Facile Synthesis and Excellent Adsorption Property of GO-Fe3O4 Magnetic Nanohybrids for Removal of Organic Dyes

In this work, we have demonstrated a facile two-steps method for synthesis of graphene oxide-iron oxide nanoparticles (GO-Fe3O4) magnetic nanohybrids. First, the GO nanosheets were fabricated by a modified Hummers method, and then, the Fe3O4 nanoparticles were decorated on surface of the GO nanosheets by coprecipitating ferrous salts in GO solution. The GO-Fe3O4 magnetic nanohybrids were characterized using X-ray diffraction, transmission electron microscopy, Fourier transformed infrared spectroscopy, and Raman spectroscopy measurements. Magnetic property of the nanohybrids was accessed by vibrating sample magnetometer. The adsorption kinetics and adsorption capacities of methylene blue (MB) cationic dye on the magnetic nanohybrids were studied under varying experimental conditions of adsorbent dose, contact time, adsorbent materials, pH value and temperature of solution. It revealed that the adsorption process was fitted by a pseudo second -order kinetic model and Langmuir isotherm, respectively. In an optimal condition, the maximum adsorption capacity and color removal efficiency reached similar to 72.9 mg/g and 97.3% with fast response of equilibrium adsorption time 3 min. The advantages of reusability, magnetic separation, high removal efficiency, and quick kinetics make these nanohybrids very promising as low-cost adsorbents for fast and effective removal of organic dyes in water solution.