Barium (II)-doped zinc ferrite-reduced graphene oxide nanohybrids for superior adsorption and magnetic properties

A one-step solvothermal method was used to prepare barium (II)-doped zinc ferrite/reduced graphene oxide (Ba2+-ZF/rGO) magnetic nanohybrid adsorbents. During the solvothermal treatment, Ba2+-ZF nanoparticles were formed from Ba2+, Fe3+and Zn2+ chlorides, which were anchored on the surface of rGO obtained from the reduction of GO with ethylene glycol. TEM and SEM results show that the Ba2+-ZF nanoparticles are uniformly distributed on the rGO sheets without any agglomeration. When used as adsorbents, the Ba2+-ZF-rGO nanohybrid with an rGO content of 35% possesses excellent adsorption capacities for methylene blue at different initial concentrations and the adsorption kinetics can be well-described by the pseudo-second-order kinetic model. The formation of Fe2+ from FeCl3·6H2O and the doping of Ba2+ into the spinel structure dramatically improve the magnetism of the zinc ferrite, which makes the magnetic separability of the nanohybrid outstanding. The Ba2+-ZF/rGO nanohybrid could be used as an efficient, magnetically separable adsorbent for removing organic dyes.