Browsing by Author "Protsenko, Vyacheslav S."

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Des-Assisted Electrodeposition and Characterization of an Electrocatalyst for Enhanced Urea Oxidation in Green Hydrogen Production
(Ukrainian State University of Science and Technologies, Dnipro, 2025) Protsenko, Vyacheslav S.; Shaiderov, D. A.; Sukhatskyi, O. D.; Butyrina, Tetiana E.; Korniy, S. A.; Danilov, F. I.
ENG: An important task of modern materials science is the development of highly efficient electrocatalysts for green hydrogen production. Specifically, this involves the urea oxidation reaction (UOR), which is an energetically advantageous and attractive alternative to the anodic oxygen evolution reaction, coupled with hydrogen evolution at the cathode. In this work, we present for the first time the use of systems based on a new generation of environmentally friendly room-temperature ionic liquids – deep eutectic solvents (DESs) – for the electrodeposition of electrocatalysts for UOR. The electrochemical performance of electrodeposited nanocomposite Ni–CeO2 electrocatalysts was evaluated in alkaline solution, showing an appreciable reduction in the anodic potential of UOR compared to oxygen evolution, reaching up to approximately 0.2 V at a current density of 0.1 mA cm–2. The obtained results are significant for the development of electrochemical synthesis methods for electrocatalysts used in green renewable energy.
Effect of Na+ vs. K+ Cations and Carbonate Presence on Urea Oxidation Reaction Coupled with Green Hydrogen Production in Alkaline Media: A Voltammetric and Electrochemical Impedance Spectroscopy Study
(Hydrogen, 2025) Protsenko, Vyacheslav S.; Shaiderov, Denys A.; Sukhatskyi, Oleksandr D.
ENG: This work reports the electrochemical behavior of a nickel hydroxide electrode, electrodeposited in a deep eutectic solvent (DES), in alkaline solutions of varying composition, aiming to elucidate the influence of the cation (Na+ vs. K+), urea, and carbonate ions on the mechanism and kinetics of anodic processes. Cyclic voltammetry and electrochemical impedance spectroscopy were employed to analyze the electrochemical responses of electrode processes in alkaline water electrolysis systems. For the urea oxidation reaction (UOR), the frequency-dependent characteristics were thoroughly characterized, and the impedance response was simulated according to the Armstrong–Henderson equivalent circuit. It was found that the addition of urea significantly transforms the impedance structure, sharply reducing the polarization resistance and increasing the pseudo-capacitive component of the constant phase element at low frequencies, indicating activation of the slow steps of urea oxidation via a direct mechanism and the formation of an extended adsorptive surface. It was demonstrated that, unlike conventional alkaline electrolysis where KOH-based systems are generally more effective, urea-assisted systems exhibit superior performance in NaOH-based electrolytes, which provides more favorable kinetics for the electrocatalytic urea oxidation process. Furthermore, the accumulation of carbonate ions was shown to negatively affect UOR kinetics by increasing polarization resistance and partially blocking surface sites, highlighting the necessity of controlling electrolyte composition in practical systems. These findings open new opportunities for the rational design of efficient urea-assisted electrolyzers for green hydrogen generation.
Electrochemical Corrosion Properties and Protective Performance of Coatings Electrodeposited from Deep Eutectic Solvent-Based Electrolytes: A Review
(Materials, 2025) Protsenko, Vyacheslav S.
ENG: The application of deep eutectic solvents (DESs) as an innovative class of environmentally friendly liquid media represents a significant advancement in materials science, especially for the development and enhancement of structural materials. Among the promising applications, DESs are particularly attractive for the electrodeposition of corrosion-resistant coatings. It is established that corrosion-resistant and protective coatings, including those based on metals, alloys, and composite materials, can be synthesized using both traditional aqueous electrolytes and non-aqueous systems, such as organic solvents and ionic liquids. The integration of DESs in electroplating introduces a unique capacity for precise control over microstructure, chemical composition, and morphology, thereby improving the electrochemical corrosion resistance and protective performance of coatings. This review focuses on the electrodeposition of corrosion-resistant and protective coatings from DES-based electrolytes, emphasizing their environmental, technological, and economic benefits relative to traditional aqueous and organic solvent systems. Detailed descriptions are provided for the electrodeposition processes of coatings based on zinc, nickel, and chromium from DES-based baths. The corrosion–electrochemical behavior and protective characteristics of the resulting coatings are thoroughly analyzed, highlighting the potential and future directions for developing anti-corrosion and protective coatings using DES-assisted electroplating techniques.
Electrodeposition of Nanocrystalline Chromium–Carbon Alloys from Electrolyte Based on Trivalent Chromium Sulfate Using Pulsed Current
(Springer, 2012) Protsenko, Vyacheslav S.; Danilov, Fedor I.; Gordiienko, Victor O.; Baskevich, Alexander S.; Artemchuk, Viktor V.
EN: The effect of pulse parameters on the electrolysis current output, nanocrystals size, composition, hardness, friction coefficient and wear resistance of nanocrystalline coatings Cr-C, obtained from the sulfuric acid-based electrolyte salts Cr (III), comprising urea and formic acid. It is shown that coatings containing ~ 9% (wt.) carbon; current density and duty cycle do not affect the composition blocked. It was found that depending on the current output from the duty cycle when there is a maximum duty cycle ~ 1.05 ... 1.1, where the output current significantly exceeds the value realized in current-mode steady-state. It is shown that if the micro-hardness Cr-C deposits obtained at DC, is close to 850-900 HV, then using a pulsed electrolysis in certain modes may increase the microhardness up to ~ 1200-1300 HV. Found that the use of pulsed electrolysis can significantly reduce the coefficient of friction chrome-carbon cover (with steel counterbody) in conditions of dry friction and under boundary lubrication, and also increases the durability of precipitation.
Electrodeposition of Ni-Based Composite Coatings Containing Cerium Compounds From a Deep Eutectic Solvent and their Electrocatalytic Performance
(Oles Honchar Dnipro National University, Dnipro, 2025) Protsenko, Vyacheslav S.; Shaiderov, Denys A.; Sukhatskyi, Oleksandr D.; Korniy, Sergiy A.
ENG: This work examines the electrodeposition of Ni-based composite coatings containing cerium compounds from a eutectic mixture of choline chloride and urea (reline), a typical deep eutectic solvent. The data reveal that depending on the concentrations of NiCl26H2O and CeCl37H2O dissolved in reline, coatings containing up to 49 wt.% cerium, present as embedded CeO2, can be formed within an electrochemically deposited nanocrystalline nickel matrix. Variation of the Ni(II) and Ce(III) salt concentrations strongly influences the resulting surface morphology. Reaction schemes for the formation of these composite coatings are proposed, and cyclic voltammetry with successive scan cycles was used to identify the potential windows in which the relevant electrochemical reactions occur in reline-based solutions. The deposited coatings were tested as electrocatalysts for water electrolysis in 1 M NaOH. Special attention was paid to the electrocatalytic activity of the Ni-based composite coatings toward the anodic oxidation of urea, a potential alternative to the oxygen evolution reaction in green hydrogen production. Incorporation of CeO2 into the nickel matrix led to a pronounced enhancement of electrocatalytic activity for hydrogen evolution, oxygen evolution and urea oxidation in alkaline aqueous solution. The proposed composite coatings may find application as multifunctional catalysts for green hydrogen generation. Moreover, adjusting the Ni(II) and Ce(III) concentrations in the deep eutectic solvent-based plating bath enables flexible and controlled tuning of the electrocatalytic behavior of deposited coatings.
Electroplating of Wear-Resistant Nanocrystalline Coatings from a Bath Containing Basic Chromium(III) Sulfate (chrome tanning agent)
(Pleiades Publishing, Ltd., 2013) Danilov, Felix I.; Protsenko, Vyacheslav S.; Gordiienko, Viktor O.; Baskevich, Aleksandr S.; Artemchuk, Viktor V.
ENG: Regularities of the electroplating of chromium–carbon alloy coatings from a bath containing basic chromium(III) sulfate, carbamide, formic acid, sodium sulfate, aluminum sulfate, orthoboric acid, and sodium dodecyl sulfate are studied. Replacement of chromium sulfate as a source of trivalent chromium ions in the solution with basic chromium sulfate (chrome tanning agent) results in a decrease in the current density when metal deposition begins. As a result, the covering power of the bath increases. The effects discovered are determined by changes in the composition of the discharged chromium complexes. A certain excess of OH– groups in the inner sphere of electroactive chromium complexes results in acceleration of electroplat ing. The studied electrolyte based on chrome tanning agent enables one to produce thick high quality nanoc rystalline Cr–C alloy coatings with improved tribological characteristics.
Improving Hardness and Tribological Characteristics of Nanocrystalline Cr-C Films Obtained from Cr(III) Plating Bath Using Pulsed Electrodeposition
(Elsevier Science Publishing Company, Inc., 2012) Protsenko, Vyacheslav S.; Danilov, Fedor I.; Gordiienko, Victor O.; Baskevich, Alexander S.; Artemchuk, Viktor V.
EN: Effect of pulsed electrodepostion on the nanocrystal size, composition, hardness, coefficient of friction and wear resistance was investigated for the Cr–C electrodeposits obtained from a trivalent chromium bath. The electrodeposits were shown to contain about 9% of carbon. Pulsed electrodeposition does not virtually affect the carbon content. At the same time, an increase in the off time duration leads to a decrease in the nanocrystals size. The hardness and wear parameters of the electrodeposits may be sufficiently improved when using pulsed current. For instance, at ton=toff=1 s, the hardness reaches the values of ~1200÷1300 HV (meanwhile, it is close to 850÷950 HV at a steady-state electrolysis).
An Integral Metric for Evaluating Electrocatalytic Activity
(Chemija, 2025) Protsenko, Vyacheslav S.; Makhota, Dmytro O.
ENG: This study introduces an integral metric of electrocatalytic activity, which is based on the comparison of the area under the polarisation curve in current density vs overpotential coordinates over a specific chosen overpotential range. This metric is applied to evaluate and compare several electrocatalysts, allowing for a more comprehensive understanding of electrocatalytic performance. Unlike traditional metrics, which characterise electrocatalyst behaviour under specific conditions (e.g. a particular overpotential or current density), the proposed integral metric provides a broader evaluation over a wide operational range. This approach is particularly useful for electrocatalysts with different Tafel slopes and polarisation characteristics. The metric is shown to be invariant to the shape of the polarisation curve and can be applied even when the exact form of the analytical dependence is unknown. The application of this metric holds promise for both fundamental studies in electrocatalysis and for practical applications in selecting the most efficient electrocatalysts for various technological processes.
Investigation of Structural, Magnetic, Optical, and Photocatalytic Properties of Fe/CoFe2O4 Composite
(MDPI AG, Basel, Switzerland, 2025) Frolova, Liliya A.; Protsenko, Vyacheslav S.; Butyrina, Tetiana E.
ENG: A Fe/CoFe2O4 nanocomposite was synthesized in one step by a hydrothermal method by processing the created iron and cobalt hydroxocomplexes. For precise characterization of the structure and morphology, X-ray diffraction (XRD), Fourier transform infrared spectroscopy, scanning electron microscopy, and ultraviolet–visible diffuse reflectance spectroscopy (UV-vis-DRS) were used. It was found that the obtained samples have a pronounced spinel crystalline structure, with the presence of metallic iron. The crystal size was determined by various methods and was 93–104 nm. The saturation magnetization, determined from the hysteresis loop, was 189.24 Emu/g, and the force coefficient was 602 Oe. UV-vis-DRS studies showed a band gap of 2.1 eV. The photocatalytic degradation of ibuprofen, streptocide, furacilin, methylene blue, and tetracycline was investigated under the influence of UV radiation in the presence of a photocatalyst. It was confirmed that the rate of degradation of pollutants obeys pseudo-first-order kinetics. Analysis of the constant rate of reactions showed that in order of decreasing stability, pharmaceutical drugs can be dissolved as follows: ibuprofen → streptocide → furatsilin → methylene blue → tetracycline. It was found that the ratio of photocatalyst and hydrogen peroxide concentrations is important for the destruction of more stable pollutants. The effect of hydrogen peroxide and catalyst concentrations is extremely strong. For unstable compounds, the most influential factor is the duration of treatment.
Towards Sustainable Urea Electro-Oxidation: a Thermodynamic and Green Chemistry Evaluation of Alternative Pathways
(Royal Society Open Science, 2025) Protsenko, Vyacheslav S.
ENG: This study presents a comparative thermodynamic analysis of various pathways for electrochemical hydrogen production coupled with the anodic oxidation of urea, offering a sustainable alternative to the conventional oxygen evolution reaction. For the first time, the feasibility and efficiency of these processes were evaluated using integrated green chemistry metrics, including atom economy and a newly proposed metric, electricity economy, which quantifies the theoretical minimum electrical energy required for the equilibrium formation of reaction products. The analysis demonstrated that urea-oxidation pathways generally require significantly less energy input than water electrolysis. Among the examined reactions, the oxidation of urea to gaseous nitrogen and carbonate ions was identified as the most efficient, with an electricity economy of –4650.83 J mol–1 and an atom economy of 6.4%. However, practical application is hindered by issues such as low product selectivity and high anodic potentials dictated by the redox thermodynamics of commonly used nickel-based catalysts. These findings underscore the need for next-generation electrocatalysts with enhanced selectivity and lower overpotentials to fully exploit the energetic advantages of urea oxidation for green hydrogen production.