Terbium Ion Adsorption from Aqueous Solution by Using Magnetic γ-Fe(2)O(3)-NH(4)OH@SiO(2) Nanoparticles Functionalized with Amino Groups

New magnetic stabilized and functionalized core@shell nanoparticles (NPs) were synthesized in a simple way and characterized in order to adsorb Tb(3+) from aqueous solution with a very low Tb(3+) concentration. For the fluorescence determination of adsorption efficiency and capacity, tiron monohydrate as a ligand was used. The obtained results confirm the potential of the synthesized magnetic γ-Fe(2)O(3)-NH(4)OH@SiO(2) NPs, functionalized with (3-Aminopropyl) trimethoxysilane (APTMS), to be used for adsorption of Tb(3+) from aqueous solution, with the possibility of its removal from aqueous solution via an external magnet. The endothermic and spontaneous adsorption follows a pseudo-second-order kinetic model, and the adsorption equilibrium data fit the Temkin isotherm well. The maximum adsorption efficiency from aqueous solution with a 2 × 10(−6) M concentration of Tb(3+) is over 90% at pH 7.