▎ 摘　　要

This study detects the removal of Cu2+ and Pb2+ metal ions, from aqueous solution using modified graphene oxide-thiosemicarbazide (mGO-TSC) nanocomposite. The chemical structure and morphology of the synthesized nanocomposite adsorbent of graphene oxide-thiosemicrbazide (mGO-TSC) were characterized using different spectroscopic analyses including: FTIR, Raman, TGA, and TEM analysis. The influences of different parameters including: immersion time, pH of the medium, initial metal ion concentration, and the used adsorbent amount were studied. Results revealed that increasing the immersion time and the adsorbent amount were increased the adsorption efficiency. Also, the efficiency was reversed after increasing the initial metal ions concentration. It was observed that the pH of themedium played a critical role on the efficiency metal ions adsorption. The adsorption study showed that the adsorption proceeds according to Freundlich adsorption isotherms. Also, the kinetic studies indicated that the adsorption process follow the pseudo-second-order kinetic model through the inter-particle diffusion mechanism. The modified adsorbent (mGO-TSC) showed effective reusability for four rounds with adsorption efficiency reached to 85% and 81.7% for Cu2+ and Pb2+, respectively. The mechanism of metal ions adsorption using GO and mGO-TSC was suggested based on the molecular energies optimization, which showed the effectiveness of sulfur and oxygen during the adsorption process. (C) 2020 Elsevier B.V. All rights reserved.