Nanostructured α-Fe2O3: Solvothermal Synthesis, Characterization, and Effect of Synthesis Parameters on Structural Properties

α-Fe2O3 is a stable, cheap, and non-toxic metal oxide with many advantages and different fields of application. Many attempts have been devoted to the synthesis of α-Fe2O3 with different crystal structures and morphologies to obtain the desired properties. In this research, nanostructured α-Fe2O3 were synthesized by a facile solvothermal route. The as-obtained samples are characterized by XRD, FESEM, EDS, FTIR, and BET surface area analysis. The results showed that the as-synthesized hematite consists of nanostructures with the morphology of distorted microspheres with an average diameter in the range of 1 to 1.5 μm each composed of self-assembled nanoparticles with an average size in the range of 10 to 30 nm. The results showed that the hematite nanostructures had a specific surface area of 41.86 m^2g^-1. The influence of temperature and duration of the solvothermal process as well as, calcination on the structural properties of the α-Fe2O3 samples was investigated. The results reveal that the crystallite size of the samples increases with increasing the temperature and duration of solvothermal treatment. Moreover, calcination leads to an increase in the crystallite size of the samples. The α-Fe2O3 nanostructures with a minimum crystallite size of 13.6 nm were synthesized at 150 °C for 4 h while the largest crystallite size of 75.4 nm was obtained at 180 °C and 8 h with subsequent calcination of the sample at 500 °C for 1 h. The results of the present study can be useful to enhance the properties of α- Fe2O3 nanostructures in various fields of application.