Fe2O3/TiO2/activated carbon (FT/AC) nanocomposites supported on silica gel beads were synthesized using a sonochemical method and fully characterized. The response surface method was applied to optimize the removal of Pb(II) ions by nanocomposites under visible light. The experiments were conducted by adjusting three parameters, i.e., initial concentration of Pb(II) ions, dosage of Fe2O3/TiO2 (FT) photocatalyst, and pH. The FT/AC nanocomposite showed higher efficiency for Pb(II) ion removal in comparison with FT due to the synergistic effect of activated carbon combined with Fe2O3/TiO2.