A Study of the Kinetics of Silver Deposition on a Lewatit K 2620 Macroporous Ion Exchanger Depending on the Nature of the Reducing Agent
DOI:
https://doi.org/10.17308/sorpchrom.2026.26/13697Keywords:
nanocomposite, kinetics, deposition, silverAbstract
Depending on the nature of the reducing agent, the kinetics of silver precipitation in the Lewatit K 2620 sulfonic cation exchange matrix was studied using titrimetry and microscopic analysis under static conditions. Alkaline solutions of sodium borohydride and dithionite, as well as hydrazine, were used as reducing agents. The structure and main physical and chemical characteristics of the obtained nanocomposites were studied in the work. The average size of the base particles of the deposited metal was calculated using X-ray structural analysis according to the Selyakov-Scherrer equation. It was found that the diameter of silver particles does not depend on the choice of the type of reducing agent and for all studied samples is in the range of 20-35 nm. It has been shown that as a result of one cycle of chemical precipitation, the sample reduced with sodium borohydride has the highest capacity for the metal component, for which the full ion-exchange capacity of the Lewatit K2620 sulfocation exchanger is achieved by the 25th minute of the reduction process. It was found that an increase in the concentration of the reducing agent, as a rule, leads to a slight increase in the capacity of nanocomposites for metal, not exceeding 10%. However, when sodium borohydride was used as a reducing agent, an increase in its concentration, on the contrary, reduces the metal content in the synthesized sample. The reason is the active release of hydrogen during the reduction process, which complicates the diffusion of the reducing agent deep into the grain. When sodium dithionite and hydrazine are used as reducing agents, the ion exchange capacity of the resin was not achieved, reaching approximately 80% and 70%, respectively. The kinetic parameters obtained experimentally were compared with those for the model known from literary sources. Within the model, a rapid stage of formation of a metal hydroxide occurred first, which was extremely unstable and almost immediately decomposed into the corresponding oxide, followed by its reduction to the zero-valent metallic state by a reducing agent. The results of theoretical calculations and experimental studies were found to be consistent. The kinetic complex, calculated theoretically and based on experimental data, showed that the slow stage of the silver deposition process is the internal diffusion transfer of reducing agent co-ions to silver oxide particles in the pores of the ion exchanger.
Downloads
References
1. Adhikari C., Polymer-plastics technolo-gy and materials, 2021; 60(18): 1996-2024. https://doi.org/10.1080/25740881.2021.1939715
2. Kondratiev V.V., Malev V.V., Eliseeva S.N., Uspekhi Chem., 2016; 85(1): 14-37. https://doi.org/10.1070/RCR4509
3. Abdulraheem M.I., Moshood A. Y., Gourkhede P. H., Xu L., Zang Y., Cadenas-Pliego G., Hu, J., Polymer Bulletin., 2025: 1-39. https://doi.org/10.1007/00289-025-05750-2
4. Verma C., Hussain C.M., Quraishi M.A., Rhee K.Y., Reviews in Chemical Engi-neering., 2024; 40(1): 35-66. https://doi.org/10.1515/revce-2022-0039
5. Volkov V.V., Kravchenko T.A., Roldug-in V.I., Uspekhi Chem., 2013; 82(5): 465-482.
6. Kozhevnikov A.V. Electron-ion ex-changers. Leningrad, Chemistry, 1972, 128 p.
7. Fertikova T.E., Fertikov S.V., Isaeva E.M., Krysanov V.A., Kravchenko, T.A., Condensed Matter and Interfaces., 2021; 23(4): 614-625. https://doi.org/10.17308/kcmf.2021.23/3682
8. Krysanov V.A., Plotnikova N.V., Kravchenko T.A., Russian Journal of Physical Chemistry, 2018; 92(3): 434-438. https://doi.org/10.17308/sorpchrom.2017.17/433
9. Aggour Y.A., Kenawy E.R., Magdy M., Elbayoumy E., RSC advances, 2024; 14(41): 30127-30139. https://doi.org/10.1039/D4RA05186F
10. Ghazzy A., Naik R.R., Shakya A.K., Polymers, 2023; 5(9): 2167. https://doi.org/10.3390/polym15092167
11. Krysanov V., Gadebskaya M., Krysano-va T., Kravchenko T., Kozaderov, O., Journal of Composites Science, 2024; 8(7): 249. https://doi.org/10.3390/ jcs8070249
12. Naganthran A., Verasoundarapandian G., Khalid F.E., Masarudin M.J., Zulkharnain A., Nawawi N.M., Ahmad S.A., Materials, 2022; 15(2): 427. https://doi.org/10.3390/ma15020427
13. Krutyakov Yu.A., Kudrinsky A.A., Olenin A.Yu., Lisichkin G.V., Uspekhi Chemii, 2008; 77(3): 242–269.
14. Farberova E.A., Katysheva A.Yu., Smirnov S.A., Tingaeva E.A., Starostin, A.G. Chemistry and chemical technology, 2020; 63(3): 46-53. https://doi.org/10.6060/ivkkt.20206303.6047
15. Selemenev V.F., Slavinskaya G.V., Khokhlov V.Yu., Ivanov V.A., Gorshkov V.I., Timofeevskaya V.D., Workshop on Ion Ex-change. Voronezh, Publishing House of the Voronezh State University, 2004, 14-17.
16. Markhol M., Ion exchangers in analyti-cal chemistry. Moscow, Mir, 1985, Part 1, 264 p.(In Russ.)
17. Pyatnitsky I.V., Sukhan V.V., Analytical chemistry of silver. Moscow, Nauka, 1975, 264 p. (In Russ.)
18. Kravchenko T.A., Metal-ion exchanger nanocomposites. Moscow, Nauka, 2009, 391 p. (In Russ.)
19. Kravchenko T.A., Kozaderov O.A., Fertikova T.E., Golovin I.A., Martynov A.E., Sorbtsionnye i Khromatograficheskie Protsessy, 2025; 25(3): 373–388. https://doi.org/10.17308/
sorpchrom.2025.25/13047
