Mokliak M. Synthesis, Structure, Catalytic and Thermomagnetic Properties of Neodymium-Doped Copper Ferrite-Based Nanocomposites.

Українська версія

Thesis for the degree of Doctor of Philosophy (PhD)

State registration number

0826U003040

Thesis Registration Form

0826U003040.pdf

Applicant for

Specialization

  • 105 - Прикладна фізика та наноматеріали

Specialized Academic Board

PhD 15292

Vasyl Stefanyk Carpathian National University

Essay

The object of the study is the formation of the structure and morphology of copper ferrites and Nd-containing nanocomposites based on them, synthesized by modified sol–gel autocombustion methods, as well as the development of their functional properties for application in catalytic water purification systems and colloidal induction heating systems. The subject of the study is the relationship between the synthesis conditions, structural and morphological parameters, physicochemical properties, and catalytic activity of the synthesized materials in water purification processes, as well as their thermomagnetic functional characteristics in colloidal induction heating systems. The research methods included X-ray diffraction analysis, scanning and transmission electron microscopy, energy-dispersive X-ray analysis, Fourier-transform infrared spectroscopy, Mössbauer spectroscopy, thermogravimetric analysis, impedance spectroscopy, optical spectroscopy in the visible and near-ultraviolet ranges, vibrating-sample magnetometry, zeta-potential measurements, thermomagnetic measurements, and tools for visualization and mathematical processing of experimental data. Scientific novelty of the obtained results: 1. For the first time, a one-step approach has been proposed for the formation of two- and three-component Type-II heterojunctions with a cascade arrangement of energy bands, namely CuFeO2/CuFe2O4 and CuO/CuFeO2/CuNdxFe2-xO4, by modifying the conditions of the sol–gel autocombustion method, including the pH of the reaction medium, precursor/chelating-agent stoichiometry, incorporation of Nd as a dopant, and the temperature and atmosphere of post-synthesis annealing. 2. The physical regularities governing the formation of the structural and phase state of nanocomposites based on Nd-doped copper ferrite under conditions of chelating-agent deficiency have been established. A corresponding mechanism has been proposed for the development of a macroporous sponge-like morphology during dendritic growth. The main structural elements of these nanocomposites are spherical nanoparticles (~20–30 nm) of the dominant spinel phase decorated with surface nanoislands of newly formed copper(II) oxide and delafossite phases. 3. For the first time, a synergistic enhancement of the photocatalytic activity of CuO/CuFeO2/CuNdxFe2-xO4 dual heterojunctions has been established. This enhancement results from the combined and competing effects of the formation and optimization of a cascade energy-band arrangement, minimization of nanocrystallite size, formation of an optimal content of the copper oxide phase, and the magnitude and sign of the catalyst surface potential. These factors determine both the rate of the photodegradation reaction and its type, depending on the nature of the pollutant. 4. For the first time, for a model cationic–anionic mixture and under conditions of a positive surface zeta potential of three-component CuO/CuFeO2/CuNdxFe2-xO4 photocatalysts, a highly synchronous character of multicenter photocatalysis of individual dye components has been established, with a common mechanism of their photodegradation as an integral supramolecular complex. 5. For the first time, the high efficiency of the magnetothermal response of CuFeO2/CuFe2O4 and CuO/CuFeO2/CuNdxFe2-xO4 nanocomposites in colloidal induction-heating systems has been demonstrated, with SAR values exceeding 33 W/g and ILP values exceeding 0.16 nH•m²/kg. This response is attributed to a synergistic effect arising from the mutual enhancement of such factors as high saturation magnetization, high anisotropy, colloidal stability, high zeta-potential values, size effects, and moderate Néel relaxation time, demonstrating the potential of these nanocomposites for biomedical applications.

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Research papers

1. Moklyak, V., Chelyadyn, V., Hrubiak, A., Ostafiychuk, B., Kotsyubynsky, V., Mizilevska, M., Moklyak, M., Lisovskyy, R., Yavorskyi, Y. (2020). Synthesis, structure, optic and photocatalytic properties of anatase/brookite nanocomposites. Journal of Nano Research, 64, 39-48. (SCOPUS, Q3). DOI: https://doi.org/10.4028/www.scientific.net/JNanoR.64.39 URL: https://www.scopus.com/pages/publications/85097368967

2. Bazaluk, O., Hrubiak, A., Moklyak, V., Moklyak, M., Kieush, L., Rachiy, B., Gasyuk,I., Yavorskyi, Y., Koveria, A., Lozynskyi, V., Fedorov, S. (2021). Structurally dependent electrochemical properties of ultrafine superparamagnetic ‘Core/Shell’γ-Fe2O3/Defective α-Fe2O3 composites in hybrid supercapacitors. Materials, 14(22), 6977. (SCOPUS, Q2). DOI: https://doi.org/10.3390/ma14226977 URL: https://www.scopus.com/pages/publications/85119717776

3. Hrubiak, A., Moklyak, V., Yavorsky, Y., Onuskiv, B., Chelyadyn, V., Karpets, M., Moklyak, M., Ivanichok, N., Ilnitsky, N. (2022). Electroconductive properties of carbon biocomposites formed by the deposition method. Physics and Chemistry of Solid State, 23(2), 302-310. (SCOPUS, Q4). DOI: https://doi.org/10.15330/pcss.23.2.302-310 URL: https://www.scopus.com/pages/publications/85133689472

4. Mazurenko, J., Kaykan, L., Sijo, A. K., Moiseienko, M., Kuzyshyn, M., Ostapovych, N., & Moklyak, M. (2023). The influence of reaction medium pH on the structure, optical, and mechanical properties of nanosized Cu-Fe ferrite synthesized by the sol-gel autocombustion method. Journal of Nano Research, 81, 65-84. (SCOPUS, Q3). DOI: https://doi.org/10.4028/p-d2fQaH URL: https://www.scopus.com/pages/publications/85182978353

5. Mazurenko, J., Kaykan, L., Moklyak, V., Moklyak, M., Moiseienko, M., Ostapovych, N., & Petryshyn, M. (2025). Inductive Heating Behavior of Copper Ferrite Magnetic Nanoparticles. Physics and Chemistry of Solid State, 26(2), 312-321. (SCOPUS, Q4). DOI: https://doi.org/10.15330/pcss.26.2.312-321 URL: https://www.scopus.com/pages/publications/105011090173

6. Mokliak, M., Kaykan, L., Mazurenko, J., Moiseienko, M., Kuzyshyn, M., Dovbnia, I., Ilnitsky, N., Yuryev, S., Mokliak, V. (2025). Influence of Neodymium Doping on the Thermomagnetic Response and Colloidal Behavior of Copper Ferrite Nanoparticles. Physics and Chemistry of Solid State, 26(3), 564-577. (SCOPUS, Q4). DOI: https://doi.org/10.15330/pcss.26.3.564-577 URL: https://www.scopus.com/pages/publications/105018688214

7. Mokliak, M., Ilnytskyi, R., Kaykan, L., Mazurenko, Y., Turovska, L., Moiseienko, M., Mokliak, V., Sheketa, V. (2026). Neodymium Doped Copper Ferrite Nanocomposites as an Effective Magnetic Catalyst for the Organic Dyes Decomposition. Physics and Chemistry of Solid State, 27(1), 215–225. (SCOPUS, Q4). DOI: https://doi.org/10.15330/pcss.27.1.215-225 URL: https://www.scopus.com/pages/publications/105034919269

8. Mazurenko, J., Turovska, L., Moklyak, M., Kaykan, L., Moklyak, V. (2026). Synthesis, Challenges, and Application Potential of Copper Ferrite Nanoparticles. Physics and Chemistry of Solid State, 27(2), 284–298. (SCOPUS, Q4). DOI: https://doi.org/10.15330/pcss.27.2.284-298 URL: https://journals.pnu.edu.ua/index.php/pcss/article/view/10471

9. Mazurenko, J., Kaykan, L., Moklyak, M., Bandura, K., Gondek, L. and Żywczak, A. Magnesium Substituted Copper Ferrite as an Effective Catalyst for the Organic Dyes Decomposition. Nanomaterials: Applications & Properties (NAP) : 2024 IEEE 14th International Conference, Riga, Latvia, 2024. P. 1–4. (SCOPUS). DOI: https://doi.org/10.1109/NAP62956.2024.10739689 URL: https://www.scopus.com/pages/publications/85212241932

10. Mazurenko, J., Kaykan, L., Michalik, J. M., Szostak, E., Moklyak, M. and Mazurenko, O. Influence of Rare Earth Substitution on the Photocatalytic Efficiency of Spinel Ferrite Nanoparticles. Nanomaterials: Applications & Properties (NAP) : 2025 IEEE 15th International Conference, Bratislava, Slovakia, 2025. P. NEE09-1–NEE09- 6. (SCOPUS). DOI: https://doi.org/10.1109/NAP68437.2025.11216285 URL: https://www.scopus.com/pages/publications/105023659771

11. Hrubiak A. B., Moklyak M. G., Chelyadyn V. L. Structurally dependent electroconductivity properties of ultrafine composites α-FeOOH/α-Fe2O3. Nanotechnologies and Nanomaterials (NANO-2022) : 10th jubilee International Conference, 25–27 August 2022, Lviv, Ukraine. P. 37. URL: https://drive.google.com/file/d/1- tx2qcGzZI_LxqaHsVAfHTmc6MqzA8Hs/view?usp=drive_link

12. Moklyak M. G., Hrubiak А. B., Moklyak V. V., Ostafyichuk B. К. Electrochemical Properties of Carbon Biocomposites. Physics and Technology of Thin 16 Films and Nanosystems : ХIX International Freik Conference, 9–14 October 2023, Ivano-Frankivsk, Ukraine. P. 49. URL: https://drive.google.com/file/d/1mJO21SzXGLGE7GgrCKv5ZNnlomT-- 0lc/view?usp=drive_link

13. Moklyak M., Mazurenko J., Bandura K., Turovska L., Vytvytskyi A. The Role of Hydrogen Peroxide in the Photocatalytic Process of Dye Removal from an Aqueous Environment Under the influence of Visible Light. XVI Rzeszowska Konferencja Młodych Fizyków, 2 czerwca 2023, Rzeszow, Polska. P. 28. URL: https://drive.google.com/file/d/18EQxEb2uD9zkVss5Y9sj5vlbjGpuJTQN/view?usp=dri ve_link

14. Moklyak M., Mazurenko J., Kaykan L., Moklyak V. Effect of Post-Synthesis Annealing Temperature and Chelating Agent on Photocatalytic Properties of Nanosized Copper Ferrite. Nanotechnology and nanomaterials (NANO-2023) : International research and practice conference, 16–19 August 2023, Bukovel, Ukraine. P. 62. URL: https://drive.google.com/file/d/18BYtMVCtC2KZFetuRQ5lJ7okV4sPobEA/view?usp= drive_link

15. Ivanichok N. Y., Rachiy B. I., Mokliak M. G., Lysiv T., Mokliak V. V. Obtaining activated carbon from biomass by thermal activation. Physics and Technology of Thin Films and Nanosystems : XX International Freik Conference, 6–10 October 2025, Ivano-Frankivsk, Ukraine. P. 151. URL: https://drive.google.com/file/d/18Lf05QCSDtSPz_XSILHB_dvdiqpecFU/view?usp=drive_link

16. Mokliak V. V., Chelyadyn V. L., Halushchak M. O., Mokliak M. G. Structural stability of lithium battery cathodes based on core (α-Fe2O3) - shell (γFeOOH) nanocomposites. Physics and Technology of Thin Films and Nanosystems : XX International Freik Conference, 6–10 October 2025, Ivano-Frankivsk, Ukraine. P. 157. URL: https://drive.google.com/file/d/1b_s-VOGlQRwk26hOeLLC3Lusu2kwsr1/view?usp=drive_link

17. Mokliak M. G., Mazurenko J. S., Kaykan L. S., Mokliak V. V. Structural and optical studies of nanocomposites based on Nd-substituted copper ferrite. Physics and Technology of Thin Films and Nanosystems : XX International Freik Conference, 6–10 October 2025, Ivano-Frankivsk, Ukraine. P. 213. URL: https://drive.google.com/file/d/1oVirxCe7ed6tq1tld4cs3tO8LpaIeY9/view?usp=drive_link

18. Dovbnia I., Mokliak M., Moiseienko M., Ostapovych N. Design and evaluation of Nd-doped copper ferrite nanoparticles for biomedical hyperthermia. Functional materials for technical and biomedical applications : International workshop for young scientists, October 14-16, 2025, Lviv, Ukraine. P. 6. URL: https://drive.google.com/file/d/1_z5qnGonKaEsorn7YLYETHPmGPMFl1H/view?usp=drive_link

19. Mokliak M., Kaykan L., Mazurenko J., Mokliak V. The Effect of Neodymium Ions Substitution on the Structure and Elastic Properties of Copper Ferrites. Nanotechnology and nanomaterials (NANO-2025) : International research and practice conference, 20–23 August 2025, Bukovel, Ukraine. P. 482. URL: https://drive.google.com/file/d/1m3F2Fw6GZXaPOE8Tk7XPGjb6Gd5Gxj1U/view?usp =drive_link

20. Спосіб отримання фотокаталізатора на основі нанорозмірного мідного фериту для очищення води від органічних барвників : пат. 163225 Україна : B01J 23/70, C02F 103/14. № u 2025 06397 / Мазуренко Ю. С., Кайкан Л. С., Туровська Л. В., Мокляк В. В., Мокляк М. Г., Мазуренко О. О. ; заявл. 19.12.2025 ; опубл. 03.06.2026, Бюл. № 22. 4 с. URL: https://sis.nipo.gov.ua/uk/search/detail/1927021/

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