A facile chemical method to produce superparamagnetic graphene oxide–Fe3O4 hybrid composite and its application in the removal of dyes from aqueous solution

Abstract

A superparamagnetic graphene oxide–Fe₃O₄ hybrid composite (GO–Fe₃O₄) was prepared via a simple and effective chemical method. Amino-functionalized Fe₃O₄ (NH₂-Fe₃O₄) particles are firmly deposited on the graphene oxide sheets. The graphene oxide sheets could prevent NH₂-Fe₃O₄ particles from agglomeration and enable a good dispersion of these oxide particles. The as-prepared GO–Fe₃O₄ hybrid composite had a much higher thermal stability than graphene oxide. The amount of NH₂-Fe₃O₄ loaded on GO was estimated to be 23.6 wt% by atomic absorption spectrometry. The specific saturation magnetization (M_s) of the GO–Fe₃O₄ hybrid composite is 15 emu g⁻¹. The magnetic GO–Fe₃O₄ composite has been employed as adsorbent for the magnetic separation of dye contaminants from water. The adsorption test of dyes (Methylene Blue (MB) and Neutral Red (NR)) demonstrates that it only takes 30 min for MB and 90 min for NR to attain equilibrium. The adsorption capacities for MB and NR in the concentration range studied are 167.2 and 171.3 mg g⁻¹, respectively. The GO–Fe₃O₄ hybrid composite can be easily manipulated in magnetic field for desired separation, leading to the removal of dyes from polluted water. These GO–Fe₃O₄ hybrid composites have great potential applications in removing organic dyes from polluted water.