Preparation and study of silica and APTES–silica-modified NiFe2O4 nanocomposites for removal of Cu2+ and Zn2+ ions from aqueous solutions
- 1 Downloads
Silica and (3-aminopropyl)triethoxysilane (APTES)–silica-modified NiFe2O4 samples were successfully synthesized by a two-/three-step process, depending on the sample, including the preparation of nickel ferrite sample by hydrothermal synthesis, the coating of its surface with silica, and the subsequent functionalization with APTES. Samples were characterized by X-ray diffraction (XRD), Fourier transform-infrared (FTIR) analysis, transmission electron microscopy, and M–H curves. XRD data of the NiFe2O4 sample shows diffraction maxima that can be indexed in a cubic symmetry of space group Fd-3m with Z = 8, compatible with an inverse spinel-type structure. The estimated average crystalline size is 22 nm. All FTIR spectra show absorption bands between 600 and 400 cm−1, characteristic of spinel-type structure. Bands attributed to the vibration of O–Si–O and Si–O–Si bonds are found in the spectra of the silica-coated samples. APTES–silica-modified NiFe2O4 nanocomposites show an increase in coating thickness as the reaction time with tetraethoxysilane increases. A practically superparamagnetic behavior was found for the synthesized NiFe2O4 sample with a magnetization of 47 emu/g. This value is slightly reduced with the thickness of the nonmagnetic coating. The ultraviolet–visible spectroscopy measurements and titration curves clearly demonstrated that the APTES–silica-modified NiFe2O4 nanocomposites could be efficient materials for the removal of Cu2+ and Zn2+ ions from aqueous solutions. The best adsorption is found in the NiFe2O4@SiO2(3)–APTES(6) sample, while the NiFe2O4@SiO2(6)–APTES(12) sample seems to be the most suitable for its application, considering its better adsorption capacity and its easy separation from the aqueous solution in the presence of an external magnetic field.
Amino-functionalized NiFe2O4@SiO2 core-shell nanocomposites are prepared.
Magnetic cores are obtained by a urea-mediated hydrothermal synthesis.
TEM confirms the formation of a uniform coating around magnetic nanoparticles.
Cu2+ and Zn2+ adsorption evidence the reaction of the cations with amino groups.
Nanocomposites reach an adsorption capacity higher than 10% of their own weight.
KeywordsNanocomposite Hydrothermal synthesis Magnetic materials Adsorption Pollutant removal
We thank the ICTS National Center for Electron Microscopy of the UCM for access.
Fundación Neurociencias y Envejecimiento has supported this work through project 359/2014 as well as MINECO through the project MAT2016-80182-R.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
PA declares that this paper is original, has not been published before, and is not currently being considered for publication elsewhere. He confirms that the paper has been read and approved by all named authors and that there are no other persons who satisfied the criteria for authorship but are not listed. He further confirms that the order of authors listed in the paper has been approved by all the authors.
- 35.Ta TKH, Trinh M-T, Long NV, Nguyen TTM, Nguyen TLT, Thuoc TL, Phan BT, Mott D, Maenosono S, Tran-Van H, Le VH (2016) Synthesis and surface functionalization of Fe3O4-SiO2 core shell nanoparticles with 3-glycidoxypropyltrimethoxysilaneand1,1-carbonyldiimidazole for bio-applications. Colloid Surf. A 504:376–383CrossRefGoogle Scholar
- 43.Jasonov PG, Nougaliev DK, Burov BV, Heller F (1998) A modernized coercivity spectrometer. Geol Carpath 49:224–225Google Scholar
- 45.Scherrer P (1918) Bestimmung der Größe und der inneren Struktur von Kolloidteilchen mittels Röntgenstrahlen. Nachrichten von der Gesellschaft der Wissenschaften zu Göttingen, Mathematisch-Physikalische Klasse 26:98–100Google Scholar
- 46.Rodríguez-Carvajal J (1990) FULLPROF: a program for Rietveld refinement and pattern matching analysis, In: Abstract of the satellite meeting of the XVth congress of the international union of crystallography, Toulouse, France Université Paul Sabatier, Toulouse, 1990Google Scholar
- 47.Roisnel T, Rodriguez-Carvajal J WinPLOTR, email@example.com, http://www-llb.cea.fr/fullweb/winplotr/winplotr.htm