Functionalized silica nanoparticles for lead adsorption

Functionalized silica nanoparticles prepared according to a method comprising:

• combining centrimonium bromide (CTAB) with water and ethanol to create a first reaction mixture;
• stirring the first reaction mixture;
• adding NH4OH to the first reaction mixture to create a second reaction mixture;
• stirring the second reaction mixture;
• adding a first amount of tetraethyl orthosilicate (TEOS) to the second reaction mixture to create a third reaction mixture;
• stirring the third reaction mixture;
• adding ethylenediaminetetraacetic acid (EDTA) and a second amount of TEOS to the third reaction mixture to provide a fourth reaction mixture;
• stirring the fourth reaction mixture to obtain formed silica spheres;
• separating the formed silica spheres;
• washing the formed silica spheres with water and ethanol;
• and
• drying the formed silica spheres in an oven to provide functionalized silica nanoparticles.