<p>This study aimed to develop an environmentally friendly hybrid nano-adsorbents for removing nickel ions (Ni (II)) from aqueous solutions. Mesoporous silica Santa Barbara Amorphous-15 (SBA-15) and silica‐coated magnetic iron oxide nanoparticles (Fe₃O₄@SiO₂) were synthesized using co-precipitation and sol–gel (Stöber) methods, respectively. These particles were then functionalized with ethylene-diamine-tetra-acetic acid (EDTA) as a chelating ligand and 3-aminopropyl triethoxysilane (APTES) as a spacer. The resulting hybrid nano-adsorbents were evaluated for its ability to remove Ni (II) from aqueous solutions, leveraging Ni (II) strong affinity for the oxygen and nitrogen donor atoms in EDTA. The adsorbent’s particle size, morphology, surface area, and successful functionalization were confirmed using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), vibrating sample magnetometry (VSM), and transmission electron microscopy (TEM). These characterization results verified the successful synthesis and functionalization of SBA-15 and Fe₃O₄@SiO₂ with amine (–NH²) groups from APTES and carboxyl (–COO) groups from EDTA. Adsorption isotherms were analyzed using Langmuir and Freundlich models. The adsorption of Ni (II) on the two adsorbents at 25 °C is best described by the Freundlich isotherm model. According to the correlation coefficient (R²) values 0.964 and 0.999 for Fe₃O₄@SiO₂-EDTA and SBA-15-EDTA, respectively. Moreover, SSE values 0.053 for Fe₃O₄@SiO₂-EDTA and 1.894 for SBA-15-EDTA, the pseudo 2nd model is the most appropriate model to depict the dynamics of the adsorption process. The maximum adsorption capacity was 20.8&#xa0;mg/g for Fe₃O₄@SiO₂-EDTA and 178.5&#xa0;mg/g for SBA-15-EDTA.</p> Graphical abstract <p></p>