A mixed organic functionalized silica-graphene oxide as advanced material for pollutant removal

Graphene oxide has been functionalized with crown-ether moieties, while silica has been functionalized with stable free radicals of nitroxide type. These two materials and their mixture were firstly characterized by IR, ESR, SEM, and Raman spectroscopy, and secondly tested further for removal of some organic and inorganic pollutants from water, like benzyl alcohol, methylene blue dye, iron (II), and copper (II) ions. It is well known that graphene oxide, as well as crown-ether compounds, has a high capacity to bind transition metal ions, whereas nitroxide free radicals are able to oxidize, under certain conditions, organic compounds. Consequently, our experiments evaluated these materials and showed that they may act synergistically in order to simultaneously remove metal ions and organic pollutants.