SiO 2 supported core@shell nanoparticles (CSNs) have recently attracted great attention due to their unique, tunable, optical, photocatalytic, and higher adsorption properties. In this study, SiO 2 @CeO 2 CSNs were synthesized using 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 analysis showed that SiO 2 particles were the core while CeO 2 particles were the shell. It was seen as a new band at 961 cm −1 of the oxygen bridge between Si and Ce atoms from FT-IR results; SiO 2 and CSNs were spherical (0.5-0.6 µ m) from SEM and TEM analyses. Different parameters such as contact time, initial concentration, pH, and temperature were investigated. The optimum conditions for temperature, pH, and contact time were 25 • C, 8.0, and 60 min, respectively. In addition, the equilibrium adsorption data were interpreted using Langmuir and Freundlich models to describe the uptake of Hg(II). The Freundlich isotherm model (R 2 : 0.99) fit better than Langmuir and the qmax value was 153.8 µ g g −1 at various concentrations (0.1-1 mg L −1). The thermodynamic parameters were also calculated and, from these results, it can be shown that our synthesized particles can be used in water purification systems to remove Hg(II).