Sulfidic GO-grafted glass stir-bar as a noble metal ions adsorbent

In this paper, an efficient, simple and environment-friendly stir-bar type adsorbent was designed and applied for the rapid extraction of noble metal ions. To obtain the mentioned sorbent, the surface of a glass stir-bar was covalently grafted by tetra sulfide functionalized graphene oxide. The potential of the modified stir-bar was studied as an effective and convenient sorbent for the adsorption and extraction of noble metal ions from aqueous solutions in a normal batch system. The effect of important variables on the adsorption efficiency of the analytes were investigated. Under the optimal conditions, the designed stir-bar showed high adsorption capacity. The static and dynamic of the adsorption process were investigated and they were matched to the Langmuir isotherm and pseudo-second-order kinetic model, respectively. In addition, the regeneration test indicated that the prepared modified stir-bar adsorption can be applied at least for seven cycles successively without any substantial loss in efficiency.