Ultralight NiCo@rGO aerogel microspheres with magnetic response for oil/water separation

Improving the adsorption capacity of the adsorbent and realizing rapid separation are quite important for water treatment. Herein, one kind of novel Ni/Co-contained reduced graphene oxide aerogel microspheres (rGOAMs-M) with high surface area and magnetic response are synthesized by a novel process comprised of electrospraying, droplets spherification, crosslinking immobilizing of metal, lyophilization and thermal reduction. The aqueous dispersion mixture of graphene oxide and sodium alginate is electrosprayed under high electric voltages to produce droplets, which are collected in a nickel/cobalt acetate tetrahydrate solution and then crosslinked between alginate and metal ions. The obtained rGOAMs-M have the cabbage-like inner structures, and possess the organic solvent/oil adsorption capacities of 107–270 g.g−1 and also extraordinary oil/water emulsion separation ability. The rGOAMs-M also can be rapidly assembled and separated from the medium under a magnetic field.