Study on the adsorption of Hg(ii) by one-pot synthesis of amino-functionalized graphene oxide decorated with a Fe3O4 microsphere nanocomposite

摘要

An easy one-pot solvothermal strategy approach has been reported on the preparation of ethylenediamine (EDA) decorated with magnetite/graphene oxide (EDA–Fe _(3) O _(4) /GO) nanocomposites and employed as a recyclable adsorbent for Hg( II ) in aqueous solution. Taking advantage of the combined benefits of graphene and magnetic nanoparticles, these EDA–Fe _(3) O _(4) /GO nanocomposites exhibit an excellent adsorption capacity (127.23 mg g ~(?1) ) much higher than that of Fe _(3) O _(4) microspheres and rapid separation from aqueous solution by an external magnetic field. The adsorption isotherm data and the kinetics of the adsorption process were fitted using the Langmuir equation and a pseudo-second-order kinetic model. The results of the thermodynamic parameters Δ H , Δ S and Δ G showed that the adsorption process was endothermic and spontaneous. The graphene oxide (GO) sheets could not only prevent agglomeration of the Fe _(3) O _(4) microspheres and enable a good dispersion of these oxide microspheres, but also substantially enhance the specific surface area of the composite. Therefore, the EDA–Fe _(3) O _(4) /GO nanocomposites may be a promising sorption material for the separation and preconcentration of heavy metal ions from aqueous solutions in environmental pollution cleanups.