Preparation of amino-functionalized CoFe₂O₄@SiO₂ magnetic nanocomposites for potential application in absorbing heavy metal ions

Abstract

The magnetic CoFe2O4@SiO2–NH2 particles with core-shell structure are designed and synthesized. They have high adsorption capacity (170.829 mg g−1), high removal efficiency (96.93%) for heavy metals, and can be recycled easily.

Diverse Surface Chemistry of Cobalt Ferrite Nanoparticles to Optimize Copper(II) Removal from Aqueous Media

“…This phenomenon assisted in the compression of the surface spin disorder layer (also called the 'dead layer') on the nanoparticles' surface by repairing the broken and dangling bonds of Fe-O/Co-O, consequently increasing magnetization. In so, these values were relatively higher than those that have been reported for silica-modified CoFe2O4 nanoparticles with similar sizes [29][30][31][32]. However, the third modification route (MNPs@ODA@PEI@DTPA) led to reduced magnetization (44 emu/g) in accordance to the larger organic layer detected from the TGA results.…”

“…As an artificial amino acid, it is known as complexone and is widely studied and used for the mobilization of heavy metals and radionuclides from contaminated soils [49][50][51]; (iii) the employment of both PEI and DTPA was expected to provide mixed functional groups (amines and carboxylates) and to increase the adsorption of metal ions. Compared to other studies on CoFe 2 O 4 MNPs that have been based on silica functionalization, the direct modification of these agents ensures a prompt response to metal ion removal [29][30][31][32].…”

“…However, the silica layer-mediated surface functionalization approach is complex, time consuming, and not favorable in large-scale applications. Importantly, the incorporation of silica into magnetic nanoparticles decreases the magnetic responsiveness of the nanocomposites due to the large total organic shell, which in some cases, has been found to reach a thickness of35 nm [31][32][33]. In addition, Si-O-Si bonds are prone to hydrolysis when exposed to harsh environments such as highly-saline conditions that are encountered in biological media [34][35][36].…”

Preparation of magnetic porous NiFe2O4/SiO2 composite xerogels for potential application in adsorption of Ce(iv) ions from aqueous solution

“…Some techniques such as solvent extraction, 2,3 membrane separation, 4,5 adsorption, [6][7][8][9][10] and ion exchange [11][12][13] have been reported for the separation of radionuclides. In contrast to other methods, adsorption has shown great promise for selective separation of Pu from HLLW, and nding an effective material to dispose of radioactive waste has become the research focus.…”

CoFe2O4/CHITOSAN MAGNETIC NANOCOMPOSITE: SYNTHESIS, CHARACTERIZATION AND APPLICATION FOR ADSORPTION OF ACIDIC YELLOW DYE FROM AQUEOUS SOLUTIONS

“…2 (b)and (c)) correspond to the stretching vibrations of Co-O and Fe-O bonds in the ferrite lattice. After chitosan coating was applied on the surface of CoFe 2 O 4 , the vibrations of Fe-O become weaker in CS/CoFe 2 O 4 14.…”