"Nanochemistry and biotechnology"
Adsorption properties of green synthesized cobalt-zinc ferrites
Liaskovska M.R.1,2, Tatarchuk T.R.1,3, Mironyuk I.F.1
1Department of Chemistry, Vasyl Stefanyk Precarpathian National University, 57, Shevchenko Str., Ivano-Frankivsk, 76018, Ukraine.
E-mail: tatarchuk.tetyana@gmail.com
2Department of Biological and Medical Chemistry named after academician Babenko H.O., Ivano-Frankivsk National Medical University, 2 Halytska Str., Ivano-Frankivsk, 76018, Ukraine
3Educational and Scientific Center of Materials Science and Nanotechnology, Vasyl Stefanyk Precarpathian National University, 201, Galytska Str., Ivano-Frankivsk, Ukraine

Materials with spinel structure have long been a topic of interest because they may exhibit different properties depending on synthesis method. In this research, we have used the method of green chemistry for synthesizing Zn-doped cobalt ferrites with the general formula ZnxCo1–xFe2O4 (0 ≤ x < 1.0 with step 0.2). This is an eco-friendly method for the synthesis of monodisperse nanoparticles with small size, which are very important for different applications. Green chemistry is considered as one of the techniques applied for nanoparticles synthesis and involves the using of the non-toxic plant extracts as effective reducing and chelating agent. The permanent porosity of the frameworks and the Lewis acidity of the functionalization of magnetic nanoparticle sites have been considered as the major contributors to the catalytic activity. Cobalt-zinc ferrites were prepared by using sol–gel autocombustion method using plant extract as an effective reducing agent. The powders were characterized by XRD, SEM, EDS, and IR spectroscopy. Crystallite sizes of the samples are obtained by Scherer and Williamson-Hall methods and were found around 10 nm. Spinel structure of magnetic nanoparticles has been confirmed by XRD and IR spectroscopy. The IR spectra contain two main peaks that correspond to tetrahedral and octahedral sites in spinel structure respectively, and few peaks in the range 1300-3700 cm-1 that shown surface functionalization of magnetic nanoparticles. The surface morphology and elemental composition were proved by using SEM and EDS respectively. The synthesized cobalt-zinc ferrites were investigated as magnetic adsorbents using anionic dye Congo red as model pollutant. In addition, the CoFe2O4 nanoparticles obtained by eco-friendly method using plant extract as chelating agent could be used as good candidate for biomedical applications, such as drug delivery and hyperthermia application.