Synthesis and application of TiO2/SiO2/Fe3O4 nanoparticles as novel adsorbent for removal of Cd(II), Hg(II) and Ni(II) ions from water samples

In the current study, SiO2/Fe3O4 core-shell nanoparticles functionalized with TiO2, using a simple method and application for removal of Cd(II), Hg(II) and Ni(II) ions from aqueous solution. The structure of the resulting product was confirmed by X-ray diffraction spectrometry, transmission electron microscopy (TEM), pH(pzc) and Brunauer, Emmett and Teller methods. The average diameter of TiO2/SiO2/Fe3O4 nanoparticles according to TEM was obtained around 48 nm. In batch tests, the effects of pH, initial metal concentration, contact time and temperature were studied. Adsorption of metal ions was studied from both kinetics and equilibrium point of view. Maximum adsorption capacity of Cd(II), Hg(II) and Ni(II) on TiO2/SiO2/Fe3O4 nanoparticles was 670.9, 745.6 and 563.0 mg g(-1), respectively. Adsorption-desorption results showed that the reusability of nanoparticles was encouraging. This adsorbent was successfully applied to removal Cd(II), Hg(II) and Ni(II) ions in real samples including tap water, electronic wastewater and medical wastewater.