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The electrochemical behavior of the biologically active redox chemicals is essential in point of view antibacterial activity. In some cases, the electronic exchanges are coupled to chemical reactions that produce new oxidative or reductive species, which might form electrodeposits. This contribution presents a comparative study of the antibacterial activities and the anodic oxidation of S-triazino-benzimidazole derivatives substituted at the triazine ring with phenyl, 4-fluorophenyl and pentafluorophenyl groups. By combining bactericidal screening against E. coli, P. aeruginosa, S. aureus, and S. typhimurium, to a cyclic voltammetry investigation, it was revealed that the fluorine phenyl substituents in the S-triazine benzimidazole derivatives enhance the electrons ejection to the platinum disk and the subsequent chemical reactions. Additionally, by cycling of potential the non-fluorinated chemical produces a rather passive film on the electrode surface, whereas the fluorinated ones generate electroactive and electrocatalytic coatings. Comparing the results obtained with S-triazino-benzimidazole derivatives to those with 2-aminobenzimidazole, plausible mechanisms of their bactericidal action are suggested. [ABSTRACT FROM AUTHOR]

The electrocatalytic activity of electrode materials synthesized by anodic selective dissolution of Ag–Pd alloys based on silver (4 and 8 at % Pd) was studied. Kinetic regularities of formic acid electrooxidation on palladium and anodically modified Ag–Pd alloys in an acidic sulfate solution have been established. The process includes the diffusion of HCOOH, its dissociative chemisorption, and irreversible ionization of atomic hydrogen. The conditions for formic acid anodic oxidation on Pd and Ag–Pd alloys were determined depending on the composition of the electrode system and the mode of preliminary electrochemical modification (selective dissolution) of the alloy using transient electrochemical measurements. The role of the surface development of an alloy in the kinetics of anodic degradation of formic acid was revealed. It was shown that the selective dissolution of Ag–Pd alloys contributes to a noticeable increase in the rate of the kinetic stage of atomic hydrogen ionization. A necessary condition for the activation of the anodically modified alloy in relation to the electrooxidation of HCOOH is the excess of both critical parameters (charge and potential) corresponding to the onset of morphological development and phase transformations in the surface layer of the Ag–Pd systems. [ABSTRACT FROM AUTHOR]

TiO2 films with a 1D nanotube structure were obtained by electrochemical anodic oxidation of titanium foil. Electrochemical reductive activation of the TiO2-nanotube-based electrodes was carried out using the method of cyclic voltammetry. The activated electrodes showed significantly higher current density and quantum efficiency of the photoelectrochemical water splitting as compared to native TiO2 nanotubes. Electrochemical treatment of the electrodes by the cyclic voltammetry leads to increase in the photocurrent density by a factor of 4 to 14, depending both on the used wavelength and applied potential. The analysis of electrochemical impedance spectra showed that the increase in the photoelectrochemical process performance is due to increase in the charge transfer rate at the semiconductor/electrolyte interface, as well as improved electronic conductivity of the oxide layer, which contributes to better charge carrier separation and decrease in their recombination rate. [ABSTRACT FROM AUTHOR]

Existence of an organic compounds, especially aromatic compounds in wastewater is observed as an emerging environmental problem because of their harmful effects on living organisms even at low concentration. Conventional wastewater treatment processes are ineffectual for an elimination of refractory organic compounds. Nowadays, it's a challenge to reduce negative impact of such hazardous compounds on environment. So, Advanced Oxidation Processes (AOPs) have received more attention over a year of decades towards removal of an aromatic compounds. Among AOPs, Electrochemical Advanced Oxidation Processes (EAOPs), especially "Anodic Oxidation" and "Electro-Fenton," have revealed good potential for mitigation of pollution caused by the presence of aqueous organic compounds in wastewater. This review has introduced an innovative collection of current knowledge on Electro-Fenton and Anodic oxidation type of processes. Fundamentals of these processes, electrolysers used, reaction mechanisms, experimental parameters affecting these electro-chemical treatment technologies with various applications are discussed in detail. This report also discusses effectiveness of EAOPs for elimination of organic compounds in aqueous systems. [ABSTRACT FROM AUTHOR]

Anodic formation in deoxygenated 0.1 М KOH solution of Ag(I) oxide on Ag–Zn alloys with zinc atomic fraction from 5 to 30 at % and its properties were examined using cyclic voltammetry supplemented by photoelectrochemical measurements. Phase composition of the alloys is confirmed by X-ray diffraction analysis. Surface morphology is studied using scanning electron microscope. Ag(I) oxide anodically formed on silver–zinc alloys is shown possessing n-type conductance, with dominating donor defects. The donor defect concentration in the Ag(I) oxide increases, as the zinc content in the alloy grows, and this leads to a decrease in the maximum photocurrent and to narrowing of the space charge region. With the increasing of the zinc concentration in the alloy, the Ag2O particles' size decreases and their surface density increases. [ABSTRACT FROM AUTHOR]

A facile and Eco-compatible synthesis of benzofuran derivatives (4a-4h) has been carried out at platinum electrode by electrochemical oxidation of catechol in the presence of active methylene groups. Electro- organic synthesis has been performed in an undivided cell at ambient conditions. The products of electrolysis have been purified and characterized by FTIR, 1H NMR and 13C NMR and mechanism was deduced by voltammetric studies. [ABSTRACT FROM AUTHOR]

A method of one-stage formation of mesoporous structures on the surface of anodically oxidized aluminum with optimized synthesis time was developed. The chemical etching of surface as a method for application of pre-structural pore pattern was introduced into a scheme of preliminary operations for the first time. The main specific features of porous structure formation under the conditions of the given system are described. [ABSTRACT FROM AUTHOR]

The effect of various factors (anodic current density, composition of electrolyte, electrode material) on current efficiency of the anodic reaction of formation of Cr(VI) ions is established on Pt and composite TiO x/PtO y under electrolysis of solutions containing Cr 3+ ions. It is shown that the current efficiency values of Cr(VI) on TiO x/PtO y decrease at an increase in the active layer thickness and increase in the electrode treatment temperature. It is found that the major part of Cr(VI) compounds formed on the anode is reduced on the cathode and as a result of homogeneous chemical reactions in the bulk of electrolyte. [ABSTRACT FROM AUTHOR]

The effect of various factors (anodic current density, composition of electrolyte, electrode material) on current efficiency of the anodic reaction of formation of Cr(VI) ions is established on Pt and composite TiO x/PtO y under electrolysis of solutions containing Cr 3+ ions. It is shown that the current efficiency values of Cr(VI) on TiO x/PtO y decrease at an increase in the active layer thickness and increase in the electrode treatment temperature. It is found that the major part of Cr(VI) compounds formed on the anode is reduced on the cathode and as a result of homogeneous chemical reactions in the bulk of electrolyte. [ABSTRACT FROM AUTHOR]

Kinetics of low-frequency adsorption of benzene oxidation products are studied in 0.5 M K 2SO 4 on an anode of boron-doped diamond. A combination of current polarograms and impedance with analysis of the impedance spectroscopy in the frequency range of 0.05–10 Hz allowed studying in detail the mechanism of adsorption oxidation of benzene under the conditions of competition between this process and the more anodic process of oxygen evolution that is also based on adsorption. A frequency-polarization diagram of dependences of characteristic frequencies (CFs) of adsorption and desorption stages on potential was obtained for the product of benzene oxidation and oxygen-containing intermediate of the oxygen evolution reaction. Controlled stages of coupled processes, potentials, and characteristic frequencies of the points of changes in the reaction mechanism are determined: 0.22 Hz at 2.0 V for benzene oxidation; 0.63 Hz at 2.22 V for oxygen evolution. The potential of maximum adsorption of the organic substance is 2.15 V. The obtained results can be useful in the studies of the mechanism of coupled reactions including organic and inorganic intermediate adsorbates. [ABSTRACT FROM AUTHOR]

Benzene oxidation at boron-doped diamond anode in 1 M KCl aqueous solution is studied by electrochemical-impedance spectroscopy method. The measurements of differential capacitance and anodic current showed that in the ideal polarizability region benzene does not adsorb at the diamond electrode (or its adsorption does not affect the electrode capacitance). At more positive potentials adsorption of an inter-mediate of the benzene oxidation occurs, which partially blocks the electrode surface and results in decrease of anodic current. Analysis of the shape of the complex-plane plots of impedance spectra points out to diffusion of part of the adsorbed intermediate into solution. [ABSTRACT FROM AUTHOR]