Comparison of nitrate removal from water via graphene oxide coated Fe, Ni and Co nanoparticles

Abstract Coating Ni and Co nanoparticles (NPs) with graphene oxide (GO) make them comparable to FeNPs in removing nitrate from water. Specifically, NaBH4 reduction of Fe3+, Ni2+ and Co2+, in the presence of GO affords quantitative yields of their corresponding magnetically functionalized nanocomposites: Ni@r-GO, Co@r-GO as well as Fe@r-GO. Efficiencies of Ni@r-GO and Co@r-GO prove comparable to that of Fe@r-GO in the removal of nitrate from water. The latter demonstrates a superior efficiency over the previously reported unanchored FeNPs. Characterizations are carried out by SEM, AFM, FT-IR, UV–vis, XRD, RAMAN and VSM. Considering the advantages of Ni and Co over Fe, this approach opens up the availability of a new class of graphene-based composites, with unique properties and outstanding performance, for nitrate removal from water.