Enhanced removal of Nickel (II) from aqueous solutions by SDS-functionalized graphene oxide

Adsorption experiments were conducted by stirring known amounts of Graphene Oxide (GO) or SDS-functionalized Graphene Oxide (GO-SDS) (ranging from 10 to 100 mg) with 25 mL of aqueous Ni (II) solutions (at concentrations ranging from 5 to 40 mg/L) for predetermined time intervals at room temperature (298 K).The concentrations of the Ni (II) solutions were measured by Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES / UNICAM 701 Series Emission Spectrometer) and a UV-Visible spectrophotometer (Cary 100 UV-Vis) by applying the Dimethylglyoxime method [28]. Fourier transform infrared (FTIR) spectra of the samples were recorded with a Varian 800 FTIR spectrometer