Radiation-induced graft copolymerization of dimethylaminoethyl methacrylate onto graphene oxide for Cr(VI) removal

• A novel graphene-based adsorbent was prepared by radiation graft copolymerization.
• The maximum Cr(VI) uptake at pH 1.1 was 82.4 mg g−1.
• The adsorption equilibrium could be achieved within 45 min.

Dimethylaminoethyl methacrylate (DMAEMA)-grafted graphene oxide hybrid materials (GO-g-P) were fabricated using γ-ray irradiation at ambient temperature. The morphology and structure of GO-g-P were characterized by Fourier-transform infrared spectroscopy (FT-IR), X-ray photoelectron (XPS), thermogravimetric analysis (TGA) and X-ray diffraction (XRD). It was confirmed that DMAEMA was grafted successfully on the surface of graphene sheet. The grafting yield of GO-g-P increased with monomer concentration (0–2.5 mol L−1) and dose (0–40 kGy). The resulting adsorbent (GO-g-P) with amine groups was highly efficient for removing Cr(VI) from its acidic aqueous solution and could be easily separated by filtration. The optimum pH for Cr(VI) removal was observed at pH 1.1 and the Cr(VI) uptake of GO-g-P at this pH was 82.4 mg g−1.

Proposed mechanism of grafting DMAEMA on the surface of GOFigure optionsDownload as PowerPoint slide