One-Step Fabrication of Amino-Functionalized Fe 3 O 4 @SiO 2 Core-Shell Magnetic Nanoparticles as a Potential Novel Platform for Removal of Cadmium (II) from Aqueous Solution

Fe 3 O 4 @SiO 2 -NH 2 core-shell magnetic nanoparticles were developed by a rapid one-step precipitation route followed by reverse microemulsion and amine functionalization. In this study, an Fe 3 O 4 @SiO 2 -NH 2 nanoparticle was used to evaluate its adsorption efficiency for the treatment of a synthetic solution of Cd(II) ion. The structural and physicochemical properties of Fe 3 O 4 @SiO 2 -NH 2 nanoparticles were characterized by XRD, SEM-EDAX, TEM, FTIR and TGA. From the TEM analysis, the morphology of Fe 3 O 4 @SiO 2 -NH 2 was found as 100–300 nm. In TGA, the first weight loss was noticed between 373 and 573 K, the second was between 673 and 773 K and the final weight loss took place above 773 K. Batch experimental tests, such as pH, dosage of Fe 3 O 4 @SiO 2 -NH 2 , Cd(II) ion concentration, temperature as well as interaction time, were conducted and evaluated. Experimental study data were used for the non-linear forms exhibited by isotherms and kinetics of the sorption procedure. The equilibrium adsorption observations were adequately combined with pseudo-first-order kinetics as well as Freundlich isotherm. Monolayer maximum adsorption capacity was found to be 40.02 mg/g, recorded at pH 6 with an interaction time of 30 min, temperature of 303 K and sorbent dose of 2.0 g/L. The thermodynamic study indicated that the adsorption process was an exothermic, spontaneous reaction (−∆o o = −15.46–7.81 (kJ/mol)). The as-synthesized sorbent had excellent recyclability, and its adsorption efficiency was maintained after five cycles of reuse. The findings of the study exhibited the magnetic Fe 3 O 4 @SiO 2 -NH 2 -nanoparticle as an alternative effective adsorbent in eradicating Cd(II) ions from aqueous solution.