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Search results for: ELECTROCHEMICAL CAPACITOR
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The effect of a polyharmonic structure of the perturbation signal on the results of harmonic analysis of the current of a first-order electrode reaction
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Atomic force microscopy based approach to local impedance measurements of grain interiors and grain boundaries of sensitized AISI 304 stainless steel
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Impedance analysis of Portevin-Le Chatelier effect on aluminium alloy
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The amplitude analysis of impedance spectra
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The fixed state in impedance measurements of a two-step electrode reaction proceeding with accompanying adsorption of an intermediate product
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Investigations of pitting corrosion of magnesium by means of DEIS and acoustic emission
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Ni-MOF-based electrodes: A promising strategy for efficient overall water splitting
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Ultrafast self-expanded reduced graphene oxide and 2D MoS2 based films as anode in Li-ion battery
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Electroactive heterojunctions of iron-based compounds in oxygen evolution reaction—Insight into synergy and mechanism
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Corrigendum to “Photocatalytical properties of maze-like MoO3 microstructures prepared by anodization of Mo plate” [Electrochim. Acta 228 (20 February) (2017) 139–145]
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Corrigendum to “Synthesis and photoelectrochemical behaviour of hydrogenated titania nanotubes modified with conducting polymer infiltrated by redox active network” [Electrochim. Acta 222 (20 December) (2016) 1281–1292]
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Phosphorus, nitrogen and oxygen co-doped polymer-based core-shell carbon sphere for high-performance hybrid supercapacitors
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Red phosphorus as self-template to hierarchical nanoporous nickel phosphides toward enhanced electrocatalytic activity for oxygen evolution reaction
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Toward elucidation of delithiation mechanism of zinc-substituted LiFePO4
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Hierarchical porous carbon materials from nanosized metal-organic complex for high-performance symmetrical supercapacitor
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Low-cost nitrogen-doped activated carbon prepared by polyethylenimine (PEI) with a convenient method for supercapacitor application
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Spectroelectrochemical characterization of euhedral anatase TiO2 crystals – Implications for photoelectrochemical and photocatalytic properties of {001} {100} and {101} facets
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Spectroscopic and microscopic study of Prussian blue film for electrochromic device application
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Impedance of cation-coupled electron transfer reaction: Theoretical description of one pathway process
PublicationIt has been assumed that cation electron coupled charge transfer can be conducted in accordance with two mutually coupled reactions. Using a differential method an expression was introduced which describes the impedance of a cation electron coupled transfer reaction. Also, an electrical equivalent circuit has been defined. The total faradaic impedance is the sum of electron transfer impedance and cation transfer impedance. Issues...
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Fluoroaromatic substituents attached to carbon nanotubes help to increase oxygen concentration on biocathode in biosensors and biofuel cells
PublicationBased on the known ability of perfluorodecalin/perfluorohydrocarbons to enhance oxygen solubility we modified oxygen sensitive biocathode by adding perfluorinated components to the catholite. This procedure improved the efficiency of the oxygen sensitive cathodes. Glassy carbon electrodes covered with single-wall carbon nanotubes (SWCNTs) with covalently bonded perfluoroaromatic groups were shown to be more sensitive to oxygen,...
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Induced-fit binding of laccase to gold and carbon electrodes for the biological fuel cell applications
PublicationAnalogues of laccase natural substrates (syringic, veratric, ferulic, vanillic, isovanillic, 3,5-dimethoxybenzoic aldehydes) were employed to bind and orient laccase molecules in a way which facilitates adsorption of the catalyst molecules and their electrical connection with the conductive support. Laccase was bound efficiently to these substrates both on gold and carbon electrodes forming, respectively, 2D and 3D films sensitive...
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Influence of electropolymerization conditions on the morphological and electrical properties of PEDOT film
PublicationIn this work the effects of electropolymerization conditions on the morphological properties and conductivity of poly(3,4-ethylenedioxythiophene) (PEDOT) film have been studied. PEDOT films were electrochemically synthesized in a one step process from acetonitrile solution containing 3,4-ethylenedioxythiophene (EDOT) and lithium perchlorate. Based on atomic force microscopy, scanning electron microscopy, cyclic voltammetry and...
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Arylated carbon nanotubes for biobatteries and biofuel cells
PublicationSinglwalled carbon nanotubes (swcnts)covalently phenylated, napthylated or terphenylated were used for the construction of cathodes in a biobattery and in a biofuel cell. zn is the anode in the biobaterry and single-walled carbon nanotubes are covalently modified with glucose oxidase/catalase (swcnt-gox/cat) and the biofuel cell anode. the cell parameters were determined and the potentials of each of the electrodes under cell working...
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Atomic force microscopy based approach to local impedance measurements of grain interiors and grain boundaries of sensitized AISI 304 stanless steel
PublicationPraca prezentuje wyniki badań uzyskane z pomiarów techniką lokalnej spektroskopii impedancyjnej (LIS) wykonanych w trybie kontaktowym mikroskopii sił atomowych (AFM), które zostały przeprowadzone w lokalnych obszarach powierzchni ziarna austenitu i na granicy ziarna austenitu wysokostopowej stali austenitycznej AISI 304 poddanej procesowi uczulania oraz na próbkach odniesienia nie poddanych obróbce cieplnej.Badania LIS-AFM były...
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Mesoscopic impedance analysis of solid materials surface
PublicationSeveral techniques have been developed in order to characterize electrical properties of surfaces in micrometer/nanometer scale. Obtaining of the spatial distribution of sample resistance, capacitance or potential requires separate measurements performed in different scanning modes. On the other hand, analysis of the frequency response of investigated system enables determination of several physical quantities in single measurement...
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Organic-inorganic composites consisted of poly(3,4-ethylenedioxythiophene)and Prussian Blue analogues
PublicationThe organic-inorganic material consisted of poly(3,4-ethylenedioxythiophene) (pEDOT) and copper hexacyanoferrate (Cuhcf) was synthesized. The pEDOT film with Fe(CN)63−/4− as counter-ions potentiodynamically polarized in aqueous CuCl2 electrolyte brings about stable hybrid material (pEDOT/Cuhcf) performing single redox activity of FeII/III at a formal potential Ef = 0.61 V (vs. Ag/AgCl/0.1 M KCl) and less clearly shaped two redox...
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Assessment of organic coating degradation via local impedance imaging
PublicationThe paper presents a new approach to organic coating condition evaluation at micrometer scale using localized impedance measurements. It is based on atomic force microscopy (AFM) in contact mode. Impedance is measured between conductive AFM tip and metal substrate covered with organic coating. A single-frequency voltage perturbation signal is applied between the electrodes and current response signal is registered. As the tip is...
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Preparation and characterisation of visible light responsive iodine doped TiO2 electrodes
PublicationPraca przedstawia charakterystykę domieszkowanego jodem ditlenku tytanu (I-TiO2) otrzymanego na drodze hydrotermicznej syntezy, gdzie prekursor stanowiły komplesy tytanu (IV) z ligandami zawierającymi atom jodu. Struktura nowego materiału została opisana za pomocą technik XPS, XRD, UV-vis i FT-IR-ATR. Badania te potwierdziły, że otrzymany proszek I-TiO2 ma zmniejszoną przerwę energetyczną. Praca prezentuje również badania elektrochemiczne...
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Detection of random transients caused by pitting corrosion
PublicationProces korozyjny może być badany za pomocą techniki szumu elektrochemicznego. Szum obserwowany jest jako fluktuacje prądowe i napięciowe w trójelektrodowym układzie pomiarowym. W celu stwierdzenia obecności korozji wżerowej wykonana została detekcja charakterystycznych sygnałów. Opracowany został algorytm oparty na analizie lokalnych zmian w spektrogramie rejestru prądowego. Spektrogram uzyskany został za pomocą krótkoczasowej...
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Towards spectroscopic monitoring of photoelectrodes: In-situ Raman photoelectrochemistry of a TiO2/prussian blue photoanode
PublicationHere, novel in-situ Raman photoelectrochemical measurements are performed. The obtained results have proved that it is possible to track the progress of a photoelectrochemical reaction that takes place on a semiconducting electrode using the spectroscopic method. As an exemplary system, the Ti/TiO2/Prussian blue electrode is investigated. Since TiO2 is an n-type semiconductor, it cannot act as an efficient anode in dark conditions....
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Multi-pathway mechanism of polydopamine film formation at vertically aligned diamondised boron-doped carbon nanowalls
PublicationBoron-doped carbon nanowall (B:CNW) electrodes were used as a platform for studying the electropolymerisation of dopamine. Due to the unique properties of B:CNW, including the fast charge-transfer kinetics and high surface conductivity, a high degree of reversibility of redox reactions was achieved. Three separated redox peaks were observed on voltammograms and attributed to three fundamental reactions in the dopamine polymerisation...
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SnO2 nanoparticles embedded onto MoS2 nanoflakes - An efficient catalyst for photodegradation of methylene blue and photoreduction of hexavalent chromium
PublicationIn this work, a molybdenum disulfide/tin oxide (MoS2/SnO2) composite was successfully prepared via a hydrothermal method. The MoS2/SnO2 composite was used as a photocatalyst for photoreduction of hexavalent chromium and photodecomposition of methylene blue. It exhibited higher photocatalytic performance under simulated solar light irradiation than MoS2 itself. The obtained material was characterized by several spectroscopic and...
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Study of oxygen electrode reactions on symmetrical porous SrTi0.30Fe0.70O3-δ electrodes on Ce0.8Gd0.2O1.9 electrolyte at 800 °C–500 °C
PublicationIron doped strontium titanates (SrTi1-xFexO3-δ) are an interesting mixed ionic-electronic conductor model used to study basic oxygen reduction/oxidation reactions. In this work, we performed an impedance spectroscopy study on symmetrical porous SrTi0.30Fe0.70O3-δ (STF70) electrodes on a ceriabased electrolyte. The sample was measured in varying oxygen concentration: from 0.3% to 100% in 800 °C - 500 °C temperature range. Low polarisation...
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Ionophores in polymeric membranes for selective ion recognition:impedance studies
PublicationW pracy badano dwa typy elektrod: membranowe elektrody jonoselektywne (ISE) oraz elektrody nowego typu all-solid-state (AAS). Elektrody AAS zawierają przewodzącą warstwę polimerową na węglu szklistym lub platynie, na który nałożona jest membrana zawierająca jonofor. Do badań użyto dwa jonofory: p-tert-butylokaliks[4]aren-korona-4 (L1) selektywnie kompleksująca jony Na+ oraz kaliks[4]aren-korona-6 (L2) selektywnie kompleksująca...
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The effect of tensile stresses on aluminium passive layer durability
PublicationW niniejszej pracy przedstawiono wyniki badań DEIS dotyczących wpływu naprężeń rozciągających na trwałość warstwy pasywnej aluminium A91050, prowadzonych w środowisku chlorków w temperaturze pokojowej.Zastosowana technika pozwoliła na wyznaczenie krytycznej wartości wydłużenia, przy której doszło do pęknięcia warstwy pasywnej na badanym stopie.
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Selection of measurement frequency in Mott-Schottky analysis of passive layer on nickel
PublicationPrzedstawiono zależności Mott'a - Schottky'ego dla różnych częstotliwości pomiarowych. Kształt uzyskanych zależności zależy od doboru tych częstotliwości. Związane jest to z tym, że stężenie defektów w warstwie pasywnej zależy od doboru częstotliwości. Metoda DEIS pozwala na uniknięcie tych niedogodności.
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Impedance analysis of Portevin-Le Chatelier effect on aluminium alloy
PublicationW niniejszej pracy przeprowadzono badania elektrochemiczne powierzchniowego efektu PLC, związanego z nierównomiernym procesem płynięcia plastycznego stopów aluminium zawierających magnez. Występujący efekt PLC w postaci serration wywołuje niehomogeniczny proces zmian zewnętrznej powierzchni rozciąganej próbki. Wykonano badania metodą Dynamicznej Spektroskopii Impedancyjnej w warunkach dynamicznych prowadzenia procesu rozciągania....
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Impedance of cation-coupled electron transfer reaction: teoretical description of one pathway process
PublicationPrzyjęto możliwość występowanie dwóch wzajemnie sprzężonych reakcji. Opisana została impedancja sprzężonej reakcji przeniesienia elektronu z kationem. Wyznaczony został również model elektrycznego schematu zastępczego. Całkowita impedancja Faradayowska jest sumą impedancji przeniesienia elektronu i impedancji przeniesienia kationu. Przykłady pomiaru impedancyjnego w warunkach potencjostatycznych i potencjodynamicznych zostały omówione....
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Understanding the capacitance of thin composite films based on conducting polymer and carbon nanostructures in aqueous electrolytes
PublicationIn this work electrochemical performance of thin composite films consisted of poly(3,4-ethylenedioxythiophene) (PEDOT), graphene oxide (GOx) and oxidized multiwalled carbon nanotubes (oxMWCNTs) is investigated in various sulphates (Li2SO4, Na2SO4, K2SO4, MgSO4) and acidic (H2SO4) electrolytes. Capacitance values, rate capability and cycling stability achieved for the composite layers are correlated with the electrolytes’ properties...
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Inhibitive effect of sodium molybdate on corrosion of AZ31 magnesium alloy in chloride solutions
PublicationIn this work, corrosion inhibition of the AZ31 magnesium alloy was investigated in NaCl solutions containing different amounts of sodium molybdate inhibitor. Electrochemical, hydrogen evolution, microscopic, and spectroscopic experiments were utilized to examine the mechanism of corrosion inhibition by molybdates. The results showed that Na2MoO4 inhibitor provides reliable inhibition at high concentrations (150 mM). Surface examination...
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Diamondized carbon nanoarchitectures as electrocatalytic material for sulfate-based oxidizing species electrogeneration
PublicationThe introduction of nanotechnology seems to be an imperative factor to intensify the synergic effects of electrocatalytic materials to produce strong oxidant species or to increase the active sites on their surfaces as well as to enhance the conversion yield in a fuel cell, high-added value products, electrolytic treatment for environmental protection or the detection limit in electroanalysis. Recently, a new type of 3D-diamond...
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The phenomenon of increasing capacitance induced by 1T/2H-MoS2 surface modification with Pt particles – Influence on composition and energy storage mechanism
PublicationIn this paper, several approaches to the synthesis of molybdenum-based electrode materials for supercapacitors are presented, including anodization, hydrothermal process and annealing. For the material prepared via anodization of a molybdenum plate, followed by a hydrothermal process in thiourea aqueous solution, a thorough study of the Pt-surface modification through repetitive cycling in 1 M sulfuric acid with Pt acting as a...
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Hydrothermal modification of TiO2 nanotubes in water and alkali metal electrolytes (LiNO3, NaNO3, KNO3) – Direct evidence for photocatalytic activity enhancement
PublicationThe influence of hydrothermal annealing (HA) of TiO2 nanotubes (TiO2-NTs) in various baths (H2O, LiNO3, NaNO3, KNO3 performed for 4 h, 24 h, 64 h), on their photocatalytic and photoelectrocatalytic properties, was studied. The use of electrolytes was to enable the monitoring of photoactivity changes as a result of the expected impact on the population of hydroxyl groups on the surface. The assumption turned out to be correct and...
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Instantaneous impedance monitoring of synergistic effect between cavitation erosion and corrosion processes
PublicationThe most common method of determination of cavitation erosion resistance as well as the magnitude of erosion-corrosion synergistic interaction is based on the weight loss measurements. Nondestructive characterization of installations elements is in most cases impossible to perform. Also, such a measurement does not include local types of failure or alteration of operating conditions. There is an urge to elaborate a method for monitoring...
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THE ROLE OF THIN FUNCTIONAL LAYERS IN SOLID OXIDE FUEL CELLS
PublicationWidespread commercialization of solid oxide fuel cells requires lowering its cost. It is generally accepted that to lower the cost of solid oxide fuel cells it is necessary to use metal alloys as interconnectors and, consequently, lower its operating temperature to slow down interconnectors degradation. As a result the area specific resistance of the cathodes should be lowered to sustain the performance of the cells. In order to...
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Voltammetric and biological studies of folate-targeted non-lamellar lipid mesophases
PublicationFolate-targeted lipid nanostructures are promising strategies for the development of biocompatible drug delivery systems. The objective of this study was to evaluate the efficacy of drug delivery to cancer cells by folate-targeted lipid mesophases, cubosomes (CUB) and hexosomes (HEX), loaded with doxorubicin (DOX). Three cancer-derived cell lines (KB, HeLa, T98G) exhibiting different expressional levels of folate receptor protein...
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Influence of the electrosynthesis conditions on the spontaneous release of anti-inflammatory salicylate during degradation of polypyrrole coated iron for biodegradable cardiovascular stent
PublicationIn this work, the spontaneous release of anti-inflammatory salicylate from polypyrrole (PPy) coated iron has been studied during degradation of the material in phosphate buffer saline at 37 C. The sodium salicylate was incorporated into PPy in a one-step electropolymerization process. The influence of the synthesis conditions such as sodium salicylate concentration, pyrrole concentration and deposition charge on drug release profile...
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Understanding the origin of high corrosion inhibition efficiency of bee products towards aluminium alloys in alkaline environments
PublicationVarious bee products were found to be efficient corrosion inhibitors of aluminium in different environments. In particular, bee pollen was found to be highly effective in alkaline electrolytes, yet its highly complex composition and possible synergistic interactions hinder determination of the compounds acting as active corrosion inhibitors. The main purpose of the following work is to investigate the effect of solvents used for...
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Determination of pitting corrosion stage of stainless steel by galvanodynamic impedance spectroscopy
PublicationThis paper investigates the methodology for differentiation of multistep process of pitting corrosion of AISI 304 stainless steel in the environment of iron (III) chloride. Measurements were performed using Galvanodynamic Electrochemical Impedance Spectroscopy (GDEIS). Application of this methodology allowed monitoring of natural corrosion process without external current (IDC = 0A) nor potential perturbation of the system. Applied...
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The influence of polarization of titania nanotubes modified by a hybrid system made of a conducting polymer PEDOT and Prussian Blue redox network on the Raman spectroscopy response and photoelectrochemical properties
PublicationIn this work we show the impact of applied potential on network vibrations and photoelectrochemical properties of a composite material containing hydrogenated titania nanotubes and poly (3,4-ethylenedioxythiophene) with iron hexacyanoferrate (H-TiO2/pEDOT:Fehcf) acting as a redox centre. For this purpose, Raman spectroscopy measurements under the working electrode (WE) polarization were carried out, allowing investigation of changes...