employed to encapsulate TiO2–SiO2 composite nanoparticles’ surface. Secondly, the PU shell was tethered to the TiO2–SiO2 core surface via surface functionalized reaction. The particle size of TiO2–SiO2 composite sol was performed on dynamic light scattering, and the microstructure was characterized by X-ray diffraction and
Fourier transform infrared. Thermogravimetric analysis and transmission electron microscopy (TEM) employed to study the hybrid
films. The average particle size of the TiO2–SiO2 composite particles is about 38 nm when the molar ratio of Ti/Si reaches to1:1. The TEM image indicates that TiO2–SiO2 composite nanoparticles are well dispersed in the PU matrix. 相似文献
13.
14.
TiCl4 and MnSO4· H2O as raw materials are hydrolyzed stiochiometrically, following the intermediate of oxide hydrating reacts at 150°C, 0.5 MPa
in high-pressure reactor, after filtering, washing and drying, nanometric TiO2-MnO2 (Ti1-X
Mn
X
O2) is prepared. The effects of the reaction temperature and time on nanometric TiO2-MnO2 are also discussed. XRD shows that the product is TiO2-MnO2 with amorphous phase. After being sintered at above 780 °C, it transfers into Ti1-X
Mn
X
O2 with a rutile structure. TEM shows that TiO2-MnO2 is the spherical particle. And the average diameter of the particles is 20 nm. The optical absorbance was determined by UV-265
spectrophotometer after dispersing the sample in the mixture of water and glycerol with the ratio of 1 : 1 equably. It is
found that the nano-material possesses the advantages of both nano-TiO2 and nano-MnO2, and it has strong absorption in the UV and visible region. Photodegradation of dyes in an aqueous solution is investigated
using nanometricTiO2-MnO2 as a photocatalyst. The results show that after 60 min illumination, the decolorization rate of the acidic red B and acidic
black 234 dye can be as high as 100%. 相似文献
15.
Lubomir Lubenov Martin Bojinov Tzvety Tzvetkoff 《Journal of Solid State Electrochemistry》2007,11(12):1613-1620
Oxidation of organics in the potential region of O2 evolution is supposed to proceed through the oxidation of water to hydroxyl radicals, which then may either be further oxidized
to give molecular oxygen or interact with organic molecules in an oxygen transfer reaction. Therefore, the electrode material
must ensure (1) the preferential adsorption of the organic compound, (2) the production of adsorbed hydroxyl radicals able
to react with this compound in a selective oxidation reaction (with as little as possible oxygen evolution), and (3) a long-term
stability. In the present paper, the oxidative decomposition of toluene in sulfuric acid solution on PbO2 coatings deposited on Ti substrate from acidic nitrate + fluoride baths containing Pb2+ and Bi3+ is investigated by voltammetry, electrochemical impedance spectroscopy, and UV spectrophotometry. The chemical composition
and structure of the catalytic coatings is characterized with X-ray photoelectron spectroscopy and X-ray diffraction. The
catalytic activity is estimated both from current density vs potential and polarization resistance vs potential plots using
measurements on the same electrodes in sulfuric acid without toluene to eliminate the oxygen evolution reaction that proceeds
in parallel to the oxidation of toluene. A skeletal reaction mechanism of the process is proposed to account for the steady-state
and transient response of the catalytic electrodes during oxidation of toluene. 相似文献
16.
Reverse micellar microemulsions were utilised to synthesise stable lead titanate colloids from typical sol–gel type molecular
precursors. The particles of a few nanometres in diameter that formed by hydrolysis in the micelle cores demonstrated a nanocrystalline
texture without the need for thermal treatment. In a chemical solution deposition routine based on the nanoparticle dispersions,
ferroelectric PbTiO3 thin films showing excellent remanent polarisation of more than 50 μC cm−2 were derived. The electrical characteristics of the layers were correlated to their microstructure which was controlled by
the precursor composition and the annealing conditions. A columnar morphology that was realised by spinning on coatings of
up to 100 nm in individual thickness proved most favourable with respect to the ferroelectric performance of the films. 相似文献
17.
Y. Akishige H. Shigematsu T. Tojo H. Kawaji T. Atake 《Journal of Thermal Analysis and Calorimetry》2005,81(3):537-540
Summary Specific heats on the single crystals of Sr2Nb2O7, Sr2Ta2O7 and (Sr1-xBax)2Nb2O7 were measured in a wide temperature range of 2-600 K. Heat anomalies of a λ-type were observed at the incommensurate phase transition of TINC (=495 K) on Sr2Nb2O7 and at the super-lattice phase transition of TSL (=443 K) on Sr2Ta2O7; the transition enthalpies and the transition entropies were estimated. Furthermore, a small heat anomaly was observed at the low temperature ferroelectric phase transition of TLOW (=95 K) on Sr2Nb2O7. The transition temperature TLOW decreases with increasing Ba content x and it vanishes for samples of x>2%. 相似文献
18.
19.
M. Yu. Shilova A. V. Vologzhanina L. B. Serezhkina V. N. Serezhkin 《Russian Journal of Coordination Chemistry》2009,35(2):153-156
The single crystals of [UO2(C2O4){CONH2N(CH3)2}2] were synthesized and studied by X-ray diffraction. The crystals are monoclinic, a = 7.461(2) Å, b = 8.828(2) Å, c = 11.756(2) Å, β = 107.21(3)°, space group Pc, Z = 2, R = 2.94%. The structure comprises infinite chains [UO2(C2O4){CONH2N(CH3)2}2] extended along [001] and corresponding to the AT11M 2 1 crystallochemical group (A = UO 2 2+ , T11 = C2O 4 2? , M1 = N,N-CONH2N(CH3)2) of uranyl complexes. The chains are connected into a three-dimensional framework by hydrogen bonds involving the oxygen atoms of oxalate and uranyl ions and the N,N-dimethylcarbamide methyl groups. 相似文献