Spherical α-Fe2O3 Nanoparticles: Synthesis and Characterization and Its Photocatalytic Degradation of Methyl Orange and Methylene Blue

The spherical iron oxide (α-Fe2O3) nanoparticles were prepared using facile, low-cost and environmental friendly one step thermal decomposition of Fe(NO3)3∙3H2O at the presence of malic acid (mass ration 1:1) at 600 °C for 3 h. The product was characterized by Fourier transform infrared (FT-IR) spectroscopy, powder X-ray diffraction (XRD), vibrating sample magnetometer (VSM), and transmission electron microscope (TEM). The FT-IR and XRD results predicted the formation of single phase of rhombohedral α-Fe2O3 nanoparticles. TEM image illustrated that the α-Fe2O3 nanoparticles had spherical shapes. VSM result showed that the as-prepared α-Fe2O3 nanoparticles were ferromagnetic materials with Ms of 1.96 emu g-1. The photocatalytic activity of the α-Fe2O3 nanoparticles was evaluated by the photodegradation of methyl orange (MO) and methyl blue (MB) in aqueous solution under visible light irradiation. The effects of pH solution, sorbent dose, contact time (0-120 min), and initial concentration of dyes (30, 50 and 70 mg l-1) were also studied. At the end of the process, the catalyst could be separated and recovered using an external magnetic field. The results indicate that the α-Fe2O3 nanoparticles can be used as an efficient photocatalyst for removal of other dyes from aqueous solution, and has benefits for large-scale production.