Size composition, structure and antioxidant properties of Cerium dioxide nanoparticles obtained by autoclave synthesis

Purpose of the study. To characterize the size composition, atomic and electronic structure, and antioxidant activity of Cerium dioxide nanoparticles synthesized by the hydrothermal method in an autoclave.

Methods. Cerium dioxide nanoparticles were synthesized in an autoclave at 150°C. The size composition of the nanoparticles was characterized by small-angle X-ray scattering diffractometry. The structural and phase composition was studied using X-ray diffractometry. Scanning electron microscopy with an energy-dispersive X-ray analysis attachment was used to analyze the elemental composition of the samples. Antioxidant activity was studied in the photochemical degradation reaction of methylene blue dye under irradiation with a diode source with a wavelength of 660 nm. The residual concentration of methylene blue in the process of photodegradation was determined using spectrophotometry.

Results. Pure Cerium dioxide nanoparticles measuring 10-25 nm were synthesized using hydrothermal synthesis in an autoclave at 150°C. In the presence of the obtained cerium dioxide nanoparticles, the process of photodegradation of the methylene blue dye under the influence of red laser radiation slows down by 80%. The addition of ammonium citrate-stabilized Cerium dioxide nanoparticles leads to a slowdown in the process of photodegradation of methylene blue under irradiation with red light due to antioxidant activity, which increases with increasing concentration of nanoparticles. Maximum antioxidant activity is manifested at a molar ratio of ammonium citrate to CeO₂ of no more than 2:1.

Conclusion. The hydrothermal synthesized CeO₂ nanoparticles stabilized by ammonium citrate exhibit pronounced antioxidant activity. The results obtained can be used to develop selective antitumor photosensitizers based on Cerium dioxide nanoparticles.

1. Kargozar S., Baino F., Hoseini S.J., Hamzehlou S., Darroudi M., Verdi J., et al. Biomedical applications of nanoceria: new roles for an old player. Nanomedicine. 2018;3(23):3051-3069. https://doi.org/10.2217/nnm-2018-0189

2. Mamontov V.A., Rodionov V.V., Ryzhenkova A.Yu., Egelsky I.V., Kalenchuk V.I., Pugachev- sky M.A. Antioxidant activity of ablated cerium dioxide nanoparticles in oxidative photocatalytic reaction. Izvestiya Yugo-Zapadnogo gosudarstvennogo universiteta. Seriya: Tekhnika i tekhnologii = Proceedings of the Southwest State University. Series: Engineering and Technologies. 2023;13(3):199-210. (In Russ.) https://doi.org/10.21869/2223-1528-2023-13-3-199-210

3. Pugachevskii M.A., Chibisov A.N., Mamontov V.A., Kuzmenko A.P. Antioxidant properties of stabilized CeO2 nanoparticles. Physica status solidi (a). 2021;218(20):2100355. https://doi.org/10.1002/pssa.202100355

4. Rao G.R., Mishra B.G.Structural, redox and catalytic chemistry of ceria-based materials. Bull. Catal. Soc. India. 2003. 2003;2:122-134.

5. Singh K.R. B., Nayak V., Sarkar T., Singh R.P. Cerium oxide nanoparticles: properties, bio-synthesis and biomedical applications. Royal society of chemistry. 2020;10(45):27194-27214. https://doi.org/10.1039/d0ra04736h

6. Bouzigues C., Gacoin T., Alexandrou A. Biological applications of rare-earth based nanoparticles. ACS Nano. 2011;5(11):8488-505. https://doi.org/10.1021/nn202378b

7. Gupta A., Das S., Neal C., Seal S. Controlling the surface chemistry of cerium oxide nanoparticles for biological application. Journal of Materials Chemistry B. 2016;4(19):3195-3202.

8. Ivanov V.K., Shcherbakov A.B., Baranchikov A.E., Kozik V.V. Nanocrystalline cerium dioxide: properties, preparation, application. Tomsk: Tomsk. un-t; 2013. 284 p. (In Russ.)

9. Ilves V.G., Sokovnin S.Yu. Production and studies of properties of nanopowders on the basis of CeO2. Nanotechnologies in Russia. 2012;7(5-6):213-226.

10. Seal S., Jeyaranjan A., Neal C.J., Kumar U., Sakthivel T.S., Sayle D.C. Engineered defects in cerium oxides: tuning chemical reactivity for biomedical, environmental, & energy applications. Nanoscale. 2020:12(13):6879-6899. https://doi.org/10.1039/d0nr01203c

11. Walkey C., Das S., Seal S., Erlichman J., Heckman K., Ghibelli L., et al. Catalytic properties and biomedical applications of Cerium oxide nanoparticles. Environ. Sci. Nano. 201;2(1):33-53. https://doi.org/10.1039/C4EN00138A

12. Syed Khadar Y.A., Balamurugan A., Devarajan V.P., Subramanian R. Hydrothermal synthesis of Gadolinium (Gd) doped Cerium oxide (CeO2) nanoparticles: characterization and antibacterial activity. Oriental journal of chemistry. 2017;33(5)2405-2411. http://dx.doi.org/10.13005/ojc/330533

13. Sayle T.X.T., Molinari M., Das S., Bhatta U.M., Mobus G., Parker S.C., Seal S., et al. Envi-ronment-mediated structure, surface redox activity and reactivity of ceria nanoparticles. Nanoscale. 2013;5(13):6063-73. https://doi.org/10.1039/c3nr00917c

14. Ivanov E.K., Shcherbakov A.B., Teplonogova M.A., Shekunova T.O., Baranchikov A.E., Ivanova O.S., et al. Method for obtaining stable aqueous colloidal solutions of cerium dioxide nano-particles. Russian Federation patent 2615688. 6 April 2017.

15. Trineeva O.V. Methods for determining the antioxidant activity of plant and synthetic objects in pharmacy (review). Razrabotka i registratsiya lekarstvennykh sredstv = Development and registration of drugs. 2017;(4):180-197. (In Russ.)