One-Step Fabrication of Amino-Functionalized Fe3O4@SiO2 Core-Shell Magnetic Nanoparticles as a Potential Novel Platform for Removal of Cadmium (II) from Aqueous Solution

Abstract

Fe3O4@SiO2-NH2 core-shell magnetic nanoparticles were developed by a rapid one-step precipitation route followed by reverse microemulsion and amine functionalization. In this study, an Fe3O4@SiO2-NH2 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 Fe3O4@SiO2-NH2 nanoparticles were characterized by XRD, SEM-EDAX, TEM, FTIR and TGA. From the TEM analysis, the morphology of Fe3O4@SiO2-NH2 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 Fe3O4@SiO2-NH2, 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 (−∆oo = −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 Fe3O4@SiO2-NH2-nanoparticle as an alternative effective adsorbent in eradicating Cd(II) ions from aqueous solution.

Experimental Investigation of Magnetorheological Behavior of Fe3O4@PVP@OA Ferrofluid for Potential Application in Gas Condensate Blockage Reduction

“…The second weight loss takes place over the temperature ranging from 230 to 350 °C, where the hydroxyl groups (OH) on the surfaces of Fe 3 O 4 nanoparticles are dehydrated at a rate of 2.4%. From 350 °C onward, the graph remains unchanged with no significant weight loss (0.5%) . In short, pure Fe 3 O 4 nanoparticles are found to withstand up to approximately 600 °C with a weight loss of 5.8% over the entire measurement owing to the inorganic nature of the magnetic Fe 3 O 4 nanoparticles .…”

“…The taken SEM images are illustrated in Figure . In Figure (b), the magnetic Fe 3 O 4 nanoparticles are covered with PVP that remain uniform and spherical in shape after coating . Unlike Fe 3 O 4 nanoparticles with no coating as observed in Figure (a), PVP could be able to decrease the formation of clusters, followed by a reduction in the agglomeration of magnetic Fe 3 O 4 nanoparticles due to the steric effect of the polymer coating …”

“…In Figure 11(b), the magnetic Fe 3 O 4 nanoparticles are covered with PVP that remain uniform and spherical in shape after coating. 60 Unlike Fe 3 O 4 nanoparticles with no coating as observed in Figure 11(a), PVP could be able to decrease the formation of clusters, followed by a reduction in the agglomeration of magnetic Fe 3 O 4 nanoparticles due to the steric effect of the polymer coating. 61 Figure 11(c) illustrates an OA layer adsorbed on the surfaces of Fe 3 O 4 @PVP nanoparticles that induced almost spherical shapes in the particles.…”

“…From 350 °C onward, the graph remains unchanged with no significant weight loss (0.5%). 60 In short, pure Fe 3 O 4 nanoparticles are found to withstand up to approximately 600 °C with a weight loss of 5.8% over the entire measurement owing to the inorganic nature of the magnetic Fe 3 O 4 nanoparticles. 63 Thus, this value can confirm that the nanoparticles would be suitable candidates with acceptable purities under high temperature.…”

Decorated Magnetic Nanocatalyst with Trinitriloacetic Acid as a Heterogeneous Catalyst used in the Synthesis of Pyrimido[4,5]quinoline‐2,4‐diones

“…This 7.50 % weight loss is related to the evaporation of water and solvent adsorbed on the surface and into the outer layer of the catalyst. [38] The second weight loss (Figure 1-b) of about 6.79 % refers to the dehydration of hydroxyl groups as well as the degradation of the other parts of the synthesized core-shell nanocatalyst's last outer layer (part that comes from the NTAA) at 279-459 °C. This range of degradation temperature has risen about twice in comparison with NTAA [18] itself.…”