Preparation of Nanocomposite Heteropoly Metalate Based Graphene Oxide: Insight into Cadmium Adsorption

Abstract

We developed a facile strategy for preparation of heteropoly metalate/graphene oxide nanocomposite as a new ion exchanger for cadmium ion removal from aqueous solution. The synthesized nanocomposite was characterized by X-ray powder diffraction (XRD), UV-Vis spectroscopy, FT-IR spectroscopy and Raman spectroscopy. Our findings indicated that the combination of heteropoly metalate nanoparticles with graphene oxide results in an excellent performance for cadmium ions removal of aqueous solution. The experimental data demonstrated that the adsorption isotherm fitted well by Langmuir model with maximum sorption capacity of 47.85 mg/g. The removal behavior of this compound was evaluated by various parameters such as contact time, concentration of metal ion, pH of solution and temperature. In addition, the effect of interfering cations on the cadmium adsorption is investigated. Dubinin–Radushkevich model represented physical sorption occurred as bold mechanism that is confirmed by thermodynamic parameters. Also, the obtained data of the recycling experiment presented excellent stability after 4 consecutive cycles.  This study indicated heteropoly metalate supported graphene oxide with good performance for removal of cadmium can be used for treating polluted solution by other heavy metal.