Effective removal of Cu(II) ions using graphene Oxide-Based surface imprinted polymeric Beads: Implications for water purification

Abstract

This study utilizes graphene oxide (GO) as a versatile support material, employing surface ion imprinting to create mesoporous polymeric beads with a substantial specific surface area of around 434 m2/g and a bead size of approximately 0.6 mm. The graphene-based Cu(II) ion-imprinted polymeric (IIP) beads were developed to fulfil the requirements of selective Cu(II) adsorption from aqueous solutions. Suspension polymerization was employed to synthesize acrylamide precursor-based polymeric beads, with the in-situ addition of GO during the polymerization reaction before the curing step. The resulting Cu(II) imprinted polymeric beads exhibited effective adsorption of Cu(II) ions, achieving a maximum adsorption capacity of 192 mg/g, fitting well with the Langmuir isotherm (R2 = 0.9997). In the presence of the competitive ions Ni(II), Zn(II), Cd(II) and Co(II) the GO-IIP beads displayed high selectivity for Cu(II), with selectivity coefficients for the Cu(II)/Ni(II), Cu(II)/Zn(II), Cu(II)(II)/Cd(II) and Cu(II)/Co(II) in binary systems determined to be 39, 27, 60 and 53, respectively. These GO-IIP beads were successfully employed in five adsorption/regeneration cycles, showcasing their remarkable selectivity, high adsorption capacity, and regenerability. This approach can be applied to create comparable GO-IIPs for water purification, presenting promising solutions for addressing environmental challenges through the selective removal of specific ions from contaminated waters.