A new efficient adsorbent in the preconcentration studies of the Cr(III) and Fe(III) ions

In this study, the imine-graphene hybrid material (HM) was used as an adsorbent for removal of Fe(III) and Cr(III) metal ions from the drinking waters. The adsorbent material (HM) was prepared at three steps. At the first step, the graphite was oxidized by Hummer's method for preparation of graphene oxide (GO), in the second step, the silanization derivative (GO-APTES) was obtained from the reaction of the 3-(trimethoxysilyl) propylamine and GO. In the final step, the hybrid material (HM) was synthesized from the reaction of the 3,5-diiodosalicylaldehyde and GO-APTES. The chemical structures of three materials GO, GO-APTES and HB were characterized by using the FT-IR, XRD, EDX, SEM, TEM and UV-vis methods. Thermal properties of the materials GO, GO-APTES and HB were investigated by TGA/DTA methods in the 25–1000°C temperature range. Adsorption and desorption studies of the hybrid material toward Fe(III) and Cr(III) metal ions were investigated using the Batch method. The effect of pH, contact time, temperature, concentration on the adsorption properties of the hybrid material were investigated by ICP-OES. The Fe(III) and Cr(III) ions have the maximum adsorption at the pH 7. The adsorption capacity decreases with the increase in pH values because above pH 9 the adsorption decreases due to the precipitation of metal hydroxide.