Preparation, characterization, and adsorption studies of core@shell SiO2@CeO2nanoparticles: a new candidate to remove Hg(II) from aqueous solutions

Abstract

SiO2supported core@shell nanoparticles (CSNs) have recently attracted great attention due to their unique,tunable, optical, photocatalytic, and higher adsorption properties. In this study, SiO2@CeO2CSNs were synthesizedusing a chemical precipitation technique and characterized by Fourier transform infrared (FT-IR), X-ray diffraction(XRD), scanning electron microscope (SEM), and transmission electron microscope (TEM) analysis. XRD analysisshowed that SiO2particles were the core while CeO2particles were the shell. It was seen as a new band at 961 cm1of the oxygen bridge between Si and Ce atoms from FT-IR results; SiO2and CSNs were spherical (0.5{0.6?m) fromSEM and TEM analyses. Different parameters such as contact time, initial concentration, pH, and temperature wereinvestigated. The optimum conditions for temperature, pH, and contact time were 25& #9702; C, 8.0, and 60 min, respectively.In addition, the equilibrium adsorption data were interpreted using Langmuir and Freundlich models to describe theuptake of Hg(II). The Freundlich isotherm model (R2: 0.99) t better than Langmuir and theqmaxvalue was 153.8?gg1at various concentrations (0.1{1 mg L1). The thermodynamic parameters were also calculated and, from theseresults, it can be shown that our synthesized particles can be used in water puri cation systems to remove Hg(II).