Synthesis and characterization of Zn-doped α-Fe2O3 nanoparticles with enhanced photocatalytic activities

In present work, the optical, magnetic and photocatalytic properties of undoped and Zn doped alpha-Fe2O3 nanoparticles was investigated intensively. The Zn doped hematite nanoparticles were synthesized by simple co-precipitation method, changing the molar ratio of zinc precursors. The obtained photocatalysts were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transform infra-red (FTIR), Raman spectroscopy, diffuse reflectance UV-visible spectroscopy (DRS) and vibrating sample magnetometer (VSM). The structural properties showed that the obtained nanoparticles are single phase rhombohedral (hexagonal) structure with the space group R-3c in all compounds. TEM and SEM results show that the size of the nanocrystals decreases with Zn-doping down to 21 nm. Raman spectroscopy was also used for confirming zinc atoms replacing iron position in Zn doped alpha-Fe2O3 crystal. The energy gap decreased gradually by increasing the doping concentration of zinc. The specific saturation magnetization (M-s) of the nanoparticles was measured at room temperature. The magnetic parameter of M-s, was found to decrease with the increase in Zn concentration. Zinc doped alpha-Fe2O3 showed the enhanced photocatalytic properties within photodegradation of methyl orange (MO). The 6% Zn-doped alpha-Fe2O3 nanoparticles showed the highest photocatalytic activity and led to an almost complete discoloration of MO solutions, i.e. 87.4% at pH = 4 after UV-visible irradiation of 140 min. (C) 2021 Elsevier B.V. All rights reserved.