Кафедра "Фізична хімія"

Постійне посилання колекціїhttps://repository.kpi.kharkov.ua/handle/KhPI-Press/1402

Офіційний сайт кафедри http://web.kpi.kharkov.ua/fchem

Кафедра "Фізична хімія" заснована в 1926 році професором Олександром Миколайовичом Щукарьовим. Свої витоки вона веде від 1918 року, коли кафедра хімії розділилася на кафедри неорганічної, органічної, аналітичної і фізичної хімії.

У різні роки нею керували професори Ілля Іванович Стрєлков, Сергій Степанович Уразовський, Аркадій Юхимович Луцький, Володимир Мойсейович Кошкін. Від 2012 року кафедру очолює доктор технічних наук, професор Микола Дмитрович Сахненко, академік АН Вищої освіти України.

Кафедра входить до складу Навчально-наукового інституту хімічних технологій та інженерії Національного технічного університету "Харківський політехнічний інститут". Наукова школа кафедри включає понад 90 кандидатів і докторів наук.

У складі науково-педагогічного колективу кафедри працюють: 2 доктора та 2 кандидата технічних наук, 1 кандидат хімічних наук; 1 співробітник має звання професора, 2 – доцента, 1 – старшого наукового співробітника, 1 – старшого дослідника.

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The Role of Electrolysis Regimes in the Formation of Metal and Metal Oxide Coatings from Complex Citrate Electrolytes
(Київський національний університет технологій та дизайну, 2020) Sachanova, Yu. I.; Sakhnenko, N. D.; Ved', M. V.; Yermolenko, I. Yu.; Pospelov, A. P.
Modified titanium oxide coatings for environmental technologies
(Chuiko Institute of Surface Chemistry of National Academy of Sciences of Ukraine, 2016) Sakhnenko, N. D.; Ved’, M. V.; Galak, A. V.
Nanocomposite electrolytic coatings based on cobalt alloys with refractory metals: obtaining, properties, application
(Kazakh University IP "Center for Operational Printing", 2022) Yar-Mukhamedova, G. Sh.; Nenastina, T. A.; Ved, M. V.; Sakhnenko, N. D.; Karakurkchi, A. V.
Modern electrochemical technologies for surface treatment of titanium alloys to create protective, antifriction, dielectric, and catalytically active materials are considered. The physicochemical fundamentals of the processes of plasma-electro-lytic formation of conversion and composite electrolytic coatings are highlighted. Separate stages of electrode reactions, regularities of the influence of electrolyte components, and electrolysis parameters on the composition, structure, and morphology of synthesized materials are examined in detail. Considerable attention is paid to improving the synthesis of multicomponent alloys and composites based on cobalt from aggregative stable and stable electrolyte solutions, and flexible control of the composition and functional properties of materials is an urgent scientific and technical problem, the solution of which is the presented study. The monograph summarizes the results of the project AP 08855457, "Development of an innovative technology for producing nanocrystalline composite coatings for fuel cell electrodes and hydrogen energy". This research has been funded by the Science Committee of the Ministry of Education and Science of the Republic of Kazakhstan. The monograph is designed for specialists in the field of chemical technology, as well as teachers, graduate students, and students of higher educational institutions.
Сorrosion behavior of the electrolytic ternary cobalt alloys with Mo(W) and Zr in alkaline solution
(Інститут загальної та неорганічної хімії ім. В. І. Вернадського, 2019) Nenastina, T. A.; Ved, M. V.; Sakhnenko, N. D.; Yermolenko, I. Yu.; Proskurina, V. A.; Volobuyev, M. M.
The ternary Co–Mo–W(Zr) coatings with total content of refractory metals of 30–40 wt.%, and Co–W–Zr alloys (12–26 wt.%) are deposited from pyrophosphate-citrate electrolytes in pulse regime. The composition of the coatings as well as the surface morphology depends on the current density. The X-ray diffraction patterns reflect the amorphous-and-crystalline ternary alloys structure. Phases of α-Co, Co–Mo intermetallic compounds, and traces of metallic molybdenum were detected in the Co–Mo–Zr coatings. Phase composition of Co–Mo–W deposits differs by emergence of Co₇W₆ phase and traces of metallic tungsten, and there is no metallic W in Co–W–Zr electrolytic alloys. The corrosion behavior of ternary coatings in alkaline medium studied by EIS shows that Co–Mo–Zr alloys are characterized by highest corrosion resistance among deposited coatings due to presence of metallic molybdenum and stoichiometric ZrO₂ with both high electrical resistivity and chemical stability. The coatings Co–Mo–W and Co–Mo–Zr containing phases of Mo or W are characterized by higher corrosion resistance as compared with that without metallic molybdenum and tungsten. The cyclic voltammetry data confirm stability of ternary coatings in alkaline solution under anodic polarization. Such properties as well as the developed globular surface make materials promising for use as anodes in fuel cells in particular based on alkali electrolytes.
Ternary Fe–Co–Mo alloys as catalytic materials in oxidations reactions of low molecular weight alcohols
(Київський національний університету технологій та дизайну, 2019) Sachanova, Yu. I.; Sakhnenko, N. D.; Ved, M. V.; Yermolenko, I. Yu.; Volobuyev, M. N.
The electrocatalytic properties of ternary Fe–Co–Mo alloys synthesized from complex Fe(III) – citrate electrolytes are discussed. The relationship between the composition and surface morphology of electrolytic alloys is considered. It was found that the optimal content of molybdenum in the alloy ranges from 12 to 18 at.%. The increase in the content of this component is not possible, since it can lead to cracking and wear of the surface due to the occurrence of internal stresses. The formation of the globular structure of the alloy Fe–Co–Mo is due to the presence of a refractory metal. The resulting alloys exhibit electrocatalytic activity in the oxidation reactions of methanol and ethanol, as evidenced by the high values of currents in the anodic and cathodic regions of cyclic voltammetric dependencies with maximum values at 0.56 V and 0.6 V, respectively. The course of adsorption of methanol and ethanol on the surface of the alloy Fe–Co–Mo has been established.
Composition, Morphology, and Topography of Galvanic Coatings Fe–Co–W and Fe–Co–Mo
(2017) Yermolenko, I. Yu.; Ved, M. V.; Sakhnenko, N. D.; Sachanova, Yu. I.
Ternary coatings Fe-Co-W with an iron content of 40–55 at.%, cobalt 39–44 at.%, and tungsten 4–12 at.% and Fe-Co-Mo with an iron content of 40–55 at.%, cobalt 39–44 at.%, and tungsten 4–12 at.% were obtained by galvanostatic and pulse electrolysis on the mild steel substrate from iron(III) citrate-based electrolyte. The influence of electrolysis mode and parameters on composition of deposited alloys was studied. The competing reduction of iron and tungsten in Fe-Co-W coatings as well as the competitive deposition of iron and cobalt in Fe-Co-Mo coatings at various current densities were defined. Simultaneously, the alloy enrichment with molybdenum is more marked at a pulse mode. Atomic force microscope analysis of the Fe-Co-W alloy coating morphology and surface topography indicates their globular structure with spherical grains in the range of 2.5–3.5 μm. The surface of Fe-Co-Mo is characterized by parts of a globular structure with an average conglomerate size of 0.3–0.5 μm and singly located cone-shaped hills with a base diameter of 3 μm. Sites with a developed surface were detected within the same scan area which topography is identical to the crystal lattice of cobalt with the crystalline conglomerate sizes in the range of 0.2–1.75 μm.
Cobalt based coatings as catalysts for methanol oxidation
(Науково-технологічний комплекс "Інститут монокристалів", 2020) Nenastina, T. A.; Ved, M. V.; Sakhnenko, N. D.; Yermolenko, I. Yu.; Volobuyev, M.; Proskurina, V. O.
The cobalt based coatings with refractory metals (Mo, W, Zr) were deposited from pyrophosphate-citrate electrolytes in a pulsed mode. It has been shown that, with increasing current density, Co-Mo-W and Co-W-ZrO2 alloys are enriched in tungsten, grain sizes decrease, but a network of cracks appears on the surface of the Co-Mo-W coating. In the Co-Mo-ZrO2 coating, with increasing current density, the zirconium content increases due to molybdenum, and the surface is the most fractured and small-globular. The surface roughness parameters for Co-Mo-ZrO2 are one order of magnitude higher than those for Co-Mo-W. Cyclic voltammograms show that the Co-Mo-ZrO2 deposits are characterized by the highest stability under anodic polarization due to the inclusion of molybdenum and zirconium(IV) oxide in their composition. The kinetics of the methanol anodic oxidation on electrodes coated with cobalt alloys was studied, and the participation of intermediate metal oxides in oxygen transport was revealed. A significant increase in the anode current peak indicates a higher electro-catalytic activity of the zirconium-containing coatings among the studied alloys.
Corrosion properties of galvanic Fe–Mo(W), Fe–Mo–W coatings
(Науково-технологічний комплекс "Інститут монокристалів", 2019) Ved, M. V.; Sakhnenko, N. D.; Karakurkchi, A. V.; Pershina, K. D.; Yermolenko, I. Yu.
The methods of analysis of polarization dependences, the electrode impedance spectroscopy and gravimetry were used for the investigation of the corrosion properties of galvanic binary Fe–Mo(W) and ternary Fe–Mo–W coatings in the media of a different acidity. It was shown that the corrosion rate of Fe–Mo–W and Fe–Mo(W) alloys is decreased with an increase in the pH of the solutions and with the enrichment of the alloys by doping refractory components. The dependence of the control of corrosion process on the composition of electrolytic alloys has been specified. It was established that the corrosion resistance of binary alloys is 1.1 to 1.5 orders of magnitude higher in comparison with the parameters of substrate materials, in particular the mild steel. The corrosion resistance indices for the coatings applied using the ternary Fe–Mo–W alloys substantially prevail over those for mild steel, individual metals and binary Fe–Mo and Fe–W coatings. The corrosion resistance of Fe–Mo–W system is equal to 8300 Ohm·cm² and it is conditioned by the formation of the two-component layer film consisting of molybdenum oxides and tungsten oxides. Using the data of gravimetric investigations we constructed the diagrams "the corrosion depth index kh, mm/year – the composition" for the Fe–Mo–W system that allow us to define the metal content ratio for Fe–Mo(W), Fe–Mo–W alloys in order to provide an appropriate corrosion resistance depending on service conditions.
Galvanic ternary Fe−Co−W coatings: structure, composition and magnetic properties
(Науково-технологічний комплекс "Інститут монокристалів", 2018) Yermolenko, I. Yu.; Ved, M. V.; Sakhnenko, N. D.; Fomina, L. P.; Shipkova, I. G.
Principles of Fe–Co–W alloys electrodeposition from complex Fe (III) based citrate electrolytes are discussed. The effect of both current density and pulse on/off time on the quality, composition and surface morphology of the electrolytic alloys were determined. The application of pulsed electrolysis provides increasing ungsten content up to 13 at.%, at current efficiency of 70-75 %. Globular surface of Fe–Co–W coatings is caused by refractory metals incorporation, and crystalline and amorphous parts of structure are visualized by X-ray spectroscopy, including inter-metallic phases Co₇W₆, Fe₇W₆ along with α-Fe and Fe₃C. The coherent-scattering region size of the amorphous part is 2-8 nm. Magnetic characteristics of amorphous Fe–Co–W coatings were measured in dependence of deposition ime. The conclusion was made that the content of magnetic phase in upper layers of coating is greater than in the bottom ones due to decreasing W atom concentration.
Effect of Electrodeposition Parameters on the Composition and Surface Topography of Nanostructured Coatings by Tungsten with Iron and Cobalt
(Institute of Combustion Problems, Kazakhstan, 2020) Yar-Mukhamedova, G. Sh.; Ved, M. V.; Yermolenko, I. Yu.; Sakhnenko, N. D.; Karakurkchi, A. V.; Kemelzhanova, A.
The electrodeposition of binary and ternary coatings Fe-W and Fe-Co-W from mono ligand citrate electrolyte has been investigated. The Fe-Co-W coatings were formed from electrolytes, which composition differs in the ratio of the concentrations of the alloying components and the ligand content. The investigation results indicate a competitive reduction of iron, cobalt and tungsten, the nature of which depends both on the ratio of electrolyte components, and electrolysis parameters. The effect of both current density amplitude and pulse on off time on quality, composition and surface morphology of the galvanic alloys was determined. Coatings deposited on a direct current with a density of more than 6.5 A/dm², crack and peel off from the substrate due to the inclusion of Fe (III) compounds containing hydroxide anions. The use of non-stationary electrolysis allows us to extend the working range of current density to 8.0 A/dm² and form electrolytic coatings of sufficient quality with significant current efficiency and the content of the refractory component. The presence of the Co₇W₆, Fe₇W₆, α-Fe, and Fe3C phases detected in the Fe-Co-W deposits reflects the competition between the alloying metals reducing from hetero-nuclear complexes. The surface of binary and ternary coatings is characterized by the presence of spherical agglomerates and is more developed in comparison with steel substrate. The parameters Ra and Rq for electrolytic alloy Fe-W are of 0.1, for Fe-Co-W are 0.3, which exceeds the performance of a polished steel substrate (Ra = 0.007 and Rq = 0.010). These properties prospect such alloys as a multifunctional layer are associated with structural features, surface morphology, and phase composition.