Modification of graphene oxide nanosheets for the removal of lead (II) and copper (II) ions from aqueous solutions

In the present study, the graphene oxide nanosheets (GO) were successfully synthesized from graphite and were modified by HCl and H2SO4. The potential of synthesized adsorbents were investigated for the removal of lead (II) and copper (II) ions from aqueous solutions. The synthesized adsorbents were characterized using X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET) analysis. The effect of sorption parameters including pH, contact time and initial concentration on the removal of lead (II) and copper (II) ions onto the GO samples were investigated. The known pseudo-first-order and pseudo-second-order kinetic models were applied to describe the kinetic data of metal ions. The equilibrium data of metal ions were fitted by Freundlich and Langmuir isotherm models. The both copper and lead experimental data were well described using pseudo-second-order kinetic and Langmuir isotherm models. The obtained results indicated that the GO can be consider as an efficient adsorbent for the removal heavy metal ions.