ННІ “Український державний хіміко-технологічний університет” (ННІ УДХТУ)

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ENG: Ukrainian State University of Chemical Technology (USUCT)

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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.
Electrochemical Discharge of Nickel With Low Internal Stresses
(Oles Honchar Dnipro National University, Dnipro, 2025) Sknar, Yuri; Sknar, Irina V.; Butyrina, Tetiana E.
ENG: The work is devoted to the current topic of electrochemical separation of nickel with low voltages from sulfate electrolytes of electroextraction. Scrap processing of strategic nickel-containing superalloys with electroextraction of nickel is an urgent task today. Electrochemically deposited nickel is characterized by high internal tensile stresses, which leads to its delamination from the cathode surface. To reduce the internal stresses of nickel deposits obtained in such systems, it is proposed to use sulfur-containing organic compounds of sodium allylsulfonate, sodium orthoarylsulfonate, and sodium propynylsulfonate. It was established that allylsulfonate and orthoarylsulfonate practically do not affect the kinetics of nickel release. Propynyl sulfonate with a concentration of more than 5 mmol/l significantly inhibits the process of electrodeposition of nickel, which is related to the adsorption capacity of this compound with the triple bond present in the molecule. It is shown that due to the presence of a sulfo group in the composition of the molecules, the used organic additives contribute to the reduction of the internal stresses of nickel deposits. It was established that allyl sulfonate and orthoaryl sulfonate are the most promising reagents that contribute to reducing the internal stresses of electrodeposited nickel. Lowstress nickel deposits can be obtained in the range of current densities from 2 to 7 A/dm2 at a concentration of these additives from 15 to 30 mmol/l.
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.