• Russ. J. Electrochem. (IF 1.043) Pub Date : 2019-12-11
T. A. Stel’mashuk, E. V. Alekseeva, O. V. Levin

A mixed catalyst based on platinum and nickel oxide was obtained as a result of the synthesis and subsequent alkaline hydrolysis of thin polymer films of poly[Ni(Salen)] with platinum nanoparticles previously electrodeposited in its pores. The efficiency of catalyst operation was tested in oxygen electroreduction in an alkaline medium. A distinction of the catalyst is its high activity and tolerance to methanol impurities compared with commercial analogs.

更新日期：2019-12-11
• Russ. J. Electrochem. (IF 1.043) Pub Date : 2019-12-11
O. L. Gribkova, V. A. Kabanova, A. A. Nekrasov

The pyrrole electrochemical polymerization in the presence of salt and acid forms of flexible-chain sulfoacid polyelectrolytes is studied comparatively. Electrochemical and spectral methods of the synthesis control showed the polypyrrole electrosynthesis in the presence of polyelectrolytes to occur more rapidly and with lesser monomer concentration than in inorganic-anion-containing aqueous solutions. With the using of the polyelectrolytes’ Н+-form, the pyrrole polymerization rate was shown to exceed that in the Na+-salt solutions. Electrochemical, spectroelectrochemical properties in visible and near-IR spectral regions, and morphology of the obtained hybrid polypyrrole films were also studied.

更新日期：2019-12-11
• Russ. J. Electrochem. (IF 1.043) Pub Date : 2019-12-11
R. V. Apraksin, S. N. Eliseeva, M. A. Kamenskii, E. G. Tolstopyatova, G. G. Lang, V. V. Kondrat’ev

This work studies the electrochemical properties of cathodic materials for lithium–ion batteries based on mixed lithium–iron–manganese phosphate LiFe0.4Mn0.6PO4 (LFMP) obtained using a conducting binder containing poly-3,4-ethylenedioxythiophene : polystyrenesulfonate (PEDOT:PSS) and carboxymethyl cellulose (CMC). The results are compared with those for the material based on LiFe0.4Mn0.6PO4 manufactured with the conventional polyvinylidene fluoride (PVDF) binder. The electrode material with the PEDOT:PSS/CMC binder manifests enhanced functional characteristics as compared to electrodes with the conventional binder. It is found that replacement of the conventional binder by the combined conducting PEDOT:PSS/CMC binder in the LFMP-based cathodic material results in an increase in the specific capacity of the cathodic material. Particularly noticeable advantages of the material with respect to specific capacity are observed at high currents (up to 10 C), which can be explained by the increasing rate of the processes of material recharge due to a significant decrease in the charge transfer resistance and an increase in the apparent diffusion coefficient of the lithium ions.

更新日期：2019-12-11
• Russ. J. Electrochem. (IF 1.043) Pub Date : 2019-12-11
Yu Liu, Suning Gao, Rudolf Holze

An aqueous rechargeable lithium ion battery with metallic cadmium as the negative electrode, LiCoO2 nanoparticles as the positive electrode, and a neutral aqueous electrolyte solution of 0.5 M Li2SO4 and 10 mM Cd(Ac)2 is reported. It has good electrochemical performance. The calculated energy density based on the practically available capacity of the two electrodes is 72 W h kg–1; this is comparable to that of Ni–Cd batteries. The positive mercury electrode of the Weston cell is replaced by a LiCoO2 electrode, the negative cadmium amalgam by a plain cadmium metal electrode. Mercury is completely avoided. Compared with Ni–Cd batteries an alkaline electrolyte solution is not needed making the system more environment-friendly.

更新日期：2019-12-11
• Russ. J. Electrochem. (IF 1.043) Pub Date : 2019-12-11
C. Gutiérrez-Cerón, N. Silva, I. Ponce, J. H. Zagal

In this work we have tested the Fe(III)/(II) redox potential of the catalysts as a reactivity descriptors of iron macrocyclic complexes (FeN4) adsorbed on multi-walled carbon nanotubes (MWCNTs) and deposited on ordinary pyrolytic graphite (OPG). The reaction examined is the oxidation of glutathione (GSH) a biologically important molecule. The experiments were conducted in 0.1 M NaOH and kinetic measurements were performed on MWCNT previously modified with FeN4 macrocycle complexes. This modified FeN4–MWCNTs were deposited on pristine OPG electrodes. From previous work it is known that for FeN4 complexes directly adsorbed on OPG, the activity as (log i)E plotted versus the Fe(II)/(I) redox potential follows a volcano correlation for the oxidation of glutathione. We wanted to test these correlations on hybrid electrodes containing MWCNTs and essentially the carbon nanotubes have no influence in these correlations and the redox potentials a are good reactivity descriptors, regardless of the way the FeN4 catalysts are attached to the electrode. Further, we find volcano correlations when using the Fe(II)/(I) and the Fe(III)/(II) redox potentials as reactivity descriptors. The volcano correlation when using the Fe(III)/(II) redox potential exhibits a maximum at E° = –0.26 V vs SCE which is close to the potential for comparing the different activities. This interesting result seems to indicate that the maximum cannot be explained only in terms of the Sabatier principle where θRS, the surface coverage of adsorbed intermediate is close to 0.5 but instead to a surface coverage of active sites θFe(II) equal to 0.5, which occurs at the Fe(III)/(II) formal potential.

更新日期：2019-12-11
• Russ. J. Electrochem. (IF 1.043) Pub Date : 2019-12-11
Xin Liu, Xinping Wang, Haiyan Zhao, Benkang Liu, Xiang Lin, Jie Bai, Zhuo Wang

Fe2O3 short nanorods, nanorods and nanowires were prepared by a facile hydrothermal method by using different flexible ligands (oxalic acid, succinic acid, adipic acid) as templates to adjust the L/D (length/diameter) ratios of the one-dimensional (1D) Fe2O3–nanostructures for the first time. The growth mechanism of Fe2O3 nanorods and nanowires were proposed. Their potential applications as anodes for lithium ion batteries were investigated by electrochemical analysis. This novel straightforward strategy to fabricate 1D metal oxide with different L/D ratios may provide a promising method to make advanced Fe2O3-based nanostructures for Li-ion battery applications.

更新日期：2019-12-11
• Russ. J. Electrochem. (IF 1.043) Pub Date : 2019-12-11
A. A. Nekrasov, O. D. Iakobson, O. L. Gribkova

Initial stages of aniline galvanostatic polymerization at platinum electrode in aqueous solutions of poly-2-acrylamido-2-methyl-1-propansulfonic acid and polystyrenesulfonic acid are studied by the method of Raman spectroelectrochemistry. A laser with wavelength of 532 nm excited the Raman scattering. The very presence of intermolecular associates able to luminescence in the polyacid solution (in the case of polystyrenesulfonic acid) was shown to result in the Raman-spectrometer photodetector overload if normal incidence of laser beam at the electrode (the angle 0°) was used. The Raman-spectrometer photodetector overload can be avoided by the varying of the incidence angle over the 0°–20° range, even without using other techniques (leading to a decrease in the reliability of the studied Raman band registration, such as the lowering of the integration time, intensity or energy of the excitation). Comparative study of aniline electropolymerization in the presence of poly-2-acrylamido-2-methyl-1-propansulfonic acid, polystyrenesulfonic acid, and HCl revealed some characteristic bands in the Raman spectra of the polyaniline–polyacid complexes in the Raman frequency range from 2000 to 3000 сm–1; these bands relate to the polyacid’s backbone and are absent in the Raman spectra of the polyaniline–HCl film. The dynamics of changes in the contribution to the integral Raman spectrum of the band of radical-cations (1330–1350 сm–1) characterizing the highly conductive emeraldine form of polyaniline was compared for the polymerization media. In the course of the electrosynthesis it was found, that the accumulation rate of these species in the film decreased in the series poly-2-acrylamido-2-methyl-1-propansulfonic acid > HCl > polystyrenesulfonic acid.

更新日期：2019-12-11
• Russ. J. Electrochem. (IF 1.043) Pub Date : 2019-12-11
A. L. Klyuev, A. D. Davydov, T. B. Kabanova, B. M. Grafov

The ergodicity of electrochemical noise of corrosion process with respect to the three-dimensional Chebyshev spectrum is studied. The electrochemical noise of “two identical electrodes of steel St-3 in the NaCl + benzotriazole solution” corrosion system is measured. The use of the Chebyshev noise spectra in the test for the ergodicity of electrochemical noise is dictated by the fact that the intensity of the second and higher Chebyshev spectral lines is resistant to the trend of electrochemical noise. It is found that in the initial period of interaction between the electrode and electrolyte, the electrochemical noise of the corrosion process is characterized by a weak ergodicity. However, even in 2.5 h, the ergodicity test shows that the steady state is reached. A similar situation is observed for the electronic noise of measuring equipment. The test for the ergodicity of electronic noise using the second component of three-dimensional Chebyshev spectrum shows that the steady state is reached in 30 min after switching on the measuring equipment. The ergodicity test with respect to the second component of three-dimensional Chebyshev spectrum can be used for the analysis of ergodic properties of random noise of any nature even under the conditions of strong trend.

更新日期：2019-12-11
• Russ. J. Electrochem. (IF 1.043) Pub Date : 2019-12-11
E. A. Dmitrieva, I. A. Chepurnaya, M. P. Karushev, A. M. Timonov

The data on polymeric complexes of nickel with salen-type Schiff bases containing electron-withdrawing nitro groups in ligand’s aromatic fragments are acquired by an in situ technique based on collecting electron paramagnetic resonance spectra simultaneously with absorption spectra in the UV, visible, and near IR regions in the course of oxidation-reduction of a polymer film on the surface of an optically transparent electrode under conditions of cyclic voltammetry. Based on the combined analysis of spectroscopic and electrochemical data, it is shown that as the potential of the polymer-modified electrode shifts in the positive region, the different types of charge carriers successively appear in the system (phenoxyl radical cations, radical pairs, and dications). The results obtained suggest that the positive charge can be delocalized either between aromatic rings in monomer fragments or between fragments of neighboring polymer chains.

更新日期：2019-12-11
• Russ. J. Electrochem. (IF 1.043) Pub Date : 2019-12-11
M. M. Petrov, D. V. Konev, A. E. Antipov, N. V. Kartashova, V. V. Kuznetsov, M. A. Vorotyntsev

The changes in indicator-electrode potential and (quasi)equilibrium solution composition in the anodic compartment of a model electrolyzer initially filled with aqueous electrolyte containing 0.5 M concentration of bromide anions are calculated under the condition that pH 2 is maintained constant in this compartment. The theoretical analysis is carried out for three different hypotheses concerning the possible depth of electrolysis and the nature of processes involved: (1) no bromine compounds with positive degree of oxidation are formed; (2) bromine compounds with the degree of oxidation not higher than +1 are formed; (3) the process can involve the formation of both bromate ions and bromine compounds with the lower degrees of oxidation ($${\text{Br}}_{{\text{3}}}^{ - },$$$${\text{Br}}_{{\text{5}}}^{ - },$$ Br2, BrO–, HBrO) in solution as well as the liquid phase of bromine $$\left( {{\text{Br}}_{{\text{2}}}^{{{\text{liq}}}}} \right).$$ All electrochemical and chemical reactions involving bromine-containing species taken into account within the framework of hypotheses of system evolution 1, 2, and 3 are assumed to be (quasi)equilibrium, and the electric current through the cell separator is assumed to be provided by supporting electrolyte ions. Methods are proposed for experimental determination of the version of evolution of Br-containing anolyte during electrolysis.

更新日期：2019-12-11
• Russ. J. Electrochem. (IF 1.043) Pub Date : 2019-12-11
Ye. O. Kondratyeva, E. V. Solovyeva, G. A. Khripoun, K. N. Mikhelson

Bulk resistance and other electrochemical properties of membranes of K+-selective electrodes (ISEs) containing valinomycin are measured by means of chronopotentiometry and electrochemical impedance. It is shown that the bulk resistance of the membranes, within the Nernstian potentiometric response range, increases along decrease of KCl concentration in solution. Analogous results were reported earlier for Ca2+ and NO$$_{3}^{ - }$$ ISEs. This non-constancy of the bulk resistance is in conflict with current views on the mechanism of ISEs response. Tentatively, this paradox is ascribed to heterogeneity of membranes due to water uptake from solution.

更新日期：2019-12-11
• Russ. J. Electrochem. (IF 1.043) Pub Date : 2019-12-11
Li Dong, Xiaolong Chen, Jie Ma, Qinsi Shao, Aijun Li, Wei Yan, Jiujun Zhang

Nitrogen-doped hierarchical porous hollow carbon microspheres (N-HPHCS) are synthesized using melamine-formaldehyde (MF) resin as carbon and nitrogen sources, sulfonated polystyrene microspheres (SPS) as the core template, and SiO2 nanoparticles as the mesopore forming agent. The obtained microspheres are composed of SPS core and MF/SiO2 composite shell (SPS@MF/SiO2). This SPS@MF/SiO2 is then calcined and acid-treated to obtain N-HPHCS. During the calcination, SPS core is removed, and the micropores are formed on the shell owing to the thermal decomposition of the MF resin. After chemical etching of the SiO2 nanoparticles, mesopores are generated on the carbon shell. The as-prepared sample of N-HPHCS has high surface area and large pore volume, and exhibits catalytic activity toward oxygen reduction reaction (ORR). The electrocatalytic performance of N-HPHCS can be ascribed not only to the doped nitrogen atoms, but also to the hierarchical porous structure.

更新日期：2019-12-11
• Russ. J. Electrochem. (IF 1.043) Pub Date : 2019-12-11
K. J. Szekeres, É. Fekete, M. Ujvári, S. Vesztergom, V. V. Kondratiev, G. G. Láng

Experimental results are presented on the electrochemical behavior of BPA at a gold | 0.1 M sodium perchlorate electrode. During the cycling of the electrode potential an adherent thin polymer layer was formed on the electrode. The film buildup process was followed in situ with an electrochemical quartz crystal microbalance (EQCM) and ex situ by electrochemical impedance spectroscopy (EIS). Scanning electron microscopy (SEM) was used for the study of the structure/morphology of the deposited polymer coating. The results imply that polymerization and degradation of the BPA monomer may occur simultaneously during its electrochemical oxidation.

更新日期：2019-12-11
• Russ. J. Electrochem. (IF 1.043) Pub Date : 2019-11-15
John Newman

An attempt is made to resolve a long standing difference in the predicted distribution of the eddy diffusivity in the viscous sublayer, where the literature shows a dependence on either the cube or the fourth power of the distance from a solid wall. The resolution suggested is that a y3 dependence prevails very close to the wall while a y4 dependence may prevail in the outer part of the viscous sublayer near the border with the outer turbulent flow. However, at high values of the Schmidt number, the overall mass-transfer rate will show behavior corresponding to the y3 dependence, and any hints of the y4 dependence would be very hard to observe experimentally.

更新日期：2019-12-11
• Russ. J. Electrochem. (IF 1.043) Pub Date : 2019-11-15
V. I. Pet’kov, A. S. Shipilov, E. Yu. Borovikova, I. A. Stenina, A. B. Yaroslavtsev

Arsenate phosphates NaZr2(AsO4)x(PO4)3 –x are synthesized by the sol–gel method with subsequent annealing at 1123 K. Thus obtained specimens are investigated using X-ray diffraction analysis, IR and impedance spectroscopy. In the NaZr2(AsO4)x(PO4)3 –x system, continuous solid solution (0 ≤ x ≤ 3) with NaZr2(PO4)3 (NASICON) structure forms. According to the impedance spectroscopy data, an increase of the content of arsenic in the NaZr2(AsO4)x(PO4)3 –x system leads to an increase of the sodium-ionic conductivity; for NaZr2(AsO4)3, it reaches 8 × 10–5 S/cm at 773 K. At the same time, the activation energy of conductivity of this material (50 ± 1 kJ/mol) appears to be twice lower than the activation energy of conductivity of NaZr2(PO4)3 (100 ± 1 kJ/mol).

更新日期：2019-12-11
• Russ. J. Electrochem. (IF 1.043) Pub Date : 2019-11-15
E. P. Grishina, N. O. Kudryakova, L. M. Ramenskaya, Yu. A. Fadeeva

The methods of viscosimetry, conductometry, densimetry, and differential scanning calorimetry are used for studying the physicochemical properties of cations (1-butyl-3-methylimidazolium [BuMeIm]+, N-butylmethylpyrrolidinium [BuMePyrr]+, and methytrioctylammonium [MeOc3Am]+) and their effect on the transport properties of bis(trifluoromethylsulfonyl)imide ionic liquids (IL). It is shown that ILs formed by cyclic amines ([BuMeIm]+ and [BuMePyrr]+) as the cations demonstrate the close values and temperature dependences of viscosity and conductivity. The cation [MeOc3Am]+ predetermines the difference in the IL structure and, thus, a substantial difference in the transport properties of the melt. For salts [BuMeIm][Tf2N], [BuMePyrr][Tf2N], and [MeOc3Am][Tf2N] at 293 К, the following transport characteristics are observed: viscosity 57.7, 88.1, and 726.5 mPa s; specific conductivity 0.376, 0.252, and 0.005 S m–1; activation energy of conductivity 21, 21, and 35 kJ mol–1; degree of “ionicity” 0.92, 0.94, and 1.00, respectively. Using the equation of Vogel–Fulcher–Tammann and based on the temperature dependences of specific conductivity and viscosity, the ideal glass transition temperatures are calculated for liquids under study. In the positive temperature range, a linear correlation is observed between the conductivity and the cation volume in these ionic liquids.

更新日期：2019-12-11
• Russ. J. Electrochem. (IF 1.043) Pub Date : 2019-11-15
Chuanzhang Ge, Zhenghua Fan, Long Shen, Yongmin Qiao, Licheng Ling, Jianming Wang

A scalable synthesis of unique pyrolysis carbons from phosphorus-doped epoxyphenolics (EPN) through a facile curing and pyrolysis process is reported. The obtained carbons with a high pyrolysis yield of ca. 48% are investigated by SEM, TEM, XRD, Raman and nitrogen adsorption, and evaluated as anode for LIBs. The results show that the nanocrystal structure, proportion of defect sites and porosity (nanovoids) of the obtained carbons are highly dependent on pyrolysis temperature, thus affecting their electrochemical properties. The EPN carbon pyrolyzed at 900°C (EPN900) delivers the largest reversible capacity of nearly 420 mA h g–1 at 0.1 C, which is higher than the theoretical capacity of graphite, mainly resulting from lithium-ions insertion into the turbostratic nanosheets and absorption on defect sites. While the EPN carbon pyrolyzed at 2800°C (EPN2800) exhibits a balanced lithium storage performance with relatively large reversible capacity of 343 mA h g–1, high initial coulombic efficiency (~86%), and superior cycling performance (299 mA h g–1 after 100 cycles at 0.3 C). This work provides a feasible solution for the large-scale preparation of high performance anode material and deepens the high-value utilization of the staple epoxy product.

更新日期：2019-12-11
• Russ. J. Electrochem. (IF 1.043) Pub Date : 2019-11-15
N. A. Rogozhnikov

A density-functional study of the interaction of Tl+ ions with the gold surface is carried out based on the cluster model of the metal surface. The geometry and energy characteristics are assessed. Ion Tl+ exists on the surface in its ad-ionic form. The electronic state of the Au–$${\text{Tl}}_{{{\text{ads}}}}^{ + }$$ system is analyzed. The involvement of the adsorbed thallium ion and the neighboring gold atoms in the formation of molecular orbitals of this system is assessed. Their formation is preferentially contributed by s-orbitals of thallium and d-orbitals of gold. It is found that in alkaline media, Tl+ ions coadsorb with OH– ions to form TlOH on the surface. The possible geometrical configuration of their associate with OH– ions is determined for the low and high surface coverages by OH– ions.

更新日期：2019-12-11
• Russ. J. Electrochem. (IF 1.043) Pub Date : 2019-11-15
V. V. Abalyaeva, O. N. Efimov

Samples of polyaniline synthesized from aniline sulfate were electrochemically cycled in LiCl, LiClO4, and lithium tetracyanoquinodimethane, with the electrolyte replacement. In all studied cases, the polyaniline is shown to retain its electrochemical activity upon the electrolyte and doping anion replacement. The electrochemical activity with the Cl– and $${\text{ClO}}_{4}^{ - },$$ dopants is reduced in the first cycles upon the electrolyte replacement; however, in the subsequent cycles the reduction decreased. When the electrode under testing has been returned to the native electrolyte, its electrochemical activity and electrochemical capacitance increased, recovering their initial values. When polyaniline has been doped with the tetracyanoquinodimethane anion, each next cycling series revealed an increase in its electrochemical activity, which manifests itself in the cyclic voltammogram area, as well as increase in the electrochemical capacitance from one cycling series to the next one.

更新日期：2019-12-11
• Russ. J. Electrochem. (IF 1.043) Pub Date : 2019-11-15
Bing Feng, Fanglin Zha, Li Li, Jiaqiang Wei, Kai Liu

In this paper, the growth process of T2 brass passive film in generator cooling water was studied, the effect of CO2’s leakage on the crystal structure and anti-corrosion performance of passive film was analyzed, and we were trying to repair the passive film by adjusting pH of solution. Electrochemical Impedance Spectroscopy (EIS), Potentiodynamic Polarization (PP), Potentiostatic Scan (PS), Scanning Electron Microscopy (SEM) and X-ray Photoelectron Spectroscopy (XPS) were used in this paper. The test results showed that a thin and dense Cu2O passive film was formed on the surface of T2 brass after immersed in the cooling water for 2 days. And then a loose CuO outside layer was formed gradually, during this period the Cu2O was further oxidized to be CuO, the dense structure of the inner Cu2O layer was thus damaged. Finally a double-layer passive film consisted by Cu2O and CuO was formed at the 24th day of immersed. Corrosion pits and cracks appeared on the outside passive film after erosed by CO2. The anti-corrosion performance of the passive film cannot be completely restored by self in alkaline solution.

更新日期：2019-12-11
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