graphene oxide (GO) shows numerous merits including high specific surface area, and thermal conductivity, high optical transmittance, and large Young’s modulus have led to researchers paying great attention to it [78]. the above significant properties. “However, GO is more easily dispersed than graphene, due to the presence epoxy, hydroxyl, and carboxyl functional groups, thus making its processing, synthesis, and application more convenient” [11]. Due to its imperishable hydrophilicity, GO found to be an efficient adsorbent and hence found many applications, including water purification [11]. Sreeprasad et al. [77] and Maaz et al. [47] have reported that nickel ferrite-GO composite is a better reaction media than iron ferrites, because of having higher catalytic and electron transfer efficiency through the Ni2+ in the nickel ferrite. Moreover, previous reports have
proved the amazing removal response of magnetic nanoparticles/graphene or GO composites for pollutants like chromium [17, 67], copper [20], arsenic [105], cadmium [14], lead [100], and cobalt and an organic dye. Recently, Ligamdinne et al. reported (Fig. 1) the removal of Co(II), Pb(II), Cr(III), As(III) and As(V), and radionuclides, U(VI) and Th(IV) from water, using the synthesis of “inverse spinel nickel ferrite incorporated-graphene oxide” based nanocomposites [35, 36, 39, 40]. The reported results demonstrated that the magnetic GO-based nanocomposites are promising, economic, could be separated by the external magnetic field.

Fig. 1 Graphical representation of (a) nano-magnetic GONF composite preparation (b) Pb(II) and Cr(III) adsorption onto GONF (reproduced from (Lingamdinne et al. 2016b) with permission)