Areas of work of the department

Areas of the Institute`s, research in which the department conducts scientific research: electrochemistry of molten, liquid and solid electrolyte and electrode systems.

History of the department

Corresponding Member of the National Academy of Sciences of Ukraine G.Y. Kolbasov, Head of the Department of Electrochemistry and Photoelectrochemistry of Nonmetallic Systems

The Department of Electrochemistry and Photoelectrochemistry of Nonmetallic Systems conducts research on the photoelectrochemical properties of semiconductor materials and oxide systems, develops electrochemical cells for the production and accumulation of "solar" hydrogen, studies the phenomenon of electrochromism on metal oxides and hybrid systems, investigates materials for electrochemical and optical sensors, studies the electrochemical properties of transition metal oxides of non-stoichiometric composition and creates materials based on them for solar collectors and chemical curent sources.

The Department was founded in 1998 under the name "Photoelectrochemistry and Chemical Current Sources named after Academician O.V. Horodysskyi" (Head: Doctor of Chemistry , Professor H.Y. Kolbasov) on the basis of the scientific groups of the Departments of Electrochemistry of Nonmetallic Systems, headed by Doctor of Chemistry, Prof. O.T. Vasko, Secondary Chemical Current Sources and Electrode Processes named after O.V. Horodysskyi (Head: Doctor of Chemistry N.D. Ivanova), Rechargeable Current Sources (Head: Doctor of Chemistry, Prof. V.Z. Barsukov). The department originate from the Department of Electrode Processes, which was founded in 1946, and its first head was Doctor of Chemistry O. Kudra. In 1952, this department was renamed into the Hydrometallurgy Department, which was headed by Ph. D. Zosymovych. From 1970 to 1992, the department was headed by Academician O.V. Horodyskyi. In 2016, the department was merged with the Department of Electrochemical Synthesis in Melts named after Academician Y.K. Delimarskyi (headed by Doctor of Chemistry, Professor E.V. Panov) and received its current name.

Photoelectrochemical research at the department began with the study of the photosensitivity of electrodes based on polycrystalline AIIBVI semiconductor compounds of the type in order to create photoelectrochemical solar energy converters (PECs). The theory of PECs, which takes into account generation-recombination processes and photostimulated transfer of charge carriers in the bulk of the semiconductor electrode and at the interface, developed, and the distribution of ionic speciesin polysulfide solutions with different values of the ratio of sulfur to sodium sulfide (Xs), which are used in regenerative PECs, was calculated. It was shown that at high illumination intensity and at Xs 2, the stage controlling the photoelectrochemical process in the CdSe - polysulfide electrolyte system is the diffusion of electroactive HS species to the surface of the photoelectrode; the mechanism of stabilizing effect of additives to the polysulfide solution of PEC, such as thiosulfate ions, etc., which allow the use of photoelectrodes for a long time, was determined.

One of the promising lines of research of the Departament is Photoelectrochemistry of nanostructured semiconductor materials, including semicobductor oxide compounds. Photoelectrochemical processes on nanostructured AIIIBV and AIIBYI semiconductor compounds and their solid solutions and Photoelectrocatalysis on Ti, Zr, Hf, Zn oxide nanoparticles were studient. Semiconduktor electrodes were nanostructured by modifying their sueface with nanoparticles of metals (Pt, Pd, Zn, Ni) or semiconductors (Cds, TiO₂,YiO₂ - ZrO₂).The results of tained on modified electrodes showed that surface nanostructuring increases greatly their photosensitivity, and the mechanism of this effect was determined.

In addition to semiconductor electrodes, photoelectrochemical processes were also studied on Cu, Rh, Li, Au, Sb, Pt electrodes [15-18], on the surface of which oxide phase layers can exist, and where electrolyte components are adsorbed and chemically interact with the metal. The composition of the surface layer can vary depending on the electrode potential and significantly affect the kinetics of charge phototransfer across the interfacial interface. Thus, in the cathodic potential region, it was shown on a number of metals that the classical photoemission process is superimposed by photostimulated charge transfer from the surface layer to the electrolyte or to the metal, which was manifested in the appearance of an additional photocurrent in the long-wave region of the spectrum. It was found that the contribution of surface phase or adsorption layers to the photoelectrochemical kinetics is very significant on almost all studied metal electrodes. These results showed that the photoelectrochemical method is a promising method for determining the state of the electrode surface in situ.

The Department developed photoelectrochemical solar energy converters in several directions. for instance, highly sensitive thin films of single-crystal compounds of the AIIIBV and AIIBVI type were used as photo electrodes of regenerative converters. The use of methods of chemical modification of the surface of these compounds, leading to a decrease in the rate of surface recombination, as well as the creation of n+-n structures with a thin n-region, where the recombination processes are significantly reduced, and the synthesis of nanocomposites based on these compounds and graphene allowed to obtain photoelectrodes that are photosensitive in a wide spectral range. A photoelectrochemical system with separated anode and cathode spaces for the production of "solar" hydrogen has been developed, which has advantages over traditional PEC5 due to the high efficiency of solar hydrogen production In addition, photoelectrochemical systems with the accumulation of reaction products were studied, which are one of the promising systems that allow to maximize the advantages of photoelectrochemical converters, such as ease of manufacture and the possibility of accumulating these products for their further use in electrochemical processes. For the synthesis of photosensitive materials to obtain the required properties, mainly low-temperature methods were used which are, characterized by relative simplicity and low cost of their production: electrochemical synthesis, in particular, pulse electrolysis, sol-gel method, photoelectrochemical method, as well as a number of chemical methods. These materials were produced mainly in the form of films and electrode structures.

A photoelectrochemical system for producing "solar" hydrogen has been developed, an important feature of which is the ability to accumulate hydrogen produced at the cathode, bypassing the stage of producing hydrogen gas. Together with the staff of the Franzevych Institute for Materials Science Problems, it was shown that for such a system it is promising to use as the cathode alloys that form compounds with hydrogen - metal hydrides (MH); such alloys provide long-term storage of hydrogen for its further use. It war shown that one of the promising ways to use hydrogen accumulated in such a system is a reversible photocell, a photoaccumulator that uses the accumulated hydrogen to provide energy to consumers in the absence of lighting.

A method for the cathodic deposition of electrochromic amorphous tungsten trioxide films with high characteristics suitable for use in electrochromic indicators and optical sensors has been developed; it was shown that the electrochromic effect in α-WO3 is associated with the sequential filling with electrons of three overlapping electroni bands formed by the discrete d-levels of W-centers, the ligand environment of which has a different number of terminal oxygen atoms. It has been found that the use of the pulsed mode of film deposition leads to a redistribution of the contrast of film color in the visible light region due to the appearance of poly-tungstate anions with a size of 1 nm in films, and the introduction of redox dye molecules into their structure leads to an increase in electrochromic color in a wide spectral region. Electrochromic MoO3 -WO3 composite films were also obtained by cathodic deposition. These films have a strong dependence of the electrochromic effect spectrum on the potential due to the symbiotic coloration of the composite components, as well as their high absorption contrast. An effective electrochromic material, which is colored in the anodic region of potential, was obtained on the basis of nickel oxide-hydroxide films. Cathodic deposition was used to obtain niobium oxide films, which have a significant electrochromic effect in the visible spectral region when lithium ions are intercalated. Based on these studies, the possibility of controlling the transmission spectrum and high values of optical density and the rate of coloration-decoloration of thin (0.5-1 μm) electrochromic films was established, which makes them promising for the creation of colored electrochromic glasses and indicators, electrochromic displays, optical filters with adjustable bandwidth and light modulators.

We have been developing electrochemical sensors for oxygen dissolved in liquid media, in particular, in biological fluids. The need to use dissolved oxygen sensors both for industrial and technological purposes and in medical practice is growing from year to year. These developments become especially relevant in monitoring the dynamics of free oxygen saturation of blood in the case of lung damage caused by viruses, in particular, coronavirus, for effective treatment. While there are already developments for technological purposes that satisfy consumers in some respects, there are very few such developments for medical purposes, although the need for them is great. The active materials of the working electrodes in such sensors were materials containing nanoparticles and nanotubes of titanium and zinc oxides, which were modified with La, Nd, and other elements. It was found that the high electrocatalytic activity of modified nanomaterials was largely due to the high negative potential of the bottom of the conduction band of nanostructured modified films. The obtained materials had a well-defined diffusion current of oxygen reduction. A technique for the joint analysis of the concentration of oxygen and toxic elements in liquids by inversion voltammetry using electrochemical multisensors was also developed. These multisensors are necessary for use in medicine in the treatment of acute poisoning by toxic elements (Se, Cr, Co, Pb, etc.), when it is necessary to conduct a rapid analysis of their content in the blood and determine the concentration of oxygen in it to prevent the rapid growth of hypoxia caused by them, as well as in determining the concentration of toxic elements in an aqueous medium, since they pose a great danger to organisms. The developed technique allows simultaneously controlling the process of biological oxygen consumption in the aqueous medium, since these substances inhibit oxygen utilization. It was found that the maximum sensitivity of the sensor to many elements in liquids is higher than their maximum permissible concentration and was, for example, (0.7-1.4)-10-3 mg/L for Se(IV), 0.03 mg/L for Co(II), 0.02 mg/L for Cr(VI), 0.3 mg/L for Cu(II), and (2-3)-10-3 mg/L for oxygen. On the basis of these electrodes, working models of electrochemical sensors of two types were made: for the rapid analysis of small volumes of biological fluids and for industrial and technological purposes, tests of which showed their prospects for practical use.

Optical sensors for explosive and toxic gases such as hydrogen, CO, and chlorine have also been developed. Among these sensors are sensors for the visual detection of dangerous concentrations of these gases, as well as highly sensitive sensors with a remote fiber optic head. Hybrid materials based on electrochromic metal oxides and some dyes, which enhance the gaso chromic effect, are used as indicator elements. A mechanism of the gaso chromic effect in the hydrogen-air environment for WO3/Pt(Pd) films is proposed, which consists in the fact that a stationary potential is established at the metal, -catalyst which corresponds to the equality of the hydrogen oxidation current and oxygen reduction current on the film surface. It has been shown that the presence of the α-Ni(OH)2 structure in films based on the β-modification of Ni(OH)2 accelerates the ir gaso - chromic bleaching by CO due to the improved conditions of ambipolar diffusion of protons and electrons in the film bulk. The WO3/Pt films were sensitive to 0.01-35 vol.% hydrogen, the NiOOH films to 0.1-95 vol.% CO, and the Ni(OH)2 films to 0.01-12 vol.% chlorine in the air. The advantages of the developed multisensors based on these materials over the known ones are their explosion safety, since optical signal recording system were used, and, at the same time, their high sensitivity, which exceeded thay of the known devices by several times.

The department carried out the electrochemical synthesis of powders and nanostructured films of transition metal oxides with disordered structure, intended mainly as cathode materials for chemical current sources (CCS) and miniature batteries. Non-stoichiometry in such materials occurs during the synthesis of compounds and is associated with the formation of defects in their structure. A fairly simple method for the electrochemical synthesis of oxide compounds of reproducible composition has been developed, which opens up wide possibilities for changing the composition and properties of these compounds by varying the electrolysis parameters. The oxide compounds obtained in this way have mixed conductivity - ionic and electronic, are characterized by a highly disordered structure, and can be obtained in the form of powders and films of Cr, Cu, Mn, Co, etc. oxides. These compounds contain water and an OH group, the presence of which contributes to the formation of redox systems of the Men+1/Men type, which largely determines the catalytic and electrochemical activity of oxide compounds and the rate of electrochemical processes occurring with their participation. It has been shown that the use of these compounds as cathode materials for CCSS leads to an increase in their specific electrical characteristics, increases the rate of mass transfer in the solid phase, i.e., higher current densities are realized, the diffusion coefficients of charge carriers increase, and a larger amount of lithium or protons is introduced into the solid phase (cathode material). Such electrode materials are promising in the development of unconventional flexible CCSs used for laptop computers, credit cards, etc. Thin-film electrodes (film thickness is 5-12 microns) are of particular interest for rechargeable power sources. In them, protons or lithium ions diffuse over a short distance, and therefore discharge and charge processes are carried out in shorter time intervals compared to those for conventional electrodes. It has been shown that the electrochemically synthesized material based on lithium-doped non-stoichiometric metal oxides has a higher ionic conductivity component than the sum of the conductivities of the main components. Such composite materials exhibited a high catalytic activity in the H2O2 decomposition reaction and showed high performance as cathode materials for a thin-film lithium-ion battery. These materials also proved to be promising for use as selective coatings for solar collectors. For instance, compared to other coatings, they had a high sunlight absorption coefficient of 98.5% and high adhesion to solar collector elements based on stainless steel, copper, nickel, and aluminum.

In the field of electrochemistry of molten salts, the fiundations of electrochemistry of the most important salt systems for the theory and practice of melts were created: electrochemical series of metals and thermodynamic properties of molten salts were established, methodological foundations for the experimental study of the kinetics and mechanism of electrode reactions were created, and the kinetic parameters of reactions in nitrate, chloride, and fluoride melts involving many depolarizers were determined. The theory of electrolysis of salt melts was developed, on the basis of which new technological processes for refining black lead and obtaining pure metals Pb, Bi, Sn, Ag, electroplating Sn, Zn, Cd, Al, synthesis of non-metals (pure silicon, silicides, carbides, nitrides, etc.) were created. The Department of Electrochemistry of Molten Salts (headed by Academician Y.K. Delimarsky) was recognized as a leading research center in the field of salt melts; the Scientific Council of the USSR Academy of Sciences on Physical Chemistry of Ionic Melts and Solid Electrolytes was established at the Institute of general and Inorganic Chemistry of the Ukrainian SSR Academy of Sciences.

In the late 1990s, a new research area was launched: liquid-phase synthesis at low temperatures (400 oC) of new nanocrystalline functional materials for chemical gas sensors (doped SnO2), lithium (sodium) ionic current sources (substituted oxides of transition metals Fe, Ni, Mn, Cr, V), and for general-purpose carbon materials such as multi-walled carbon nanotubes and graphenes. The materials are obtained from a liquid-phase medium based on salt melts or ethylene glycols and by the electrolysis of salt melts with a carbon graphite electrode. Materials for a gas sensor based on SnO2 nanocrystals with surface impurity metals Pd, Pt, Mo, Co, which are sensitive to 0.1 ppm of VOC volatile organic compound vapors of the group of toxic and explosive compounds, with a response time of 5-8 seconds have been developed.

A new composite sensor material is being developed based on SnO2/M (M=Pd, Mo, Pt) crystals (obtained by liquid-phase synthesis) and, - nanocarbon, graphene, tubes, obtained by electrolysis of salt melts which is characterized by high sensitivity to VOC vapors. The creation of such a composite is a necessary step in solving the problem of too high resistance of the base material.

The developed cathode based on nanocrystalline LiFePO4 showed promising performance in the model of a lithium-ion battery: reverse capacity 145 mAh/g; Coulombic efficiency 0.98, EMF 4.0 V. Electrode materials for a sodium-ion battery based on NaCrO2 oxide substituted with Fe, V are at the stage of experimental testing.

Modern composition of the department

Head of the department
	Kolbasov Gennady Yakovlevich
Leading researcher
	Eduard Vasilyevich Panov
Senior researcher
	Vorobets Vira Stefanivna		Mikhail Olegovich Danilov		Viktor Mykolayovych Zaichenko
	Malyovanyi Serhii Myronovych		Rusetsky Igor Anatolyevich		Sergey Stanislavovich Fomaniuk
Researcher
	Sergey Vladimirovich Chivikov
Junior Research Scientist
	Oblovatna Svitlana Yaroslavovna

Implemented projects of the department

1. STCU project #5335 "Production and storage of solar hydrogen in a photoelectrochemical system with high efficiency", 2011-2014.

2. STCU project №4418 "Nanovoid-structured photorefractive amorphous media for information technologies", 2008 - 2010.

3. STCU project №4123 "Development of a new method of hydrogen accumulation under sunlight exposure", 2006-.2008.

Projects currently being implemented by the department

1. Budget topic of the Department of Chemistry of the Ukrainian National Academy of Sciences "Synthesis, electrochemical, photoelectrochemical and electrochromic properties of nanocomposites and heterostructures based on graphene, chalcogenides, oxides, vanadates of a number of metals and Li-Fe phosphates and silicates", 2019-2023.

2. Project "Portable photoelectrochemical cells with hydrogen storage" of the Target Research Program of the Ukrainian National Academy of Sciences "Development of scientific principles of hydrogen production, storage and use in autonomous energy supply systems", 2019 -2021.

3. Project "New generation electrochemical multisensors for the rapid analysis of low concentrations of toxic elements and oxygen in liquid media" of the Comprehensive Scientific and Technical Program of the Ukrainian National Academy of Sciences "Smart" sensor devices of the new generation based on modern materials and technologies, 2018 - 2022.

4. Project "Development of a gas-sensitive material based on doped SnO2 nanocrystals and a chemical multisensor for toxic volatile organic compound vapors" of the Comprehensive Scientific and Technical Program of the Ukrainian National Academy of Sciences "Smart" sensor devices of the new generation based on modern materials and technologies, 2018 - 2022.

5. Project "Creation and properties of composite nanomaterials and heterostructures based on clusters of polyoxometalates, metal oxides, chalcogenides and carbon structures for alternative power, electrochromic and sensor systems", 2020-2024.

Awards of the department

Hennadii Kolbasov was awarded the Certificate of Honor of the Verkhovna Rada of Ukraine on July 16, 2018, Order No. 790-k.

The most significant and cited articles

1. Kolbasov H.Y., Horodyskyi O.V. Processes of photostimulated charge transfer in the system semiconductor-electrolyte.-Kyiv: Naukova Dumka, 1993.- 192 p.

2. Kuzminskyi E.V., Kolbasov H.Y., Tevtul Y.Y., Holub N.B. Non-traditional electrochemical energy conversion systems. Kyiv, Akademperiodyka, 2002, 182 p.

3. Kuzminskyi E. V., Kolbasov H.Y. Electrochemical systems for converting solar energy // Solar Energy Materials and Solar Cells. 1999. V.56, No1. P. 93-115.

4. Horodyskyi O.V., Ivanova N.D., Ivanov S.V., Boldyrev E.I. Method of electrochemical synthesis of compounds of oxide character of reproducible composition // Surface & Coatings Technology.-1986.-№29.-P.59-71.

5. Krasnov Y. S., Sych O. A., Patsyuk F. N., Vasko A. T. Method of cathodic deposition of electrochromic amorphous tungsten trioxide films // Electrokgimiya -1988. -24, № 11. -pp. 1468-1474

6. Kolbasov H.Y., Oleynikov S.L., Ye.V. Kuzminskyi et al. Photoelectrochemical currents and noise on a lithium electrode. // J. Power Sources.- 1995.- 54, No 3.- P. 525-527.

7. Kublanovsky V.S., Kolbasov H.Ya., Belinskyi V.N. Photoelectrochemical kinetics on a copper electrode. // J. Electroanalyt. Chem.- 1996.- 415, No 1.- P. 161-163.

8. Volkov S.V., Kolbasov H.Y., Nechaeva N.E. et al. Optical and photoelectrochemical studies of Rh-Sn complexes in H2SO4 solutions. // Zhurn. Prikladnoi Khimii. - 1998.- 71, №4.- pp. 613-616.

9. Kolbasov H.Y., Kublanovsky V.S., Taranets T.A., Litovchenko K.I.. Photoelectrochemical currents on the Ats electrode at negative potentials // Electrokhimiya, 2002. vol. 38, № 6, pp. 732-735.

10. Ivanova N.D., Boldyrev E.I., Ivanov S.V., Sokolskyi H.V. High-performance oxide-manganese cathodes for the CO oxidation reaction in CO2// Zhurn. Prikl. Khimii.- 2002.-75, №6.- P.953-955.

11. Ivanova N.D., Boldyrev E.I., Ivanov S.V., Makeeva I.S. Comparative characteristics of chemical current sources of MnO2-Zn system based on various samples of manganese dioxide // Zhurn. Prikl. Khimii.-2002.-75, №6.-P.953-955.

12. Ivanova N.D., Ivanov S.V., Boldyrev E.I. et al. Highly efficient oxide-manganese cathodes for the reaction of oxidation of CO in CO2 //Zhurn. Prikl. Khimii.-2003.-76, №7. -pp.1099-1102.

13. Krasnov Yu.S., Kolbasov H.Ya. Electrochromism and reversible changes in the position of fundamental absorption edge in cathodically deposited amorphous WO3. // Electrochimica Acta.. - 2004. - V. 49, N 15. - P. 2425-2433.

14. Kolbasov H.Y., Ivanova N.D. Photoelectrochemistry and chemical current sources: state of research and prospects for development. Ukr.khim.zhurn., 2004, Vol. 70, No. 7, P. 67-73.

15. Yu.S. Krasnov, S.V. Volkov, H.Ya. Kolbasov Optical and kinetic properties of cathodically deposited amorphous tungsten oxide films.// Journal of Non-Crystalline Solids – 2006 – V. 352, № 38–39 – P. 3995-4002.

16. Shcherbakova L.G., Dan`ko D.B., Muratov V.B., Kolbasov H.Ya., et al. Metal hydride use for solar energy accumulation // NATO Security through Science Series – A: Chemistry and Biology. Hydrogen Materials Science and Chemistry of Carbon Nanomaterials. Ed. by T.N. Veziroglu, S.Yu. Zaginaichenko, D.V. Schur. 2007 Springer, р. 699-706.

17. Kolbasov H.Y., Vorobets V.S., Blinkova L.V., Karpenko S.V., Oblovatna S.Y. Electrodes based on TiO2 nanotubes for electrochemical sensor of dissolved oxygen // Sonsornaya Elektrtronika i Mikrosistemnye Tekhnologiii - 2012 - Т3(9), №2 - P39-42.

18. H.Y. Kolbasov, V.S. Vorobets, O.M. Korduban, et al. Photoelectrochemical properties of TiO2 films obtained by the method of electric explosion // Teoretychna ta Eksperymentalna Khimiya. -2012. - VOL.48, NO.1. - PP.34-37.

19. S.S. Fomanyuk, Yu.S. Krasnov, H.Ya. Kolbasov. Kinetics of electrochromic process in thin films of cathodically deposited nickel hydroxide // J. of Solid State Electrochemistry − 2013 − V. 17, N.10 − P.2643-2649

20. Sokolskyi G. V., Ivanov S. V., Boldyrev E. I., Ivanova N. D. Rechargable xLi2MnO3_(1-x)Li4/3Mn5/3O4 electrode nanocomposite material as a modification product of chemical manganese dioxide by lithium additives // Materials Research Bulletin.- 2015.- 72, -P. 133–142.

21. Danilov M.O., Rusetskyi I.A., Slobodyanyuk I.A., Kolbasov H.Ya. / Assessment of electrocatalytic properties of nanocomposites based on carbon nanotubes for oxygen electrodes of alkaline fuel cells // SOP Transactions on Catalysis- 2015- No 1, р. 1-8.

22. Мikhail O. Danilov, Ivan A. Slobodyanyuk, Ihor A. Rusetskyi, and Hennadii Ya. Kolbasov. Synthesis of Reduced Graphene Oxide Obtained from Multiwalled Carbon Nanotubes and Its Electrocatalytic Properties // Graphene Science Handbook: Fabrication Methods / Edited by Mahmood Aliofkhazraei, Nasar Ali, William I. Milne, Cengiz S. Ozkan, Stanislaw Mitura, Juana L. Gervasoni. – CRC Press Taylor & Francis Group, Section II – chemical-based methods, Chapter 13, 2016, P. 205-226.

23. Fomanyuk S.S., Kolbasov H.Ya., Chernii V.Ya., Tretyakova I.N.. Gasochromic α,β–Ni(OH)2 films for the determination of CO and chlorine content //Sensors and Actuators B: Chemical , 2017 Vol. 244, P. 717–726.

24. Ihor A Rusetskyi, Larisa Shcherbakova, Mikhail Olehovych Danilov, et. al. Accumulation of Solar Hydrogen in a Photoelectrochemical System Based on CdSe Photoanode and MH Cathode // ECS Trans. 2018 87(1): 335-342;

25. Nataliya Chorna, Nataliya Smirnova, Vera Vorobets, Hennadiyi Kolbasov, Oksana Linnik. Nitrogen doped iron titanate films: photoelectrochemical, electrocatalytic, photocatalytic and structural features// Applied Surface Science. – 2019.– V. 473. – P. 343–351.

26. Smilyk V.О., Fomanyuk S.S., Kolbasov H.Ya., Rusetskyi I.A., Vorobets V.S. Electrodeposition, optical and photoelectrochemical properties of BiVO4 and BiVO4/WO3 films // Research on chemical intermediates, – 2019. –V.45, №8 – vol №45 – Р. 4149–4161.

27. Danilov M.O., Rusetskyi I.A., Slobodyanyuk I.A., Dovbeshko H.I., et al. // Fuel cells, 2019, Volume 19, Issue 3, P. 202-210

28. Rusetskyi I.A ., Danilov M. O. , Fomanyuk S. S. , et al. Photoelectrochemical properties of composites based on TiO2 nanotubes, CdSe and graphene oxide// Research on chemical intermediates, – 2019. – V.45, №8 – Р. 4121–4132

29. Fomanyuk S.S., Smilyk V.О., Kolbasov H.Ya., Rusetskyi I.A. Optical properties of NiOOH films in formaldehyde solutions // Chemical Papers, 74, 581–589 (2020).

30. Halahuz V.A. Diffusion characteristics of the LiFePO4/C composite in an electrolyte based on LiBOB / V.A. Halahuz, O.V. Potapenko, E.V. Panov // Research & Reviews in Electrochemistry. – 2015. – 6(2). – P. 049-057.

31. Halahuz V. Synthesis of LiFePO4 nanocrystals and properties of cathodic material on their basis / V. Halahuz, S. Malyovanyi, E. Panov // J. Serb. Chem. Soc. – 2018 – 83(10) – pp. 1123-1129.