Amine-functionalized magnetite-silica nanoparticles as effective adsorbent for removal of uranium(VI) ions

In our studies the Fe3O4/SiO2/C3H6NH2 (MSA) adsorbent was synthesized by the green-chemistry method based on hydrolysis and condensation of tetraethoxysilane and (3-aminopropyl)triethoxysilane. The obtained material was fully characterized by a wide range of instrumental techniques and employed as an adsorbent for removal of uranium(VI) ions which is considered as a hazardous metal. It was found that the adsorption process is very fast, and equilibrium is reached after about 4 h. The data was fitted with the pseudo-1st (PFO) and pseudo-2nd order (PSO) equations. It was turned out that better fit was obtained for the PSO kinetic model. The Freundlich, Langmuir-Freundlich and Dubinin-Radushkevich isotherm equations were used to calculate the equilibrium adsorption data. The static sorption capacity was 118 mg.g(-1). The energy value E-n = 14.8 kJ.mol(-1) (293 K) calculated based on the Dubinin-Radushkevich isotherm equation indicates that chemisorption is a dominant mechanism. The obtained data show that MSA material can be used as a promising adsorbent for radioactive metals removal. (C) 2019 Elsevier B.V. All rights reserved.