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

Abstract

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 En = 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.