Development of foamy-like 3-dimensional graphene networks decorated with iron oxide nanoparticles for strontium adsorption

Three-dimensional magnetic graphene foam (3D-MGF) was improved for removal of strontium ions. Chemical Vapor Deposition (CVD) method and hydrothermal method were used to obtained 3D-MGFs, respectively. Central Composite Design (CCD) method was conducted to establish the optimum conditions for adsorption of strontium ions on 3D-MGFs. At the optimum conditions, the maximum adsorption capacity was calculated 39.68 mg/g. Freundlich isotherm model showed that a multilayer formation occurred in the 3D-MGF's surface. Moreover, the adsorption process was endothermic, and recycle experiments showed there was about 25% loss in the adsorption capacity of 3D-MGFs for strontium ions after 5 times reuse.