The synthesis of polypyrrole/Ag2O nanocomposite and its adsorption performance for Pb(ІІ) and Co(ІІ) ions: kinetics, thermodynamic and isotherm studies

ABSTRACT Heavy metal ions are highly toxic to health, lung, kidney and nervous systems. A special featured polypyrrole with environmental stability and reusability was engaged for removal of metal ions from aqueous solution. In the present study, a new nanocomposite of polypyrrole (PPy/Ag2O) in the presence of hydroxypropylcellulose (HPC) as the surfactant was synthesized via in situ chemical oxidative polymerization method in aqueous medium. The synthesized nanocomposites were characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD). Results indicated that the Ag2O and hydroxypropylcellulose (HPC) influenced the properties of the synthesized nanocomposites. The aim of this research was to investigate the sorption characteristics of PPy/Ag2O nanocomposites for the removal of heavy metal ions including Pb(II) and Co(II) from aqueous solution. The factors that affected the adsorption equilibrium as well as the removal efficiency of the nanoadsorbents, i.e., contact time, metal ion concentration, pH and adsorption conditions, were investigated in detail. The equilibrium data were fitted to Langmuir, Temkin and Freundlich isotherm models. From the kinetic results, it was concluded that the pseudo-second-order kinetic model was the best at describing the adsorption process for Pb(II) and Co(II) on PPy-HPC/Ag2O.