Highly efficient removal of Cd(II) ions by composite of GO and layered double hydroxide composite

Abstract

Herein, we report a novel nanocomposite (graphene oxide/Ni-Co LDH) via a simple and effective chemical precipitation route. First, the GO nanosheets were synthesized by Marcano method, and then, Ni-Co LDH sheets were deposited on the surface of GO by chemical precipitation. The synthesized nanocomposite was characterized by field emission scanning electron microscopy (FE-SEM), Fourier-transform infrared spectroscopy and x-ray diffraction measurements. The prepared nanocomposite was investigated as an adsorbent for cadmium (II) ions removal from aqueous solutions. Batch studies have been done for obtaining optimal experimental conditions for maximizing metal sorption on the nanocomposite. The nanocomposite shows highest adsorption capacity toward Cd(II) in aqueous solution (126.58 mg g−1). The influence of experimental parameters like time of contact between adsorbent and adsorbate, pH, adsorbent dosage, initial heavy metal concentration and temperature on the removal efficiency of Cd(II) ions was extensively investigated. Kinetic and isotherm parameters of adsorption of Cd(II) were also evaluated. The pH = 7 was chosen as an optimal pH for study of the Cd(II) removal from aqueous solutions. Langmuir isotherm and pseudo-second-order kinetic models were fitted well with experimental data of Cd(II) removal. The reusability of nanocomposite exhibited reasonable values. However, the current nanocomposite could be used as a new adsorbate for adsorption of Cd(II) from contaminant water sources.